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This study presents novel composites of biochar (BC) derived from spinach stalks and zinc oxide (ZnO) synthesized from water hyacinth to be used for the first time in a hybrid system for activating persulfate (PS) with photocatalysis for the degradation of bromothymol blue (BTB) dye. The BC/ZnO composites were characterized using innovative techniques. BC/ZnO (2:1) showed the highest photocatalytic performance and BC/ZnO (2:1)@(PS + light) system attained BTB degradation efficiency of 89.47% within 120 min. The optimum operating parameters were determined as an initial BTB concentration of 17.1 mg/L, a catalyst dosage of 0.7 g/L, and a persulfate initial concentration of 8.878 mM, achieving a BTB removal efficiency of 99.34%. The catalyst showed excellent stability over five consecutive runs. Sulfate radicals were the predominant radicals involved in the degradation of BTB. BC/ZnO (2:1)@(PS + light) system could degrade 88.52%, 84.64%, 81.5%, and 77.53% of methylene blue, methyl red, methyl orange, and Congo red, respectively. Further, the BC/ZnO (2:1)@(PS + light) system effectively activated PS to eliminate 97.49% of BTB and 85.12% of dissolved organic carbon in real industrial effluents from the textile industry. The proposed degradation system has the potential to efficiently purify industrial effluents which facilitates the large-scale application of this technique. [Display omitted] • Hybrid photocatalysis/PS activation system could efficiently degrade BTB dye. • 99.34% degradation efficiency of BTB was achieved under the optimal condition. • Sulfate radicals were the main radicals involved in the degradation system. • The constituents of water matrices inhibited the accelerated degradation rates. • The proposed system could degrade 97.49% BTB and 85.12% DOC from real wastewater. [ABSTRACT FROM AUTHOR]

The Iguaçu River basin, known for its rich endemic ichthyofauna, faces a significant threat from chemical pollution. The Jordão River, a major tributary, drains extensive agricultural and livestock areas and receives poorly treated domestic and industrial effluents before joining the Iguaçu River. This study investigated the pollution and toxic effects of water samples from the Iguaçu upstream (UI), Jordão (JR), and their confluence (DI) on Steindachneridion melanodermatum embryos and larvae. Chemical analyses of the water samples revealed that most contaminants were present at levels below detection limits or within the limits established by Brazilian legislation. However, cadmium in UI, aluminum in JR, and lead in DI exceeded the legal limits. Exposure up to 96 h post-fertilization revealed higher mortality and deformity rates in individuals exposed to water samples from UI and JR, despite JR having fewer detected pollutants. JR and DI samples induced increased superoxide dismutase activity, indicating activation of the antioxidant defense system due to xenobiotic exposure. Overall, the integrated biomarker response indexes showed that individuals exposed to JR water displayed the most significant variations in their responses compared to the control treatment, suggesting a higher level of contamination and toxicity. Although a direct link between water quality and toxicity in the Jordão and Iguaçu Rivers was inconclusive, the results confirmed pollution and risks to local wildlife. The study highlighted the harmful effects of pollutants, even at low concentrations. These findings underscore the need for conservation measures to safeguard endemic and endangered species in the Iguaçu River basin. Understanding pollutant effects on native species is crucial for effective mitigation strategies and ecological health preservation. [Display omitted] • Toxicity to S. melanodermatum larvae indicates chemical pollution in Jordão River. • Higher mortality/deformity rates in Iguaçu upstream and Jordão River treatments. • Activation of the antioxidant defense system due to xenobiotics in water samples. • Importance of testing native and endemic species with implications to conservation. • Endemic ichthyofauna at risk due to pollution threat in Iguaçu River basin. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) and other organic matters in textile wastewater have posed a formidable challenge for treatment processes, particularly in the primary stages such as ultrafiltration (UF). UF plays a crucial role in preventing the entry of pollutants into subsequent treatment steps. However, the performance efficiency of UF membranes is compromised by the potential fouling of membrane pores by MPs, dyes and other organic pollutants such as bovine serum albumin (BSA). This study focuses on enhancing UF membrane performance, specifically its antifouling properties, through the development of high-performance membranes using MIL-53(Fe) metal-organic framework (MOF) particles (noted as MIL-53 here). Various concentrations of the MIL-53 (0.05, 0.1, 0.2, and 0.5 wt%) were integrated into the membrane structure through phase inversion process. Streaming zeta potential results confirmed the negatively charged surface of the membranes and their high hydrophilicity was validated through contact angle analysis. FTIR, SEM, EDS, and XRD confirmed the presence of MIL-53 particles on the surface of membranes. The developed membranes were tested for 24 h to assess their antifouling properties, with a subsequent 30-min hydraulic flush to measure their flux recovery ratios. Methylene Blue (MB) dye was used as a cationic dye present in textile wastewater to evaluate the efficiency of the developed membranes in dye removal and the synergistic effects of dye rejection in the presence of organic matters (i.e., MPs and BSA). Since previous studies have not fully addressed the combination of dyes and organic matter, this study thoroughly investigated the effect of particle-type foulants (MPs) and their interactions with dye (MB), as well as water soluble protein-type foulants (BSA) and their interaction with MB. The results indicated that the developed membranes exhibited higher MB rejection when the dye was present with either MP or BSA, along with improved antifouling properties. The optimised UF membrane integrated with 0.1 wt% MIL-53 demonstrated nearly 96% BSA rejection and around 86% MB rejection in the mixed foulant case (BSA-MB). The modified membrane exhibited a substantial increase in water flux from 176 L m−2.h−1 to 327 L m−2.h−1. The findings of this research show the potential of iron-based MOFs in improving the performance of UF membranes and provide a platform for future studies on significant areas such as long-term stability studies and testing with other pollutants found in textile wastewater. [Display omitted] • MIL-53 (Fe) MOF integrated UF membranes were fabricated and tested for methylene blue (MB) dye removal. • Langmuir model showed a stronger fit to the adsorption behaviour of MB on the membranes. • Fouling study of microplastics (MPs), bovine serum albumin (BSA), and MB dye was performed. • Water flux increased by 85% with an 82% flux recovery ratio against mixed foulants for the optimised membrane. • MOF membranes had high performance and antifouling properties against mixed foulants. [ABSTRACT FROM AUTHOR]

This study explores a novel and sustainable approach to reusing textile wastewater for irrigation. This is investigated by degrading Evans blue dye, a model azo dye, in wastewater by combining iron oxide predecessor (IOP) catalyst with gaseous species generated by multi-electrode cylindrical plasma device (MCPD). Analysis of IOP-plasma gaseous species revealed the generation of different types of reactive oxygen species in solution which were responsible for degradation of model dye. Key factors influencing the degradation process were studied by performing optimization experiments that resulted in rates of up to 0.008 L mg−1 min−1, more than twice as fast as using plasma gas treatment alone. These studies included mechanistic response of MCPD generated gaseous species with the IOP. In particular, reusability testing of IOP affirmed the robustness and performance efficiency up to three cycles. Finally, toxicity analysis revealed not only reduced negative effects on plant growth by the treated wastewater, but also it can used as minerals to plants. These findings highlight the feasibility of the IOP-MCPD system as a sustainable and eco-friendly solution to reduce scarcity of water in irrigation by treating textile effluent. [Display omitted] • Iron oxide predecessor (IOP) can be synthesized inside ten minute. • IOP enhances degradation capacity of plasma-gaseous species, more than doubling rates. • IOP boost ozone conversion to other reactive oxygen species, enhancing treatment. • IOP are reusable for multiple cycles maintaining effectiveness. • IOP suppresses acidification and peroxide in treated water and aids plant growth. [ABSTRACT FROM AUTHOR]

Microplastic (MP) pollution is currently one of the most serious environmental issues. MPs were investigated in the Kürtün Dam Lake in healthy individuals of the native leuciscid hybrid (Alburnus derjugini x Squalius orientalis) species and individuals infected with the Ligula intestinalis parasite. Although MP abundance appeared to be higher in non-infected fish (NIF) than in L. intestinalis (L) and infected fish (IF), the MP abundance in IF was higher, because the parasite theoretically belongs to IF. In addition to the observation of MPs in the gastrointestinal tract (GIT) of fish, the diffusion of MPs by parasites settled in the body cavity indicates that MPs are not only present in the GIT. Therefore, predation on existing fish by birds causes MP dispersion. In the present study, the most common MP shape was fiber (100% for NIF and IF, 85.7% for L), the MP color was black (57.1% for IF and L) and orange (50% for NIF), and the polymer type was polyamide (57.1% for IF, 50% for NIF) and polyethylene terephthalate (28.5% for L). These MP compositions led us to believe that textile effluents and aquaculture operations in dam lakes could be sources of pollution. Therefore, this study provides insights for future research to elucidate the connection between MP consumption and parasite infection. [Display omitted] • Parasitic infection increased MP accumulation in fish. • Fibers were the most frequently observed MP type in fish and parasites. • Predation of the hybrid fish species by birds may result in MP dispersal. • MP sources from aquaculture activities and textile effluents were likely most important. [ABSTRACT FROM AUTHOR]

Owing to extensive plastic consumption, wastewater from households, business establishments, and industrial activities have been recognised as a significant contributor to microplastics (MPs) in aquatic environments. This case study represents the first investigation of MPs in the Nakdong River, Republic of Korea, that traverses through the largest industrial complex midstream and densely populated cities of Daegu and Busan downstream before flowing into the sea. Monitoring of MP abundance in effluents discharged from three municipal, two industrial, and one livestock wastewater treatment plant (WWTP) into the Nakdong River was conducted over four seasons from August 2022 to April 2023. Identification and quantification of MPs were performed using micro-Fourier transform infrared spectrometry. Seasonal variation in MPs in the Nakdong River was found to be strongly influenced by the nearest upstream WWTPs and rivers, exhibiting a linear relationship that decreased gradually with increasing distance from the WWTPs. The average concentrations of MPs in the six effluent sources ranged from 101 ± 13 to 490 ± 240 particles/L during the yearly monitoring period, while MP concentrations in the river ranged between 79 ± 25 and 120 ± 43 particles/L. Industrial effluents contained higher amounts of discharged MPs (314 ± 78 particles/L) than municipal sources (201 ± 61 particles/L). Notably, two municipal WWTPs, located in the highly densely populated city, discharged the highest total MP amounts per day and released the greatest volumes of effluents. This study provides valuable insights into the monitoring and impact of effluents on MPs in rivers, which could inform MP treatment and management strategies for in river and marine environments. [Display omitted] • For the first time, MPs in the Nakdong River and WWTPs effluents was investigated. • Seasonal variation in MPs in the river was affected by the nearest upstream WWTPs. • A linear relationship decreased as the distance between the river and WWTPs increased. • The total effluent volume contributed to the total MP amount discharged to the river. • Shape and types of MPs in the river were distinguished by the waste type. [ABSTRACT FROM AUTHOR]

Vanadate-based photocatalysts have recently attracted substantial attention owing to their outstanding photocatalytic activity for degrading organic pollutants and generating energy via photocatalytic processes. However, the relatively high price of vanadium has hindered the development of vanadate-based photocatalysts for various applications. Spent catalysts obtained from oil refineries typically contain a significant quantity of vanadium, making them valuable for recovery and utilization as precursors for the production of high-value-added photocatalysts. In this study, we transformed the V present in spent catalysts produced by the petrochemical industry into ternary vanadate-based photocatalysts [BiVO 4 /InVO 4 /Ag 3 VO 4 (BVO/IVO/AVO, respectively)] designed for water remediation. The ternary composites revealed an enhanced photocatalytic capability, which was 1.42 and 5.1 times higher than those of the binary BVO/IVO and pristine AVO due to the facilitated charge separation. The ternary photocatalysts not only effectively treated wastewater containing various organic dyes, such as methylene blue (MB), rhodamine 6G (R6G), and brilliant green (BG), but also exhibited remarkable photocatalytic performance in the degradation of antibiotics, reduction of Cr(VI), and bacterial inactivation. This paper proposes a feasible route for recycling industrial waste as a source of vanadium to produce highly efficient vanadate-based photocatalysts. [Display omitted] • Recycling spent catalyst as photocatalysts increases its economic value. • Vanadium has been recycled from spent catalysts from oil refinery. • The ternary BiVO 4 /InVO 4 /Ag 3 VO 4 photocatalysts have been prepared. • The dual Z-scheme ternary photocatalysts show improved degradation efficiency. • The removal efficiency of antibiotics and inactivation of E. coli were evaluated. [ABSTRACT FROM AUTHOR]

and polyfluorinated alkyl substances, especially perfluorooctanoic acid and perfluorooctane sulfonic acid (PFOX), have attracted considerable attention lately because of their widespread occurrence in aquatic environment and potential biological toxicity to animals and human beings. The development of economical, efficient, and engineerable adsorbents for removing PFOX in water has become one of the research focuses. This review summarized the recent progress on natural mineral and industrial solid based adsorbent (NM&ISW-A) and removal mechanisms concerning PFOX onto NM&ISW-A, as well as proposed the current challenges and future perspectives of using NM&ISW-A for PFOX removal in water. Kaolinite and montmorillonite are usually used as model clay minerals for PFOX removal, and have been proved to adsorb PFOX by ligand exchange and electrostatic attraction. Fe-based minerals, such as goethite, magnetite, and hematite, have better PFOX adsorption capacity than clay minerals. The adsorbent prepared from industrial solid waste by high temperature roasting has great potential application prospects. Fabricating nanomaterials, amination modification, surfactant modification, fluorination modification, developing versatile composites, and designing special porous structure are beneficial to improve the adsorption performance of PFOX onto NM&ISW-A by enhancing the specific surface area, positive charge, and hydrophobicity. Electrostatic interaction, hydrophobic interaction, hydrogen bond, ligand and ion exchange, and self-aggregation (formation of micelle or hemimicelle) are the main adsorption mechanisms of PFOX by NM&ISW-A. Among them, electrostatic and hydrophobic interactions play a considerable role in the removal of PFOX by NM&ISW-A. Therefore, NM&ISW-A with electrostatic functionalities and considerable hydrophobic segments enables rapid, efficient, and high-capacity removal of PFOX. The future directions of NM&ISW-A for PFOX removal include the preparation and regeneration of engineerable NM&ISW-A, the development of coupling technology for PFOX removal based on NM&ISW-A, the in-depth research on adsorption mechanism of PFOX by NM&ISW-A, as well as the development of NM&ISW-A for PFOX alternatives removal. This review paper would be helpful the comprehensive understanding of NM&ISW-A potential for PFOX removal and the PFOX removal mechanisms, and identifies the gaps for future research and development. [Display omitted] • Preparation and modification of NM&ISW-A for PFOX removal was reviewed firstly. • Adsorption mechanism of PFOX on NM&ISW-A was systematically summarized. • Electrostatic and hydrophobic interactions are main cause of PFOX adsorption. • Current challenges and future perspectives on NM&ISW-A were proposed. [ABSTRACT FROM AUTHOR]

In this study, the Fe(III)/WS 2 /peroxymonosulfate (PMS) system was found to remove up to 97% of cyclohexanecarboxylic acid (CHA) within 10 min. CHA is a model compound for naphthenic acids (NAs), which are prevalent in petroleum industrial wastewater. The addition of WS 2 effectively activated the Fe(III)/PMS system, significantly enhancing its ability to produce reactive oxidative species (ROS) for the oxidation of CHA. Further experimental results and characterization analyses demonstrated that the metallic element W(IV) in WS 2 could provide electrons for the direct reduction of Fe(III) to Fe(II), thus rapidly activating PMS and initiating a chain redox process to produce ROS (SO 4 •−, •OH, and 1O 2). Repeated tests and practical exploratory experiments indicated that WS 2 exhibited excellent catalytic performance, reusability and anti-interference capacity, achieving efficient degradation of commercial NAs mixtures. Therefore, applying WS 2 to catalyze the Fe(III)/PMS system can overcome speed limitations and facilitate simple, economical engineering applications. [Display omitted] • Fe(III)/WS 2 /PMS system can achieve 97% removel rate of CHA within 10 min. • •OH, SO 4 •−, and 1O 2 are main ROS in the Fe(III)/WS 2 /PMS system. • W(IV) contained in WS 2 can promoting Fe(III)/Fe(II) cycle by providing electrons. • Fe(III)/WS 2 /PMS system can achieve efficient degradation of commercial NAs. • Fe(III)/WS 2 /PMS system exhibits excellent reusability and anti-interference. [ABSTRACT FROM AUTHOR]

Organic contaminants such as polycyclic aromatic compounds (PACs) occurring in industrial effluents can not only persist in wastewater but transform into more toxic and mobile, substituted heterocyclic products during treatment. Thus, predicting the occurrence of PACs and their heterocyclic derivatives (HPACs) in coking wastewater is of utmost importance to reduce the environmental risks in water bodies that receive industrial effluents. Although HPACs can be monitored through sampling and analysis, the characterisation techniques used in their analyses are costly and time-consuming. In this study, we propose 3 distinct kernel-based machine learning (ML) models for predicting PACs including substituted HPACs and alkylated PACs occurring in coking wastewater. By using routinely measured wastewater quality data as input for our models, we predicted the occurrence of 14 HPACs in the final effluent of a coking wastewater treatment plant. Support Vector Machine based regression model (SVR) used for HPAC prediction showed the highest R2 of 0.83. Performance assessment of SVR model showed a mean absolute logarithmic error (MALE) of 0.46 and root mean square error (RMSE) of 0.073 ng/L. Comparatively, K-Nearest Neighbor and Random Forest models showed lower R2 of 0.75 and 0.76 respectively for HPAC prediction. Feature analysis attributed the superior predictability of SVR model likely to its higher weightage (81%) towards dissolved organic carbon and total ammonia as input variables. Both these variables could capture the underlying secondary PAC transformations likely occurring in the treatment plant. Partial dependence plots predicted that ammonia levels higher than 120 mg/L and DOC levels of 50–60 mg/L were likely linked to higher HPACs occurring in the final effluent. This work highlights the capability of kernel-based ML models in capturing nonlinear wastewater chemistry and offers a tool for monitoring trace organic contaminants released in coking effluents. Application of machine learning for predicting the occurrence of polycyclic aromatic compounds in coking wastewater treatment. [Display omitted] • Transformation of PAHs during treatment led to the occurrence of substituted HPACs in coking effluent. • 16 PAHs, 31 APACs and 14HPACs were characterized in coking wastewater samples acquired from industrial facilities. • Kernel ML models using wastewater quality parameters as input variables predicted HPACs occurrence with R2 ≥ 0.75 in coking effluent. • PDPs suggest total ammonia >120 mg/L and DOC of 50–60 mg/L in SVR and RFR could mean increased HPACs. • NH 3 -T and DOC are key features capturing substituted and unsubstituted PAC occurrences in coking wastewater. [ABSTRACT FROM AUTHOR]

The vast discharge of methylene blue (MB) dye in industrial effluent, risks the ecological environment, thus making its removal unavoidable. Recently, metal organic frameworks (MOFs) due to their larger pore volume, surface area and easy synthesis have proved to be exceptionally promising materials for contaminant treatment. Based on 1,3,5-benzenetricarboxylic acid (BTC) as a modifier, a new composite material consisting of BTC and Zr-based MOF (UIO-66-BTC) was fabricated for the effective removal of MB from the effluent. Its synthesis and efficient application has been confirmed by characterization analysis. The influencing factors, adsorption isotherms, and adsorption kinetics of MB adsorption by adsorbent were studied. It was demonstrated that the removal rate of MB adsorption by UIO-66-BTC reached 98.45% and the adsorption amount reached 393.80 mg g−1 at temperature (298 K), pH 7, adsorbent dosage (0.5 g L−1), MB initial concentration (200 mg L−1), and contact time of 720 min, respectively. The maximum adsorption of MB by UIO-66-BTC was 20.827 times higher than that of UIO-66 (18.908 mg g−1). The experimental data fits with the pseudo-second-order kinetic model and Langmuir isotherm, implying that the adsorption process is a monolayer chemisorption process. The thermodynamic and regeneration experiments showed that the spontaneous process enhanced the adsorption of MB at lower temperatures and the adsorption efficiency of MB remained above 68% after five successive cycles. The mechanism of MB adsorption on adsorbents is mainly based on electrostatic interactions, pore filling, hydrogen bonding and π-π interactions. It is concluded that this new adsorbent can be effectively used to treat MB in effluents. [Display omitted] • BTC modified Zr-based MOF (UIO-66-BTC) was prepared. • MB could be efficiently removed by UIO-66-BTC. • PSO kinetic model and Langmuir isotherms model were applicable to the adsorption of UIO-66-BTC for MB. • The removal rate of MB still above 68% after five regeneration cycle. [ABSTRACT FROM AUTHOR]

The present study demonstrates, for the first time, the feasibility of a two-step process consisting of Electro-Fenton (EF) followed by microalgae to treat highly loaded real food processing wastewater along with resource recovery. In the first step, EF with a carbon felt cathode and Ti/RuO 2 –IrO 2 anode was applied at different current densities (3.16 mA cm−2, 4.74 mA cm−2 and 6.32 mA cm−2) to decrease the amount of organic matter and turbidity and enhance biodegradability. In the second step, the EF effluents were submitted to microalgal treatment for 15 days using a mixed culture dominated by Scenedesmus sp., Chlorosarcinopsis sp., and Coelastrum sp. Results showed that current density impacted the amount of COD removed by EF, achieving the highest COD removal of 77.5% at 6.32 mA cm−2 with >95% and 74.3% of TSS and PO 4 3− removal, respectively. With respect to microalgae, the highest COD removal of 85% was obtained by the culture in the EF effluent treated at 6.32 mA cm−2. Remarkably, not only 85% of the remaining organic matter was removed by microalgae, but also the totality of inorganic N and P compounds, as well as 65% of the Fe catalyst that was left after EF. The removal of inorganic species also demonstrates the high complementarity of both processes, since EF does not have the capacity to remove such compounds, while microalgae do not grow in the raw wastewater. Furthermore, a maximum of 0.8 g L−1 of biomass was produced after cultivation, with an accumulation of 32.2% of carbohydrates and 25.9% of lipids. The implementation of the two processes represents a promising sustainable approach for the management of industrial effluents, incorporating EF in a water and nutrient recycling system to produce biomass that could be valorized into clean fuels. [Display omitted] • A novel two-step electro-Fenton (EF)-microalgae process was proposed. • EF reduced organic load and suspended solids from a raw real industrial effluent. • After EF, microalgae removed remaining N and P compounds as well as Fe catalyst. • Microalgae accumulated carbohydrates and lipids with potential for biofuel production. • EF-microalgae is a sustainable option for wastewater treatment with resources recovery. [ABSTRACT FROM AUTHOR]

Textile and cosmetic industries generate large amounts of dye effluents requiring treatment before discharge. This wastewater contains high levels of reactive dyes, low to none-biodegradable materials and chemical residues. Technically, dye wastewater is characterised by high chemical and biological oxygen demand. Biological, physical and pressure-driven membrane processes have been extensively used in textile wastewater treatment plants. However, these technologies are characterised by process complexity and are often costly. Also, process efficiency is not achieved in cost-effective biochemical and physical treatment processes. Membrane distillation (MD) emerged as a promising technology harnessing challenges faced by pressure-driven membrane processes. To ensure high cost-effectiveness, the MD can be operated by solar energy or low-grade waste heat. Herein, the MD purification of dye wastewater is comprehensively and yet concisely discussed. This involved research advancement in MD processes towards removal of dyes from industrial effluents. Also, challenges faced by this process with a specific focus on fouling are reviewed. Current literature mainly tested MD setups in the laboratory scale suggesting a deep need of further optimization of membrane and module designs in near future, especially for textile wastewater treatment. There is a need to deliver customized high-porosity hydrophobic membrane design with the appropriate thickness and module configuration to reduce concentration and temperature polarization (CP and TP). Also, energy loss should be minimized while increasing dye rejection and permeate flux. Although laboratory experiments remain pivotal in optimizing the MD process for treating dye wastewater, the nature of their time intensity poses a challenge. Given the multitude of parameters involved in MD process optimization, artificial intelligence (AI) methodologies present a promising avenue for assistance. Thus, AI-driven algorithms have the potential to enhance overall process efficiency, cutting down on time, fine-tuning parameters, and driving cost reductions. However, achieving an optimal balance between efficiency enhancements and financial outlays is a complex process. Finally, this paper suggests a research direction for the development of effective synthetic and natural dye removal from industrially discharged wastewater. [Display omitted] • Discharge of dye effluent requires robust and cost-effective treatment processes. • Membrane distillation emerged as a promising tool towards dye remediation. • The current study reviewed research advancement towards environmental dye remediation. • However, fouling and thermal efficiency of MD remain a major challenge. • The reviewed study suggested optimization of membrane and module designs for effective dye remediation. [ABSTRACT FROM AUTHOR]

Toxic organic and heavy metal contaminants commonly exist in industrial waste stream(s) and treatment is of great challenge. In this study, a dielectric barrier discharge (DBD) non-thermal plasma technology was employed for the simultaneous treatment of two important contaminants, chloramphenicol (CAP) and Cr(VI) in an aqueous solution through redox transformations. More than 70% of CAP and 20% of TOC were degraded in 60 min, while Cr(VI) was completely removed in 10 min. The hydroxyl radicals were the main active species for the degradation. Meanwhile, the consumption of hydroxyl radicals was beneficial to the reduction of Cr(VI). The synergistic effect was investigated between CAP degradation and Cr(VI) reduction. The reduction of Cr(VI) would be enhanced in the presence of CAP with a low concentration and could be inhibited under a high concentration, because part of hydroxyl radicals could be consumed by the low-concentration CAP and the obtained intermediates with a higher kinetic rate. However, CAP with a high concentration could react with such reductive species as e aq − and •H, which could compete with Cr(VI) and inhibit the reduction. In addition, the presence of Cr(VI) enhanced the degradation and mineralization of CAP; the study of obtained intermediates indicated that the presence of Cr(VI) changed the degradation path of CAP as Cr(VI) would react with reductive species, enhance the generation of hydroxyl radicals, and cause more hydroxylation reactions. Moreover, the mechanism for the simultaneous redox transformations of CAP and Cr(VI) was illustrated. This study indicates that the DBD non-thermal plasma technology can be one of better solutions for simultaneous elimination of heavy metal and organic contaminants in aquatic environments. [Display omitted] • Dielectric barrier discharge plasma works well in treating contaminants. • Synergistic effect exists in treatment of chloramphenicol and Cr(VI). • Presence of Cr(VI) changes degradation path of chloramphenicol. [ABSTRACT FROM AUTHOR]

Antimony (Sb) decontamination in water is necessary owing to the worsening pollution which seriously threatens human life safety. Designing bismuth-based photocatalysts with hydroxyls have attracted growing interest because of the broad bandgap and enhanced separation efficiency of photogenerated electron/hole pairs. Until now, the available photocatalysis information regarding bismuth-based photocatalysts with hydroxyls has remained scarce and the contemporary report has been largely limited to Bi 3 O(OH)(PO 4) 2 (BOHP). Herein, Bi 3 O(OH)(AsO 4) 2 (BOHAs), a novel ultraviolet photocatalyst, was fabricated via the co-precipitation method for the first time, and developed to simultaneous photocatalytic oxidation and adsorption of Sb(III). The rate constant of Sb(III) removal by the BOHAs was 32.4, 3.0, and 4.3 times higher than those of BiAsO 4 , BOHP, and TiO 2 , respectively, indicating that the introduction of hydroxyls could increase the removal of Sb(III). Additionally, the crucial operational parameters affecting the adsorption performance (catalyst dosage, concentration, pH, and common anions) were investigated. The BOHAs maintained 85% antimony decontamination of the initial yield after five successive cycles of photocatalysis. The Sb(III) removal involved photocatalytic oxidation of adsorbed Sb(III) and subsequent adsorption of the yielded Sb(V). With the acquired knowledge, we successfully applied the photocatalyst for antimony removal from industrial wastewater. In addition, BOHAs could also be powerful photocatalysts in the photodegradation of organic pollutants studies of which are ongoing. It reveals an effective strategy for synthesizing bismuth-based photocatalysts with hydroxyls and enhancing pollutants' decontamination. [Display omitted] • Novel Bi 3 O(OH)(AsO 4) 2 photocatalyst was synthesized for the first time. • The BOHAs exhibited enhanced photocatalytic remediation of Sb(III). • Photocatalytic oxidation of adsorbed Sb(III) and adsorption of the yielded Sb(V). • Thirty-fold higher Sb(Ⅲ) decontamination than BiAsO 4. • Bi 3 O(OH)(AsO 4) 2 is efficient for Sb(III) removal from actual water. [ABSTRACT FROM AUTHOR]

The escalation of industrial activities has escalated the production of pharmaceutical and dyeing effluents, raising significant environmental issues. In this investigation, a hybrid approach of Fenton-like reactions and adsorption was used for deep treatment of these effluents, focusing on effects of variables like hydrogen peroxide concentration, catalyst type, pH, reaction duration, temperature, and adsorbent quantity on treatment effectiveness, and the efficacy of acid-modified attapulgite (AMATP) and ferric iron (Fe(III))-loaded AMATP (Fe(III)-AMATP) was examined. Optimal operational conditions were determined, and the possibility of reusing the catalysts was explored. Employing Fe 3 O 4 as a heterogeneous catalyst and AMATP for adsorption, COD Cr was reduced by 78.38–79.14%, total nitrogen by 71.53–77.43%, and phosphorus by 97.74–98.10% in pharmaceutical effluents. Similarly, for dyeing effluents, Fe(III)-AMATP achieved 79.87–80.94% COD Cr , 68.59–70.93% total nitrogen, and 79.31–83.33% phosphorus reduction. Regeneration experiments revealed that Fe 3 O 4 maintained 59.48% efficiency over three cycles, and Fe(III)-AMATP maintained 62.47% efficiency over four cycles. This work offers an economical, hybrid approach for effective pharmaceutical and dyeing effluent treatment, with broad application potential. [Display omitted] • Acid-modified attapulgite effectively treats pharmaceutical and dyeing effluents. • Fe(III)-loaded AMATP shows high efficiency in effluent treatment. • Hybrid approach combines Fenton-like reactions and adsorption for optimal results. • Hybrid approach achieves significant reduction in COD Cr , nitrogen, and phosphorus. • Fe 3 O 4 and Fe(III)-AMATP catalysts demonstrate effective regeneration for reuse. [ABSTRACT FROM AUTHOR]

Generally, the pH of fluorinated groundwater or many industrial wastewater is neutral, while the majority of metal-modified adsorbents can work efficiently only under acidic conditions. In this study, we synthesized a novel hybrid adsorbent, Mg–Zr-D213, by loading nano-Mg/Zr binary metal (hydrogen) oxides in a strong-base anion exchanger, D213, to enhance the adsorption of fluoride from neutral water. Mg–Zr-D213 exhibited a better fluoride-removal capacity in neutral water than monometallic modified resins. Under the interference of competing anions and coexisting organic acids, Mg–Zr-D213 exhibited superior selectivity. The Langmuir model indicated that the fitted maximum sorption capacity of Mg–Zr-D213 was 41.38 mg/g. The results of column experiments showed that the effective treatment volume of Mg–Zr-D213 was 8–16-times higher than that of D213 for both synthetic groundwater and actual industrial wastewater, and that NaOH–NaCl eluent could effectively recover more than 95% of fluoride. Adsorption experiments with Mg/Zr metal (hydrogen) oxide particles and D213 separately demonstrated a synergistic effect between –N+(CH 3) 3 and Mg/Zr metal (hydrogen) oxide particles. The ligand exchange or metal-ligand interaction of Mg/Zr metal (hydrogen) oxide particles on fluoride was further demonstrated via X-ray photoelectron spectroscopy. Overall, Mg–Zr-D213 has great potential for enhanced fluoride removal in neutral water. [Display omitted] • Novel binary metal (hydrogen) oxides modified resin (Mg–Zr-D213) for the enhanced removal of fluoride from neutral water. • Mg–Zr-D213 exhibits excellent adsorption capacity for fluoride in neutral water. • A synergistic effect between Mg/Zr metal (hydrogen) oxide nanoparticles and host D213. • Nanoparticles loaded in D213 can selectively adsorb fluoride via specific ligand exchange or metal-ligand interactions. • A binary solution of NaOH–NaCl eluent can effectively regenerate the exhausted adsorbent. [ABSTRACT FROM AUTHOR]

Chlorella vulgaris was cultivated for 15 days in 10 different treatments under mixotrophic and heterotrophic conditions, using wastewater from oil and poultry industries as the culture medium. The blends were made with produced water (PW), sterilized produced water (PW s), sterilized poultry wastewater (PoW s), sterilized seawater (SW s), and the addition of sodium nitrate to evaluate cell growth in treatments and the removal of PAHs. The heterotrophic condition showed more effective removal, having an initial concentration of 3.93 μg L−1 and a final concentration of 0.57 μg L−1 of total PAHs reporting 83%, during phycoremediation of (PW) than the mixotrophic condition, with an initial concentration of 3.93 μg L−1 and a final concentration of 1.96 and 43% removal for the PAHs. In the heterotrophic condition, the blend with (PWs + SWs) with an initial concentration of 0.90 μg L−1 and a final concentration of 0.32 μg L−1 had 64% removal of total PAHs compared to the mixotrophic condition with 37% removal having an initial concentration of 0.90 μg L−1 and a final concentration of 0.56 μg L−1. However, the best result in the mixotrophic condition was obtained using a blend of (PWs + PoWs) that had an initial cell concentration of 1.18 × 105 cells mL−1 and reached a final cell concentration of 4.39 × 105 cells mL−1, an initial concentration of 4.76 μg L−1 and a final concentration of 0.37 μg L−1 having a 92% total removal of PAHs. The biostimulation process increased the percentage of PAHs removal by 45% (PW) in the mixotrophic condition. This study showed that it is possible to allow an environmental remediation strategy that significantly reduces effluent toxicity and generates high value-added biomass in contaminated effluents rich in nutrients and carbon, based on a circular bioeconomy model. [Display omitted] • Blend of wastewater industrial showed the best result in the phycoremediation. • Higher cellular concentration in blend of industrial wastewater. • The bio-stimulation process increased the removal of PAHs total. [ABSTRACT FROM AUTHOR]

In this work, a one-stage dual internal circulation airlift anaerobic/anoxic/aerobic (DCAL-A2O) bioreactor was continuously operated for concurrent removal of nutrients and organics from milk processing wastewater (MPW). Special configuration of the airlift A2O bioreactor created possibility of the formation of desired anaerobic, anoxic and aerobic zones in a single unit. The process functionality of the bioreactor was examined under three influential operating variables i.e. hydraulic retention time (HRT; 7–15 h), air flow rate (AFR; 1–3 L/min) and aerobic volume ratio (AVR; 0.324–0.464). The optimum region was identified at HRT of 13h, AFR of 2L/min and AVR of 0.437, leading to TCOD, TN and TP removal efficiency of 94.5 %, 59.6 %, and 62.2 %, respectively, and effluent turbidity of 8 NTU. The impact of feed biodegradability on the process performance of the bioreactor treating the MPW, soft drink wastewater (SDW) and soybean oil plant wastewater (SOW) was also assessed. From the results, the feed characteristics affected significantly the nutrients removal. Moreover, the feeding location played an effective role in the nutrient removal while treating the MPW at optimum operating conditions. In this study, the change in residual organic matters as soluble microbial products (SMP) was monitored at various operating conditions. In addition, the impact of SMP extracted from sludge, extracellular polymeric substances (EPS) comprising of loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) was analyzed on sludge characteristics as bio-flocculation and settleability properties. According to the obtained data, the increase in operating variables led to the reduction in contents of effluent SMP, sludge SMP, LB-EPS, turbidity, and SVI, thereby, the enhancement in the sludge characteristics. Meanwhile, analysis of microbial communities verified the presence of various functional bacterial species. The cost operating evaluation confirmed the cost effectiveness of the airlift A2O bioreactor in reduction of energy consumption for the MPW treatment. One-stage dual internal circulation airlift A2O bioreactor. [Display omitted] • Simultaneous CNP removal was investigated in a one-stage DCAL-A2O bioreactor. • The impact of wastewater biodegradability and feeding location was evaluated on the bioreactor performance. • The sludge characteristics were explored throughout multiple experimental runs. • Operational cost estimates were performed under different operating conditions. • The coexistence and mutualistic development of various functional bacterial were observed in the context of PCR assays. [ABSTRACT FROM AUTHOR]

Swine farming produces large quantities of nutrient-rich wastewater, which often contains metals such as Cu and Zn, used as feed additives for pigs. These metals must be removed from the wastewater before discharge but their retention in the biomass can limit its subsequent utilization. Photobioreactors are a very promising alternative for swine wastewater treatment, as the consortium of microalgae and bacteria growing symbiotically in these reactors allows high nutrient and metal removal efficiency at moderate costs. This work studies the mechanisms of removal of Cu(II) and Zn(II) by the two types of microorganisms growing in these photobioreactors. A microalga commonly used in wastewater treatment (Scenedesmus almeriensis) and an activated sludge were kept in contact with synthetic wastewater containing 100 mg/L of Cu and Zn. After 72 h, Scenedesmus almeriensis removed 43% of Cu and 45% of Zn, while activated sludge removed 78% of Cu and 96% of Zn. Single and sequential extractions of the biomasses using different extracting reagents revealed that biosorption on protonable groups is the dominant removal mechanisms. Mild reagents solubilized 69% of Cu and 94% of Zn from the microalgae and 76% of Cu and 93% of Zn from the activated sludge. Low metal concentrations in the oxidizable and residual fractions evidenced minimal bioaccumulation inside the cells. FTIR and ESEM-EDX analysis confirmed biosorption by ion exchange and complexation as the main metal remediation mechanisms. The weak bonds of the biosorbed Cu and Zn ions are beneficial for the valorization of biomass and the obtaining of safe bioproducts. [Display omitted] • Sewage sludge more effective than microalga S. almeriensis to remove Cu and Zn from wastewater. • Cu is more strongly biosorbed than Zn by both sewage sludge and microalgae. • Metal biosorption on protonable electron donor groups is the main bioremoval mechanism. • Cu and Zn are biosorbed on groups –COOH, –OH, –NH contained in proteins and carbohydrates of the cell membrane. • Most metal accumulated by the biomasses is acid soluble/exchangeable and readily available. [ABSTRACT FROM AUTHOR]

The present study has focused on the mainstream integration of polyhydroxyalkanoate (PHA) production with industrial wastewater treatment by exploiting three different technologies all operating in sequencing batch reactors (SBR): conventional activated sludge (AS-SBR), membrane bioreactor (AS-MBR) and aerobic granular sludge (AGS). A full aerobic feast/famine strategy was adopted to obtain enrichment of biomass with PHA-storing bacteria. All the systems were operated at different organic loading (OLR) rate equal to 1-2-3 kgCOD/m3∙d in three respective experimental periods. The AS-MBR showed the better and stable carbon removal performance, whereas the effluent quality of the AS-SBR and AGS deteriorated at high OLR. Biomass enrichment with PHA-storing bacteria was successfully obtained in all the systems. The AS-MBR improved the PHA productivity with increasing OLR (max 35% w/w), whereas the AS-SBR reduced the PHA content (max 20% w/w) above an OLR threshold of 2 kgCOD/m3∙d. In contrast, in the AGS the increase of OLR resulted in a significant decrease in PHA productivity (max 14% w/w) and a concomitant increase of extracellular polymers (EPS) production (max 75% w/w). Results demonstrated that organic carbon was mainly driven towards the intracellular storage pathway in the AS-SBR (max yield 51%) and MBR (max yield 61%), whereas additional stressors in AGS (e.g., hydraulic selection pressure, shear forces) induced bacteria to channel the COD into extracellular storage compounds (max yield 50%) necessary to maintain the granule's structure. The results of the present study indicated that full-aerobic feast/famine strategy was more suitable for flocculent sludge-based technologies, although biofilm-like systems could open new scenarios for other biopolymers recovery (e.g., EPS). Moreover, the AS-MBR resulted the most suitable technology for the integration of PHA production in a mainstream industrial wastewater treatment plant, considering the greater process stability and the potential reclamation of the treated wastewater. [Display omitted] • A mainstream process for PHA production was integrated with wastewater treatment. • A comparison between AS, AGS and MBR as the enrichment/treatment stage was assessed. • MBR enabled the highest PHA production potential and effluent water eligible for reuse. • Biomass enrichment under full aerobic in AGS promoted extracellular storage pathways. • Integration of PHA production in the mainstream of a WWTP resulted feasible using MBR. [ABSTRACT FROM AUTHOR]

The release of organic dyes, such as Rhodamine B (RhB), into industrial wastewater has led to significant issues with color pollution in aquatic environments. Herein, we prepared a cobalt nanoparticles (NPs)-based catalyst with the nitrogen-doped carbon-support (Co@N–C) for effective PMS activation. The Co@N–C/PMS system demonstrated the excellent catalytic activity of Co@N–C for activating PMS, achieving nearly 100% degradation of RhB. Singlet oxygen (1O 2) and sulfate radicals (SO 4 •-) were dominant reactive oxygen species for RhB degradation. Density functional theory (DFT) calculations substantiated that the production of 1O 2 commenced with the initial generation of *OH through hydrogen abstraction from PMS, culminating in the direct release of oxygen to form 1O 2 (PMS→*OH→O*→1O 2). The generation of SO 4 •- was attributed to electron transfer to PMS from the surface of Co NPs (Co0→Co2+→Co3+) and the C–N shell (Co2+→Co3+). The research findings provided new insights into the development of Co-based heterogeneous catalysis for advanced oxidation of refractory organic pollutants in wastewater treatment. [Display omitted] • Cobalt nanoparticles-based Co@N–C catalyst in a core-shell structure was synthesized. • The Co@N–C catalyst exhibit good metal stability and magnetic separation property. • The Co@N–C/PMS system achieved highly efficient degradation of dye RhB. • DFT calculations revealed the active sites and ROS production mechanisms of Co@N–C. • PMS was activated by Co@N–C through radical (SO 4.•-) and non-radical (1O 2) pathways. [ABSTRACT FROM AUTHOR]

Accurate analyses of total organic carbon (TOC) encompassing particulate organic carbon in wastewater are key for evaluating the behavior of particulate organic contaminants and maintaining the carbon mass balance throughout the wastewater treatment process. This study was conducted to develop candidate reference materials of environmental origin from excess sludge collected from wastewater treatment facilities, primarily receiving industrial wastewater and livestock manure as the main sources. Homogeneity and stability assessments for total carbon (TC) and TOC were conducted in the particle samples following the standardized procedures of ISO Guide 35 and ISO 13258. The results showed that high inorganic carbon (IC) content in particles, such as YJ (500) (IC: 29%), rendered them unsuitable for TOC quality control (QC), as they increased uncertainty in both homogeneity and stability assessments. Additionally, a13C NMR analysis revealed that samples with a high (O-alkyl)/(C–H-alkyl) ratio in their carbon structures exhibited relatively low stability. Through the homogeneity and stability assessments, a particle sample, YJ (100) , was selected as the reference material (RM); the assigned values were as follows: 30.78% for TC and 27.94% for TOC, with uncertainties of 0.01% and 1.1%, respectively. Furthermore, considering sample transportation conditions, the safe storage period for the RM particles was determined to be 2 weeks under harsh conditions (at 40 °C). In our inter-laboratory test (n = 8) using the particle samples, we confirmed that the particle samples can effectively enhance particle processing QC and validate a proposed suspended solids pretreatment method. This study showcases valuable environmental particle sample production and evaluation, offering potential advancements in the QC of TOC analysis for wastewater samples. [Display omitted] • Sludge-based particles for QC in TOC analysis of wastewater were developed. • Assessments affirmed the stability and homogeneity of particles for TOC analysis. • High inorganic carbon in particles raised the TOC QC uncertainty. • High O-alkyl/C, H-alkyl ratio, and polar OC content in samples decreased the stability. • We advanced particle sample production and TOC analysis in solids-rich water. [ABSTRACT FROM AUTHOR]

In this study, novel nanohybrids of biosynthesized zinc oxide (ZnO) and magnetite-nanocarbon (Fe 3 O 4 –NC) obtained from the carbonization of toner powder waste were fabricated and investigated for persulfate (PS) activation for the efficient degradation of tetracycline (TCN). The chemical and physical properties of the synthesized catalysts were analyzed using advanced techniques. ZnO/Fe 3 O 4 –NC nanohybrid with mass ratio 1:2, respectively in the presence of PS showed the highest TCN removal efficiency compared to the individual components (ZnO and Fe 3 O 4 –NC) and other nanohybrids with mass ratios of 1:1 and 2:1. The results indicated that efficient degradation of TCN could be attained at pH 3–7. The optimum operating parameters were TCN concentration of 12.8 mg/L, PS concentration of 7 Mm, and catalyst dose of 0.55 g/L. The high stability of ZnO/Fe 3 O 4 –NC (1:2) nanocomposite was assured by the slight drop in TCN degradation percentage from 97.27% to 85.45% after five successive runs under the optimum conditions and the concentrations of leached iron and zinc into the solution were monitored. The quenching experiments explored that the prevailing reactive entities were sulfate radicals. Additionally, the degradation of TCN in various water matrices was investigated, and a degradation pathway was suggested. Further, degradation of real pharmaceutical waste was conducted showing that the removal efficiencies of TCN, total organic carbon (TOC), and chemical oxygen demand (COD) were 89.79, 80.65, and 78.64% after 2 h under the optimum conditions. The effectiveness of the proposed system (ZnO/Fe 3 O 4 –NC (1:2) @ PS) for the degradation of real samples compiled from industrial effluents as well as its inexpensiveness and green nature qualify this system for the full-scale application. [Display omitted] • Novel nanohybrids of ZnO and carbonized toner powder were synthesized. • ZnO/Fe 3 O 4 –NC (1:2) nanohybrid showed the best performance for degrading TCN. • Optimum operating parameters were determined. • Sulfate radicals were the dominant reactive species. • Effective mineralization of real wastewater was attained. [ABSTRACT FROM AUTHOR]

The release of industrial effluents, comprising of organic dyes, antibiotics, and heavy metals poses substantial environmental and ecological threats. Among the different approaches, the utilization of heterogeneous photocatalysis based on semiconducting metal oxides is of paramount important to removal of organic (MB dye and TC antibiotic) and inorganic pollutants (Cr (VI)) in wastewater. In this work, a new approach for creating type-II heterojunction photocatalysts named xNiCo 2 O 4 /BiVO 4 or BNC is suggested. The as-prepared samples were thoroughly examined by means of several sophisticated analytical tools to investigate their physicochemical properties. These composites were utilized in the decomposition of MB dye, TC drug and the reduction of Cr (VI) under visible light irradiation. According to the findings, the creation of type-II heterojunction at BiVO 4 –NiCo 2 O 4 interface greatly improved charge transportation while successfully preventing electron-hole recombination. Among the various composites studied, BNC-2 demonstrated an enhanced photocatalytic activity towards degradation of MB and TC, which were found to be 91 % over a period of 150 min and 95 % within only 60 min, respectively. Moreover, the photocatalytic reduction of Cr (VI) was accomplished 96 % within just 25 min. Additionally, it is discovered that BNC-2 displayed promising photostability and recyclability with a retention of >90 % after five consecutive cycles. The enhanced photocatalytic activity of BNC-2 is evidently attributed to the expedited separation and transfer of charges, as proven by photocurrent measurement, photoluminescence and electrochemical impedance spectroscopy analyses. Hence, the current amalgamation of NiCo 2 O 4 and BiVO 4 heterojunction composite has paved novel paths towards photocatalytic removal of organic as well as inorganic contaminants. [Display omitted] • A facile in-situ construction of NiCo 2 O 4 /BiVO 4 type II heterojunction photocatalyst is reported for MB dye, TC drug degradation and reduction of Cr (VI) to Cr (III). • The NiCo 2 O 4 :BiVO 4 weight ratio is varied to achieve optimal MB dye, TC degradation and Cr (VI) reduction performance. • The BNC-2 nanocomposites has performed well to produce an efficient photocatalytic activity with degradation of MB (91 % in 2.5h), TC (95 % in 1h) and Cr (VI) reduction (96 % in 25 min). • The rate of recombination of charge carriers (e - and h + ) in BNC-2 is supressed effectively as compared with other studied samples. [ABSTRACT FROM AUTHOR]

Currently, the vast majority of studies on microplastics (MPs) focus on determining the quantity and presence of these particles in various receiving environments and their treatment in domestic wastewater treatment plants. However, little research has been conducted on the treatment of microplastics in industrial effluent. Therefore, in this study, effluent samples from the cooling water tank of a local food packaging manufacturing company were analyzed to determine the presence and quantity of MPs for the first time. MPs removal from industrial wastewater using the electrocoagulation (EC) method was optimized using the Box Behnken Design (BBD). A second-order model was developed to estimate the microplastic removal efficiency, and the R2, adjusted R2, and predicted R2 of the model were 0.9994, 0.9985, and 0.9962, respectively. The optimal reaction parameters resulting in the maximum removal rate of microplastics (99 %) were determined to be pH 6.74, current density of 3.16 mA cm−2, and duration of 13.58 min. The cost of microplastic treatment per m3 of wastewater in the EC system, operated under optimal conditions, was calculated as 0.125 $. In this study, it was concluded that the EC process is a highly efficient technique for the removal of MPs from industrial wastewater at a low cost. Determining the most favorable conditions with BBD for the EC process at the feasibility stage of treatment plants will provide economic benefits and increase treatment efficiency during the installation of large-scale plants. [Display omitted] • Even cooling waters of plastic industries contain microplastics. • Microplastics can easily treated by using the electrocoagulation (EC) method. • Removal of microplastics by EC was modeled using BBD with high accuracy. • The optimal conditions; pH: 6.74, current density: 3.16 mA cm-2, time: 13.58 min. • The cost of microplastic treatment per m3 of wastewater was calculated as 0.125 $. [ABSTRACT FROM AUTHOR]

Cheese whey (CW) is a nutrient deficient dairy effluent, which requires external nutrient supplementation for aerobic treatment. CW, supplemented with ammonia, can be treated using aerobic granular sludge (AGS) in a sequencing batch reactor (SBR). AGS are aggregates of microbial origin that do not coagulate under reduced hydrodynamic shear and settle significantly faster than activated sludge flocs. However, granular instability, slow granulation start-up, high energy consumption and CO 2 emission have been reported as the main limitations in bacterial AGS-SBR. Algal-bacterial granular systems have shown be an innovative alternative to improve these limitations. Unfortunately, algal-bacterial granular systems for the treatment of wastewaters with higher organic loads such as CW have been poorly studied. In this study, an algal-bacterial granular system implemented in a SBR (SBR AB) for the aerobic treatment of ammonia-supplemented CW wastewaters was investigated and compared with a bacterial granular reactor (SBR B). Mass balances were used to estimate carbon and nitrogen (N) assimilation, nitrification and denitrification in both set-ups. SBR B exhibited COD and ammonia removal of 100% and 94% respectively, high nitrification (89%) and simultaneous nitrification-denitrification (SND) of 23% leading to an inorganic N removal of 30%. The efficient algal–bacterial symbiosis in granular systems completely removed COD and ammonia (100%) present in the dairy wastewater. SBR AB microalgae growth could reduce about 20% of the CO 2 emissions produced by bacterial oxidation of organic compounds according to estimates based on synthesis reactions of bacterial and algal biomass, in which the amount of assimilated N determined by mass balance was taken into account. A lower nitrification (75%) and minor loss of N by denitrifying activity (<5% Ng, SND 2%) was also encountered in SBR AB as a result of its higher biomass production, which could be used for the generation of value-added products such as biofertilizers and biostimulants. [Display omitted] • Synthetic dairy wastewaters were treated in microalgal-bacterial granular SBR (SBR AB). • Bacterial SBR (SBR B) and microalgal-bacterial SBR (SBR AB) were compared. • Higher removal rates of cheese whey and NH 3 –N were found in SBR AB. • Higher N assimilation and less SND led to higher useful biomass production in SBR AB. • SBR AB microalgae growth could reduce 20% of CO 2 emissions from bacterial activity. [ABSTRACT FROM AUTHOR]

This study investigates our hypothesis that how effect of arsenic stress on okra (Abelmoschus esculentus L.) can be alleviated through the use of waste materials such as steel slag (SS) and corncob biochar (BC). Different growth variables, biochemical parameters, oxidative stress markers, enzymatic and non-enzymatic antioxidants and glyoxylase enzyme activities were assessed. When okra was exposed to As, there was a noticeable decrease in seedling length, biomass, relative water content, various biochemical attributes, however, electrolyte leakage and lipid peroxidation in okra were enhanced. The supplementation of SS and BC—either individually or in combination—improved the growth parameters and reduced oxidative stress markers. Application of SS and BC also lowered As accumulation in roots and shoots of okra mitigating adverse effects of As exposure. Additionally, the activities of antioxidant and glyoxalase enzyme increased when SS and BC were present, concurrently reducing methylglyoxal content. Arsenic-induced stress led to oxidative damage, an enhancement in both enzymatic and non-enzymatic antioxidants, induced the synthesis of thiol and phytochelatins in roots and shoots. These may play a vital function in alleviating oxidative stress induced by As. Superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase activities were significantly enhanced in As-treated plants. These enhancement were further amplified when SS and BC were amended to As-treated okra. Therefore, synergistic application of SS and BC effectively protects okra against oxidative stress induced by As by increasing both antioxidant defense and glyoxalase systems. Both SS, an industrial byproduct, and BC, generated from agricultural waste, are cost-effective, environmentally friendly, safe, and non-toxic materials which can be used for crop production in As contaminated soil. [Display omitted] • Steel slag and corncob biochar enhanced growth of okra plants under arsenic stress. • ROS scavenging mechanism was strengthened by osmolytes accumulation. • Total acid soluble thiol and phytochelatin contents were enhanced in okra roots and shoots under arsenic stress. • Steel slag and corncob biochar declined arsenic-incited oxidative damage by boosting antioxidant and glyoxalase system. [ABSTRACT FROM AUTHOR]

Chromium-containing wastewater causes serious environmental pollution due to the harmfulness of Cr(VI). The ferrite process is typically used to treat chromium-containing wastewater and recycle the valuable chromium metal. However, the current ferrite process is unable to fully transform Cr(VI) into chromium ferrite under mild reaction conditions. This paper proposes a novel ferrite process to treat chromium-containing wastewater and recover valuable chromium metal. The process combines FeSO 4 reduction and hydrothermal treatment to remove Cr(VI) and form chromium ferrite composites. The Cr(VI) concentration in the wastewater was reduced from 1040 mg L−1 to 0.035 mg L−1, and the Cr(VI) leaching toxicity of the precipitate was 0.21 mg L−1 under optimal hydrothermal conditions. The precipitate consisted of micron-sized ferrochromium spinel multiphase with polyhedral structure. The mechanism of Cr(VI) removal involved three steps: 1) partial oxidation of FeSO 4 to Fe(III) hydroxide and oxy-hydroxide; 2) reduction of Cr(VI) by FeSO 4 to Cr(III) and Fe(III) precipitates; 3) transformation and growth of the precipitates into chromium ferrite composites. This process meets the release standards of industrial wastewater and hazardous waste and can improve the efficiency of the ferrite process for toxic heavy metal removal. [Display omitted] • FeSO 4 hydrothermal treatment removes most Cr(VI) from alkaline wastewater. • Cr(VI) turns into magnetic chromium ferrite composites. • Hydrothermal treatment boosts ferrochromium spinel multiphase formation and growth. [ABSTRACT FROM AUTHOR]

Effective capturing of anionic pollutants from wastewater under industrial operating conditions, which requires high processing flux and fast adsorption rate remains a challenge. Here, a commercially available melamine sponge (MS) with reticulated 3D macroporous structures was covalently modified with positively charged moieties using a single step functionalization under mild conditions. The developed novel polycationic melamine sponge (MS+) was formed by a nucleophilic addition reaction between glycidyltrimethylammonium chloride (GMTA) and MS, followed by a self-propagation of GMTA. The produced MS+ possessed strong electrostatic interactions with different anions such as Rose Bengal (RB) and phosphates (P) under a wide pH range (3–11). The MS+ exhibited promoted static adsorption efficiencies of 400 mg g−1 (P) and 600 mg g−1 (RB), within 5 min and 60 s, respectively. Furthermore, the MS+ showed high stability and recyclability for up to 15 cycles of uses, and the recycling process was environmentally friendly by using 1 M NaCl as a releasing solution. Benefiting from fast flow through the macroporous MS+ and highly positive charged skeleton, the MS+ was applied for rapid dynamic enrichment process of P from real manure wastewater with an enrichment factor of 4.4. Utilization of the MS+ as the substrate brings additional advantages such as low cost, availability, and flexibility to fit into existing filtration devices. The developed MS+ could be expanded for enrichments of other anionic species from various polluted water sources. [Display omitted] • Polycationic chains were covalently introduced to melamine sponge (MS) without free radical polymerization. • The MS functionalization was through single step under mild acidic conditions. • MS + exhibit high positive zeta-potential value at pH range (3–11). • MS + exhibit (P) and (RB) capacity of 400 and 600 mg g−1, within 5 min and 60 s, respectively. • MS + showed high stability and recyclability up to 15 cycles of uses. [ABSTRACT FROM AUTHOR]

Advanced treatment of refractory industrial wastewater is still a challenge. Coking wastewater is one of coal chemical wastewater, which contains various refractory organic pollutants. To meet the more and more rigorous discharge standard and increase the reuse ratio of coking wastewater, advanced treatment process must be set for treating the biologically treated coking wastewater. To date, several advanced oxidation processes (AOPs), including Fenton, ozone, persulfate-based oxidation, and iron-carbon micro-electrolysis, have been applied for the advanced treatment of coking wastewater. However, the performance of different advanced treatment processes changed greatly, depending on the components of coking wastewater and the unique characteristics of advanced treatment processes. In this review article, the state-of-the-art advanced treatment process of coking wastewater was systematically summarized and analyzed. Firstly, the major organic pollutants in the secondary effluents of coking wastewater was briefly introduced, to better understand the characteristics of the biologically treated coking wastewater. Then, the performance of various advanced treatment processes, including physiochemical methods, biological methods, advanced oxidation methods and combined methods were discussed for the advanced treatment of coking wastewater in detail. Finally, the conclusions and remarks were provided. This review will be helpful for the proper selection of advanced treatment processes and promote the development of advanced treatment processes for coking wastewater. [Display omitted] • The advanced treatment processes of coking wastewater were summarized and analyzed. • The major organic pollutants in the effluent of coking wastewater was introduced. • The performance of advanced treatment of coking wastewater by various AOPs was discussed. • The future direction of advanced treatment processes was proposed. [ABSTRACT FROM AUTHOR]

In regulatory environmental monitoring programs, only a very small fraction of the vast number of per- and polyfluoroalkyl substances (PFAS) are investigated by target analysis. Therefore, non-target analysis (NTA) studies are increasingly conducted to detect unknown or unnoticed PFAS. These studies are often based on a few grab samples. Thus, discontinuously emitted PFAS from industrial batch processes might be easily overlooked. To address this deficiency and obtain in-depth information on the occurrence and temporal trend of PFAS in surface water impacted by treated industrial waste water, a comprehensive target and NTA study was implemented for 29 months. Elevated PFAS concentrations with up to 10.8 μg L−1 were detected in the river water by target analysis. In addition to PFAS target analysis, the water samples were analyzed by liquid chromatography-high-resolution tandem mass spectrometry (LC-HRMS/MS). Data processing strategies and various filtering steps were applied to prioritize PFAS. Substances were identified by comparing data to available internal and external PFAS suspect lists, a fragment ion and neutral loss list, and spectral libraries. Several compounds were unequivocally identified based on reference standards. Fifty-five PFAS were (tentatively) identified using NTA. Of those, 43 could be assigned to 13 different homologous series. Partly fluorinated short-chain carboxylic acids (H-PFCA) and sulfonic acids (H-PFSA) were predominantly found in addition to perfluoroalkyl carboxylic acids (PFCA) and the alkyl ether carboxylic acid DONA. To the best of our knowledge, 12 PFAS were reported in surface water for the first time. Signal intensities of individual PFAS and signal ratios varied widely over time, which may indicate batch operations leading to discontinuous emission. Results and insights from this screening approach on PFAS can be used to optimize forthcoming surface water monitoring programs by including newly identified PFAS and selecting appropriate sampling intervals. [Display omitted] • Development of a monitoring strategy for known and unknown PFAS in highly impacted surface waters. • Non-target analysis (NTA) over a period of 29 months. • Novel data processing workflow for the identification and characterization of unknown PFAS. • Signal intensities and signal ratios of individual PFAS varied strongly over time. [ABSTRACT FROM AUTHOR]

Beauty salons (BS) are places that deal with a wide range of cosmetics with potentially hazardous chemicals, and their effluent should be properly treated before going to the sewage system, once it represents characteristics of industrial wastewater. This work provides an extensive characterization of a BS effluent and its respective electrochemical treatment by comparing NaCl, Na 2 SO 4 , and Na 2 S 2 O 8 as supporting electrolytes with a boron-doped diamond (BDD) as anode, applying 10 or 30 mA cm−2 of current density (j). The inclusion of UVC irradiation was also performed but the improvements achieved in removing the organic matter were null or lower. The analysis of chemical oxygen demand (COD) removal, energy consumption, and total current efficiency (TCE) was required to prove the efficacy of the processes and the comparative study of the performance of different technologies. Precipitate analysis was also done due to the high turbidity of the raw effluent and the appearance of a precipitate before and during the electrolysis, mainly with Na 2 S 2 O 8. The precipitate confirmed the presence of silicates and small amounts of heavy metals. The results clearly showed that 6 h of treatment with Na 2 SO 4 achieved 58% of COD removal with an energy consumption of about 0.52 kWh m−3, being the best electrolyte option for treating BS effluent by applying 10 mA cm−2. Under these experimental conditions, the final wastewater can be directly discharged into the sewage system with a lower amount of visible precipitate, and with 73% less turbidity. The treatment here proposed can be used as an alternative to decision-makers and governments once it can be a step further in the implementation of better and advanced politics of water sanitation. [Display omitted] • Electrochemical treatment of beauty salon effluent with BDD anode depends on its composition and electrolyte. • High turbidity of beauty salon wastewater turns UVC/Na 2 S 2 O 8 infeasible for its treatment. • Heavy metals such as Hg, Cr, and Cu are evidenced in the precipitated oxidized silicon. • The lesser Na 2 SO 4 electrolyte concentration (0.04 M) together with a minor j (10 mA cm−2) proved to be more efficient. [ABSTRACT FROM AUTHOR]

Chlorella bears excellent potential in removing nutrients from industrial wastewater and lipid production enriched with polyunsaturated fatty acids. However, due to the changing nutrient dynamics of wastewater, growth and metabolic activity of Chlorella are affected. In order to sustain microalgal growth in wastewater with concomitant production of PUFA rich lipids, RSM (Response Surface Methodology) followed by heuristic hybrid computation model ANN-MOGA (Artificial Neural Network- Multi-Objective Genetic Algorithm) were implemented. Preliminary experiments conducted taking one factor at a time and design matrix of RSM with process variables viz. Sodium chloride (1 mM–40 mM), Magnesium sulphate (100 mg–800 mg) and incubation time (4th day to 20th day) were validated by ANN-MOGA. The study reported improved biomass and lipid yield by 54.25% and 12.76%, along with total nitrogen and phosphorus removal by 21.92% and 18.72% respectively using ANN-MOGA. It was evident from FAME results that there was a significantly improved concentration of linoleic acid (19.1%) and γ-linolenic acid (21.1%). Improved PUFA content makes it a potential feedstock with application in cosmeceutical, pharmaceutical and nutraceutical industry. The study further proves that C. sorokiniana MSP1 mediated industrial wastewater treatment with PUFA production is an effective way in providing environmental benefits along with value addition. Moreover, ANN-MOGA is a relevant tool that could control microalgal growth in wastewater. [Display omitted] • Wastewater remediation using Chlorella sorokiniana MSP1 is reported. • The GA-ANN based tools gave substantial lipid production and phycoremediation. • Chlorella sorokiniana MSP1 reported the TP and TN removal efficiency increase by 20%. • It reports innovative eco-friendly wastewater remediation with low-cost lipid production. [ABSTRACT FROM AUTHOR]

The rapid development in industrialization and urbanization coupled with an ever-increasing world population has caused a tremendous increase in contamination of water resources globally. Synthetic dyes have emerged as a major contributor to environmental pollution due to their release in large quantities into the environment, especially owing to their high demand in textile, cosmetics, clothing, food, paper, rubber, printing, and plastic industries. Photocatalytic treatment technology has gained immense research attention for dye contaminated wastewater treatment due to its environment-friendliness, ability to completely degrade dye molecules using light irradiation, high efficiency, and no generation of secondary waste. Photocatalytic technology is evolving rapidly, and the foremost goal is to synthesize highly efficient photocatalysts with solar energy harvesting abilities. The current review provides a comprehensive overview of the most recent advances in highly efficient visible light-activated photocatalysts for dye degradation, including methods of synthesis, strategies for improving photocatalytic activity, regeneration and their performance in real industrial effluent. The influence of various operational parameters on photocatalytic activity are critically evaluated in this article. Finally, this review briefly discusses the current challenges and prospects of visible-light driven photocatalysts. This review serves as a convenient and comprehensive resource for comparing and studying the fundamentals and recent advancements in visible light photocatalysts and will facilitate further research in this direction. [Display omitted] • An extensive review of high-performing visible-light-activated photocatalysts for dye degradation. • Summary of various methods of synthesis and strategies to further improve the photocatalytic activity. • Discussion on recyclability and regeneration performance of the photocatalysts. • Critical analysis of various factors affecting photocatalytic dye degradation. • Discussion on challenges that need to be addressed and future perspectives to achieve sunlight-driven dye degradation. [ABSTRACT FROM AUTHOR]

Calcite-biochar composites are attractive materials with outstanding adsorption capabilities for removing various recalcitrant contaminants in wastewater treatment, however, the complexity of their synthesis limits their practical applications. In this work, we have prepared calcite-rich biochar (Ca-BC) from a single precursor (Tamarindus indica bark), which simplifies the synthetic route for preparing calcite-biochar composite. The as-synthesized composite is utilized to make a heterogeneous catalytic system containing the supported silver nanoparticles (Ag@Ca-BC) formed by the reduction of Ag+ ions on the surface of the composite. The formation of Ag@Ca-BC is confirmed by various characterization techniques such as PXRD, FT-IR, UV–Vis, cyclic voltammetry, impedance measurement, SEM, and TEM analyses. Especially, the TEM analysis confirms the presence of Ag nanoparticles with size ranging between 20 and 50 nm on the surface of Ca-BC composite. The nano-catalyst Ag@Ca-BC efficiently promotes the conversion of 4-nitrophenol to 4-aminophenol using NaBH 4 as the reductant in water within 24 minutes at room temperature, suggesting that Ag@Ca-BC can be an efficient catalyst to remove nitroaromatics from the industrial effluents. The straightforward synthesis of Ca-BC from a single precursor along with its utility as a catalytic support presents a compelling proposition for application in the field of materials synthesis, catalysis, and green chemistry. [Display omitted] • Valorisation of biomass debris into a valuable support material for catalysis. • Calcite-rich biochar preparation from a single source (Tamarindus Indica). • Reduction of Ag + ions over calcite-rich biochar yields a cost effective and energy efficient catalyst (Ag@Ca-BC). • Facile conversion of toxic 4-nitrophenol to useful 4-aminophenol over Ag@Ca-BC. • The observed k app value of 4.88 × 10−3 s−1 demonstrates the competitiveness of Ag@Ca-BC with most of reported Ag-based catalysts. [ABSTRACT FROM AUTHOR]

Currently, scarcity/security of clean water and energy resources are the most serious problems worldwide. Industries use large volume of ground water and a variety of chemicals to manufacture the products and discharge large volume of wastewater into environment, which causes severe impacts on environment and public health. Fossil fuels are considered as major energy resources for electricity and transportation sectors, which release large amount of CO 2 and micro/macro pollutants, leading to cause the global warming and public health hazards. Therefore, algae-bacterial consortium (A-BC) may be eco-friendly, cost-effective and sustainable alternative way to treat the industrial wastewaters (IWWs) with Bio-H 2 production. A-BC has potential to reduce the global warming and eutrophication. It also protects environment and public health as it converts toxic IWWs into non or less toxic (biomass). It also reduces 94%, 90% and 50% input costs of nutrients, freshwater and energy, respectively during IWWs treatment and Bio-H 2 production. Most importantly, it produce sustainable alternative (Bio-H 2) to replace use of fossil fuels and fill the world's energy demand in eco-friendly manner. Thus, this review paper provides a detailed knowledge on industrial wastewaters, their pollutants and toxic effects on water/soil/plant/humans and animals. It also provides an overview on A-BC, IWWs treatment, Bio-H 2 production, fermentation process and its enhancement methods. Further, various molecular and analytical techniques are also discussed to characterize the A-BC structure, interactions, metabolites and Bio-H 2 yield. The significance of A-BC, recent update, challenges and future prospects are also discussed. [Display omitted] • Scarcity and security of clean water and energy resources are the most critical today's problem. • IWWs are rich in color, nutrients, organic pollutants and heavy metals. • IWWs are highly toxic to human/animal/plant/soil/water and microbes. • A-BC is cost-effective and eco-friendly methods of IWWs treatment with Bio-H 2 production. • Bio-H 2 is a future fuel to fulfil the world's energy demand in eco-friendly manner. [ABSTRACT FROM AUTHOR]

Pyrrhotite-sulfur-limestone composite (PSLC) was prepared and PSLC autotrophic denitrification biofilter (PSLCAD) was constructed with PSLC particle (2–4.75 mm) in this study. During treating synthetic, municipal and industrial secondary effluent, PSLCAD showed good NO 3 −-N and PO 4 3--P removal, and the highest TON (Total oxidized nitrogen) removal rate of PSLCAD was up to 1749.91 mg/L/d. At HRT 0.5 h, and influent NO 3 −-N 21.09 mg/L, TON removal rate was up to 1005.12 mg/L with effluent NO 3 −-N 0.10 mg/L. PSLCAD achieved effluent PO 4 3--P below 0.2 mg/L when influent PO 4 3--P was around 0.5 mg/L. HRT down to 0.5 h had no negative impacts on N removal. Effluent pH below 7 was harmful to denitrification performance of PSLCAD. TON removal rate increased with influent NO 3 −-N increasing, but influent NO 3 −-N over 103.55 mg/L decreased NO 3 −-N removal rate. In PSLCAD biofilter, the most dominant bacteria were Thiobacillus and Sulfurimonas , and they played the most important role in denitrification, but the abundance of heterotrophic denitrifiers was also quite high. PO 4 3− was mainly removed through precipitate of Fe–P in PSLCAD. The synergistic effects between pyrrhotite and sulfur autotrophic denitrification were much enhanced, and that caused PSLCAD to achieve high rate N and P removal. [Display omitted] • The synergistic effects between PAD and SAD were much enhanced in PSLCAD. • PSLCAD has high rate N and P removal from secondary effluent. • The highest NO 3 −-N removal rate of PSLCAD was up to 1749.91 mg/L/d. • HRT, effluent pH and influent NO 3 −-N had important effects on N and P removal performance of PSLCAD. • The most dominant bacteria were Thiobacillus and Sulfurimonas in PSLCAD. [ABSTRACT FROM AUTHOR]

Discharging microplastics into the environment with treated wastewater is becoming a major concern around the world. Wastewater treatment plants (WWTPs) release microplastics into terrestrial and aquatic habitats, mostly from textile, laundry, and cosmetic industries. Despite extensive research on microplastics in the environment, their removal, and WWTP management strategies, highlighting their environmental effects, little is known about microplastics' fate and behaviour during various treatment processes. Microplastics interact with treatment technologies differently due to their diverse physical and chemical characteristics, resulting in varying removal efficiency. Microplastics removed from WWTPs may accumulate in soil and harm terrestrial ecosystems. Few studies have examined the cost, energy use, and trade-offs of large-scale implementation of modern treatment methods for the removal of microplastics. To safeguard aquatic and terrestrial habitats from microplastics' contamination, focused and efficient management techniques must bridge these knowledge gaps. This review summarizes microplastic detection, collection, removal and management strategies. A compilation of treatment process studies on microplastics' removal efficiency and their destiny and transit paths shows recent improvement. Bioremediation, membrane bioreactor (MBR), electrocoagulation, sol-gel technique, flotation, enhanced filtering, and AOPs are evaluated for microplastic removal. The fate and behaviour of microplastics in WWTPs suggest they may be secondary suppliers of microplastics to receiving ecosystems. Innovative microplastic removal strategies and technologies such as nanoparticles, microorganism-based remediation, and tertiary treatment raise issues. These new WWTP technologies are examined for feasibility, limitations, and implementation issues. Pretreatment modifies microplastic size, adsorption potential, and surface morphology to remove microplastics from WWTPs. Membrane bioreactors (MBR) can remove 99.9% of microplastics more efficiently than other approaches. MBR systems require membrane cleaning and fouling control, which raises operational and capital costs. To reduce MPs, plastic alternatives and strict controls, including microplastic waste transformation, should be prioritized. Microplastics must be controlled through monitoring policy execution and awareness. [Display omitted] • Discharging microplastics (MPs) via industrial wastewater is a pressing global issue. • MPs harm soil and ecosystems requiring a search for effective removal technologies. • Membrane bioreactor (MBR) showed effectiveness in removing more than 99.9 % of MPs. • Despite being expensive, bioremediation is demonstrated as an effective approach. • Plastic alternatives and stringent control approaches should be prioritized. [ABSTRACT FROM AUTHOR]

Globally freshwater ecosystems and associated biota including phytoplankton communities are at extreme risk from trace metal pollution originating from geogenic as well as from anthropogenic sources such as release of untreated industrial effluents. In the present study influence of iron- and arsenic-enrichments on structure and metabolism of phytoplankton communities of River Ganga, one of the largest rivers of South Asia, was assessed under laboratory-based microcosm experiments. Surface water samples were collected and subsequently enriched with higher than recommended concentrations of iron (10 mg/L) and arsenic (10 μg/L). The set-up comprised of nine containers of 25 L volume with three containers each for iron- and arsenic-enrichment and was maintained for 30 days. Trace metal enrichment rapidly changed the phytoplankton community structure and chemistry of nutrients uptake. Iron-enrichment prompted diatom blooms comprising of Thalassiosira , succeeded by green algae Coelastrum. Arsenic-enrichment maintained cyanobacteria for longer time-spans compared to the control and iron-enriched containers but significantly lesser abundance of diatoms. Variations in community composition was also reflected in nutrient uptake rates with silicate release in the arsenic-enriched containers at the end of the experiment. Changes in macronutrient dynamics also altered genus growth rates wherein both iron- and arsenic appeared to lower the death rate of Thalassosira but stimulated growth of other genera including Skeletonema and Pandorina. Iron appeared to influence lesser number of genera compared to arsenic which altered growth rates of both diatoms and green algae. This consequently influenced the gross primary productivity values which lowered both in the iron- and arsenic-enriched containers compared to the control owing to decrease in phytoplankton diversity. Iron appeared to drive phytoplankton communities toward a less general and more specialized composition with high abundance of selective species comprising of small diatoms such as Thalassio s ira , whereas arsenic appears to select for green algal enrichment in freshwater ecosystems. [Display omitted] • Enrichment of iron and arsenic using microcosm showed rapid change in uptake of nutrients by phytoplankton. • Iron-enrichment prompted diatom blooms followed by green algae.. • Arsenic-enrichment maintained cyanobacteria for longer time-span.. • Iron favored more specialized composition led by small-sized diatoms. • Gross primary productivity values found to be lower in iron- and arsenic-enriched conditions. [ABSTRACT FROM AUTHOR]

The advantages of microbial induced carbonate precipitation (MICP) as bio-cementation technology for tailings-solidification are under extensive investigation. In order to improve performance of bio-cementation, many strengthening materials were applied to the bio-cementation of tailings. Steel slag (SS) is a kind of industrial solid waste, its chemical composition and mineral composition are similar to cement, and it has a certain application prospect as an auxiliary cementing material. In this study, the properties and mechanism of SS strengthening MICP cementation of cyanide tailings (CT) were investigated. The results showed that Sporosarcina pasteurii growth is not inhibited by SS, and Sporosarcina pasteurii can promote the hydration reaction of SS, providing a suitable alkaline environment and Ca2+, promoting the production of more CaCO 3 in the MICP process. When 200 mL of CT leachate was added 1.4 g SS (200–400 mesh), the adsorption of Cu, Pb, Zn, Cd, total cyanide (T-CN), and free cyanide (F–CN) reached 48.05%, 44.28%, 36.25%, 16.67%, 79.05%, and 67.20%, respectively. The maximum unconfined compressive strength（UCS） of the cemented body (with 5%, 150 mesh SS) was 1.97 MPa, which was 3.396 times as high as that without SS. The cemented body with the addition of SS (5%, 150 mesh) contained more carbonate bound Cu (2.75%), Pb (4.89%), Zn (5.37%), and Cd (5.75%), and less exchangeable Cu (3.65%), Pb (6.85%), Zn (2.27%), and Cd (4.42%) than that without SS. In summary, the addition of SS improved the UCS of cemented bodies and the stability of heavy metals and cyanide, reduced the environmental risks existing in the process of CT storage. Meanwhile, it also provides new ideas for resource utilization of industrial solid waste SS and improvement of mine filling materials. The advantages of microbial induced carbonate precipitation (MICP) as bio-cementation technology for tailings-solidification are under extensive investigation. In order to improve performance of bio-cementation, many strengthening materials were applied to the bio-cementation of tailings. Steel slag (SS) is a kind of industrial solid waste, its chemical composition and mineral composition are similar to cement, and it has a certain application prospect as an auxiliary cementing material. In this study, the properties and mechanism of SS strengthening MICP cementation of cyanide tailings (CT) were investigated. The results showed that Sporosarcina pasteurii growth is not inhibited by SS, and Sporosarcina pasteurii can promote the hydration reaction of SS, providing a suitable alkaline environment and Ca2+, promoting the production of more CaCO 3 in the MICP process. When 200 mL of CT leachate was added 1.4 g SS (200–400 mesh), the adsorption of Cu, Pb, Zn, Cd, total cyanide (T-CN), and free cyanide (F–CN) reached 48.05%, 44.28%, 36.25%, 16.67%, 79.05%, and 67.20%, respectively. The maximum unconfined compressive strength (UCS) of the cemented body (with 5%, 150 mesh SS) was 1.97 MPa, which was 3.396 times as high as that without SS. The cemented body with the addition of SS (5%, 150 mesh) contained more carbonate bound Cu (2.75%), Pb (4.89%), Zn (5.37%), and Cd (5.75%), and less exchangeable Cu (3.65%), Pb (6.85%), Zn (2.27%), and Cd (4.42%) than that without SS. In summary, the addition of SS improved the UCS of cemented bodies and the stability of heavy metals and cyanide, reduced the environmental risks existing in the process of CT storage. Meanwhile, it also provides new ideas for resource utilization of industrial solid waste SS and improvement of mine filling materials. [Display omitted] • Sporosarcina pasteurii can promote the hydration reaction of steel slag to form more C–S–H gel. • Steel slag can adsorb the heavy metals and cyanide. • Steel slag improved the mechanical properties of cemented bodies, and stabilized heavy metals and cyanide better. [ABSTRACT FROM AUTHOR]

Sulfate radical-based oxidation processes were investigated to understand the relationship between persulfate (PS) consumption and total organic carbon (TOC) removal from industrial wastewater under various PS concentrations. First, the degradation and mineralization of Bisphenol A (BPA) (initial concentration: 11 mg/L) were investigated in ultraviolet (UV)/PS systems. Complete degradation was achieved within 30 min of UV irradiation, and 41%–72% TOC removal was achieved at PS concentrations of 200 and 400 mg/L. The consumed concentration of S 2 O 8 2− and generated concentration of SO 4 2− increased gradually to similar levels. The ratio of the PS consumption to TOC removal based on the mass concentration (mg/L) was 14.5 and 23.2 at 180 min for 200 and 400 mg/L of S 2 O 8 2−, respectively. Three types of coagulation-treated industrial wastewater from metal-processing, food-processing, and adhesive-producing plants were obtained, and TOC removal was analyzed using the same UV/PS systems (initial TOC concentration: 100 mg/L). The TOC removal rates ranged from 16.9% to 94.4% after 180 min of UV irradiation at PS concentrations of 1,000, 2,000, 4,000, and 8,000 mg S 2 O 8 2−/L. Despite the higher TOC removal at higher PS concentrations, the PS activation efficiency decreased significantly as the PS concentration increased. Only approximately 30%–40% activation efficiency was achieved at a PS concentration of 8,000 mg/L. In this study, the ratio of PS consumption to TOC removal ranged from 20.6 to 43.9. [Display omitted] • UV activated sulfate-radical oxidation processes were investigated. • BPA solution and three industrial wastewaters were tested in the UV/PS systems. • Higher TOC removals were achieved with higher PS concentrations. • The ratio of PS consumption to TOC removal ranged from 20.6 to 43.9. [ABSTRACT FROM AUTHOR]

Discharge of untreated dyeing wastewater nearby water-bodies is one of major causes of water pollution. Generally, bacterial strains isolated from industrial effluents and/or contaminated soils are used for the bioremediation of Methyl orange (MO), a mutagenic recalcitrant mono-azo dye, used in textiles and biomedical. However, MO degradation by biofilm producing plant growth-promoting rhizobacteria (BPPGPR) was not studied yet. In this study, 19 out of 21 BPPGPR strains decolorized 96.3–99.9% and 89.5–96.3% MO under microaerophilic and aerobic conditions, respectively from Luria-Bertani broth (LBB) followed by yeast-extract peptone and salt-optimized broth plus glycerol media within 120 h of incubation at 28 °C. Only selected BPPGPR including Pseudomonas fluorescens ESR7, P. veronii ESR13, Stenotrophomonas maltophilia ESR20, Staphylococcus saprophyticus ESD8, and P. parafulva ESB18 were examined for process optimization of MO decolorization using a single factor optimization method. This study showed that under optimal conditions (e.g., LBB, 100 mg L−1 MO, pH 7, incubation of 96 h, 28 °C), these strains could remove 99.1–99.8% and 97.6–99.5% MO under microaerophilic and aerobic conditions, respectively. Total azoreductase and laccase activities responsible for biodegradation were also remarkably activated in the biodegraded samples under optimal conditions, while these activities were repressed under unfavorable conditions (e.g., 40 °C and 7.5% NaCl). This study confirmed that MO was degraded and detoxified by these bacterial strains through breakage of azo bond. So far, this is the first report on bioremediation of MO by the BPPGPR strains. These BPPGPR strains are highly promising to be utilized for the bioremediation of dyeing wastewater in future. [Display omitted] • 19 biofilm forming PGPR strains effectively decolorized MO from Luria Bertani broth. • Examined strains decolorized 99.1–99.8% in ideal and microaerophilic conditions. • Studied PGPR strains removed 92.8–99.7% MO in optimum and aerobic conditions. • MO degradation confirmed by analytical, enzymatic and TOC studies. • Degraded metabolites are less toxic than parent dye. [ABSTRACT FROM AUTHOR]

Heavy metals present in industrial wastewater contribute to human and ecosystem health risk when discharged without proper treatment. Low-cost biosorbents with high metal-binding capacity are increasingly being utilized for the removal of heavy metals. Inherent physico-chemical properties of biosorbents significantly influence their adsorption capacity. Studies quantifying the influence exerted by these properties on adsorption capacity are scarce. This study quantifies the influence and relative importance of selected physico-chemical properties on the adsorption capacity of three divalent heavy metals; Cu2+, Cd2+ and Pb2+ using multivariate analysis. Twenty one biosorbent mixtures were created, systematically varying their physico-chemical properties using tea factory waste and coconut shell biochar. Their adsorption capacities were measured using batch sorption studies. The influence of physico-chemical properties on the adsorption capacity is comparable for all three metal cations. Regression models were developed to quantify the influence of physico-chemical parameters on the adsorption capacity based on regression coefficients. All models were found to have high reliability with R2 values above 0.98. Acidic surface functional groups were found to act as the key property that governs the adsorption capacity of Pb2+, Cu2+ and Cd2+. Carboxylic groups played a major role in the adsorption of Cu2+ and Pb2+, while lactonic groups were more important in providing binding sites to Cd2+. SSA failed to demonstrate a significant impact on the adsorption capacity of these three metals on its own when the biosorbent had a low surface functional group density. Image 1 • The influence of acidic surface functional groups is prominent in metal adsorption. • SSA alone does not exert a significant influence on metal adsorption. • Carboxylic groups exert more influence on binding hard acids. • Lactonic groups are more important in providing binding sites to soft acids. [ABSTRACT FROM AUTHOR]

Agriculture is considered as the main source of water contamination by pesticides. However, food packaging or processing industries are also recognised as relevant point sources of contamination by these compounds, not yet investigated in depth. The objective of this work has been to improve current knowledge about the presence and concentration of pesticides in the effluent of a food processing industry, as well as to investigate their main transformation products (TPs). An analytical strategy combining target and suspect analysis has been applied to provide an evaluation of the effluents. The methodology involves solid-phase extraction (SPE) of wastewater samples followed by (i) liquid chromatography quadrupole-linear ion trap tandem mass spectrometry (LC-QqLIT-MS/MS) for quantitative target analysis and (ii) liquid chromatography coupled to quadrupole-time-of-flight high resolution mass spectrometry (LC-QTOF-HRMS) to identify non-target pesticides and possible TPs. The results revealed the presence of 17 of the target pesticides analysed and 3 additional ones as a result of the suspect screening performed by HRMS. The TPs were investigated for the pesticides found at the highest concentrations: imazalil (7038-19802 ng/L), pyrimethanil (744-9591 ng/L) and thiabendazole (341-926 ng/L). Up to 14 TPs could be tentatively identified, demonstrating the relevance of this type of studies. These data provide a better understanding of the occurrence of pesticides and their TPs in agro-food industrial effluents. Image 1 • Analysis of pesticides in wastewater effluent of an agro-food industry was carried out. • Imazalil, pyrimethanil, thiabendazole, propiconazole and etoxazole were detected at the highest concentrations. • Presence of imazalil, pyrimethanil and thiabendazole TPs was also evidenced in the effluents. • Imazalil and cyprodinil concentrations can eventually pose a risk for the environment. [ABSTRACT FROM AUTHOR]

Management of olive mill wastewaters is one of the most challenging environmental issue in Mediterranean countries due to its high organic load, color, presence of phenolic compounds and need for high energy cost. Performance of electrohydrolysis (EH) process in terms of removal of organic compounds, detoxification and discoloration of olive mill wastewater (OMW) with simultaneous energy production in the hydrogen gas form has been investigated using aluminum electrodes. Different reaction times and electric potential gradients have been tested in order to determine the most effective conditions for removal of pollutants. The optimum reaction time and current were determined as 8 h and 8 V, respectively. Under these conditions, removal efficiencies for tCOD, suspended solids, color and phenol were obtained as 73%, 84%, 91% and 75%, respectively. At the end of the operating period of 8 h, 1037 ml hydrogen gas was obtained. The results show that electrohydrolysis process can be used as an alternative solution for the management of OMW and the process can be upgraded with a better reactor design or combined with different treatment processes to achieve a better effluent quality to meet discharge standards. • Electrohydrolysis at 8 V for 8 h provided about 60% COD and 80% phenol removal. • Almost all color and turbidity of OMW is removed by electrohydrolysis. • At the end of the operating period of 8 h, 1037 ml hydrogen gas was obtained. [ABSTRACT FROM AUTHOR]

Azo dyes are the most varied class of synthetic chemicals with non-degradable characteristics. They are complex compounds made up of many different parts. It was primarily utilized for various application procedures in the dyeing industry. Therefore, it's crucial to develop an economical and environmentally friendly approach to treating azo dyes. Our present investigation is an integrated approach to the electrooxidation (EO) process of azo dyes using RuO 2 –IrO 2 –TiO 2 (anode) and titanium mesh (cathode) electrodes, followed by the biodegradation process (BD) of the treated EO dyes. Chemical oxygen demand (COD) removal efficiency as follows MB (55%) ≥ MR (45%) ≥ TB (38%) ≥ CR (37%) correspondingly. The fragment generated during the degradation process which was identified with high-resolution mass spectrometry (HRMS) and its degradation mechanism pathway was proposed as demethylation reaction and N–N and C–N/C–S cleavage reaction occurs during EO. In biodegradation studies by Aeromonas hydrophila AR1, the EO treated dyes were completely mineralized aerobically which was evident by the COD removal efficiency as MB (98%) ≥ MR (92.9%) ≥ TB (88%) ≥ CR (87%) respectively. The EO process of dyes produced intermediate components with lower molecular weights, which was effectively utilized by the Aeromonas hydrophila AR1 and resulted in higher degradation efficiency 98%. We reported the significance of the enhanced approach of electrochemical oxidation with biodegradation studies in the effective removal of the pollutants in dye industrial effluent contaminated water environment. [Display omitted] • The decolorization of azo dyes was aided by the EO process. • N–N and C–N/C–S cleavage reaction occurs during EO decolorization. • The COD removal efficiency was around 90% by Aeromonas hydrophila AR1. • The integrated treatment process resulted in higher degradation efficiency 98%. [ABSTRACT FROM AUTHOR]

Due to its complex and, often, highly contaminated nature, treating industrial wastewater poses a significant environmental problem. Many of the persistent pollutants found in industrial effluents cannot be effectively removed by conventional treatment procedures. Advanced Oxidation Processes (AOPs) have emerged as a promising solution, offering versatile and effective means of pollutant removal and mineralization. This comprehensive review explores the application of various AOP strategies in industrial wastewater treatment, focusing on their mechanisms and effectiveness. Ozonation (O 3): Ozonation, leveraging ozone (O 3), represents a well-established AOP for industrial waste water treatment. Ozone's formidable oxidative potential enables the breakdown of a broad spectrum of organic and inorganic contaminants. This paper provides an in-depth examination of ozone reactions, practical applications, and considerations involved in implementing ozonation. UV/Hydrogen Peroxide (UV/H 2 O 2): The combination of ultraviolet (UV) light and hydrogen peroxide (H 2 O 2) has gained prominence as an AOP due to its ability to generate hydroxyl radicals (ȮH), highly efficient in pollutant degradation. The review explores factors influencing the efficiency of UV/H 2 O 2 processes, including H 2 O 2 dosage and UV radiation intensity. Fenton and Photo-Fenton Processes: Fenton's reagent and Photo-Fenton processes employ iron ions and hydrogen peroxide to generate hydroxyl radicals for pollutant oxidation. The paper delves into the mechanisms, catalyst selection, and the role of photoactivation in enhancing degradation rates within the context of industrial wastewater treatment. Electrochemical Advanced Oxidation Processes (EAOPs): EAOPs encompass a range of techniques, such as electro-Fenton and anodic oxidation, which employ electrode reactions to produce ȮH radicals. This review explores the electrochemical principles, electrode materials, and operational parameters critical for optimizing EAOPs in industrial wastewater treatment. TiO 2 Photocatalysis (UV/TiO 2): Titanium dioxide (TiO 2) photocatalysis, driven by UV light, is examined for its potential in industrial wastewater treatment. The review investigates TiO 2 catalyst properties, reaction mechanisms, and the influence of parameters like catalyst loading and UV intensity on pollutant removal. Sonolysis (Ultrasonic Irradiation): High-frequency ultrasound-induced sonolysis represents a unique AOP, generating ȮH radicals during the formation and collapse of cavitation bubbles. This paper delves into the physics of cavitation, sonolytic reactions, and optimization strategies for industrial wastewater treatment. This review offers a critical assessment of the applicability, advantages, and limitations of these AOP strategies in addressing the diverse challenges posed by industrial wastewater. It emphasizes the importance of selecting AOPs tailored to the specific characteristics of industrial effluents and outlines potential directions for future research and practical implementation. The integrated use of these AOPs, when appropriately adapted, holds the potential to achieve sustainable and efficient treatment of industrial wastewater, contributing significantly to environmental preservation and regulatory compliance. [Display omitted] • Several distinct categories of advanced oxidation processes (AOPs). • The mechanism of various types of AOPs. • Possible contributors to an increase in the rates of several AOPs. • Obstacles in the way of AOPs and their future possibilities. [ABSTRACT FROM AUTHOR]

In response to the growing global concern over environmental pollution, the exploration of sustainable and eco-friendly materials derived from biomass waste has gained significant traction. This comprehensive review seeks to provide a holistic perspective on the utilization of biomass waste as a renewable carbon source, offering insights into the production of environmentally benign and cost-effective carbon-based materials. These materials, including biochar, carbon nanotubes, and graphene, have shown immense promise in the remediation of polluted soils, industrial wastewater, and contaminated groundwater. The review commences by elucidating the intricate processes involved in the synthesis and functionalization of biomass-derived carbon materials, emphasizing their scalability and economic viability. With their distinctive structural attributes, such as high surface areas, porous architectures, and tunable surface functionalities, these materials emerge as versatile tools in addressing environmental challenges. One of the central themes explored in this review is the pivotal role that carbon materials play in adsorption processes, which represent a green and sustainable technology for the removal of a diverse array of pollutants. These encompass noxious organic compounds, heavy metals, and organic matter, encompassing pollutants found in soils, groundwater, and industrial wastewater. The discussion extends to the underlying mechanisms governing adsorption, shedding light on the efficacy and selectivity of carbon-based materials in different environmental contexts. Furthermore, this review delves into multifaceted considerations, spanning the spectrum from biomass and biowaste resources to the properties and applications of carbon materials. This holistic approach aims to equip researchers and practitioners with a comprehensive understanding of the synergistic utilization of these materials, ultimately facilitating effective and affordable strategies for combatting industrial wastewater pollution, soil contamination, and groundwater impurities. [Display omitted] • Bio-based carbon materials play crucial role for improving soil and water quality. • Biochar, carbon nanotubes, and graphene materials used for soil and water remediation. • Biowastes including forestry, agricultural wastes such as husks have been explored. • Bioderived carbon materials are used as bio adsorbents for pollutants removal. [ABSTRACT FROM AUTHOR]