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Wastewater pollution is a worldwide concern, and wastewater treatment is gaining growing global attention. Electro-Fenton is a promising method for the treatment of wastewater containing organic pollutants. This work offers an overview and bibliometric analysis of research on electro-Fenton treatment of wastewater. The literatures, consisting of 1898 documents from 2000 to 2021 collected from the Web of Science database, were analyzed using bibliometric tools such as Bibliometrix package, CiteSpace, and VOSviewer. Document types, publication trends, subject categories, journals, institutions, countries, authors, keywords, and highly cited papers were analyzed. Research in this field has undergone three stages with the rapid development in the past 5 years. Environmental Sciences (24.42%) is the leading Web of Science category, and Engineering (48.37%) is the leading research area. China (38.46%) is the most productive country, followed by Spain (8.59%), Iran (8.11%), France (6.27%), and India (5.80%), while University of Barcelona (7.38%) is the most productive institute. Enric Brillas is the leading author and has the most publications (120 papers) and the highest h-index (58). The top five clusters include "landfill leachate", "heterogeneous electro-Fenton", "electrochemical oxidation", "photoelectro-Fenton", and "photocatalytic degradation". With the rapidly growing number of electro-Fenton related studies, novel research interests and feasible large-scale applications, various techniques are proposed. [ABSTRACT FROM AUTHOR]

Treatment of micropollutants even after tertiary treatment and developing cost-effective, sustainable and energy-efficient technology for the same still remains an active area of research. The present study reports the feasibility and efficacy of hydrodynamic cavitation (HC)-based advanced oxidation process (AOP) for the degradation of norfloxacin. Experiments using HC were carried out in a sequential manner starting with the optimization of the cavitating device (orifice plate) using computational fluid dynamics (CFD) followed by optimizing the operational parameters such as pH, inlet pressure and initial concentration. An experimental study revealed that under optimized conditions of pH – 2, inlet pressure – 6 bar and initial conc – 250 μg/L, NRF degradation of 22.26% was obtained using HC in an experimental run of 60 min. For further improvement of the HC process, experiments were carried out by integrating with H2O2, O3 and Fenton's reagent. Under the optimized conditions, integrating with H2O2, O3 and Fenton's reagent enhanced the extent of NRF degradation. The energetics of the process was further evaluated to understand the techno-economic viability. The study revealed that HC + H2O2 consumed less energy of 8.01 kWh/m3 at the economics of Rs. 82.53/m3. Thus, HC combined with oxidizing agents can be a novel technique in the genre of AOP for the degradation of micropollutants. HIGHLIGHTS CFD optimization study of orifice-based cavitating device.; Micropollutant degradation using hydrodynamic cavitation coupled with other conventional means.; The study of the synergistic effect of HC with H2O2.;

This research emphasized the importance of removing organic pollutants from wastewater discharges. In this review, different advanced oxidation processes are discussed. A broad classification of advanced oxidation processes was used for wastewater treatment. An overview of TiO2-based photocatalysis, the Fenton process, and photocatalytic ozonation has been done. The mechanism of different methods has been studied. The advantages and limitations of these processes are also discussed. Various kinds of catalyzed were used in TiO2-based photocatalysis for various categories of organic contaminants, and several factors with crucial effects on TiO2-based photocatalytic degradation were examined. The typical treatment scheme of Fenton's method was reviewed. Also similarly, a review of photocatalytic ozonation: mechanism of the reaction, its applications with different catalysts, and economic aspects of photocatalytic ozonation were done. HIGHLIGHTS Overview of advanced oxidation processes (AOPs) and their potential for wastewater treatment.; Photocatalysis: using catalysts and light to produce reactive oxygen species (ROS) for oxidation.; Ozonation: using ozone to generate ROS for oxidation.; AOPs effective at removing organic compounds that are resistant to biological treatment.;

Cobalt/zinc bimetallic porous oxide composites were prepared by the oxalate-pyrolysis method and used as a catalyst for activating peroxymonosulfate(PMS) to degrade methylene blue(MB) solution. Taking Co(NO3)2·6H2O and Zn(NO3)2·6H2O as metal ion sources and oxalic acid as precipitant, cobalt-zinc oxalate precursor was first obtained through simultaneously precipitating Co2+ and Zn2+. The porous Co3O4/ZnO composite oxide catalysts with different Co/Zn molar ratios were attained by calcining the oxalate precursor. The results show that the Co1Zn5 composite with an initial Co/Zn raw material ratio of 1∶5 has the best catalytic activity. When the catalyst dosage is 0.02 g·L-1 and PMS concentration is 0.6 mmol·L-1, MB degradation rate of 98.49% can be reached. Electron paramagnetic resonance (EPR) results identify that the degradation of MB by Co1Zn5/PMS follows both free radical and non-free radical mechanisms. Moreover, it is found that more exposure of active component Co3O4 in the Co1Zn5 composite, which is resulting from the partial dissolution of ZnO in the weak acidic environment caused by PMS, is mainly responsible for the boosting catalytic performance due to the increase of reaction chances between Co3O4 and PMS.

Background: In the last few decades, concern over environmental safety has increased significantly. One of the main causes of environmental degradation is the discharge of untreated pollutants into water bodies. This study examined the efficiency of the photo-Fenton oxidation process to remove chemical oxygen demand (COD) and total organic carbon (TOC) from petroleum wastewater.Methods: Experiments were designed using the Box-Behnken method- a model of the response surface method (RSM) by MINITAB software. First, a wooden chamber equipped with UV lamps installed in the center was applied. The effect of effective parameters on the photo-Fenton process, including naphthalene concentration (10-70 μg/L), pH (2-7), H2O2 (50-800 mg/L), Fe (5-80 mg/L), contact time (10-120 minutes) and UV rays was investigated.Results: The highest removal efficiency of the COD (case 89.27) was at achieved at pH = 2, UV = 24, naphthalene concentration 10 μg/L, Fe concentration 36.06 mg/L, hydrogen peroxide content 800 mg/L, and contact time 120 min. Besides, the highest removal efficiency of the process in removing TOC was 71.04% obtained at 2 pH = 24, UV = 24, and a reaction time of 120 min.Conclusion: Based on the results of this research, the photo-Fenton process has a significant efficiency in removing COD and TOC from petroleum effluents containing cyclic aromatic hydrocarbons and can be utilized as an efficient method for the treatment of petroleum wastewaters.

In the ozonation process, the phenol degradation in wastewater undergoes a low mass transfer mechanism. In this study, ozonized packed bubble column reactor was designed and constructed to remove phenol. The reactor’s inner diameter and height were 150 and 8 cm, respectively. The packing height was kept constant at 1 m in accordance with the reactor hydrodynamics. The gas distributor was designed with 55 holes of 0.5 mm. The phenol removal efficiency was evaluated at ozone concentrations of 10, 15, and 20 mg/L, contact times of 15, 30, 45, 60, 75, 90, 105, and 120 min, and phenol concentrations of 3, 6, 9, 12, and 15 mg/L. The results indicated that the highest phenol removal efficiency of 100% was achieved at 30 min in presence of packing. Moreover, the use of packing improved the contact between the gas and liquid, which significantly enhanced the phenol degradation. Actually, a thin film over a packing surface enhances the mass transfer. Also, it was found that the phenol is degraded into CO2 and H2O through a series of reaction steps. Additionally, a kinetic study of a first-order reaction provided an efficient estimation of reaction parameters with a correlation factor of 0.997.

Background and Objective: Pharmaceutical compounds can cause potential risks to aquatic and terrestrial organisms. So far, different methods have been used to eliminate these pollutants, photocatalytic processes are one of the most efficient processes to eliminate pharmaceutical compounds. In this study, the efficiency of a novel MOF-based nanocomposite, PMo/UiO-66 as a photocatalyst for amoxicillin degradation under visible light irradiation was evaluated. Materials and Methods: The study of the chemical decomposition of amoxicillin using the PMo/UiO-66 system was conducted at different stages. First, the PMo/UiO-66 MOF nanocomposite was synthesized using the solvothermal method, then the properties of the synthesized nanocomposite were investigated using XRD, FTIR, and SEM techniques. The effect of different operational parameters such as pH (3, 6, and 9), catalyst concentration (15, 20, 25, and 30 %w/w), initial concentrations of amoxicillin (20, 30, 40, and 50 mg/L) at different times on the removal efficiency was investigated. The reusability of the catalyst for four cycles was assessed. Results: The results showed that PMo/UiO-66 nanocomposite at pH 6, 25 %w/w nanocomposite concentration, and the amoxicillin concentration of 20 mg/L led to complete decomposition of amoxicillin after 120 min. The kinetic of amoxicillin removal followed the first-order model. Reusability tests showed that the photocatalytic efficiency of the synthesized catalyst was not substantially reduced after four cycles. Conclusion: The current study confirmed that the PMo/UiO-66 system has an appropriate efficiency for photocatalytic removal of amoxicillin under optimized test conditions.

Two−dimensional (2D) supports confined single−atom catalysts (2D SACs) with unique geometric and electronic structures have been attractive candidates in different catalytic applications, such as energy conversion and storage, value−added chemical synthesis and environmental remediation. However, their environmental applications lack of a comprehensive summary and in−depth discussion. In this review, recent progresses in synthesis routes and advanced characterization techniques for 2D SACs are introduced, and a comprehensive discussion on their applications in environmental remediation is presented. Generally, 2D SACs can be effective in catalytic elimination of aqueous and gaseous pollutants via radical or non−radical routes and transformation of toxic pollutants into less poisonous species or highly value−added products, opening a new horizon for the contaminant treatment. In addition, in−depth reaction mechanisms and potential pathways are systematically discussed, and the relationship between the structure−performance is highlighted. Finally, several critical challenges within this field are presented, and possible directions for further explorations of 2D SACs in environmental remediation are suggested. Although the research of 2D SACs in the environmental application is still in its infancy, this review will provide a timely summary on the emerging field, and would stimulate tremendous interest for designing more attractive 2D SACs and promoting their wide applications.

The narrow pH application range and lower utilization of ferrous ions (Fe(II)) restrict the application of Fe(II)/persulfate (PS) technology. In this paper, simulated sunlight and citric acid (Cit) as a chelator were introduced in an Fe(II)/PS system to overcome the drawbacks and enhance the degradation of typical antibiotic sulfamethoxazole (SMX) in secondary wastewater. The degradation kinetics, mechanism, and influence factors of SMX in a sunlight/Fe(II)/Cit/PS system and a sunlight/Fe(II)/Cit system as a comparable system were investigated. The removal efficiency of SMX can reach 71.15% and 85.25% in the sunlight/Fe(II)/Cit system and sunlight/Fe(II)/Cit/PS system with 0.1 mM Fe(II), 0.6 mM Cit, and 1 mM PS. The increase of Fe(II) concentration in both systems proved that sunlight promoted the regeneration of Fe(II) from the ferric ion chelates. However, the Fe(II) concentration decreased after 30 min in the sunlight/Fe(II)/Cit/PS system because of the decomposition of Cit. Radical quencher experiments indicated that SO4·−, ·OH, and O2·− contributed 2.48%, 88.43%, and 6.91% to the removal of SMX, respectively. Electron paramagnetic resonance spectra also proved the formation of ·OH and O2·−. The degradation of SMX was proposed to proceed via isomerization, cleavage of S–N bond, and hydroxylation. Overall, the sunlight/Fe(II)/Cit/PS process can be used as an advanced treatment technology for antibiotics in municipal wastewater.

Soil contamination by polycyclic aromatic hydrocarbons (PAHs) has been an environmental issue worldwide, which aggravates the ecological risks faced by animals, plants, and humans. In this work, the composites of nanoscale zero-valent iron supported on carbonylated activated carbon (nZVI-CAC) were prepared and applied to activate persulfate (PS) for the degradation of PAHs in contaminated soil. The prepared nZVI-CAC catalyst was characterized by scanning electron microscopy (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). It was found that the PS/nZVI-CAC system was superior for phenanthrene (PHE) oxidation than other processes using different oxidants (PS/nZVI-CAC > PMS/nZVI-CAC > H2O2/nZVI-CAC) and it was also efficient for the degradation of other six PAHs with different structures and molar weights. Under optimal conditions, the lowest and highest degradation efficiencies for the selected PAHs were 60.8% and 90.7%, respectively. Active SO4−• and HO• were found to be generated on the surface of the catalysts, and SO4−• was dominant for PHE oxidation through quenching experiments. The results demonstrated that the heterogeneous process using activated PS with nZVI-CAC was effective for PAH degradation, which could provide a theoretical basis for the remediation of PAH-polluted soil.

Contamination of groundwater with fluoride represents a significant global issue, with high concentrations posing serious public health threats. While fluoride is a critical element in water, excessive levels can be detrimental to human health and potentially life-threatening. Addressing the challenge of removing fluoride from underground water sources via nanotechnological approaches is a pressing concern in environmental science. To collate relevant information, extensive literature searches were conducted across multiple databases, including Google Scholar, PubMed, Scopus, Web of Science, the American Chemical Society, Elsevier, Springer, and the Royal Society of Chemistry. VOS Viewer software version 1.6.20 was employed for a systematic review. This article delivers an exhaustive evaluation of various groundwater fluoride removal techniques, such as adsorption, membrane filtration, electrocoagulation, photocatalysis, and ion exchange. Among these, the application of nanoparticles emerges as a notable method. The article delves into nano-compounds, optimizing conditions for the fluoride removal process and benchmarking their efficacy against other techniques. Studies demonstrate that advanced nanotechnologies—owing to their rapid reaction times and potent oxidation capabilities—can remove fluoride effectively. The implementation of nanotechnologies in fluoride removal not only enhances water quality but also contributes to the safeguarding of human health.

Cobalt–nitrogen co-doped carbon nanotubes (Co3@NCNT-800) were synthesized via a facile and economical approach to investigate the efficient degradation of organic pollutants in aqueous environments. This material demonstrated high catalytic efficiency in the degradation of carbamazepine (CBZ) in the presence of peroxymonosulfate (PMS). The experimental data revealed that at a neutral pH of 7 and an initial CBZ concentration of 20 mg/L, the application of Co3@NCNT-800 at 0.2 g/L facilitated a degradation rate of 64.7% within 60 min. Mechanistic investigations indicated that the presence of pyridinic nitrogen and cobalt species enhanced the generation of reactive oxygen species. Radical scavenging assays and electron spin resonance spectroscopy confirmed that radical and nonradical pathways contributed to CBZ degradation, with the nonradical mechanism being predominant. This research presents the development of a novel PMS catalyst, synthesized through an efficient and stable method, which provides a cost-effective solution for the remediation of organic contaminants in water.

The introduction of the first list of priority pathogenic fungi by the World Health Organization stresses the need to research and develop public health actions to mitigate infections caused by fungi. One of those actions involves the water disinfection systems, which comprise classical and alternative methods that have been developed in the last decades. Thereby, this work reviews the disinfection of fungi by classical methods such as chlorination, ozonation, and ultraviolet (UV) treatments and alternative advanced oxidation processes (AOPs) such as photo-Fenton, photocatalysis, or couplings of UV with peroxides. The matrices of aquatic systems (sewage, groundwater, drinking water, among others) were considered. A bibliometric analysis is performed initially, and then some aspects of the resistance to antifungals are presented, and the efficiency of the diverse processes in the reduction in fungal loading is also revised. Herein, it is shown the role of the disinfecting agents (e.g., chlorine, hydroxyl radical, or light) and their effects on fungi structures (e.g., direct DNA damage, or indirect damage due to the action of radicals). Moreover, gaps, such as the treatment of antifungal-resistant fungi and limited information about combinations among AOPs, related to the disinfection of water polluted by fungi, were identified.

A large variety of pharmaceutical compounds have recently been detected in wastewater and natural water systems. This review highlighted the significance of removing pharmaceutical compounds, which are considered indispensable emerging contaminants, from wastewater and natural water systems. Various advanced oxidation processes (AOPs), including UV-H2O2, Fenton and photo-Fenton, ozone-based processes, photocatalysis, and physical processes, such as sonolysis, microwave, and electron beam irradiation, which are regarded as the most viable methods to eliminate different categories of pharmaceutical compounds, are discussed. All these AOPs exhibit great promising techniques, and the catalytic degradation process of the emerging contaminants, advantages, and disadvantages of each technique were deliberated. Heterogeneous photocatalysis employing metal oxides, particularly anatase TiO2 nanoparticles as catalysts activated by UV light irradiation, was reviewed in terms of the electron–hole separation, migration of the charge carriers to the catalyst surfaces, and redox potential of the charge carriers. This brief overview also emphasized that anatase TiO2 nanoparticles and TiO2-based nanomaterials are promising photocatalysts, and a combination of photocatalysis and other AOPs enhanced photocatalytic degradation efficiency. Finally, the challenges of applying anatase TiO2-based photocatalysis in environmental remediation and wastewater treatments to degrade pharmaceutical compounds, including mass spectroscopic analysis and a biological activity test of by-products of the emerging contaminants resulting from photocatalysis, are summarized.

Nowadays, antibiotics are widely used, increasing the risk of contamination of the water body and further threatening human health. The traditional water treatment process is less efficient in degrading antibiotics, and the advanced oxidation process (AOPs) is cleaner and more efficient than the traditional biochemical degradation process. The combined ozone/peroxymonosulfate (PMS) advanced oxidation process (O3/PMS) based on sulfate radical (SO4•−) and hydroxyl radical (•OH) has developed rapidly in recent years. The O3/PMS process has become one of the most effective ways to treat antibiotic wastewater. The reaction mechanism of O3/PMS was reviewed in this paper, and the research and application progress of the O3/PMS process in the degradation of antibiotics in drinking water and wastewater effluent were evaluated. The operation characteristics and current application range of the process were summarized, which has a certain reference value for further research on O3/PMS process.

The release of organic contaminants has grown to be a major environmental concern and a threat to the ecology of water bodies. Persulfate-based Advanced Oxidation Technology (PAOT) is effective at eliminating hazardous pollutants and has an extensive spectrum of applications. Iron-based metal–organic frameworks (Fe-MOFs) and their derivatives have exhibited great advantages in activating persulfate for wastewater treatment. In this article, we provide a comprehensive review of recent research progress on the significant potential of Fe-MOFs for removing antibiotics, organic dyes, phenols, and other contaminants from aqueous environments. Firstly, multiple approaches for preparing Fe-MOFs, including the MIL and ZIF series were introduced. Subsequently, removal performance of pollutants such as antibiotics of sulfonamides and tetracyclines (TC), organic dyes of rhodamine B (RhB) and acid orange 7 (AO7), phenols of phenol and bisphenol A (BPA) by various Fe-MOFs was compared. Finally, different degradation mechanisms, encompassing free radical degradation pathways and non-free radical degradation pathways were elucidated. This review explores the synthesis methods of Fe-MOFs and their application in removing organic pollutants from water bodies, providing insights for further refining the preparation of Fe-MOFs.

A 3D supramolecular metal organic framework of dysprosium has been fabricated through a facile hydrothermal procedure with the ligand, 2,6-naphthalene disulphonic acid and the co-ligand, 4,4′-bipyridine. The MOF has been characterized as [C60H81DyN8O30S4] by routine analytical procedures. SXRD studies of the MOF show the existence of a hydrogen-bonded 3D supramolecular structure with high porosity. It crystallizes in monoclinic space group P21/n with unit cell parameters, a = 16.5424(6) Å, b = 37.0052(14) Å, c = 24.4361(9) Å, β = 100.7410°, α = γ = 90°. The Dy-MOF has eight coordinated water molecules around the metal centre and exhibits square anti-prismatic geometry. The band gap is 3.11 eV. The degradation experiments under visible light confirmed that Dy-MOF can act as a photocatalyst. Addition of hydrogen peroxide remarkably increases the degradation efficiency of the MOF through an advanced oxidation process. The newly synthesized MOF produced sharp emission peaks characteristic of dysprosium ion.

Advanced oxidation processes (AOPs) based on ultrasound (US) have attracted considerable attention in recent years due to its advantages in the degradation of landfill leachate. The review summarizes the existing treatment methods of leachate from lab-scale, compares their advantages and disadvantages by focusing on the degradation of emerging contaminants (ECs) in the leachate. Then the US-based AOPs are introduced emphatically, including their degradation mechanisms, influencing factors, energy consumption, further optimization methods as well as the possibility of field-scale application are systematically described. Moreover, this review also expounds on the advantages of dual-frequency US (DFUS) technology compared with single-frequency US, and a theoretically feasible DFUS process is proposed to treat ECs in the leachate. Finally, suggestions and prospects for US technologies in treating landfill leachate are put forward to aid future research on landfill leachate treatment. Meaningfully, this manuscript will provide reference values of US-based technologies in landfill leachate treatment for the practical use, facilitating the development of US-based AOPs in landfill leachate management and disposal.

Heat-activated peracetic acid (PAA) was used to degrade diclofenac (DCF) in this study. Electron paramagnetic resonance and radical scavenging experiments proved that organic radicals (i.e. CH3C(=O)O• and CH3C(=O)OO•) were the primary active species for DCF removal in the heat/PAA process. The degradation efficiency of DCF increased with the increase of temperature or initial PAA concentration in the heat/PAA process, and the optimal reaction pH for DCF removal was neutral. The presence of NO3− or SO42− insignificantly affected DCF degradation, while Cl− was favourable for DCF removal in this process. In contrast, an obvious inhibition on the removal of DCF was observed with the addition of natural organic matter, which might be responsible for the lower DCF removal in real waters. Finally, dechlorination, formylation, dehydrogenation and hydroxylation were proposed to be four degradation pathways of DCF in the heat/PAA system based on the five detected transformation products. [ABSTRACT FROM AUTHOR]

Iron-based metal-organic frameworks (MOFs) have been received extensive attentions over the past years due to the low biotoxicity, multi-function, and wide applications. MIL-100(Fe) bearing unique structure has become the most popular Fe-based MOF up to now, and it is well-recognized as desirable environmental function material, especially for water purification. To provide systematic insight into MIL-100(Fe) for oriented design of novel materials, we review the recent progress and characteristics of MIL-100(Fe)-based materials, including MIL-100(Fe)-based composites, derivatives, and monoliths for water decontamination via adsorption, separation, and advanced oxidation processes (AOPs). Based on existing challenges and limitations discussed in this review, we further propose the future perspectives of MIL-100(Fe)-based materials for sustainable application in water remediation. [ABSTRACT FROM AUTHOR]

A major problem coming across humanity in the early 21st century is related to environmental crises, including shortage and pollution of water sources. For this reason, extensive studies have been conducted to find effective techniques for purifying water from industrial pollutants. Advanced oxidation process (AOP) has lately caught the attention of researchers, which is an efficient, clean and contemporary method to remedy wastewater effluents. However, primitive versions of AOP methods lacked several aspects like strict pH requirements and involvement of sediments, which is why further modifications to the technique have been developed, including an electrochemical catalytic degradation approach, namely, electro‐Fenton and similar processes. This study will look through a set of novel papers investigating the application of various electrodes for the electrochemical treatment of solutions contaminated with phenol and phenolic compounds, which tried to address several shortcomings of more outdated practices and optimize the method for a set of different scenarios. [ABSTRACT FROM AUTHOR]

The research aims for the simultaneous use of chlorine and UV irradiation (UV/Chlorine) to decolorize and detoxify Navy Blue 250 (NB250) and raw dye wastewater. The UV/Chlorine was the most effective in removing NB250 and color intensity (American Dye Manufacturers Institute, ADMI unit). The UV/Chlorine removed NB250 approximately 1.47-1.50 times faster than chlorination alone. The degradation constants in UV/Chlorine were 0.3317 mM-1min-1 and 0.3384 mM-1min-1 for NB250 and its ADMI color intensity, respectively. The optimum pH for decolorization was between 6 and 7. The UV/Chlorine with a chlorine dose of 1.0-2.0 mM was recommended for decolorization to meet the industrial discharge standard (300 ADMI). Reactive chlorine species (RCS) were more significant oxidants for NB250 removal than HO•. The presence of NB250 inhibited the germination of morning glory (Ipomoea aquatica) seeds, and exposure to raw dye wastewater (color = 6,658 ± 227 ADMI) completely inhibited seed germination. However, the samples treated by the UV/Chlorine were less toxic to seed germination and root growth. Therefore, the UV/Chlorine has a high potential in the decolorization and detoxification of dye wastewater. This is the first study to use the UV/Chlorine to treat industrial dye wastewater. [ABSTRACT FROM AUTHOR]

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Water pollution has emerged as a serious problem worldwide in recent years. Aquatic ecosystem disruption damages ecological homeostasis and leads to disturbances in living beings. Conventional water treatment methods entail new implementations to eliminate pollutants due to excessive anthropogenic activities and the increasing requirements for treating industrial effluents. Recently, developments in conducting polymer-based catalytic materials have brought important achievements in water treatment and provide a perspective for enhancing conventional materials and processes. The advanced oxidation process is a state-of-the-art method that led to being used in this area depending on generating highly active radical species. The interaction between the conducting polymer and their composites was emphasized offering unique properties such as photosensitivity with low band gap energy levels, suitable processing, electrical conductivity, environmental stability, corrosion resistance, and most significantly low cost, low energy requirement, and reusability performance. Thus, high-quality elimination of pollutants in the water was associated with promising potential owing to developing catalytic properties gained by combining nanoparticles with conducting polymers. This review presents a brief overview of the recent updates of polyaniline, polypyrrole, polythiophene, poly(3,4-ethylenedioxythiophene), poly(phenylene) poly(o-phenylenediamine), and poly(1-naphthylamine), their derivatives, nanocomposites, and their advanced oxidation process applications in water treatment. [ABSTRACT FROM AUTHOR]

The tetracycline group (TCs) includes the most common antibiotics for treatment of both human and animal infections. TCs are resistant to biological degradation; hence, conventional wastewater treatments are unable to remove these contaminants. Here, the utilization of different electrochemical processes, such as electro‐Fenton (EF), direct anodic oxidation (AO) and indirect oxidation by electrogenerated active chlorine (EAC), for the treatment of aqueous solutions of oxytetracycline (OTC), which is one of the TCs, was studied. The effect of various operating conditions was evaluated to optimize the selected processes. EAC gave the fastest abatement of OTC, but the lowest removal of TOC and formation of chlorate. However, the utilization of carbon felt cathodes allowed the formation of chlorate to be reduced. AO gave the highest TOC removals, but it required the use of an expensive anode, as BDD, and high cell potentials. EF performed with pressurized‐air (5–10 bar) presented intermediate removals of OTC and TOC with respect to AO and EAC and consumed the least energy. © 2023 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

In this study, the degradation of Azithromycin (AZM) by Fenton oxidation process (H2O2/Fe2+) was examined. The experiments were carried out in a batch reactor at ambient temperature and the efficiency of this treatment was monitored by analysing the overall parameter chemical oxygen demand (COD). Efficacy of Fenton's reagent for AZM degradation was studied concerning the process variables including (A) pH, (B) [H2O2]/[AZM], and (C) [H2O2]/[Fe2+]. The effect of these process variables and the interaction amongst each other was studied by a general full factorial design (GFFD) (3-level 3-factor) and response surface methodology, Box-Behnken design (BBD) was used to optimize this process. Additionally, a comparative analysis was conducted to assess the effectiveness of the GFFD and BBD methods in predicting COD removal. According to results of the analysis of variance ANOVA for COD removal efficiency by GFFD model, the model is suggested to be significant by the model F-value of 4.69. The accepted model was fit with an R-square of 0.91, in order to simulate the reaction over the selected ranges of the process variables, a BBD model was obtained, model statistics showed that a significant model was obtained, with an F-value of 64.82 for the corresponding probability of < 0.0005. The accepted model was fit with an R-square of 0.9942 and an adjusted R-square of 0.9798. Based on the optimized of the two models, the ideal process conditions were determined as pH = 2.5, [H2O2]/[AZM] = 145, and [H2O2]/[Fe2+] = 8., during a 90 min reaction time, the COD elimination rate is 94.13%. The results obtained from this study offer valuable insights for optimizing the Fenton process and achieving efficient degradation of AZM, thereby contributing to the field of wastewater treatment and environmental remediation. [ABSTRACT FROM AUTHOR]

In this work, an eco-friendly sol-gel synthesis of pure and doped TiO2, previously developed at lab-scale, is applied in three different environmental applications at lab-scale and then, upscaled towards industrial applications. For each application, the TiO2 is used as a coating deposited mainly on steel substrates. The three applications are: (i) the development of a photocatalytic reactor made of a UV lamp, an ozonation part and a TiO2 photocatalytic coating to treat water from swimming pools, (ii) the development of a new generation of low energy sterilizers by an advanced oxidation process using a photocatalytic coating illuminated by a blue LED, and (iii) an easy-to-clean coating for outdoor steel. In each application, the up-scale results were similar to those obtained in the laboratory with respect to the crystallinity, the visual aspect, the hydrophilicity, and the photocatalytic properties of the produced coatings. These developments showed the possibility to bring sol-gel TiO2 products outside the laboratory towards pilot and industrial applications, and opens the way for many possible up-scaled sol-gel based environmental applications. Highlights: Eco-friendly sol-gel synthesis of pure and doped TiO2 developed for industrial applications. TiO2 is deposited on steel substrates for three applications. TiO2 coatings used for decontamination of swimming pool and fountain waters. TiO2 layer also used as easy-to-clean coating for outdoor pre-painted steel. The efficiency of the layers is successfully up-scaled from laboratory to industrial applications. [ABSTRACT FROM AUTHOR]

Prochloraz and tebuconazole are well-known fungicides for broad applications, including medical, industrial, and agricultural. They are frequently used simultaneously which increases the probability of their co-existing in various water sources. In this study, the analysis of PCZ or TBZ in water was performed by a direct analysis using the liquid chromatography-tandem mass spectrometry technique (LC-MS/MS). The optimized method was fully validated according to the European guidelines, SANTE/11312/2021. The complete degradation of these fungicides (each of 2 mg/L) in their single presence in the water was accomplished just after 15 min using 4.2 mM persulfate at 50 °C, while a lower concentration of persulfate (1.4 mM) leads to a degradation of prochloraz and tebuconazole, in their single existence in water, at percentages of 97 % and 98 %, respectively, after 30 min at 50 °C. On the other hand, it takes a complete hour to degrade a mixture of prochloraz and tebuconazole at percentages of 99 % and 94 %, respectively, using 1.4 mM persulfate at 50 °C. Degradation products (DPds) of prochloraz and tebuconazole, either in their single or simultaneous existing in water, were also identified and monitored during the whole degradation process by LC-MS/MS using at least two mass transitions for each DPd at both positive and negative ionization modes. It was elucidated that the persulfate degradation of prochloraz was conducted by the cleavage of the imidazole ring and the subsequent formation of a trichlorophenol, while persulfate degradation of tebuconazole was mainly accomplished by the formation of a hydroxyl structure, cleavage of the tert-butyl chain, and the subsequent formation of a ketone structure. Furthermore, a new DPd of tebuconazole (m/z = 263 Da) with a diketone structure was identified and confirmed. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) are one of the most promising advanced heterogeneous catalysts for the activation of peroxymonosulfate (PMS) to degrade organic contaminants in water, and have been extensively studied. However, MOFs in powder form usually have the disadvantage of poor separation and regeneration, making it significantly challenging for practical applications. In this study, ultralight zeolitic imidazolate framework‐67@poly(vinyl alcohol)/citric acid nanofibrous aerogel (ZIF‐67@PVA/CA NFA) was prepared by a convenient and facile in‐situ growth method and it had excellent catalytic efficiency and recyclability. The factors affecting the activation of PMS by ZIF‐67@PVA/CA NFA, such as PMS concentration, reaction temperature, solution pH, and organic pollutant concentration, were investigated. Taking advantage of the distinctive structural characteristics of MOF and nanofibrous aerogels, the obtained ZIF‐67@PVA/CA NFA exhibited ultralow density, hierarchical porosity, remarkably high catalytic activity for activation of PMS for the degradation of organic pollutants. Furthermore, ZIF‐67@PVA/CA NFA also displayed excellent recyclability along with retention of high catalytic stability. The present study provides a new strategy for the efficient fabrication of three‐dimensional heterogeneous catalyst for the activation of PMS, with great potential in wastewater treatment. [ABSTRACT FROM AUTHOR]

The present research is related to the study of p-cresol oxidation reaction in aqueous phase. Firstly, the conventional advanced oxidation process (AOP) in a lab-scale batch reactor was used, seeking to identify the most impacting process variables and then to propose an optimization approach for ensuring the complete p-cresol degradation and the highest total organic carbon (TOC) conversion. In the AOP with the use of hydrogen peroxide as the oxidizing agent, the oxidation reaction was optimized with the aid of a factorial design, and a maximum TOC conversion of 63% was obtained. The Lumped Kinetic Model (LKM) was used to describe the profile of residual TOC concentration due to chemical species, which were categorized into two groups (refractory and non-refractory compounds). The model was able to satisfactorily describe the profile of the residual fractions of these two classes of organic compounds and allowed estimating the related kinetic constants (k) at two different temperatures, namely (a) 3.19 × 10−1 and 2.82 × 10−3 min−1 for non-refractory and refractory compounds at 80 °C and (b) 4.73 × 10−1 and 5.09 × 10−3 min−1 for the same compound classes at 90 °C, while the activation energy (Ea) of the process was 42.02 and 62.09 kJ mol−1, respectively. The kinetic modeling of organic pollutants oxidation in liquid effluents would allow to perform in situ seawater treatment on vertical reactors installed in offshore platforms and to properly release treated water into the oceans. In this way, ocean contamination caused by the exploration on offshore platforms of oil and natural gas, the main energy sources and vectors in the current world, may be remarkably reduced, thus favoring a more eco-friendly energy production. [ABSTRACT FROM AUTHOR]

Natural zeolite is a widely used material with excellent environmental cleaning performance, especially in water and wastewater treatment. Natural zeolite (Zini) calcined by CO2-laser radiation (ZL) was tested as a catalyst for the photodegradation and the adsorption of industrial azo dye Lanasol Yellow 4G (LY4G) in water. Morphology, chemical structure, and surface composition of Zini and ZL were analyzed by XRD, SEM, EDS, and XPS. UV/Visible spectrophotometry was used to evaluate the photocatalytic activity of Zini and ZL. The photocatalytic activity of the studied zeolites was associated with the presence of Fe oxides in their composition. Laser-treated natural zeolite showed higher efficiency as a photocatalyst compared to untreated natural zeolite. [ABSTRACT FROM AUTHOR]

Water is a fundamental resource for human civilisation, yet there is a critical water shortage happening all across the world in the twenty-first century. In some areas of underdeveloped nations, people drink water that has been extensively polluted and comes from rivers that are home to deadly diseases. Microbial infections in drinking water can cause illness and increase the prevalence of disease. There are several treatment methods available to remove microorganisms from drinking water. This study suggests employing two techniques, photocatalytic semiconductor and photo Fenton, as an enhanced oxidation process to get rid of diverse water impurities and offer a reliable water treatment approach. A test on samples of river water was undertaken, and the analysis of a number of parameters was used to determine how well the test had removed contaminants and pathogens. The physiochemical criteria were used to evaluate the reaction and determine the properties of safe water using both approaches. The two techniques effectively eliminated between 80 and 100 percent of the contaminants that were detected in the river sampled. Variations in Titanium Dioxide concentration correlated with changes in reactivity and degradation rates. Results showed that light absorption was reduced dramatically as titanium dioxide concentration rose to saturation. Besides, the rate of degradation was directly correlated with light intensity. [ABSTRACT FROM AUTHOR]

The shortage of water resources has caused extensive research to be conducted in this field to develop effective, rapid, and affordable wastewater treatment methods. For the treatment of wastewater, modern oxidation techniques are desirable due to their excellent performance and simplicity of implementation. In this project, wet impregnation and the hydrothermal technique were applied to synthesize a modified catalyst. Different analysis methods were used to determine its characteristics, including XRD, BET, FT-IR, NH 3 − TPD , and FE-SEM. The catalyst features a spherical shape, large surface area, high crystallinity, and uniform active phase dispersion. In order to eliminate the methylene blue dye as a modeling effluent, the catalyst's performance was examined in a heterogeneous quasi-electro-Fenton (EF) reaction. The impact of various performance characteristics, such as catalyst concentration in the reaction medium, solution pH, and current intensity between the two electrodes, was elucidated. According to the results, the best operational circumstances included a pH level of 2, a catalyst concentration of 0.15 g/L, and a current of 150 mA, resulting in the greatest elimination efficiency of 101%. The catalyst's performance was stable during three consecutive tests. A pseudo-first-order model for the elimination reaction's kinetics was developed, which showed acceptable agreement with the experimental results. This study's findings help clarify how well the heterogeneous zeolite catalyst functions in the pseudo-EF reaction. The results revealed the method's potential to be implemented in wastewater treatment. An artificial neural network model is utilized to predict the removal percentage. The hyperparameter tuning is used to find the best model, and the model achieved an MAE of 1.26% and the R 2 was 0.99. [ABSTRACT FROM AUTHOR]

Iron-based materials are widely applied in Fenton chemistry, and they have promising prospects in the processing of wastewater. The composition complexity and rich chemistry of iron and/or oxides, however, hamper the precise understanding of the active sites and the working mechanism, which still remain highly controversial. Herein, iron oxides of four different model systems are designed through a conventional precipitation method plus H2 reduction treatment. These systems feature Fe@Fe3O4 with abundant oxygen vacancy, Fe0 and Fe3O4 particles with interface structures, and Fe3O4-dominated nanoparticles of different sizes. These materials are applied in the decomposition of methyl orange as a model reaction to assess the Fenton chemistry. The Fe@Fe3O4 with core–shell structures exhibits significantly higher decomposition activity than the other Fe3O4-rich nanoparticles. A thin Fe3O4 layer formed by auto-oxidation of iron particles when exposed to air can boost the activity as compared with the Fe0 and Fe3O4 particles with interface structures but poor oxygen vacancy. The unique hetero-structure with the co-existence of both metallic iron and oxygen vacancy displays excellent redox propensity, which might account for the superior Fenton activity. This finding provides a new perspective to understand and design highly efficient iron-based Fenton catalysts. [ABSTRACT FROM AUTHOR]

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In this work, FeS supported SBA-15 mesoporous silica catalyst (FeS@SBA-15) was synthesized successfully, characterized and first applied to persulfate (PS) activation for the degradation of imidacloprid in wastewater. The as-prepared 3.5-FeS@SBA-15 presented an impressive imidacloprid removal efficiency of 93.1% and reaction stoichiometric efficiency (RSE) of 1.82% after 5 min, ascribed to the synergetic effects of improved FeS dispersion and abundant surface sites by SBA-15. Electron paramagnetic resonance spectra and quenching experiments proved that both SO4·- and ·OH were produced in FeS@SBA-15/PS system, and SO4·- played a dominant role in the degradation process. The S2- can accelerate the cycling of Fe(III)/Fe(II) during activation and increase the steady-state concentration of Fe(II). More importantly, the constructed heterogeneous system exhibited an efficient and stable catalytic activity over a wide range of pH (3.0-9.0), temperature (283K-313K), inorganic ion (NO3-) and humic acid (1-20 mg/L). Moreover, the density functional theory calculations were conducted to predict the potential reaction sites of imidacloprid. Based on eighteen identified intermediates, four main degradation pathways were proposed: hydroxylation, dechlorination, hydrolysis, and the ring cleavage of the imidazolidine. ECOSAR analysis indicated hydroxylation and dechlorination played a key role in the detoxification of the formed compounds. These findings would provide new insights into the application of FeS@SBA-15 catalyst in wastewater treatment and the removal mechanism of imidacloprid from wastewater. [ABSTRACT FROM AUTHOR]

The persulfate-based advanced oxidation process has been an effective method for refractory organic pollutants' degradation in aqueous phase. Herein, α-MnO2 with nanowire morphology was facially fabricated via a one-step hydrothermal method and successfully activated peroxymonosulfate (PMS) for Rhodamine B (RhB) degradation. Influencing factors, including the hydrothermal parameter, PMS concentration, α-MnO2 dosage, RhB concentration, initial pH, and anions, were systematically investigated. The corresponding reaction kinetics were further fitted by the pseudo-first-order kinetic. The RhB degradation mechanism via α-MnO2 activating PMS was proposed according to a series of quenching experiments and the UV-vis scanning spectrum. Results showed that α-MnO2 could effectively activate PMS to degrade RhB and has good repeatability. The catalytic RhB degradation reaction was accelerated by increasing the catalyst dosage and the PMS concentration. The effective RhB degradation performance can be attributed to the high content of surface hydroxyl groups and the greater reducibility of α-MnO2, and the contribution of different ROS (reactive oxygen species) was 1O2 > O 2 · − > SO 4 · − > ·OH. [ABSTRACT FROM AUTHOR]

[Display omitted] Electrochemical manufacture of H 2 O 2 through the two-electron oxygen reduction reaction (2e– ORR), providing prospects of the distributed production of H 2 O 2 in remote regions, is considered a promising alternative to the energy-intensive anthraquinone oxidation process. In this study, one glucose-derived oxygen-enriched porous carbon material (labeled as HGC 500) is developed through a porogen-free strategy integrating structural and active site modification. The superhydrophilic surface and porous structure together promote the mass transfer of reactants and accessibility of active sites in the aqueous reaction, while the abundant C O species (e.g., aldehyde groups) are taken for the main active site to facilitate the 2e– ORR catalytic process. Benefiting from the above merits, the obtained HGC 500 possesses superior performance with a selectivity of 92 % and mass activity of 43.6 A g cat –1 at 0.65 V (vs. RHE). Besides, the HGC 500 can operate steadily for 12 h with the accumulation of H 2 O 2 reaching up to 4090±71 ppm and a Faradic efficiency of 95 %. The H 2 O 2 generated from the electrocatalytic process in 3 h can degrade a variety of organic pollutants (10 ppm) in 4–20 min, displaying the potential in practical applications. [ABSTRACT FROM AUTHOR]

The biochar was prepared by the high temperature calcination, the biochar@ CoFe2O4 was hydrothermal synthesized, was further used to activate the peroxy monosulfate (PMS) to degrade the ciprofloxacin (CIP) in the water, and explored effect of different biochai/CoFe204 mass ratio, PMS concentration, CIP concentration in the degradation efficiency of CIP ・ Based on the above, the degradation mecha・ nism also investigated・ The obtained results presented the mass ratio of biochar/CoFe2O4 was 1: 1 with the PMS concentration of 0・ 25 g/L have excellent degradation efficiency between the 5 ~40 mg/L CIP solution. It could be reused over 5 times with excellent activated property for the PMS and the CIP degradation rate reached to 80. 0% ・ In the process of degradation, sulfate radicals produced by the PMS with activation of biochar@ CoFe2O4 was the main degradation route of CIP. [ABSTRACT FROM AUTHOR]

In this paper, Cobalt-doped α-MnO2 (i.e., Co-α-MnO2) were synthesized through hydrothermal method. Phenol was employed as targeted pollutants to investigate the catalytic ozonation performance of Co-α-MnO2. Results showed that Co-α-MnO2 significantly improved the phenol removal increased to 97.47 % after 40 min, which was 16.46 %, 38.92 % higher than that of α-MnO2 catalytic ozonation and single ozonation without catalyst. Additionally, the physicochemical properties of α-MnO2 and Co-α-MnO2 were analyzed using technologies such as XRD, TEM, BET and XPS. Compared to α-MnO2, Co-α-MnO2 has larger specific surface area (79.496 m²/g) and pore volume (0.0396 cm³/g), higher Mn3+ relative content (41.16 %) and adsorbed oxygen content (18.99 %). Also, the oxygen vacancy content, lattice defect content and surface hydroxyl content of Co-α-MnO2 are higher than that of α-MnO2, which could result in higher catalytic oxidation performance of Co-α-MnO2. The influence of masking agent showed that surface hydroxyl group, •OH and •O2- were involved in the catalytic ozonation of phenol. This study could help recognize the role of surface hydroxyl groups and active free radicals and demonstrate the contribution of reactive oxygen species on phenol removal in Co-α-MnO2 systems. [ABSTRACT FROM AUTHOR]

This article investigates the advanced oxidation processes (TiO2/UV; O3/UV, and PDS/Vis) for final treatment of real municipal treated wastewater containing chlorfenvinphos at a concentration of 1 mg/l. During the advanced oxidation processes, the mineralization tests and kinetics described by pseudo-first-order model were performed. An approach using specific energy consumption and electric energy per order indicators was used to estimate the minimum energy requirement to degrade the chlorfenvinphos. MICROTOX® was used for the assessment of toxicity. Within 20 min, chlorfenvinphos concentration in the three studied advanced oxidation processes was reduced by between 51 and 81%, but the most effective process was PDS/Vis. The Total Organic Carbon mineralization index indicated that chlorfenvinphos is not fully degraded. The maximum Total Organic Carbon removal percentage of 81% was obtained for the PDS/Vis process, as well as the reduction in toxicity was the highest for this process. The solutions subjected to the TiO2/UV and PDS/Vis showed less toxicity than the chlorfenvinphos contaminated wastewater. The conducted study showed that the visible-light-driven activation of sodium persulfate is the most effective for: (1) lowering the final concentration of chlorfenvinphos, (2) the mineralization degree and (3) toxicity of the solution. PDS/Vis was also the most effective process from the economic point of view. Experimental research showed that the PDS/Vis process can be a valuable alternative to TiO2/UV and O3/UV processes. [ABSTRACT FROM AUTHOR]

In this work, the effect of gamma irradiation emitted by Cobalt 60 source has been investigated for the degradation of hydroxychloroquine (HCQ). The monitoring of the gamma irradiation treatment of HCQ aqueous solutions was followed by UV–visible, chemical oxygen demand, total organic carbon (TOC) and LC/MS analyses. Effects of several important parameters such as concentration, dose rate and pH on the degradation efficiency were studied then evaluated. Achieved results showed that % TOC removal efficiency of 98.5 was obtained after 8 kGy absorbed dose which warrants HCQ mineralization. The process was found to be more efficient when the initial pollutant concentration was low, with higher dose rate and at neutral pH. Furthermore, HCQ degradation kinetic study revealed a pseudo-first-order kinetic. Additionally, based on by-products identified by LC/MS, a degradation mechanistic schema mediated through hydroxyl radicals generated by water radiolysis has been proposed. Finally, in order to check the potential industrial application viability the energy consuming was evaluated. [ABSTRACT FROM AUTHOR]

With the advancement of the landfill stabilization process of municipal solid waste, landfill leachate containing a large amount of refractory organic matter is formed. In this study, homogeneous Fenton and heterogeneous Fenton-like (activation by zero valent iron (Fe0), pyrite (FeS2) and magnetite (Fe3O4) as solid iron materials) processes have been compared for the removal of refractory organics from landfill leachate. The removal efficiency of organics in the Fenton process was slightly higher than those in the Fenton-like processes. The removal efficiencies based on total organic carbon, UV absorbance at 254 nm (UV254) and colour number in the Fenton process were as high as 57.42%, 71.63% and 81.03%, respectively. In the Fenton-like processes, the Fe0/H2O2 process achieved 35.74%, 66.24% and 86.29% removal efficiencies, respectively. Moreover, the degradation effect on refractory organic substances proved to be better. In the Fenton-like processes, the activation mechanisms with Fe0 and FeS2 involve the homogeneous activation of Fe2+ in solution and heterogeneous activation of iron oxides produced during the reaction, respectively. With Fe3O4, the activation mechanism is mainly a heterogeneous process involving its intrinsic iron oxide constituents. This study may provide a theoretical basis for the treatment of refractory organics in landfill leachate. [ABSTRACT FROM AUTHOR]

This study addresses a systematic review of the scientific literature to evaluate the most common advanced oxidation processes (AOP) for the removal of phthalate esters (PE) in aqueous matrices. Six AOP were reviewed for PE degradation such as processes based on photolysis, Fenton, ozonation and sulfate radicals ( SO 4 • − ), combined AOP and other processes. The PE degradation efficiencies by AOP processes ranged from 40.3 to 100%. In the reviewed literature, an initial PE concentration within 0.04–250 mg/L was applied. The H2O2 concentrations used in the UV/H2O2 process and O3 concentrations in ozonation-based processes ranged between 0.85–1,360.6 mg/L and 2–4,971 mg/L, respectively. Based on the reported results, the PE oxidation data fit well to the pseudo-first order kinetic model. A review of the studies revealed that many oxidant species are produced in the AOP, including hydroxyl radicals (•OH), SO 4 • − , superoxide radical anions ( O 2 − • ), hydroperoxyl radicals (HO2•), hydrogen peroxide (H2O2), and singlet oxygen (O2). Among these oxidants, •OH play a key role in the degradation of PE. However, SO 4 • − are more effective and efficient than •OH since SO 4 • − has a higher oxidation power (E = 2.5–3.1 V) compared to •OH radicals (E = 1.8–2.7 V). In different AOP processes, the aromatic rings of PE are destroyed by •OH and produce intermediates such as phthalic acid (C6H4(CO2H)2), benzoic acid ethyl ester (C9H10O2), 2, 5-dihydroxybenzoic acid (C7H6O4), formic acid (CH2O2), acetic acid (CH3COOH), and oxalic acid (C2H2O4), among some others. Until now, limited data have been reported on PE toxicity assessment. The reviewed literature has shown that AOP can be used effectively to degrade PE from aqueous matrices. However, this systematic study suggests focusing more on the evaluation of the toxicity of the effluent resulting from AOP for the decomposition of PE in future studies. [ABSTRACT FROM AUTHOR]

Amoxicillin (AMX) is one of the antibiotics in the penicillin category that is used in various fields. Considering the harmful effects of its remains, it is necessary to survey the ways to remove this compound. Advanced oxidation process (AOPs), specially photo-Fenton has been used for the removal of AMX. This study has been conducted based on PubMed, Google Scholar, DOAJ, Web of Science, and Scopus databases during the years 2008–2019. Some factors such as the aquatic solution, light source characteristics, iron, and H2O2 concentration, AMX degradation percentage, removal of total organic carbon percentage, and AMX concentration have been surveyed to optimize the process. Studies showed that the photo-Fenton process is highly dependent on pH, and in most studies, the highest efficiency has been observed in acidic pH values. Using a more energy light source can be effective in reducing the use of catalysts and oxidizers. The combined methods of AOPs such as photo-Fenton, electro-Fenton, and photo-electro-Fenton have higher efficiency in increasing mineralization than the photon process. The use of synthetic wastewater has a higher efficiency in the degradation of AMX than in real wastewater in the photo-Fenton process, which can be due to the absence of the interfering agents in synthetic environments. [ABSTRACT FROM AUTHOR]

Conventional wastewater treatment is inefficient in removing Rhodamine B (RhB) from dying wastewater. Wastewater treatment is a promising advanced oxidation process (AOP) based on biochar and iron-activated persulfate. Therefore, the current study explored the potential of iron-loaded biochar-activated persulfate to remove RhB. Based on morphology observation, iron-loaded biochar could be successfully prepared using slow pyrolysis inside an N2 environment at 800°C. Structure analysis revealed that the surface area of iron-loaded biochar was 1.5 times the size of unmodified biochar. Under the optimum reaction condition, the maximum removal rate of RhB was 99.96%, determined by single-factor experiments. The RhB removal rate was improved with increased activator dosage, PS dosage, and temperature but decreased with increased pH and initial dye concentration. The RhB adsorption rate was governed by pseudo-first-order reaction kinetics, and the Langmuir-Hinshelwood kinetic model (R2 = 0.99853) helped explain the adsorption behavior. Recycling experiments of Fe-BC indicated a twice-cycle capacity which could be improved. Free radical quenching experiments showed that sulfate-free (SO4 •-) and hydroxyl (•OH) radicals worked together in the RhB removal process, dominated by •OH. [ABSTRACT FROM AUTHOR]

Nanomaterials are preferred for scientific studies due to their spectral properties and perfect surface appearance. This study aims to introduce a novel, environmentally friendly, photocatalytic method for degrading methylene blue (MB) in aqueous solutions. With this purpose in mind, the study synthesizes nanoceria particles and coats them with zahter (Thymbra spicata; zahter-coated nanoceria, ZCNC) following the main outlines of green chemistry as characterized by SEM and FTIR analyses. The study proposes this new nanoparticle (with the aid of H2 O2 and UV combinations) as an alternative to iron in Fenton-type reactions for enabling MB degradation. The maximum efficiency was observed through the ternary combination of zahter-coated nanoceria, UV light, and H2 O2 at 63% concentration. The degradation of the MB solution was achieved by installing a small amount of ZCNC (0.1g), after which the absorbance values were measured at 664 nm. According to the possible reaction kinetics discussed within the study, the reaction rate was calculated at 1.49 × 10-2 min -1, thus enabling a faster reaction for a better evaluation of the reaction mechanism compared to other degradation processes that have been previously investigated.

Antibiotics are generally applied for the treatment of infections in humans and animals due to their economic value, easy accessibility, and potency. The use of veterinary pharmaceuticals such as antibiotics for the treatment of various infections in aquaculture cannot be overemphasized; the discharge of aquaculture effluent without necessary remediation techniques leads to the toxicity of the ecosystem. In this work, zinc oxide hexagonal-nanorods were synthesized via a precipitation method and calcined at 5000C in a muffle furnace for the catalytic degradation of ciprofloxacin (CIP) formulated aquaculture effluent. The characterization of nano-sized ZnO (n-ZnO) was conducted using scanning electron microscopy-electron dispersive spectroscopy (SEM-EDS), transmission electron microscopy (TEM), x-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR) and Brunauer, Emmett and Teller (BET) surface area determination. The SEM micrograph depicted both hexagonal and rod-like structures. The TEM micrograph subjected to ImageJ software showed an average particle size of 42.69 nm. The weight percent of the elements from the electron dispersive spectroscopy (EDS) followed the trend of Zn>O>C>Cl. The sharp peak of the Zn-O band was observed around 463.12 cm-1. The results from XRD showed that pure n-ZnO was achieved at a temperature of 5000C with a BET surface area of 8.3 m2/g, pore volume of 0.072 cm3/g, and pore size of 184.77 A0. The percentage of chemical oxygen demand (COD) removal of CIP formulated aquaculture effluent followed the trend of 42.8%, 73.9%, and 94.8% for the ultrasound (US), US/n-ZnO, and US/n-ZnO/H2O2systems.The US/n-ZnO/H2O2system showed the highest removal efficiency of CIP from the aquaculture effluent. The kinetics best fit the pseudo-second order, while the mechanism of degradation followed the Langmuir-Hinshelwood model for the US/n-ZnO/H2O2system. Hence, the utilization of US/n-ZnO/H2O2for the degradation of CIP formulated aquaculture effluent has proven to be a sustainable system that is dependable, faster, less tedious, and does not generate additional waste superior performance compared to individual materials. As such, findings from this study confirmed the performance and effectiveness of the Mg-(OH)2-Ca-NPs nanocomposite on the removal of Mn from real river water. This will go a long way in curtailing the impacts of Mn in drinking water and further afield.