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The growing pharmaceutical industry has increased the production of wastewater containing pollutants that are resistant to conventional treatment. This study aimed to evaluate the effectiveness of an integrated Advanced Oxidation Process (AOP) combining ozonation and Fenton oxidation for treating pharmaceutical wastewater. The objective was to determine whether this combined approach could achieve higher removal efficiencies for key pollutants, including turbidity, Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and Total Organic Carbon (TOC), compared to individual processes. The research involved applying ozonation and Fenton oxidation, both separately and in combination, to wastewater samples. The study identified the optimal conditions for the integrated treatment by adjusting the concentrations of Fenton reagents and the duration of ozone exposure. The effectiveness of the treatment was assessed based on the removal efficiencies of turbidity, BOD, COD, and TOC. The results demonstrated that the combined ozone-Fenton process was highly effective, achieving removal efficiencies of 98.74% for turbidity, 96% for BOD, 99.56% for COD, and 96.63% for TOC. These findings highlight the potential of this combined AOP as a promising approach for improving the degradation of pollutants in pharmaceutical wastewater. However, the study's limitations include the need for further research to optimize the process for different wastewater types and to evaluate its long-term environmental impact and cost-effectiveness. The study's practical value lies in its potential industrial application, providing a more effective alternative to conventional treatment methods. The originality of the research is in systematically exploring the synergistic effects of combining ozonation and Fenton oxidation, contributing to advanced wastewater treatment development.

Abstract Rapid industrial growth in Bangladesh, especially in the textile industry, has led to water pollution from toxic azo dyes like orange-II, which are harmful to ecosystems and enter the food chain via irrigation. This study examined the use of chemical coagulation (using $${\text{C}}_{6} {\text{H}}_{11} {\text{NO}}_{4} {\text{X}}_{2}$$ C 6 H 11 NO 4 X 2 and $${\text{FeCl}}_{3} \cdot 6{\text{H}}_{2} {\text{O}}$$ FeCl 3 · 6 H 2 O ) and advanced oxidation process (using $${\text{NaOCl}}$$ NaOCl ) to treat orange-II dye for irrigation. However, $${\text{C}}_{6} {\text{H}}_{11} {\text{NO}}_{4} {\text{X}}_{2}$$ C 6 H 11 NO 4 X 2 and $${\text{FeCl}}_{3} \cdot 6{\text{H}}_{2} {\text{O}}$$ FeCl 3 · 6 H 2 O showed limited effectiveness in removing orange-II dye across various pH (3, 6, 9, and 12) levels. In contrast, $${\text{NaOCl}}$$ NaOCl achieved significant dye removal rates of over 90–99%. The study focused on high color removal, limited $${\text{ClO}}_{2}$$ ClO 2 and neutral pH after the test. Variables included $${\text{NaOCl}}$$ NaOCl doses (0.5 ml, 2.5 ml, and 5 ml), orange II dye doses (50 mg, 100 mg, and 150 mg) under different pH (3, 6, 8, 9 and 12) conditions. The manuscript is the first to assess orange-II dye using higher doses (2.5 ml and 5 ml) of $${\text{NaOCl}}$$ NaOCl compared to other studies, as an alkaline chemical to neutralize pH levels post-test. The highest dye removal occurred at pH 9 with similar results at other pH levels except pH 12. However, despite effective color removal, the pH remained alkaline at pH 8, 9, and 12 after the test. Hence, optimal experimental conditions of operational parameters were pH = 3 or 6, 2.5 ml $${\text{NaOCl}}$$ NaOCl dose with 100 mg/L or 150 mg/L dye doses. Further research is recommended on the degradation process, toxicological analysis of the final product, and cost-effectiveness for safe irrigation water.

This study focuses on utilization of a zero-valent metal (zero-valent iron, zero-valent aluminum, and nanoscale zero-valent copper) in conjunction with H2O2 conducted to treat real dye wastewater. Box - Behnken methodology was applied to describe effects of five independent factors involved in optimization of advanced oxidation system, which was type of zero-valent metals, dosage of zero-valent metals, pH, time and dosage of H2O2, for treating dye wastewater. Correlation coefficients for model, shown by the value R2, were 0.9996 for removing color and 0.9708 for reducing COD. Mass of nZVC equaled 1.09 g/L, [H2O2] equaled 5.39 mg/L were found to be the optimal reaction conditions when the pH was equal to 3.71. After 120 minutes of optimal settings, there was a reduction of 87.3% in COD and 98.72% in color of dye wastewater after heterogeneous treatments (nZVC/H2O2). The reusability of nZVC for degrading dye wastewater has been tested in four cycles and showed up to 70% COD removal. Ecotoxicological testing indicated that the raw textile effluent was extremely toxic to Chlorella sp. and V. fischeri. Even while wastewater after treatment collected definitely had a lower toxicity level with both V. Fischeri and Chlorella sp. This research findings highlight the nZVC/H2O2 process as a feasible and effective method for real dye wastewater treatment and detoxification, positioning it as a valuable alternative oxidation process for treating organic contaminants.

It is necessary to treat textile effluents before discharging them into natural water bodies as they harm the environment. Compared to conventional treatment methods, catalytic ozonation has gained attention due to its effectiveness in removing refractory organic pollutants. In this study, the coprecipitation method was used to synthesize a composite metal oxide of silver and cerium oxide, and the synthesized catalyst was used to eliminate the Reactive Black 5 (RB5) dye. X-ray diffraction, scanning electron microscopic, and Brunauer–Emmett–Teller surface area analyses were performed to characterize the synthesized catalyst. Afterwards, relevant experimental parameters, such as pH, ozone and catalyst dosages, and initial dye concentration, were investigated. The experiments revealed that the optimal experimental conditions were a pH value of 10, a catalyst dosage of 0.7 g/L, and an ozone dosage of 60 L/h. In these optimized conditions, the RB5 dye was entirely removed, and a chemical oxygen demand removal efficiency of 88% was achieved within a reaction time of 80 min. Furthermore, the recycling potential of the catalyst was tested for three cycles, and no deterioration in its activity was observed. Additionally, studies were conducted using a hydroxyl radical scavenger in order to understand the reaction pathway of the system. As a result, the indirect pathway was more dominant than the direct pathway in the system.

With the rapid development of industry, agriculture, and urbanization, various organic pollutants have accumulated in natural water, posing a potential threat to both the ecological environment and human beings, and removing organic pollutants from water is an urgent priority. Piezoelectric techniques, with the advantages of green, simple operation, and high efficiency, are highly sought after in the degradation of environmental organic pollutants. Moreover, combining piezoelectric techniques with advanced oxidation processes (AOPs), photocatalysis, or electrocatalysis can further effectively promote the efficient degradation of target pollutants. Therefore, a perspective is presented on the recent progress of piezoelectric techniques for the degradation of various organic pollutants from aqueous solutions. The classification of various piezoelectric materials, as well as modification strategies for improving piezocatalysis, are first systematically summarized. Furthermore, the latest research on piezocatalysis and its combination with other technologies, such as AOPs, photocatalysis, and electrocatalysis, in the degradation of environmental pollutants is discussed. The potential mechanisms of piezocatalysis are also analyzed in depth. Finally, the urgent challenges and future opportunities for piezoelectric techniques in the degradation of organic pollutants are provided.

In recent years, studies on the degradation of emerging organic contaminants by sulfate radical (SO4−·) based advanced oxidation processes (SR-AOPs) have triggered increasing attention. Metal-loaded biochar (Me-BC) can effectively prevent the agglomeration and leaching of transition metals, and its good physicochemical properties and abundant active sites induce outstanding in activating persulfate (PS) for pollutant degradation, which is of great significance in the field of advanced oxidation. In this paper, we reviewed the preparation method and stability of Me-BC, the effect of metal loading on the physicochemical properties of biochar, the pathways of pollutant degradation by Me-BC-activated PS (including free radical pathways: SO4−·, hydroxyl radical (·OH), superoxide radicals (O2–·); non-free radical pathways: singlet oxygen (1O2), direct electron transfer), and discussed the activation of different active sites (including metal ions, persistent free radicals, oxygen-containing functional groups, defective structures, etc.) in the SR-AOPs system. Finally, the prospect was presented for the current research progress of Me-BC in SR-AOPs technology. HIGHLIGHTS The characteristics of the preparation methods for metal-loaded biochar are summarized.; The effects of metals on the physicochemical properties of biochar are discussed.; The free radical and non-radical pathways for activation of persulfate by metal-loaded biochar are discussed.; The potential mechanisms of metal-loaded biochar catalysts are discussed.; The future blueprint for metal-loaded is described.;

Abstract Municipal wastewater treatment systems use the chemical oxygen demand test (COD) to identify organic contaminants in industrial effluents that impede treatment due to their high concentration. This study reduced the COD levels in tannery wastewater using a multistage treatment process that included Fenton oxidation, chemical coagulation, and nanotechnology based on a synthetic soluble COD standard solution. At an acidic pH of 5, Fenton oxidation reduces the COD concentration by approximately 79%. It achieves this by combining 10 mL/L of H2O2 and 0.1 g/L of FeCl2. Furthermore, the author selected the FeCl3 coagulant for the coagulation process based on the best results of comparisons between different coagulants. At pH 8.5, the coagulation dose of 0.15 g/L achieved the maximum COD removal efficiency of approximately 56.7%. Finally, nano bimetallic Fe/Cu was used to complete the degradation and adsorption of the remaining organic pollutants. The XRD, SEM, and EDX analyses proved the formation of Fe/Cu nanoparticles. A dose of 0.09 g/L Fe/Cu NPs, 30 min of contact time, and a stirring rate of 200 rpm achieve a maximum removal efficiency of about 93% of COD at pH 7.5. The kinetics studies were analyzed using pseudo-first-order P.F.O., pseudo-second-order P.S.O., and intraparticle diffusion models. The P.S.O. showed the best fit among the kinetic models, with an R2 of 0.998. Finally, the authors recommended that technique for highly contaminated industrial effluents treatment for agriculture or industrial purposes.

In this study, a potassium ferrate (K2FeO4)-modified biochar (Fe–BC) was prepared and characterized. Afterwards, Fe–BC was applied to activated periodate (PI) to degrade tetracycline (TC), an antibiotic widely used in animal farming. The degradation effects of different systems on TC were compared and the influencing factors were investigated. In addition, several reactive oxygen species (ROS) generated by the Fe–BC/PI system were identified, and TC degradation pathways were analyzed. Moreover, the reuse performance of Fe–BC was evaluated. The results exhibited that the Fe–BC/PI system could remove almost 100% of TC under optimal conditions of [BC] = 1.09 g/L, initial [PI] = 3.29 g/L, and initial [TC] = 20.3 mg/L. Cl−, HCO3−, NO3−, and humic acid inhibited TC degradation to varying degrees in the Fe–BC/PI system due to their quenching effects on ROS. TC was degraded into intermediates and even water and carbon dioxide by the synergistic effect of ROS generated and Fe on the BC surface. Fe–BC was reused four times, and the removal rate of TC was still maintained above 80%, indicating the stable nature of Fe–BC. HIGHLIGHTS Fe–BC with excellent morphology and composition was successfully prepared.; Fe–BC could effectively activate periodate in degrading tetracycline (TC).; The response surface methodology was utilized to determine the optimum conditions.; The reactive oxygen species generated were responsible for TC degradation.;

Hydroxychloroquine (HCQ), a 4-amino quinoline derivative, has antimalarial and anti-inflammatory activity and was most recently proposed in the treatment of SARS-COVID-19. Its pharmacokinetics and toxic side effects necessitate the monitoring of its presence in the environment and its removal from wastewater. In this study, HCQ was removed from an aqueous solution with a removal efficiency of between 80% and 90% under electron beam (EB) irradiation. The degradation of HCQ was propagated by reactions involving both the hydroxyl radical and aqueous electron. The degradation was observed to follow a pseudo-first-order kinetic reaction. The applied radiation dose, pH, and initial HCQ concentration were influential in the degradation efficiency under EB irradiation. Acidic and alkaline pH favored the removal of HCQ under EB irradiation. Even though the initial HCQ was successfully degraded, it was not completely mineralized. The TOC and chemical oxygen demand (COD) remained at a relatively stable level following EB irradiation of the aqueous solutions. This is attributed to the formation of other organic compounds that were not degraded under the investigated experimental conditions.

The global population and economic development surge has substantially increased water demand, resulting in heightened sewage and pollutant generation, posing environmental hazards. Addressing this challenge necessitates the implementation of efficient and cost-effective water reclamation methods. Non-thermal plasma technology (NTP) has emerged as a promising solution, garnering attention for its superior efficiency compared to alternatives. While existing studies have predominantly focused on energy efficiency and pollutant removal, limited research has delved into the biological removal aspect, particularly concerning algae. This study utilized a dielectric barrier plasma diffuser to eliminate Spirulina microalgae (Spirulina platensis) from wastewater solutions, demonstrating higher algae removal and superior mass transfer compared to alternative plasma methods. The effect of sample volume, input voltage and power, flow rate, and initial solution concentration on the algae removal was investigated. Investigation of operational parameters revealed the best condition resulting in a 98 % removal rate and 20 g/kWh energy efficiency. The best conditions for the removal of Spirulina microalgae were considered in a sample volume of 50 mL, a voltage of 7.6 kV, a flow rate of 700 mL/min, and an initial solution concentration of 1280 mg/liter. Scanning Electron Microscope (SEM) images illustrated the impact of active species on cell structure, leading to the destruction of spiral form and loss of reproductive ability. The study underscores the potential of NTP for efficient algae removal and identifies key active species involved in the process. The removal of Spirulina microalgae was attributed to a combination of singlet oxygen (1O2), hydroxyl radicals, and ozone.

To address the problem of petrochemical organic pollutants in water, specifically monoethylene glycol (MEG) present in industrial process streams, in this research, we synthesized and evaluated a multifunctional nanocomposite, Fe3O4@MC/MWCNT-CuO/Ag. The nanocomposite was produced by combining magnetic Fe3O4 nanoparticles, methylcellulose (MC), multi-walled carbon nanotubes (MWCNTs), and CuO/Ag nanoparticles by an integrated synthesis process. A consistent dispersion of nanoparticles, with diameters ranging from 30-40 nm, was discovered by FESEM analysis, showing effective integration without aggregation. Effective synthesis was demonstrated by well-doped and evenly dispersed CuO and Ag nanoparticles. Functional groups that improve electrostatic interactions with contaminants hence enhancing catalytic performance and adsorption efficiency, were validated by FTIR analysis. XRD indicated an unchanged crystal structure with an average crystallite size of 8.67 nm. The anticipated elemental composition was verified by EDS & mapping. A VSM study revealed magnetic characteristics (9.33 emu/g) that simplify nanocomposite separation and reuse. TGA proved thermal stability to be up to 600 °C. A BET study showed a highly specific surface area of 67.661 m2/g, enhancing adsorption. According to DRS and PL studies, the bandgap was lowered by 1.31 eV, which led to better optical absorption. The nanocomposite exhibited notable MEG removal efficiency, with 72 % in adsorption, 65 % in photocatalysis, and 56 % in sonocatalysis. This makes it a promising alternative for the remediation of organic pollutants in water treatment.

The research aims to develop an advanced electrooxidation process for decolorization of recalcitrant dye. To enhance the radical formation, a combination of UV irradiation and electrooxidation (UV/EO) is used. Methylene Blue (MB), Rhodamine B (RB) and Congo Red (CR) dyes were used as model compounds to represent recalcitrant dyes. The performance of UV/EO process was investigated under various operating factors (i.e., current density (CD), voltage, pH, NaCl, anodic material), and compared with chlorination, UV irradiation, and electrooxidation (EO) process. MB was the highest resistant dye to the UV/EO process. The UV/EO process exhibited a synergistic effect on decolorization, and it removed MB 1.35 time faster than the EO process. Based on indirect determination of •OH, the •OH formation in the EO process was 2.4 ×10−13 M, which lower than that in the UV/EO process by 4 times. The second-order rate constant for MB oxidation by HO• (kHO•,MB) was 3.31 × 109 M−1s−1. The pseudo 1st-order decolorization kinetic (k’) was independent with voltages, but directly depended on CD and NaCl concentrations. Lower pH enhanced the k’ value. The specific energy consumption was in a range of 0.408 – 5.303 kWh/m3, depending on the k’ value. The energy consumption decreased with higher the k’ value, except for increasing CD. The Boron Doped Diamond (BDD) was more effective in the decolorization rate than dimensional active anode (DSA) by 1.6 times. Treatment of industrial dye wastewater by the UV/EO process eliminated color intensity (ADMI), COD, and BOD5 by 80 %, 91 %, and 9 %, respectively.

Abstract Nanomaterials have been extensively employed in various applications over the past several decades, however, the stability of functional nanoparticle catalysts (NPCs) for effective degradation of organic contaminants remains a significant challenge. Herein, we present a cost-effective biochar loaded uniformly dispersed ultra-stable Co nanoparticles with an average diameter of 8 nm as a highly efficient peroxymonosulfate (PMS) activation catalyst. The reactive radicals produced from the catalyst/PMS system are able to degrade several model organic pollutants of environmental and public health concerns, including trichlorobiphenyl, bisphenol A and diethyl phthalate, with less pH limitation and Co2+ leaching. Mechanism investigation demonstrates that the CoN plays the key role in the catalyst stability and PMS activation via acid resistance and electron bridging effects, respectively. Meanwhile, the incorporation of nitrogen (N) and sulfur (S) atoms within the substrate is considered to bolster the adhesion strength between metal nanoparticles and the carbon matrix via strong metal-support interaction. The catalyst was further applied in practical treatment of water and soil polluted by organic pollutants, exhibiting a satisfactory degradation efficiency (> 90% in 60 min) for environmental applications.

A catalyst based on zero-valent iron nanoparticles (nZVI) supported by zeolite Y (zeolite Y-nZVI) was synthesized to improve the performance of the heterogeneous electro-Fenton-like process for treating a toxic pesticide wastewater with pH of 6. Central Composite Design (CCD) under Response Surface Methodology (RSM) was applied to design the experiments and find the optimal parameters including time, current intensity, hydrogen peroxide volume (or concentration) and the synthesized catalyst dosage. The results showed that the chemical oxygen demand (COD) removal under the optimal conditions (time of 125 min, current intensity of 272 mA, hydrogen peroxide volume (or concentration) of 0.19 ml (8.102 × 10−3 M), and zeolite Y-nZVI catalyst dosage of 1.78 g) was at 83.69 % for treating a wastewater with pH of 6 although this increased to 91.26 % at pH of 3 under the Fenton reactions. In fact, the synthesized catalyst could properly treat wastewater in a pH close to neutral one. Since electro-Fenton is as efficient technique for treating the hazardous pollutants such as pesticide, it can successfully be used by their manufacturing factories. Since it properly works in the acidic pHs, it is not as applied technique for most of industries. Therefore, catalytic electro-Fenton process can be performed in (or near) a neutral pH. Since electro-Fenton is basically associated with iron, a catalyst based on it (such as Fe°) was chosen and supported on an abundant and suitable material such as zeolite. The synthesized catalyst was initially synthesized and characterized, and then successfully applied in the electro-Fenton process to treat a real pesticide containing wastewater obtained from industry.

The increase in pork consumption and its reputation as one of the best sources of protein has led to growth in this industry, however, its production generates a significant amount of swine wastewater (SWW). Conventional biological treatment methods are typically used to treat SWW. However, their applicability in small and medium sized enterprises (SMEs) in the swine industry is limited due to their high space requirements. Therefore, advanced oxidation processes (AOPs) such as photofenton (PF) and electrocoagulation (EC) represent a potential alternative for SWW treatment due to their lower space requirements. The aim of this study was to treat SWW by integrating the PF process followed by EC as a technological couple to optimize the removal efficiency of pollutants present in SWW. Experiments were conducted in a 2 L batch reactor, examining the effects of hydrogen peroxide (H2O2) concentration (0.5, 2.5, 5.0 g L−1) and current density (10, 50, 90 A m−2) on pH, organic matter, nutrients, and germination index (GI). The results showed that the optimum process conditions correspond to 2.6 g L−1 H2O2 and a current density of 41 A m−2. Under these conditions, an effluent is obtained with pH values of 7.8, TSS of 385 mg L−1, COD of 254 mg L−1, BOD5 of 139.8 mg L−1, TN of 190.4 mg L−1 and GI of 117 %. The results showed that the effluent complies with the Colombian standards. From a cost perspective, the use of Photo-Fenton to treat wastewater under these conditions would be US$ 0.7 per liter.

تعتبر المياه المصاحبة للنفط من أخطر أنواع التلوث على البيئة، لأنها تحتوي على العديد من الملوثات الضارة بالبيئة وصحة الإنسان مثل (النفط، المواد الصلبة العالقة، المواد الذائبة، والعديد من الملوثات الأخرى). يتناول هذا المقال عمليات الأكسدة المتقدمة (AOPs) التي تمت دراستها لتنقية المياه المنتجة من حقل الخباز النفطي الواقع في شمال العراق - محافظة كركوك من المحتوى النفطي. نظرًا لسهولة استخدام AOPs والأداء والسعر المنخفض، فهي طريقة شائعة لتنقية هذا النوع من مياه الصرف الصحي. في هذا العمل تم استخدام عمليات التحفيز الضوئي المتجانسة (Photo-Fenton (H2O2+Fe+2+UV)،) Fenton (H2O2+Fe+2، وUltra Violet (UV) فقط) في نظام الدفعات تحت أفضل الظروف (الزمن = 120 دقيقة، الرقم الهيدروجيني = 2.5، H2O2 = 20 مل في عملية فوتو فنتون، H2O2 = 80 مل في عملية فنتون، 2 مصباح UV (قدرة كل واحد = 8 وات) في عملية فوتو فنتون، 10 مصابيح UV في عملية UV مباشرة، و Fe+2=18 مجم في عمليات فوتو فنتون وفنتون). تم في هذا البحث دراسة تأثير جرعات H2O2 وFe+2 وزمن التشعيع وقيمة الرقم الهيدروجيني وشدة الأشعة فوق البنفسجية على فعالية إزالة النفط. حققت هذه الدراسة أعلى كفاءة في الفوتو-فنتون هي 85.68%، الفنتون= 75.01%، والتحليل الضوئي فوق البنفسجي المباشر= 56.64%. ونتيجة لذلك تم التوصل إلى أن عملية الفوتو فنتون هي أفضل طريقة لإزالة النفط من المياه المصاحبة للنفط.

The wastewater containing both Cr（Ⅵ） and dyes is frequently produced in the industrial manufacturing processes including printing and dyeing，tanning，etc. Based on the concept of “treating waste with waste”，the feasibility of simultaneous removal of Rhodamine B（RhB） and Cr（Ⅵ） by activating sulfite with Cr（Ⅵ）（Cr（Ⅵ）/S（Ⅳ） system） was investigated. The active species in the reaction system were identified，and the effects of initial concentrations of Na2SO3 and Cr（Ⅵ），the initial pH and the amount of dissolved oxygen on the degradation of RhB and Cr（Ⅵ） were investigated. The results showed that，at the initial pH was 3，95.1% of RhB and 87.4% of Cr（Ⅵ） was removed within 60 min by 1.00 mmol/L Na2SO3 and 0.15 mmol/L Cr（Ⅵ）. The dissolved oxygen was involved in the conversion of sulfur-oxygen free radicals in the reaction process，and played a key role in the degradation of RhB and the reduction of Cr（Ⅵ）. The finding of EPR detection and quenching experiments demonstrated that，SO4·-，SO5·-，·OH and 1O2 cooperatively engaged in the reaction process of Cr（Ⅵ）/S（Ⅳ） system，in which SO4·-is the main active species. Meanwhile，the contribution of 1O2 formed from SO4·-should not be ignored. In addition，the possible degradation pathway of RhB was proposed according to the results of ultraviolet full-wavelength scanning and GC/MS.

Advanced oxidation processes are emerging technologies for the decomposition of organic pollutants in various types of water by harnessing solar energy. The purpose of this study is to examine the physicochemical characteristics of tungsten(VI) oxide (WO3) photoanodes, with the aim of enhancing oxidation processes in the treatment of water. The fabrication of WO3 coatings on conductive fluorine-doped tin oxide (FTO) substrates was achieved through a wet coating process that utilized three different liquid formulations: a dispersion of finely milled WO3 particles, a fully soluble WO3 precursor (acetylated peroxo tungstic acid), and a combination of both (applying a brick-and-mortar strategy). Upon subjecting the WO3 coatings to firing at a temperature of 450 °C, it was observed that their properties exhibited marked variations. The fabricated photoanodes are examined using a range of analytical techniques, including profilometry, thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and voltammetry. The experimental data suggest that the layers generated through the combination of particulate ink and soluble precursor (referred to as the brick-and-mortar building approach) display advantageous physicochemical properties, rendering them suitable for use as photoanodes in photoelectrochemical cells.

This work aimed to investigate the influence of modified titanium(IV) oxide by different nanosized particles on photocatalytic capacity to decompose the chosen organic pollutant under simulated sunlight. For that purpose, rutile-phased titanium(IV) oxide (r-TiO2) was decorated with iron vanadate (FeVO4/r-TiO2) and vanadium-substituted goethite (Fe1-xVxOOH/r-TiO2). The obtained composites were characterized by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X ray powder diffraction, Brunauer-Emmett-Teller, Fourier transform infrared spectroscopy – attenuated total reflec-tance and ultraviolet–visible diffuse reflectance spectroscopy techniques. Both synthesized photocatalysts showed higher photoactivity than the base r-TiO2 for the degradation of the target contaminant - thiophanate-methyl (2.5 h vs. 5 h). During the tests, parameters like the irradiation time, catalysts amount, and pesticide concentration were systematically investigated. Furthermore, photocatalysts were applied in multicycle degradation tests for examining their effectiveness during exploitation time. Monitoring of the removal rate was performed both by UV/visible spectrometry and high-performance liquid chromatography (HPLC). In order to prove completion of fungicide degradation chemical oxygen demand was measured in the course of the photocatalytic experiment. The final concentration of the observed contaminant in treated samples was under the prescribed legislative level. The fabricated materials displayed great reliability, durability and photocatalytic activity repre-senting good potentials for implementing this process in real wastewater treatment plants.

Nanofiltration (NF) has been used as the default sulfate removal process in platforms to treat seawater for water flooding. Seawater is generally pretreated by chlorination and cartridge filters to reduce fouling of the membranes; however, this pretreatment is insufficient to provide water quality high enough to maintain the productivity of the NF membranes. In this study, the performances of two different pretreatment routes were evaluated. Microfiltration (MF) was evaluated as a replacement for cartridge filters, and the advanced oxidation process UV/H2O2 was evaluated as an additional stage of pretreatment upstream of the cartridge filters. The permeability of the NF membranes after 12 h of seawater sulfate removal in a bench system was 4.4 L·h−1·m−2·bar−1 when the UV/H2O2 process was adopted as the pretreatment and 2.9 L·h−1·m−2·bar−1 when the MF process was adopted, compared to 1.6 L·h−1·m−2·bar−1 achieved for the pretreatment with the cartridge filter alone. These results indicate that NF membrane fouling was significantly higher when seawater was pretreated only by the cartridge filter in comparison to both proposed pretreatments. An economic analysis showed that both systems are economically viable and can potentially reduce the operational costs of the NF sulfate removal process on platforms. HIGHLIGHTS Comprehensive analysis of cartridge filters, microfiltration, and advanced oxidation process UV/H2O2 pretreatments for seawater desalination by nanofiltration, the last which has not been well stated in the literature.; UV/H2O2 impact on reducing seawater fouling in membranes.; Economic analysis showing the impact on operational costs of the pretreatments on the nanofiltration sulfate removal process in offshore platforms.;

The degradation of diisopropyl methylphosphonate (DIMP) in aqueous solutions was studied using ultrasound irradiation with a fixed frequency of 26.2 kHz, following the first-order kinetic model. The study's primary goal was to determine the influence of the following experimental parameters: the pH (at different values of 2, 7 and 10), the initial concentration of DIMP (at different concentrations: 7, 14, 30, 50, 80 mg/L), the processing time (at different periods: 15, 30, 45, 60, 80, 90 min), and the concentration of the additive CCl4 (at different concentrations: 0.002, 0.004, 0.006, 0.008 mg/L). A DIMP removal efficiency of 98% from aqueous solution was obtained at pH 10 and 0.008 mg/L CCl4, after an ultrasound irradiation time of 45 min, pointing out the influence of the above-mentioned experimental parameters on the DIMP degradation process.

Pharmaceutical industry effluents often contain high concentrations of refractory organic solvents, chemical oxygen demand (COD), and total dissolved solids (TDSs). These wastewaters, including N-containing organic solvents known for their persistence and toxicity, pose significant environmental challenges. The study evaluated the efficacy of 3D/Granular Activated Carbon (GAC)/O3 treatment compared to linear process additions when treating real pharmaceutical wastewater, and revealed a 2.73-fold enhancement in COD mineralization. The process primarily involves the direct oxidation of monoprotic organic acids found in real pharmaceutical effluents, such as acetic and formic acid, crucially influencing mineralization rates. Optimal conditions determined via the response surface methodology were 125 g/L GAC, 30 mA/cm2, and 75 mg/L O3, achieving high total organic carbon (TOC) and COD removal efficiencies of 87.19 ± 0.19% and 89.67 ± 0.32%, respectively (R2 > 0.9), during verification runs. Current density emerged as the key parameter for organic abatement, aligning with the emphasis on direct oxidation at the anode surface. This integrated approach enhances biodegradability (BOD5/COD) and reduces acute toxicity associated with persistent N-containing solvents, demonstrating promising applications in pharmaceutical wastewater treatment.

Persulfate-based advanced oxidation processes have emerged as a promising approach for the degradation of organic pollutants in aqueous environments due to their ability to generate sulfate radicals (SO4−·) within catalytic systems. In this study, peroxydisulfate (PDS) and peroxymonosulfate (PMS) were investigated with the natural vanadium–titanium magnetite (VTM) as the activator for the degradation of acid orange II. The degradation efficiency increased with higher dosages of VTM or persulfate (both PDS and PMS) at lower concentrations (below 10 mM). However, excessive PMS (higher than 10 mM) in the PMS/VTM system led to the self-consumption of free radicals, significantly inhibiting the degradation of acid orange II. The VTM-activated PDS or PMS maintained an effective degradation of acid orange II in a wide pH range (3~11), suggesting remarkable pH stability. The SO4−· was the main active species in the PDS/VTM system, while hydroxyl radical (·OH) also contributed significantly to the PMS/VTM system. In addition, PMS exhibited better thermal stability during VTM activation. Coexisting ions in an aqueous environment such as bicarbonate (HCO3–), carbonate (CO32–), and hydrogen phosphate (HPO42–) had obvious effects on persulfate activation. Our study systematically investigated the different activation processes and influencing factors associated with PDS and PMS when the natural VTM was used as a catalyst, thereby providing new insights into the persulfate-mediated degradation of organic pollutants in aqueous environments.

This study developed a new system for removing antibiotics using UV/ZIF-67 (Co)-activated peroxymonosulfate. The presence of antibiotic organic pollutants in urban sewage presents a substantial challenge for sewage treatment technologies. Due to the persistent chemical stability of antibiotics, their low environmental concentrations, and their resistance to degradation, effectively removing residual antibiotics remains a significant issue in urban wastewater treatment. This study introduces an eco-friendly photocatalytic technology designed to enhance the removal of oxytetracycline (OTC) from municipal wastewater using a UV/ZIF-67 (Co)/PMS system. The results showed that compared with UV, UV/PMS, ZIF-67 (Co), ZIF-67 (Co)/PMS, and UV/ZIF-67 (Co) systems, the UV/ZIF-67 (Co)/PMS system had the highest OTC removal rate. When 10 mg ZIF-67 (Co) and 1 mM PMS were applied to 100 mL 30 mg/L OTC solution, the degradation efficiency reached 87.73% under 400 W ultraviolet light. Increasing the dosage of ZIF-67 (Co) and PMS can improve the removal rate of OTC, but the marginal benefit of additional dosage is reduced. The highest degradation efficiency was observed at weakly acidic pH, which may be due to potential damage to the internal structure of the catalyst and reduced performance under extreme pH conditions. The influence of chloride ions and nitrate ions on the reaction system is minimal, while bicarbonate ions exhibit a significant inhibitory effect on the removal of OTC. The UV/ZIF-67 (Co)/PMS system exhibits adaptability to various water sources, including tap water, Guitang River water, and pure water. The results of free radical identification indicate the presence of hydroxyl and sulfate groups in the UV/ZIF-67 (Co)/PMS system, both of which play important roles in the degradation of OTC. This study offers valuable insights and technical support for the green, efficient, and environmentally friendly removal of antibiotics from urban wastewater.

Over the past few decades, peroxymonosulfate (PMS)-driven advanced oxidation processes (AOPs) have garnered substantial interest in the field of organic decontamination. The copper (Cu)/PMS system is intriguing due to its diverse activation pathways and has been extensively employed for the clearance of refractory organic pollutants in water. This article is designed to offer a comprehensive overview of the latest trends in Cu-based catalysts such as single-metal and mixed-metal catalysts aimed at treating recalcitrant pollutants, highlighting PMS activation. Subsequently, investigative methodologies for assessing PMS activation with copper-based catalysts are reviewed and summarized. Then, the implications of pH, PMS and catalytic agent concentrations, anions, and natural organic matter are also addressed. The combination of Cu-based catalyst/PMS systems with other advanced oxidation technologies is also discussed. Following that, the degradation mechanisms in the Cu-based catalyst-activated PMS system are considered and synopsized. Lastly, potential future research avenues are proposed to enhance the technology and offer support for developing of economically viable materials based on copper for activating PMS.

The textile industry is one of the most important and economically significant industries in the world. China is the largest textile producer, for countries such as India, Pakistan, Bangladesh and Malaysia this sector is of crucial importance and it is also a growing sector in Latin America. This industry is responsible for 10 % of annual global carbon emissions and 20 % of global wastewater. This figure is worrying as this wastewater is highly recalcitrant, which has led to research into different treatment methods that are efficient and can provide a sustainable solution to this problem. The aim of this literature review was to identify the existing methods for the treatment of dry scrubber wastewater (TWWT) and the effects of this wastewater and its composition, focusing on biological, chemical and physicochemical processes from the point of view of advantages and disadvantages. It was analyzed which are the most important scientific areas of TWWT and which countries are the most important in this field, as well as the primary pollutants and TWWT processes. Finally, this analysis provides a context for current trends in TWWT research. In general, coagulation methods have been found to be fast but present difficulties due to the use of toxic coagulants; advanced oxidation processes (AOPs) are positioned as very effective methods that can disinfect and decontaminate these effluents. Currently, biological systems coupled with AOPs are a growing trend. Microalgae and cyanobacteria processes coupled with AOPs have attracted great interest due to the possibility of obtaining high added value products through the biorefining of biomass.

The use of antibiotics has increased in the last five years due to the COVID-19 pandemic, which has led to an increase in antibiotic concentrations in wastewater. Therefore, there is a need for the implementation of technology for antibiotic degradation. This research aimed to determine the efficiency of the advanced oxidation process (AOP) using a combination of UV/H2O2 for antibiotic degradation. The degradation was conducted using the antibiotic amoxicillin in a batch-wise experiment. Response Surface Methodology with Central Composite Design (RSM-CCD) was employed to optimize the efficiency of the degradation process. The result revealed that the degradation rate constants and efficiency using UV/H2O2 were 0.0127/min and 62.43 %, respectively, which was higher than that of UV (0.0043/min and 30.524 %) or H2O2 (0.0033/min and 20.365 %) after 90 min of treatment. The optimum solution was achieved at an initial pH of 4.2, an amoxicillin concentration of 45.85 mg/L, and an H2O2 concentration of 10.093 mM. Under these optimal conditions, the degradation efficiency of amoxicillin could reach 99.98 %. In addition, the results of the study demonstrate the inhibitory effect of the degraded amoxicillin on pathogenic bacteria, thus indicating that the photochemical oxidation process can effectively degrade amoxicillin residues in wastewater. This study showed that photochemical oxidation has the potential to be an effective approach for antibiotic degradation.

In this research, nanoparticles of NiFe2O4, Zn0.5Ni0.5Fe2O4, TiO2-Zn0.5Ni0.5Fe2O4 and TiO2-Zn0.5Ni0.5Fe2O4-rGO were synthesized respectively by combustion sol-gel method, co-precipitation and two nanocomposite samples by physical mixing method. For the characterization of nanoparticles from Fourier transform infrared (FT-IR) analysis, X-ray diffraction pattern (XRD), Scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), Diffuse Reflectance Spectroscopy (DRS) and porosimetry measurements. Adsorption and desorption have been used with BET. The results show that the synthesized particles are nanoscale ,and the absorption process takes place inside the holes. Also, the advanced oxidation process (AOP) was evaluated using photocatalyst for nanoparticles and the best performance was TiO2-Zn0.5Ni0.5Fe2O4-rGO nanocomposite with saturation magnetism (emu/g) of 65.88 with It showed a destruction of 95%.

Per- and polyfluoroalkyl substance (PFAS) contamination has emerged as a significant environmental concern, necessitating the development of effective degradation technologies. Among these technologies, ultrasonication has gained increasing attention. However, there is still limited knowledge of its scale-up or on-site applications due to the complexity of real-world conditions and its high energy consumption. Herein, we provide an overview of recent advancements in the ultrasonic degradation of PFAS toward hybrid technologies. This review contains information regarding the physical and chemical properties of PFAS, followed by an exploration of degradation challenges, the mechanisms of ultrasonication, and recent experimental findings in this field. The key factor affecting ultrasonication is cavitation intensity, which depends on ultrasonic frequency, power density, and PFAS structure. Its main advantages include the generation of reactive species without chemicals and the compatibility with other degradation technologies, while its main disadvantages are high energy consumption and limited applications to liquid-based media. We also highlight the integration of ultrasonication with other advanced oxidation processes (AOPs) to create hybrid systems for enhanced degradation of PFAS in order to significantly improve PFAS degradation efficiency, with enhancement factors ranging between 2 and 12. Finally, we discuss prospects for scaling up the ultrasonic degradation of PFAS and address the associated limitations. This review aims to deepen the understanding of ultrasonication technology in addressing PFAS contamination and to guide future research and development efforts.

To explore advanced oxidation catalysts, peroxymonosulfate (PMS) activation by Co-Ni-Mo/carbon nanotube (CNT) composite catalysts was investigated. A compound of NiCo2S4, MoS2, and CNTs was successfully prepared using a simple one-pot hydrothermal method. The results revealed that the activation of PMS by Co-Ni-Mo/CNT yielded an exceptional Rhodamine B decolorization efficiency of 99% within 20 min for the Rhodamine B solution. The degradation rate of Co-Ni-Mo/CNT was 4.5 times higher than that of Ni-Mo/CNT or Co-Mo/CNT, and 1.9 times as much than that of Co-Ni/CNT. Additionally, radical quenching experiments revealed that the principal active groups were 1O2, surface-bound SO4•−, and •OH radicals. Furthermore, the catalyst exhibited low metal ion leaching and favorable stability. Mechanism studies revealed that Mo4+ on the surface of MoS2 participated in the oxidation of PMS and the transformation of Co3+/Co2+ and Ni3+/Ni2+. The synergism between MoS2 and NiCo2S4 reduces the charge transfer resistance between the catalyst and solution interface, thus accelerating the reaction rate. Interconnected structures composed of metal sulfides and CNTs can also enhance the electron transfer process and afford sufficient active reaction sites. Our work provides a further understanding of the design of multi-metal sulfides for wastewater treatment.

Following the goals of the circular economy, this work demonstrates that an industrial by-product can be used in environmental remediation. Metallurgical slag and citric acid were used to form an Fe:Cit complex by simultaneously carrying out the lixiviation of the iron and the chelating stages with an 87% iron recovery. This complex was evaluated in the photo-Fenton process to produce HO• through salicylic acid dosimetry or salicylic acid hydroxylation, producing 0.13 ± 0.1 mM HO• after 30 min of operation; such a value is three orders of magnitude higher than the one reported for the metallurgical slag (as a heterogeneous catalyst, 22 μM) in the photo-Fenton-like process. The system was tested for its ability to degrade a mixture of drugs, including dexamethasone (DEX), naproxen (NAP), and ketorolac (KTR), which are often used to treat the symptoms of COVID-19. The drug degradation tests were performed in two stages. In the first stage, the Fe:Cit complex from the metallurgical slag was compared to the one formed by analytical-grade reactants; the drug degradation was faster for the former, with the major difference being observed at 5 cm and 500 W/m2. Here, 85–90% of the drugs was degraded in 5 min using Fe:Cit from slag, while at least 20 min was necessary to achieve such degradation with the analytical reagent, conceivably because of the trace compounds being lixiviated from the slag. Then, the effects of the liquid depth (5, 10, and 15 cm) and irradiance (250, 500, and 750 W/m2) were tested; the pseudo-first-order kinetic degradation constants for the three model pollutants were in the range of 0.009 > kD > 0.09 min−1, showing that degradation is more feasible for DEX than for NAP and KRT because the radical attack feasibility is related to the molecular structures.

Advanced oxidation processes (AOPs) are projected as relatively cleaner technologies for the abatement of water pollution. This paper investigates the Fenton process as a potential tool for the degradation and eventual mineralization of a textile dye, Rhodamine B (RhB), in water. The effects of activation sources such as microwave (MW), ultrasound (US), and solar energy (SL) on the efficiency of the process were tested. Solar and solar catalytic Fenton processes are identified as the best processes and accordingly, relevant reaction parameters are identified and optimized. The optimum ratio of Fe2+:H2O2 obtained is 1:3 at 15 mg/l of RhB concentration and at pH 3–3.5, showing a degradation efficiency of 47% within 30 min of solar irradiation. ZnO enhanced solar Fenton mineralization of RhB. Persulfate (PS) enhances degradation moderately. The study demonstrated the potential of recycling Fe2+ by periodic replenishment of H2O2. Major reaction intermediates formed were identified by the LC-MS method. Photoluminescence (PL) spectral studies showed a progressive increase in •OH radical formation during solar irradiation. The study has proven that solar Fenton and solar catalytic Fenton processes are efficient AOPs for the complete mineralization of RhB and thus present an economic and environment-friendly technology to remove recalcitrant RhB pollutants from water. HIGHLIGHTS Solar Fenton and solar photocatalytic Fenton processes are identified as efficient treatment processes for the complete removal of dye pollutants.; The presence of ZnO as the catalyst enhanced Fenton-assisted mineralization of RhB under solar irradiation.; The recycling of Fe2+ by periodic replenishment of H2O2 offers an environment-friendly solution to the accumulation of iron in the waste sludge.;

AbstractDue to the increase in population and industrial activities, the demand for clean water has increased. On the other hand, the amount of fresh water has decreased; As a result, wastewater treatment, including municipal and industrial wastewater, has become very necessary. One of the wastewater treatment methods is the Advanced Oxidation Process (AOP). This research used the advanced oxidation process using the photo-catalyst based on modified activated carbon to treat municipal wastewater in Yasouj City. Activated carbon was prepared from the walnut shell using the chemical activation method and then modified by a composite of ZnO and SnO2 nanoparticles and used as a photo-catalyst in the designed reactor for wastewater treatment. The results of FTIR, XRD, and EDX analyses confirmed the presence of ZnO/SnO2 nanoparticles on the modified activated carbon surface. Due to the coating of these nanoparticles on the surface of the activated carbon and inside its pores, the specific surface area of the modified activated carbon is greatly reduced compared to the activated carbon. The results of the DRS analysis show the low band gap of the synthesized photocatalyst and its applicability in the presence of visible light. To optimize the effect of the parameters, the central composite design method was used to design the experiment. The results showed that the maximum amount of COD reduction of 97.41% has been achieved at a pH of 3, the amount of photocatalyst of 1.25 g/L, and the duration of light irradiation of 45 minutes.

Elucidating physicochemical processes in the degradation of pollutants may optimize their removal from water sources. Although the photodegradation of carbamazepine (CBZ) in Advanced Oxidation Processes (AOPs) has been widely studied, there is no detailed report on the elementary steps of the kinetics. This study proposes a set of elementary steps for the AOP of CBZ, combining short-wave ultraviolet radiation (UVC), a homogeneous reagent (H2O2), and a heterogeneous catalyst (TiO2), which includes the excitation of both reagents/catalysts by UVC photons, the adsorption of CBZ by the excited TiO2, or its oxidation by hydroxyl radicals. Assuming the steady-state approximation on the intermediate products (excited TiO2, CBZ-excited TiO2 complex, and hydroxyl radicals) leads to rate laws for the degradation of CBZ, in which UVC radiation, TiO2, and H2O2 are pseudo-first-order at all concentrations or intensities and have no direct influence on CBZ pseudo-order, whereas CBZ shifts from pseudo-first-order at low concentrations to pseudo-zero-order at high concentrations. Several experiments to test the mechanism were conducted by varying CBZ, H2O2, and TiO2 concentrations and UVC radiation intensities. The measured results indeed fit the suggested mechanism for the first three, but the irradiation intensity appears to shift the CBZ influence from pseudo-second- to pseudo-first-order with increased intensities. Part of the elementary steps were changed to fit the results.

In the realm of industrial development, a variety of organic pollutants, including petroleum compounds, have emerged as persistent environmental concerns due to their non-degradable nature. To effectively address this issue, plasma technology has garnered significant attention as a promising approach for wastewater treatment, offering the capability to eliminate a wide spectrum of contaminants. This research capitalizes on Response surface methodology (RSM) to explore the independent and combined effects of key factors such as initial concentration, pH, applied voltage, and time on the degradation of a specific pollutant known as PNP, utilizing non-thermal discharge plasma technology. The outcomes of this investigation unveiled several noteworthy trends. Enhancing the initial pH, applied voltage, and reaction time while reducing the initial concentration exhibited a positive influence on the removal efficiency. Additionally, the study examined the interactions among these variables, revealing both antagonistic and synergistic effects. Specifically, antagonistic relationships were observed between initial concentration and initial pH, initial concentration and applied voltage, as well as applied voltage and time. On the other hand, a synergistic effect was noted between initial concentration and time. By employing an optimization approach, the optimal conditions for achieving PNP degradation were determined to be as follows: an initial concentration of 50 mg/L, pH of 9.7, applied voltage of 13.75 kV, and a reaction time of 8 min, resulting in an impressive removal efficiency of 96.503%. The findings of this study underscore the immense potential of non-thermal discharge plasma technology and the utilization of RSM in advancing the optimization of advanced oxidation processes for effective wastewater treatment.

Background and Objective: Vacuum Ultraviolet (VUV)-based advanced oxidation is a new category of advanced purification processes, so this study aimed to compare the efficiency of VUV and Ultraviolet-C (UVC) processes in combination with H2O2 and PMS in degrading Remdesivir. Materials and Methods: The photoreactor was investigated with VUV and UVC lamps in combination with H2O2 and PMS for Remdesivir degradation. Also, the effect of variables such as solution pH, H2O2 dose, Remdesivir concentration, the presence of radical scavengers and anions, as well as hydraulic retention time was considered in the continuous process of Remdesivir removal. Results: The findings showed that the optimal pH in the processes of VUV, UVC, and their derivatives was equal to 7. By adding 1 mM of PMS and H2O2 to the VUV process, the degradation efficiency of Remdesivir was increased from 92.2 ± 0.4% to 98.3 ±2.1% and 100 ± 0.3%, respectively, after 30 min. Also, in the UVC process combined with H2O2 and PMS, the degradation efficiency reached 77.8 ± 1.5 and 85.2 ± 1.3% after 40 min, respectively. The degradation kinetics in the examined processes were as follows: VUV/H2O2 > VUV/PMS > VUV > UVC/H2O2 > UVC/PMS > UVC. The hydroxyl radical was the main reactive oxygen species that led to the decomposition of Remdesivir. The continuous operation of VUV/H2O2 showed that the removal efficiency of Remdesivir reached 94.7 ±0.8% after 40 min. Conclusion: Considering the high rate of Remdesivir degradation by adding H2O2, the VUV/H2O2 process can be introduced as an efficient technology for the removal of antiviral drugs.

Pesticides usage has tremendously increased to enhance crop production; however some pesticides are toxic and harmful to human health and the environment. This review discusses the eco-toxicological impacts of pesticides on the environment. This study extensively evaluates various sustainable remediation technologies such as advanced oxidation processes (AOPs), electrochemical processes, membrane separation, and adsorbent types (carbon nanotubes, carbon nanofiber, carbon aerogel, graphene oxide, carbon dot, biochar, biosorbents, polymers, metal-organic framework, and nanocomposite) that are used for removal of toxic pesticides from aqueous bodies. Further, various equilibrium isotherm and kinetic models that are used for understanding the mechanisms along with challenges in the techniques are discussed. From the studies, it is observed that the nanocomposites could degrade and remove pesticides efficiently due to their unique properties, making them promising adsorbents for water and wastewater remediation. This review will be an inclusive paper for readers to easily define research gaps and develop novel treatment methods for removing pesticide-contaminated waters.

Abstract Interfacial solar evaporation is regarded as the promising technology to mitigate freshwater scarcity. However, when polluted water is used, toxic pollutants might accumulate in the bulk water. Herein, we report the production of Ni‐MOF nanorod from waste poly(ethylene terephthalate) and fabricate bifunctional Ni‐MOF‐based evaporators. Owing to high light absorption and photothermal conversion, low thermal coefficient, and vaporization enthalpy, it shows an exciting evaporation rate (2.25 kg m−2 h−1) with good flexibility/durability, rated as one of most advanced evaporators. Density functional theory and COMSOL results show that the combination of nickel‐sites in Ni‐MOF and local heat plays a crucial role in peroxymonosulfate activation to produce reactive species. Thereby, it exhibits the high degradation activity of tetracycline. In outdoor, the freshwater production reaches 5.54 kg m−2 per day, and the tetracycline removal efficiency is 91%. This work provides a sustainable approach to produce solar evaporators capable of freshwater production and contaminant degradation.

Struvite (MAP, magnesium ammonium phosphate hexahydrate, MgNH4PO4.6H2O) precipitation-aided Fenton's OXidation (MAPFOX process) was explored in the treatment of high-strength real sheep slaughterhouse wastewater (RSSW) for the first time under a comprehensive soft-computing-based modeling study. The experimental results showed that under the highest-efficiency conditions (chemical combination of MgCl2.6H2O + NaH2PO4.2H2O, a molar ratio of Mg2+:NH4+-N:PO43–P = 1.2:1:1, a reaction pH of 9.0 ± 0.10, [NH4+-N]0 = 240 ± 20 mg/L, and a reaction time of 15 min), MAP precipitation could effectively remove more than 80 %, 60 %, 55 %, and 70 % of color, total chemical oxygen demand (TCOD), soluble COD (SCOD), and ammonium nitrogen (NH4+-N) from the raw RSSW. The results of the Fenton's oxidation used as the post-treatment unit of the proposed MAPFOX system indicated that the integrated advanced oxidation process (AOP) was able to reduce the residual pollutant levels in the MAP-pretreated RSSW to the relevant discharge standards. Under the subsequent condition of [Fe2+]0 = 90 mmol/L, [H2O2]0 = 180 mmol/L, reaction pH = 3.25, and total reaction time = 60 min, more than 97 % of color, TCOD, SCOD, and NH4+-N could be removed from the RSSW via the Fenton's oxidation after the MAP-based physicochemical treatment. According to SEM micrographs, surface morphology of dehydrated struvite exhibited irregular-shaped and overlapping sharp-edged particles of various sizes with an average size of about 50.9 μm. The Fourier Transform Infrared (FTIR) spectroscopy confirmed the active functional groups and type of bonds for the high-strength RSSW-oriented struvite (heated) within the spectral range of 4000–450 cm−1. Thermogravimetric Analysis (TGA), Derivative Thermogravimetry (DTG), Differential Thermal Analysis (DTA), and Differential Scanning Calorimetry (DSC) of the dehydrated struvite revealed that the weight loss occurred in three temperature zones, the maximum weight loss rate of 0.252 mg/min was recorded at around 224 °C and at time of 20.83 min, and the sample had strong endothermic and medium exothermic peaks at about 241 °C and 679 °C, respectively. The predictive successes of the implemented soft-computing approaches were benchmarked in terms of various statistical goodness-of-fit parameters. The performance assessment indices corroborated the superiority of the support vector machines-Pearson VII universal kernel function (SVM-PUKF)-based model (correlation coefficient (CC) = 0.9999–1.0000), mean absolute error (MAE) = 0.0222–0.0389 %, mean absolute percentage error (MAPE) = 0.0270–0.0506 %, root mean squared error (RMSE) = 0.0258–0.0415 %, coefficient of variation of RMSE (CV(RMSE) = 0.0003–0.0008, Nash–Sutcliffe efficiency (NSE) = 0.9998–1.000, Legates and McCabe's index (LMI) = 0.9894–0.9952) over other data-intelligent models in predicting the pollutant removal efficiencies. The computational results also indicated that the narrowest uncertainty bands (±1.96Se = 0.0537–0.1483 %) and the lowest amounts of expanded uncertainty (U95 = 3.1224–5.3124 %) values for all efficiency sets were achieved for the applied SVM-PUKF-based strategy. This study demonstrated the first-ever and successful application of the proposed MAPFOX process in treatability of the RSSW and capability of the implemented soft-computing strategy in modeling a highly nonlinear treatment system.

The zinc oxide (ZnO) nanoparticle on a two - electron oxygen reduction reaction is a particularly promising candidate for in-situ application. Herein, we prepared the Cd doped ZnO nanocomposites through a simple hydrothermal method. The X-ray diffraction (XRD) analysis has been carried out to confirm the structure and size of the nanomaterial. The optical absorption and energy gap of the prepared nanoparticles have been identified by UV–vis-NIR studies. Photoluminescence (PL) studies on the synthesized nanomaterials confirm the characteristic existence of blue and green emission bands. Fourier transform infrared (FTIR) spectroscopy has been studied on the ZnO nanoparticles to analyze the -OH and CO-O vibrations. The structural and surface morphology analysis was inferred by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) microanalysis. Cd doped ZnO nanocomposites are environmentally friendly and can be utilized to quickly remove contaminants from wastewater. The findings from the adsorption equilibrium fit the Brunauer-Emmett-Teller (BET) model very well, showing multi-layer adsorption. The photodegradation studies on Cd doped ZnO nanocomposites were carried out, which is an advanced oxidation process widely used for methylene blue removal. Therefore, the higher photocatalytic performance revealed that Cd doped ZnO nanocomposites could be a promising photocatalyst for environmental remediation applications.

The mineralization kinetics of petroleum refinery wastewater (PRW) released from Iraq's AL-Smood petroleum refinery plant by a solar photo-electro-Fenton (SPEF) process were evaluated. A new configuration of the electrochemical system was adopted in which an electro-Fenton (EF) cell was combined with a solar collector thermo-reactor and operated the system at a batch recirculation mode. The EF cell is a tubular electro-Fenton reactor composed of two concentric porous graphite electrodes provided with an air diffuser. Impacts of operating factors such as current density, Fe2+ concentration, and NaCl addition on the efficiency of COD removal (RE %), specific energy consumption (SEC), and pseudo-first-order rate constant (kapp) were investigated. Results showed that increasing each current density, Fe2+, and NaCl concentrations improves the removal efficiency and Kapp with a reduction in SEC. All COD decays followed pseudo-first-order kinetics with a regression fitting (R2) greater than 0.99. Results confirmed the ability of the present system to decrease COD from 375 ppm to 30 ppm within 90 min when it is operated at an applied current density of 30 mA/cm2, Fe2+ concentration of 0.5 mM, and NaCl addition of 1 g/L in which an SEC value not exceeded 73.4 kWh/kg COD is needed.

In present work, one-pot preparation of Fe3O4/NiFe2O4 nanocomposite catalyst was investigated using iron rust waste as precursor. The synthesis was performed by coprecipitation followed by hydrothermal method using iron rust waste as iron precursor, and NiCl3 as nickel precursor. The catalytic properties of material were tested on methyl violet catalytic oxidation. The results from x-ray diffraction, x-ray photoelectron spectroscopy, and scanning electron spectroscopy confirmed the formation of Fe3O4/NiFe2O4 without any other impurities. Particle size analysis using and transmission electron microscopy revealed that the use of iron rust waste gave the smaller particle's size of the nanocomposite compared to the use of Fe(III) precursor. The sample expressed the smaller saturation magnetization, but higher specific surface area and porosity are supporting feature to increase the catalytic activity in methyl violet oxidation. The optimum degradation efficiency of >95% is expressed for degradation of methyl violet (MV) with concentration range of 10–50 ppm. Reusability of the nanocomposite was demonstrated as there is insignificant change of the activity until 5th usage. The research revealed the potency of iron rust waste to be source of functional material and can be notified as a potential strategy for environmental management and application.

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.