Search

Among different pollutants, organic dyes, phenolic compounds, and antibiotics are three types of hazardous contaminants that have become serious environmental issues. This work deals with the synthesis of new visible-light responsive CsM 0.25 W 1.75 O 6 (M = Ni, Co, Mn, Cu) compounds with a solid-state reaction induced defect pyrochlore structure followed by crushing in a ball mill. The prepared materials were characterized using scanning electron microscopy, X-ray diffraction with Rietveld refinement, X-ray photo-electron spectroscopy, differential thermal analysis, and nitrogen adsorption-desorption measurements at low-temperature. The optimized CsNi 0.25 W 1.75 O 6 (CsNiWO-2) compound was tested for its photocatalytic abatement efficient for several contaminants including methylene blue, phenol, as well as levofloxacin and isoniazid antibiotics. The influence of the various key aspects, such as photocatalyst dosage and hydrogen peroxide concentration, on the degradation efficiency of CsNiWO-2 was examined. The degradation efficiency of CsNiWO-2 (0.6 g L−1) towards methylene blue, phenol, levofloxacin, and isoniazid in the presence of H 2 O 2 (0.06 mol L−1) was 81.4, 47.9, 84.6, and 37.4 %, respectively. Thus, the developed material demonstrates promising properties to degrade methylene blue and levofloxacin. Also, the mechanism and comprehensive schemes for the photooxidation of methylene blue and levofloxacin were elucidated over CsNiWO-2. The present research potentially contributes to designing efficient defect pyrochlores for wastewater treatment under visible light irradiation. [Display omitted] • CsM 0.25 W 1.75 O 6 (M = Ni, Co, Mn, Cu) materials were prepared by a solid-state method. • First report of CsM 0.25 W 1.75 O 6 (M = Ni, Co, Mn, Cu) photodegradation activity. • Grinded CsNi 0.25 W 1.75 O 6 displayed highest activity in the degradation of MB and LFX. • Potential of CsNi 0.25 W 1.75 O 6 photocatalyst for wastewater treatment under LED light. [ABSTRACT FROM AUTHOR]

Singlet oxygen (1O2) has attracted great attention owing to its superior comprehensive oxidizing performance and extensive application in dealing with ever‐growing environmental pollution. However, the efficient catalytic generation of 1O2 is very challenging due to the low catalytic activity of most catalysts and the generation of oxygen‐containing radicals in the catalytic reaction. Herein, C‐doped Co nanoparticles (CoNPs) supported on porous carbon (C─Co/C) as highly reactive and selective 1O2‐producing catalysts are demonstrated for efficient catalytic oxidation of recalcitrant organics via activation of peroxymonosulfate (PMS). The doped C 2p orbitals can accept Co 3d electrons, thereby weakening the Co─O bonding between Co and PMS or other oxygen‐containing intermediates such as *SO4, *OH, *OOH, and *O. The adsorption and cleavage energy of PMS on Co nanoparticle is reduced from 8.09 to 4.64 eV by C doping. The energy barrier of the *OOH to 1O2 step is also lowered significantly, thereby kinetically improving the activity for the generation of 1O2. The C─Co/C catalysts promotes the efficient and 100% selective generation of 1O2 with high modified kinetic model (K) values of 457.0 and 94.5 µmol s−1 g−1 for rhodamine (RhB) and 2,4‐dichlorophenol (2,4‐DCP), respectively. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDH) exhibit macromolecular behavior due to their layered structure, providing unique properties that make them suitable for various applications. Their crystal structure allows for intercalation of various species, demonstrating excellent thermal stability and mechanical strength. Synthesis methods, such as co-precipitation, ion exchange, and hydrothermal techniques, enable the preparation of well-defined LDH macromolecules with tailored characteristics. These materials find applications in catalysis, drug delivery systems, environmental remediation processes, and energy storage devices. Our research described here an LDH material based on nickel, copper, and aluminum was synthesized, characterized and used as a catalyst for the oxidation of Acetaminophen (Ac) using H2O2. Our materials were created using the co-precipitation process at a constant pH. Fourier Transform infrared spectroscopy (FTIR), Raman spectroscopy (RAMAN), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray Spectroscopy (EDS) were used to characterize the synthesized material. The material was crystalline and devoid of contaminants, according to the characterization. The CuNiAl-CO3 material was used to catalyze the elimination of the Ac (1 g.L−1) from an aqueous solution. The amount of the LDH, the molar ratio (oxidant/pollutant), the temperature, and the pH were among the experimental factors that were modified to get superior results. The kinetic analysis revealed that using 3 g L−1 of LDH with a molar ratio (oxidant/pollutant) of 2.5 for 3 h at room temperature and without modification of the pH of the solution resulted in a complete degradation of the Ac, and that our LDH performed best in acidic conditions. [ABSTRACT FROM AUTHOR]

A novel organic-inorganic photocatalyst like layer structured graphitic carbon nitride (g-C3N4 or CN) hybrid with strontium titanate (SrTiO3 or STO) was prepared by a precipitation-sonication technique for photocatalytic activity. The crystal phases, morphologies, elemental composition, optical properties, and porous structure of the prepared pristine and STO/CN hybrid composite were measured using various physicochemical characterizations. It is indicated that STO nanospheres were effectively loaded on the g-C3N4 nanosheets, resulting in the STO/CN hybrid composite, high surface area, enhanced visible-light absorption, enhancing photoinduced charge separation and suppressing the recombination rate. Furthermore, the 3 wt% of g-C3N4 composited STO (STO/CN-3) catalyst demonstrated higher photocatalytic activity than pristine STO in 100 min under white light irradiation, reaching the degradation efficiency of 92.66 % and 93.31 % toward methylene blue (MB) and tetracycline (TC), respectively. The improved photocatalytic activity of STO/gCN hybrid composite could be ascribed to the synergistic effect between STO and CN with strong interfacial interaction facilitating efficient charge separation and inhibiting the charge recombination of photogenerated electron-hole pairs. Moreover, a possible photocatalytic mechanism has been proposed for the degradation of MB and TC. Besides, the excellent photocatalytic performance, STO/CN-3 nanocomposite also exhibits outstanding photostability under the current factors, suggesting that they are suitable for practical applications. [ABSTRACT FROM AUTHOR]

Heterogeneous catalytic ozonation (HCO) emerges as a promising chemical industrial wastewater treatment solution, offering enhanced ozone utilization and reduced secondary pollutants. However, challenges in scaling HCO arise from a limited understanding of the catalytic mechanisms of metal oxides, particularly in generating active ozone sites. Here, we demonstrated the improvement of catalytic ozonation efficiency by enhancing the covalent bonding between FeO in Fe/Co spinel oxides. This alteration exploits the stronger electron‐donating capacity of Fe (II), enhancing FeOM bonds and electron enrichment at iron sites, leading to a significant reduction in the activation energy for ozone. Pilot experiments demonstrated a 75.3% COD removal efficiency and a threefold increase in ozone utilization efficiency compared to pure ozone system for chemical industrial wastewater treatment. This study not only advances our understanding of spinel oxides in ozone catalysis but also opens new avenues for practical HCO applications in water treatment. [ABSTRACT FROM AUTHOR]

Peroxymonosulfate‐(PMS) based advanced oxidation processes (AOPs) are effective in degrading refractory organic pollutants in water. The unique internal chemical tunability of Prussian blue analogues (PBAs), a type of metal–organic framework materials (MOFs), makes them promising catalysts for PMS‐AOPs. However, the pristine PBA is limited in practical application due to its structural instability and easy leaching of metal ions. To this end, various methods have been developed to enhance the recycling and catalytic performance of PBAs. In this paper, the recent advances in the modification and composite strategies of PBA catalysts are systematically reviewed. PBA modification by the regulation of synthesis conditions and postsynthesis treatment, along with composite strategy involving metal and nonmetal‐based materials are introduced. The structural morphology improvement, physical and chemical property adjustment, vacancy design, and crystal surface modulation of PBAs induced by these modification and composite strategies are discussed in depth. In addition, the performance of the modified and composite catalysts to activate PMS for organic pollutant degradation is demonstrated. The radical pathway via SO4•−, •OH, and O2•−, nonradical pathway through 1O2, electron transfer process and high‐valent metal–oxo species, or a combination of radical and nonradical pathways are revealed in PMS‐AOPs with PBAs and their derivatives as catalysts. [ABSTRACT FROM AUTHOR]

The mechanism of persulfate activation is introduced, and the production pathway of sulfate radical is reviewed・ Sulfate radical can be produced by different persulfate activation methods, such as thermal activation, alkali activation, UV activation, transition metal ion activation, microwave activation, metal oxide activation, etc・, and can effectively treat organic wastewater・ The advanced oxidation technology based on sulfate radical has a good application prospect, but it still has many problems and some limitations ・ In the future, it is necessary to increase the purification experiments of advanced oxidation process based on sulfete free radicals in real organic wastewater and develop new catalysts with low price, high efficiency, stability and easy recovery, so as to explore the catalytic performance of natural organic compounds and reduce application costs and secondary pollution. [ABSTRACT FROM AUTHOR]

Heterogeneous Advanced Oxidation Processes (H-AOPs) are considered a new process for removing emerging pollutants. In this case, the high reactivity of hydroxyl radicals is used to degrade persistent organic pollutants. This review explores the state-of-the-art catalyst for hydroxyl radical generation in AOPs. As a parasite reaction, chloride ions appear in alkaline conditions and compete with the active sites. The theoretical foundation of catalyst performance is explored, focusing on the fundamental principles that govern the efficiency and mechanism of hydroxyl or chloride radical production. The synthesis and electronic modification sections explore the modifications of catalysts. It discusses key methodologies for catalyst preparation, with a particular emphasis on electronic modification that enhances both activity and stability. Finally, laboratory and pilot applications highlight the effectiveness of novel or modified catalysts in different scenarios. These last findings provide insights into the future directions for research and application, aiming to draw attention to the gap between laboratory studies and real-world implementations. [ABSTRACT FROM AUTHOR]

A pilot-scale investigation of ozonation combined with electrolysis (E-O3) was performed to treat concentrated wastewater from a reverse osmosis system from the printing and dyeing industry. It was found that E-O3 only exhibits an efficiency advantage after the removal of carbonate ions. The synergy of ozone and electrolysis lies not only in the generation of hydroxyl radicals, but also in the degradation of organic compounds. Moreover, the combination of electrolysis and ozonation has an inhibitory effect on the decrease in pH, which plays an important role in the synergistic generation of hydroxyl radicals. This pilot-scale study holds reference significance for the engineering applications of the E-O3 technology. [ABSTRACT FROM AUTHOR]

The increasing pollution of water bodies, due to the constant release of highly toxic and non-biodegradable organic pollutants, requires innovative solutions for environmental remediation and wastewater treatment. In this study, the effectiveness of different Advanced Oxidation Processes (AOPs) for the purification of water contaminated with Rhodamine B (RhB) dye at a concentration of 5 mg/L were investigated and compared. Using the classical ozonation strategy as a benchmark treatment, the research showed over 99% degradation of RhB within 4 min in a laboratory-scale batch setup with a capacity of 0.2 L. In contrast, a "chemical-free" process exploiting ultrasound (US) technology achieved a 72% degradation rate within 60 min. Further experiments were conducted using a pilot-scale rotor-stator hydrodynamic cavitation (HC) reactor on a 15 L solution leading to 33% of RhB removal in the presence of hydrogen peroxide (H2O2) at 75 mg/L. However, the use of an innovative cavitational reactor, which hybridizes HC with cold plasma, showed remarkable efficiency and achieved 97% degradation of RhB in just 5 min when treating a 5 L solution at an inlet pressure of 20 bar in a loop configuration. In addition, a degradation rate of 58% was observed in a flow-through configuration, emphasising the robustness and scalability of the HC/electrical discharge (ED) plasma technology. These results underline the potential of hybrid HC/ED plasma technology as an intensified and scalable process for the purification of water, as it offers a catalyst- and oxidant-free protocol. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The extensive application of neonicotinoid insecticides (NNIs) has resulted in its worldwide detection in waters, leading to risks to human health and ecology safety. Presently, various remediation techniques for NNIs have been developed. However, the critical reviews concerning the remediation approaches for the elimination of NNIs from water are limited. Considering tremendous efforts have been made in the research topic of NNIs removal recently, this study systematacially reviewed the current advances on NNIs remediation approaches, including adsorption, Fenton, ozonation, photodegradation, sulfate radicals based-advanced oxidation processes (AOPs), electrochemical AOPs, percarbonate-based AOPs, periodate-based AOPs, microbial remediation, and phytoremediation. Moreover, NNIs removal by these methods have been critically discussed, compared, and analyzed. Furthermore, mechanisms of different treatment processes have been summarized in detail. Finally, the challenges and perspectives have been proposed. This study highlights the current progresses on NNIs removal technologies and proposes the future research needs in this area, which will provide support to further researches to halt the NNIs contamination. [ABSTRACT FROM AUTHOR]

The management of landfill leachate presents a significant environmental challenge, necessitating a comprehensive and dynamic treatment approach. This comprehensive review delves into the critical issue of landfill leachate treatment, exploring its environmental impact, treatment technologies, regulatory frameworks, and the path towards sustainable management practices. This review explores the complexities of landfill leachate, emphasizing the need for sustainable waste management practices to safeguard environmental health. Our analysis highlights the evolution of conventional and advanced treatment technologies designed to mitigate these risks, focusing on membrane technologies, advanced oxidation processes, and the promising potential of emerging techniques such as adsorption and biological nutrient removal. These technologies are evaluated for their efficiency, cost implications, and sustainability impacts, underscoring the challenges and opportunities within the current landscape of leachate treatment. The review aims to provide insights into designing efficient and effective treatment systems through a detailed analysis of conventional and advanced treatment methods. By examining a case study in Changsha City, the effectiveness of a comprehensive treatment system integrating various technologies is demonstrated. The review underscores the interconnectedness of human activities, environmental health, and waste management, emphasizing the importance of a holistic approach. It stresses the continuous improvement of leachate treatment technologies and the adoption of sustainable practices to reduce the environmental footprint of landfills. Ultimately, it calls for integrating multiple treatment processes, economic considerations, and readiness to address future challenges in landfill leachate treatment, contributing to the advancement of sustainable waste management practices. [ABSTRACT FROM AUTHOR]

Due to enormous quantities with hazards and complexity in nature is a big challenge for effective treatment of wastewater from pharmaceutical processes including herbal extraction through conventional methods of distillation. The situation is further aggravated in countries facing high rising population, urbanization, and industrialization resulting in the generation of industrial wastes. The study has been carried out in the herbal extraction industry by conducting stage-wise sampling of ETP based on the conventional method and further coupled with ozonation as an advanced treatment to comply with regulatory standards. Additionally, the same process was studied that implementing the best available technology (BAT) by providing ETP with advanced technology modules such as MBR (membrane bioreactor) + RO + O3 has not only resulted in compliance with standards but also reuse of treated wastewater into the process and utilities has been proved to be techno-economically a viable and sustainable option. Modifying existing aeration tanks and advanced oxidation through ozone injection post-biological treatment has resulted in COD and BOD reduction of 96.42% and 99.0% respectively. Whereas in the case of MBR + RO + O3, the values of pH, BOD, COD, TSS, and sulfide have been observed as 8.32, 2.0 mg.L-1, 14.0 mg.L-1, 1.0 mg.L-1 and 0.0 mg.L-1 respectively and 98% recovery of treated effluent, thus saving 44 KL.day-1 of freshwater resulting into significant financial benefits of Rupees 12.59 lacs annually, which otherwise was outsourced through tankers. [ABSTRACT FROM AUTHOR]

Heterogeneous advanced oxidation processes (AOPs) based on non-radical reactive species are considered as a powerful technology for wastewater purification due to their long half-lives and high adaptation in a wide pH range. Herein, we fabricate surface Co defect-rich spinel ZnCo2O4 porous nanosheets, which can generate ≡CoIV=O and 1O2 over a wide pH range of 3.81–10.96 by the formation of amphoteric ≡Zn(OH)2 in peroxymonosulfate (PMS) activation process. Density functional theory (DFT) calculations show Co defect-rich ZnCo2O4 possesses much stronger adsorption ability and more electron transfer to PMS. Moreover, the adsorption mode changes from terminal oxygen Co–O–Co to Co–O, accelerating the polarization of adjacent oxygen, which is beneficial to the generation of ≡CoIV=O and 1O2. Co defect-rich ZnCo2O4 porous nanosheets exhibit highly active PMS activation activity and stability in p-nitrophenol (PNP) degradation, whose toxicity of degradation intermediates is significant reduction. The Co defect-rich ZnCo2O4 nanosheet catalyst sponge/PMS system achieved stable and efficient removal of PNP with a removal efficiency higher than 93% over 10 h. This work highlights the development of functional catalyst and provides an atomic-level understanding into non-radical PMS activation process in wastewater treatment. [ABSTRACT FROM AUTHOR]

The residues of pharmaceutical compounds are often resistant to degradation, causing an environmental problem. Our research aimed to perform a study of the photocatalytic and photoelectrocatalytic degradation of non-opioid analgesic paracetamol and some of the non-steroidal anti-inflammatory drugs (NSAIDs) (ketoprofen, naproxen, diclofenac, and ibuprofen). Semiconductor WO3, Fe2O3, and WO3/Fe2O3 photocatalysis using solar energy lamps were applied for this purpose. As a result of the photocatalytic processes, high decomposition efficiency was obtained for ketoprofen (97%) and naproxen (70%). Low photodegradation yields were achieved for diclofenac. Under the used measurement conditions, both paracetamol and ibuprofen were not degraded. [ABSTRACT FROM AUTHOR]

Organic dye pollutants present in wastewater pose a significant global challenge. Among pollutants, the synthetic dye Rhodamine B (RB) stands out due to its non-biodegradable nature and associated neurotoxic, carcinogenic, and respiratory irritant properties. Extensive research has been conducted on the efficacy of adsorption and photodegradation techniques for the removal of RB from wastewater. While adsorption and advanced oxidation processes (AOPs) have gained considerable attention for their effectiveness in recent years, the underlying behaviors and mechanisms of these technologies remain incompletely understood. Therefore, a comprehensive summary of recent research progress in this domain is imperative to clarify the basics and present the up-to-date achievements.This review provides an in-depth exploration of the fundamentals, advancements, and future trajectories of RB wastewater treatment technologies, mainly encompassing adsorption and photodegradation. This work starts with a general introduction of outlining the sources, toxicity, and diverse applicable removal strategies. Subsequently, it thoroughly examines crucial techniques within non-photochemical, photochemical, and adsorption technologies, such as UV light assisted AOP, catalyst assisted AOP, ozonation, Fenton system, electrochemical AOP, and adsorption technology. The primary objective is to furnish a broad overview of these techniques, elucidating their effectiveness, limitations, and applicability. Following this, the review encapsulates state-of-the-art computational simulations pertaining to RB adsorption and interactions with clays and other adsorbents. Lastly, it delves into column adsorption of RB dye, and elucidates various influencing factors, including bed height, feed concentration, pollutant (RB) feeding or flow rate, and column regeneration. This panoramic review aims to provide valuable insights into suitable techniques, research gaps, and the applicability of non-photochemical, photochemical, and adsorption technologies in the treatment of wastewater containing RB dye.

The biochar carrier was constructed based on pomelo peel biomass, and the surface crystallization, organic polymer protection and pyrolysis cascade strategies were used to effectively embed Co and CoO species in biochar to achieve efficient degradation of tetracycline organic. [Display omitted] The development of highly catalytic activity, low-cost and environmentally friendly catalysts is crucial for the use of advanced oxidation processes (AOPs) to treat organic pollutants. In this study, to reduce costs, enhance catalytic activity and avoid secondary pollution form metal ions, pomelo peel was used as raw material, combined with surface crystallization, carbon layer protection and heat treatment technology to effectively construct AOPs catalyst that can efficiently activate peroxymonosulfate (PMS) to degrade harmful organic pollutants. Under the optimal conditions, the Co/BC-PMS system can degrade about 100 % of tetracycline (TC, a spectral antibiotic) within 5 min, and the degradation rate of TC can still reach 100 % even if Co/BC (cobalt anchored on biochar) was reused for 6 times. The Co/BC-PMS system can resist complex environmental conditions, including acidic solution, alkaline solution, coexisting ions, different water quality, and is universal for the degradation of most organic pollutants. The integrated purification column with Co/BC as the core realizes the continuous and complete degradation of organic pollutants and has the ability of practical application. Radical capture and monitoring combined with density-functional-theory calculations confirmed that the Co(111) and amorphous CoO sites in Co/BC are the key to driving PMS to degrade organic pollutants, Co/BC can efficiently adsorb PMS and promote the dissociation of PMS into highly active OH, SO 4 − and 1O 2 , and these reactive oxygen species jointly promote the degradation of organic pollutants. This study provides experimental support and theoretical insights for the design of efficient AOPs catalysts, and plays an important role in promoting the development of AOPs. [ABSTRACT FROM AUTHOR]

[Display omitted] Peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) are attractive approaches for solving the global problem of water pollution, due to the generation of highly-active reactive oxygen species (ROS). Therefore, highly-efficient PMS activation is crucial for promoting the catalytic degradation of environmental pollutants. Here, bimetallic CoGeO 2 (OH) 2 nanosheets with abundant surface hydroxyl groups (CGH) were synthesized via a simple hydrothermal route for PMS activation and degradation of various organic contaminants for the first time. The abundant surface hydroxyl groups (≡Co–OH/≡Ge–OH) could promptly initiate PMS to generate highly-active species: singlet oxygen (1O 2), sulfate radicals (SO 4 ·−) and hydroxyl radicals (HO•), while the asymmetric electron distribution among Co–O–Ge bonds derived from the higher electronegativity of Ge than Co further enhances the quick electron transfer to promote the redox cycle of Co2+/Co3+ and Ge2+/Ge4+, thereby achieving an outstanding catalytic capability. The optimal catalyst exhibits nearly 100 % catalytic degradation performance of dyes (Methylene blue, Rhodamine B, Methyl orange, Orange II, Methyl green) and antibiotics (Norfloxacin, Bisphenol A, Tetracycline) over a wide pH range of 3–11 and under different coexisting anion conditions (Cl−, HCO 3 –, NO 3 –, HA), suggesting the excellent adaptability for practical usage. This study could potentially lead to novel perspectives on the remediation of water areas such as groundwater and deep-water areas. [ABSTRACT FROM AUTHOR]

Antibacterial agents like triclosan (TCS, 5-chloro-2-(2,4-dichlorophenoxy)phenol) and triclocarban (TCC, 3-(4-chlorophenyl)-1-(3,4-dichlorophenyl)urea are commonly found in everyday household and personal care products. Both compounds are widely distributed in the environment, acting as potential sources of contamination to ecological safety and human health problems such as algal growth-inhibiting effects; bioaccumulation in algae; endocrine-disrupting effects; development of microbial resistance, and formation of toxic degradable products. Environmentalists are increasingly concerned about the emergence of these micro-organic pollutants in the environment. This review paper focuses on the current state of knowledge, occurrence, effects, detection, and removal techniques for triclosan and triclocarban in the environment. People are exposed to these antibacterial agents when transported from wastewater treatment plants, air, dust, household products, and personal care products. These exposures lead to bioaccumulation in human tissue and biomagnification in the food chain. Surveys have revealed that TCC and TCS under sunlight formed toxic and persistent constituents like chlorinated phenols, methyl triclosan (MTCS), and biphenyl ethers. Different analytical approaches have been used to detect and degrade these compounds to ensure their complete removal in the environment but are found inadequate to effectively eliminate TCS and TCC. Advanced oxidation processes (AOPs) have shown to be promising in successfully breaking down TCS and TCC, considering material and energy consumption and emission of carbon (IV) oxide. Therefore, robust strategies such as electrochemical and nanomaterial methods should be implemented to determine and sequester TCS and TCC in the environment. Furthermore, regulatory bodies and environmental experts should be concerned about the fate and nanocatalyst photodegradation of triclosan and triclocarban in the environment. [ABSTRACT FROM AUTHOR]

The discharge of untreated electroplating wastewater could lead to the formation of toxic metal-organic complexes that is harmful for the environment. There are several processes reported to treat electroplating wastewater such as chemical precipitation, adsorption, coagulation and flocculation, ion exchange, electrocoagulation, membrane filtration, advanced oxidation process and biorecovery. These methods provide the possibility to capture different toxic metals and remove organic pollutants. The combination of different processes together has shown higher efficiencies in removing a wide range of contaminants than single treatment systems. The main challenge is identifying the highest treatment performance and most cost-efficient process. This review provides an overview of treatment technologies for electroplating wastewater and describes the strengths and drawbacks among them. The efficiency of different systems and kinds of pollutants removed, along with a comparison between these systems have been analysed. When comparing the treatment technologies, it is hard to identify the most efficient one as each method has been successful in removing certain pollutants that has not been recovered from the other methods. Therefore, making the decision on identifying the best treatment technology depends on the objective of the treatment and the targeted pollutants. Furthermore, the cost of different technologies has been evaluated based on literature to have a brief look at cost differences between the technologies. When targeting removal of heavy metals, the highest cost of treatment has been reported at around 4.45 $/m3 for the adsorption method employing nano zero valent iron (nZVI). While the lowest cost of treatment has been reported at about 0.35 USD/m3 employing an adsorption method followed by electrodeposition. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ru monoatoms are stabilized on LDH, which is proved by HAADF-STEM and XANES. • Ru@NiFe-LDH/ PMS system showed excellent degradation efficiency to SMX. • Ru@NiFe-LDH maintains its excellent catalytic activity over a wide pH range. • High-valent species (Ru(V) = O) as the main active species in PMS-based AOPs. • DFT calculations indicate the formation of Ru-PMS* complexes intermediate product. The application of single-atom catalysts (SACs) to advanced oxidation processes (AOPs) based on peroxymonosulfate (PMS) has attracted considerable attention. However, the catalytic pathways and mechanisms underlying these processes remain unclear. In this study, NiFe-LDH was synthesized and single Ru atoms were stably loaded onto it by forming Ru–O–M (M=Ni or Fe) bonds (Ru@NiFe-LDH). This was demonstrated using high-angle annular dark-field scanning TEM (HAADF-STEM) and X-ray absorption fine structure spectra (XANES). The Ru@NiFe-LDH/PMS system showed a high catalytic reactivity (100 % sulfamethoxazole degradation in only 30 min), high stability (97 % reactivity was maintained after continuous operation for 400 min), and wide pH suitability (working pH range 3–11) for AOPs. The crucial roles of the high-valent species (Ru(V) = O) and 1O 2 in this reaction were verified. Density functional theory (DFT) calculations revealed that electron transfer produced a positively charged Ru. This enhances the adsorption of negatively charged PMS anions onto the Ru monoatomic sites, thereby, causing the formation of Ru-PMS* complexes. This study implies that the structure–function relationship between organic compounds and SACs plays a significant role in PMS-based AOPs, and provides a comprehensive mechanism for the role of high-valent species in heterogeneous Fenton-like systems. [ABSTRACT FROM AUTHOR]

Background: LaCuMnOx (LCMO) perovskite was designed as an effective catalyst to activate peroxydisulfate (PDS) to remove bisphenol A (BPA) in hypersaline wastewater. Results: In the LCMO/PDS system, BPA (10 mg/L) was removed completely and the mineralization degree reached 74.9% in the presence of 0.12 g/L catalyst and 1.2 mM PDS. The BPA removal efficiency was still almost 100% even after five cycles. Metal ion leakage also indicated the stability of the catalytic system. •OH, SO4•−, 1O2, and O2•− all contributed to BPA removal, and O2•− accounted for the greatest contribution. The presence of oxygen vacancies (Vo··) on the surface of the catalyst was important for PDS activation and the formation of active species. In addition, the system could still maintain outstanding performance even when [Cl−] and [SO42−] were 100 g/L. CO32− and HCO3− inhibited BPA degradation greatly, even at very low concentrations. The inhibitory effect was related to changes in the pH of the solution caused by the addition of CO32− and HCO3−. This effect could be eliminated by adjusting the pH. Conclusion: The system showed excellent catalytic performance, stability, and inorganic anion tolerance, indicating its potential for application in hypersaline wastewater treatment. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Organic dye pollutants present in wastewater pose a significant global challenge. Among pollutants, the synthetic dye Rhodamine B (RB) stands out due to its non-biodegradable nature and associated neurotoxic, carcinogenic, and respiratory irritant properties. Extensive research has been conducted on the efficacy of adsorption and photodegradation techniques for the removal of RB from wastewater. While adsorption and advanced oxidation processes (AOPs) have gained considerable attention for their effectiveness in recent years, the underlying behaviors and mechanisms of these technologies remain incompletely understood. Therefore, a comprehensive summary of recent research progress in this domain is imperative to clarify the basics and present the up-to-date achievements. This review provides an in-depth exploration of the fundamentals, advancements, and future trajectories of RB wastewater treatment technologies, mainly encompassing adsorption and photodegradation. This work starts with a general introduction of outlining the sources, toxicity, and diverse applicable removal strategies. Subsequently, it thoroughly examines crucial techniques within non-photochemical, photochemical, and adsorption technologies, such as UV light assisted AOP, catalyst assisted AOP, ozonation, Fenton system, electrochemical AOP, and adsorption technology. The primary objective is to furnish a broad overview of these techniques, elucidating their effectiveness, limitations, and applicability. Following this, the review encapsulates state-of-theart computational simulations pertaining to RB adsorption and interactions with clays and other adsorbents. Lastly, it delves into column adsorption of RB dye, and elucidates various influencing factors, including bed height, feed concentration, pollutant (RB) feeding or flow rate, and column regeneration. This panoramic review aims to provide valuable insights into suitable techniques, research gaps, and the applicability of nonphotochemical, photochemical, and adsorption technologies in the treatment of wastewater containing RB dye. [ABSTRACT FROM AUTHOR]

Single-atom catalysts (SACs) exhibit outstanding catalytic activity due to their highly dispersed metal centers. Activating persulfates (PS) with SACs can generate various reactive oxygen species (ROS) to efficiently degrade emerging organic contaminants (EOCs) in aqueous environments, offering unique advantages such as high reaction rates and excellent stability. This technique has been extensively researched and holds enormous potential applications. In this paper, we comprehensively elaborated on the synthesis methods of SACs and their limitations, and factors influencing the catalytic performance of SACs, including metal center characteristics, coordination environment, and types of substrates. We also analyzed practical considerations for application. Subsequently, we discussed the mechanism of SACs activating PS for EOCs degradation, encompassing adsorption processes, radical pathways, and non-radical pathways. Finally, we provide prospects and outline our vision for future research, aiming to guide advancements in applying this technique. HIGHLIGHTS Summarized the synthesis methods of single-atom catalysts and limitations.; Discussed the factors influencing the performance of single-atom catalysts and practical factors.; Elucidated the mechanism of SACs activating PS for EOCs degradation and prospects for the future.;

Abstract Clean water is a necessity for all life to survive and flourish. However, natural waters are being continuously contaminated due to the release of waste streams in water. Hence, it is important to remove pollutants from wastewater to fulfill human needs. Conventional treatment methods are neither efficient nor economical for wastewaters that especially contain refractory toxic pollutants. This requires novel techniques like Advanced oxidation processes (AOPs), that may successfully degrade persistent micropollutants more efficiently. In this study, an azo dye Acid Red 1 was removed by three AOPs, namely Photocatalytic oxidation, Ozonation and Photocatalytic Ozonation, by employing heterogenous catalysts. TiO2 was used as photocatalyst, whereas Fe-Zeolite has been further added as Ozonation catalyst. The study revealed that photocatalysis degraded only 28% Acid red dye after 15 min, whereas for ozonation, the degradation percentage was 95% in same time. In combined photocatalytic ozonation process using TiO2, 95% degradation was achieved in just 9 min and treatment time further reduced to 5 min when Fe-zeolite was added. Optimization studies for initial concentration, UV intensity and catalyst loading were performed. Finally, rate constants and Electrical Energy per Order (EEO) values were determined for all AOPs, and mechanism was proposed.

Abstract Bisphenol A (BPA) is widely used in manufacturing various consumer products and detected in various water sources. Epidemiological studies reveal a correlation between BPA exposure and metabolic system disorders, including obesity, diabetes, and cardiovascular issues. Experimental studies further support these findings by demonstrating the adverse impact of BPA on physiological processes, contributing to the onset of metabolic disorders. Despite its detrimental health effects, removal of BPA poses a formidable challenge due to its intricate molecular structure, resistant to conventional water treatment methods. To address this, our review comprehensively summarizes human BPA exposure data and in vivo/in vitro mammalian studies, offering a comparative analysis of treatment technologies with a focus on documented health impacts. Biological treatment removes BPA efficiently, however, maintaining ideal bacterial populations and controlling biomass concentration provide difficulties that affect operational stability and scalability. In the meantime, despite the high removal rate of physiochemical treatment such as absorption and membrane technology, they consume significant amounts of energy and generate chemical residues that could retain toxicity. In this regard, a hybrid photocatalytic membrane emerges as a promising solution, forming the basis for our comparative evaluation in wastewater treatment and water purification. By effectively degrading BPA and mitigating the BPA toxicity, the photocatalytic membrane helps reduce human exposure to this harmful compound. This technology presents a viable approach to tackle BPA-related environmental challenges while shedding light on its intricate metabolic effects on human health.

Antibiotic resistant bacteria (ARB) with antibiotic resistance genes (ARGs) can reduce or eliminate the effectiveness of antibiotics and thus threaten human health. The United Nations Environment Programme considers antibiotic resistance the first of six emerging issues of concern. Advanced oxidation processes (AOPs) that combine ultraviolet (UV) irradiation and chemical oxidation (primarily chlorine, hydrogen peroxide, and persulfate) have attracted increasing interest as advanced water and wastewater treatment technologies. These integrated technologies have been reported to significantly elevate the efficiencies of ARB inactivation and ARG degradation compared with direct UV irradiation or chemical oxidation alone due to the generation of multiple reactive species. In this study, the performance and underlying mechanisms of UV/chlorine, UV/hydrogen peroxide, and UV/persulfate processes for controlling ARB and ARGs were reviewed based on recent studies. Factors affecting the process-specific efficiency in controlling ARB and ARGs were discussed, including biotic factors, oxidant dose, UV fluence, pH, and water matrix properties. In addition, the cost-effectiveness of the UV-based AOPs was evaluated using the concept of electrical energy per order. The UV/chlorine process exhibited a higher efficiency with lower energy consumption than other UV-based AOPs in the wastewater matrix, indicating its potential for ARB inactivation and ARG degradation in wastewater treatment. Further studies are required to address the trade-off between toxic byproduct formation and the energy efficiency of the UV/chlorine process in real wastewater to facilitate its optimization and application in the control of ARB and ARGs.

Pharmaceutically active compounds are the most widely produced and consumed consumer products that pose a substantial threat to the environment and living organisms owing to their pharmacokinetics, side effects, and contraindications. In this study, the degradation of chloroquine (CQ), a popular antimalarial and recently proposed COVID-19 drug, was investigated under electron beam (EB) irradiation of aqueous solutions. Both the hydroxyl radical and hydrated electron generated in the radiolysis of water contribute to the degradation of CQ in aqueous solution. The overall removal efficiency for 125 mg·L-1 of the CQ solution under EB treatment is reported to be >80% at neutral pH at a maximum irradiation dose of 7 kGy. Removal efficiency is further favored by acidic and slightly alkaline conditions where reactions with hydroxyl radicals and hydrated electrons are favored, respectively. Additionally, increments in the applied dose resulted in the increased removal efficiency for the same concentration of CQ. Conversely, the removal efficiency decreased with increasing concentration of CQ at the same irradiation dose. The initial solution pH, applied irradiation dose, and initial pollutant concentration play an important role in the EB-induced degradation of CQ by influencing the available oxidizing and reducing species. The chemical oxygen demand (COD) and total organic carbon (TOC) were not significantly decreased during the treatment process and indicated the formation of organic byproducts, which were not further degraded under the current experimental conditions.

The current study aims to degrade Procion Golden Yellow H-R through ultrasound-induced cavitation coupled with various oxidants. A comprehensive investigation was conducted to examine the impact of parameters, specifically pH, power, and frequency, on the extent of degradation. The primary aim was to optimize degradation by solely utilizing a cavitation reactor where only 23.8% degradation was observed under the established optimum conditions of pH 2.5, frequency of 22 kHz, and power of 200 W. The investigation of the combined process of cavitation with H2O2, Fenton reagent (H2O2/Fe2+), NaOCl, and potassium persulphate (KPS) was subsequently conducted under optimized conditions. The combined operations greatly enhanced degradation with the use of H2O2 loading of 0.1 g/L leading to 53.3% degradation and the H2O2/Fe2+ ratio of 1:0.25 resulting in 94.6% degradation, while the NaOCl quantum of 0.075 g/L yielded 90% degradation and the KPS quantity of 2 g/L resulted in 97.5% degradation in the specific combinations. A toxicity test on two bacterial strains, Staphylococcus aureus and Escherichia coli, was carried out using the original dye solution and after treatment. The various individual and combination processes were compared using the parameters of cavitational yield and total treatment cost. The study elucidates that combining ultrasonic cavitation with KPS is an effective method for treating wastewater containing Procion Golden Yellow H-R dye, especially when implemented at a larger scale of operation. [ABSTRACT FROM AUTHOR]

The textile industry contributes significantly to the expansion of the world economy, however, it is also notorious for producing large amounts of trash and harming the environment. Effective waste management techniques depend on having a thorough understanding of the forms and makeup of waste from the textile sector. The objective of this paper is to study effluent wastewater technologies to efficiently treat and control the wastewater produced during textile production operations. It is well known that the textile industry generates vast amounts of wastewater, some of which may be contaminated with heavy metals, chemicals, dyes, and organic compounds. This effluent can have serious negative effects on the environment if it is not adequately treated, including contaminating soil and water sources, removing aquatic life, and possibly endangering human health. Due to the inclusion of dyes, heavy metals, and other chemicals, the discharge of untreated or improperly treated effluent from textile processes leads to water contamination. Textile waste can leak hazardous compounds into the environment and contaminate the soil, both of which have an impact on air quality. The environmental impact of the textile industry is further exacerbated by the energy and resource use involved in production. At several points in the textile supply chain, waste is generated. Fibre trimmings, fly waste, and yarn waste are produced during the fibre production, spinning, and weaving operations. There are numerous ways and technologies for treating wastewater, including advanced oxidation processes (AOPs), biological treatment systems, and membrane-based technologies. The formation of eco-friendly materials and advancements in recycling technology help to make the textile industry more closed-loop and sustainable. In conclusion, managing waste from the textile sector is a significant environmental concern that calls for creative solutions and environmentally friendly procedures. [ABSTRACT FROM AUTHOR]

The widespread presence and use of Bisphenol A (BPA) in aquatic environments has caused significant ecological damage. Coal gangue (CG), a byproduct of coal mining, poses a major environmental concern due to its vast land occupation and potential for pollution. A magnetic recyclable geopolymer (MnFe2O4-CGP) using coal gangue geopolymer (CGP) as the carrier was successfully synthesized and was evaluated for its ability to Fenton-like degrade BPA. The characterization techniques revealed the successful incorporation of spherical MnFe2O4 onto the CGP surface and that CGP serves as an excellent platform for the immobilization and dispersion of MnFe2O4. The degradation rate reached 100% within 60 min at pH = 5, 15 mmol/L H2O2, 0.6 g/L catalyst, and 50 mg/L BPA, significantly higher than MnFe2O4 and CGP alone. It was indicated that the degradation rate of BPA in MnFe2O4-CGP composites was 0.1121 min−1, which was consistent with the first-order kinetic model. The saturation magnetization of MnFe2O4-CGP was measured to be 10.96 emu/g, enabling convenient recovery. MnFe2O4-CGP exhibited excellent stability, as the degradation rate of BPA remained above 95% even after five reaction cycles. This efficiency may be due to the MnFe2O4-CGP induced generation of reactive radicals. Quenching and EPR radical trapping experiments unequivocally confirmed that the reactive radical was hydroxyl radical (•OH). These results indicate that MnFe2O4-CGP has potential application prospects as a magnetic recyclable geopolymer composite in Fenton-like catalysis. [ABSTRACT FROM AUTHOR]

Clean water is a necessity for all life to survive and flourish. However, natural waters are being continuously contaminated due to the release of waste streams in water. Hence, it is important to remove pollutants from wastewater to fulfill human needs. Conventional treatment methods are neither efficient nor economical for wastewaters that especially contain refractory toxic pollutants. This requires novel techniques like Advanced oxidation processes (AOPs), that may successfully degrade persistent micropollutants more efficiently. In this study, an azo dye Acid Red 1 was removed by three AOPs, namely Photocatalytic oxidation, Ozonation and Photocatalytic Ozonation, by employing heterogenous catalysts. TiO2 was used as photocatalyst, whereas Fe-Zeolite has been further added as Ozonation catalyst. The study revealed that photocatalysis degraded only 28% Acid red dye after 15 min, whereas for ozonation, the degradation percentage was 95% in same time. In combined photocatalytic ozonation process using TiO2, 95% degradation was achieved in just 9 min and treatment time further reduced to 5 min when Fe-zeolite was added. Optimization studies for initial concentration, UV intensity and catalyst loading were performed. Finally, rate constants and Electrical Energy per Order (EEO) values were determined for all AOPs, and mechanism was proposed. [ABSTRACT FROM AUTHOR]

The evaluation of the photocatalytic properties of electrospun TiO2 nanofibres (TiO2-NFs) synthesised in the same experimental conditions using two distinct precursors, tetraisopropyl orthotitanate (TTIP) and tetrabutyl orthotitanate (TNBT), with morphology and crystalline structure controlled by annealing at 460 °C for 3 h is presented. The presence of circular-shaped TiO2-NFs was corroborated by scanning electron microscopy (SEM). By using X-ray photoelectron spectroscopy (XPS), the chemical binding energies and their interactions of the TiO2 with the different incorporated impurities were determined; the most intense photoelectronic transitions of Ti 2p3/2 (458.39 eV), O 1 s (529.65 eV) and C 1 s (284.51 eV) were detected for TTIP and slightly blue-shifted for TNBT. By using energy-dispersive X-ray spectroscopy (EDS), the chemical element percentages in TiO2 were determined. Using X-ray diffraction, it was found that the annealed electrospun TiO2-NFs presented the anatase crystalline phase and confirmed by Raman scattering. Bandgap energies were determined by diffuse reflectance spectroscopy at room temperature. The photocatalytic degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide under exposure to ultraviolet light was studied using the TiO2-NFs obtained with the two molecular precursors. The results showed that the catalyst, prepared with the TTIP precursor, turned out to be the one that presented the highest photocatalytic activity with a half-life time (t1/2) of 28 min and a degradation percentage of 93%. The total organic carbon (TOC) in the solutions resulting from the 2,4-D degradation by the TiO2-NFs was measured, which showed a TOC removal of 50.67% for the TTIP sample and 36.14% for the TNBT sample. Finally, by using FTIR spectroscopy, the final chemical compounds of the degradation were identified as H2O and CO2. [ABSTRACT FROM AUTHOR]

In this study, the synthesis, characterization, and photocatalytic activity of zinc-doped cadmium aluminum ferrite ZnxCdX−1Al0.1Fe1.9O4 (X = 0,0.3) nanoparticles were investigated for the degradation of atrazine. The nanoparticles were synthesized via a sol–gel method, and their structural, morphological, and optical properties were characterized using various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and UV–Vis diffuse reflectance spectroscopy. The photocatalytic activity of the synthesized nanoparticles was evaluated under visible-light irradiation, and the influence of various parameters, such as Zn doping concentration, initial atrazine concentration, pH, temperature, catalyst dose, light intensity, and addition of hydrogen peroxide (H2O2), was investigated. The results demonstrated a significant enhancement in atrazine degradation with Zn-doped cadmium aluminum ferrite, achieving a removal efficiency of 93% compared with 75% for undoped cadmium aluminum ferrite at normal conditions. Scavenger analysis suggested that hydroxyl radicals (OH˙) played a crucial role in the photodegradation process. These findings contribute to the development of efficient and sustainable photocatalysts for the degradation of atrazine and other organic pollutants. [ABSTRACT FROM AUTHOR]

This current study explored the effect of pyrite on the treatment of chlorophenolic compounds (CP) by Fenton process with micron-sized zero-valent iron (ZVI) as the catalyst. The experiments were conducted in batch reactors with 100 mg L−1 CP, 0–0.02 M H2O2, and variable pyrite and ZVI doses (0–1 g L−1). Our findings show that while the reactor with 1 g L−1 ZVI as the only catalyst achieved only 10% CP removal efficiency due to rapid ZVI surface passivation and ZVI particle aggregation, the CP removal efficiency increased with increasing pyrite dose and reached 100% within couple of minutes in reactors with 0.8 g L−1 pyrite and 0.2 g L−1 ZVI. The CP removal was mainly driven by the oxidative treatment of CPs with some strong radicals such as hydroxyl radicals (•OH) while the adsorption onto the catalyst surface was only responsible for 10 to 25% of CP removals, depending on the type of CP studied. The positive impact of pyrite on CP removal by the ZVI/H2O2 system could be attributed to the ability of pyrite to (1) create an acidic environment for optimum Fenton process, (2) provide support material for ZVI to minimize ZVI particle agglomeration, and (3) stimulate iron redox cycling for improved surface site generation. Following oxidative Fenton treatment, the degradation intermediate products of CPs, including some aromatic compounds (benzoquinone, hydroquinone, etc.) and organic acids (e.g., acetic acid), became more biodegradable in comparison to their mother compounds. Overall, the treatment systems with a mixture of ZVI and pyrite as catalyst materials could offer a suitable cost-effective technology for the treatment of wastewater containing biologically non- or low-degradable toxic compounds such as chlorophenols. [ABSTRACT FROM AUTHOR]

Featured Application: Elimination of Emerging Pollutants (pesticides) present in effluents from industrial wastewater treatment plants. Emerging pollutants in wastewater pose significant risks to human health and wildlife, particularly due to their persistence in treated effluents from WWTPs. Very recent research has focused on developing new techniques based on advanced oxidation processes using inorganic and organic photocatalysts for treating polluted effluents under visible light. This study investigates a pesticide-removal system utilizing heterogeneous photoactive polymeric materials P2, P3, and P4. These materials, engineered as hydrophilic polymeric microparticles and functionalized with Rose Bengal, have demonstrated efficient singlet oxygen generation and first-order kinetics in the degradation of AHMPD, a pyrimidine fungicide. Given that most studies in the literature have concentrated on urban WWTPs, with less emphasis on industrial wastewater treatment, this research focused on real water samples from the effluent of an industrial WWTP in the agri-food sector, which processes large volumes of citrus and where high concentrations of AHMPD and other pesticides were detected at certain times of the year. The degradation potential of photoactive materials P3 and P4 was evaluated, achieving removal rates of AHMPD up to 85% under conditions of pH = 11 with 48 h of exposure to visible light. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is widely used in manufacturing various consumer products and detected in various water sources. Epidemiological studies reveal a correlation between BPA exposure and metabolic system disorders, including obesity, diabetes, and cardiovascular issues. Experimental studies further support these findings by demonstrating the adverse impact of BPA on physiological processes, contributing to the onset of metabolic disorders. Despite its detrimental health effects, removal of BPA poses a formidable challenge due to its intricate molecular structure, resistant to conventional water treatment methods. To address this, our review comprehensively summarizes human BPA exposure data and in vivo/in vitro mammalian studies, offering a comparative analysis of treatment technologies with a focus on documented health impacts. Biological treatment removes BPA efficiently, however, maintaining ideal bacterial populations and controlling biomass concentration provide difficulties that affect operational stability and scalability. In the meantime, despite the high removal rate of physiochemical treatment such as absorption and membrane technology, they consume significant amounts of energy and generate chemical residues that could retain toxicity. In this regard, a hybrid photocatalytic membrane emerges as a promising solution, forming the basis for our comparative evaluation in wastewater treatment and water purification. By effectively degrading BPA and mitigating the BPA toxicity, the photocatalytic membrane helps reduce human exposure to this harmful compound. This technology presents a viable approach to tackle BPA-related environmental challenges while shedding light on its intricate metabolic effects on human health. [ABSTRACT FROM AUTHOR]

Sulfate radical–based advanced oxidation processes (SR-AOPs) are renowned for their exceptional capacity to degrade refractory organic pollutants due to their wide applicability, cost-effectiveness, and swift mineralization and oxidation rates. The primary sources of radicals in AOPs are persulfate (PS) and peroxymonosulfate (PMS) ions, sparking significant interest in their mechanistic and catalytic aspects. To develop a novel nanocatalyst for SR-AOPs, particularly for PMS activation, we synthesized carbon-coated FeCo nanoparticles (NPs) using solvothermal methods based on the polyol approach. Various synthesis conditions were investigated, and the NPs were thoroughly characterized regarding their structure, morphology, magnetic properties, and catalytic efficiency. The FeCo phase was primarily obtained at [OH−] / [Metal] = 26 and [Fe] / [Co] = 2 ratios. Moreover, as the [Fe]/[Co] ratio increased, the degree of xylose carbonization to form a carbon coating (hydrochar) on the NPs also increased. The NPs exhibited a spherical morphology with agglomerates of varying sizes. Vibrating-sample magnetometer analysis (VSM) indicated that a higher proportion of iron resulted in NPs with higher saturation magnetization (up to 167.8 emu g−1), attributed to a larger proportion of FeCo bcc phase in the nanocomposite. The best catalytic conditions for degrading 100 ppm Rhodamine B (RhB) included 0.05 g L−1 of NPs, 2 mM PMS, pH 7.0, and a 20-min reaction at 25 °C. Notably, singlet oxygen was the predominant specie formed in the experiments in the SR-AOP, followed by sulfate and hydroxyl radicals. The catalyst could be reused for up to five cycles, retaining over 98% RhB degradation, albeit with increased metal leaching. Even in the first use, dissolved Fe and Co concentrations were 0.8 ± 0.3 and 4.0 ± 0.5 mg L−1, respectively. The FeCo catalyst proved to be effective in dye degradation and offers the potential for further refinement to minimize Co2+ leaching. [ABSTRACT FROM AUTHOR]

Heterogeneous Fenton technology was employed for the advanced treatment of Maotai-flavored Baijiu wastewater. Novel catalysts were prepared by loading different active ingredients (Mn, Fe, and Cu) on γ-Al2O3 using an impregnation method. The effects of active ingredient, reaction time, initial pH, H2O2 dosage, catalyst dosage, and other factors on the reaction were examined. The properties of the new catalysts were analyzed using BET analysis, XPS, and SEM. Moreover, the mechanisms of Fenton-like oxidation and its reaction kinetics were explored through experiments and analyses including GC–MS and intermediate active species scavenging by tertiary butyl alcohol (TBA) and/or para-benzoquinone. The results revealed that the most effective removal of organic matter was achieved with a Mn-Fe/Al (2:1 wt%) catalyst dosage of 30 g/100 g water, pH of 5.0, H2O2 dosage of 0.3 g/L, and reaction time of 60 min; the effluent COD value was 12 ± 1 mg/L, and the degradation rate was 65.7 ± 3%, approximately 14% higher than that of the conventional Fenton catalyst under similar conditions; moreover, the catalytic efficacy remained high after seven cycles. Kinetic analysis indicated that the heterogeneous Fenton oxidation reaction followed a third-order kinetics model, with R2 = 0.9923 and K = 0.0006 min−1. [ABSTRACT FROM AUTHOR]

The rapid growth of economics and industry has caused significant damage to the environment and shortages of energy. The field of semiconductor photocatalysis is currently obtaining a significant deal of interest due to its great potential to aid in resolving issues such as energy scarcity and environmental pollution. One of the most creative strategies for achieving electron-hole pair separation is the construction of heterojunctions, which is accomplished by connecting two semiconductors in series. The methods of charge transfer are discussed in an overview of various heterostructures, including type-II and Z-scheme. Due to its narrow advantageous band edge being placed and band gap, Ag3PO4 is the subject of intense research to induce the appropriate redox reactions. Despite its relevance, Ag3PO4 has inherent limitations such as restricted visible light response and significant charge carrier recombination. This review discussing the performance of Ag3PO4/graphene oxide-based heterojunction against numerous organic contaminants under visible light illumination. The second part of this article reviews and discusses recent findings of the degradation of wastewater pollutants. These pollutants include organic dyes, antibiotics, and other compounds. This study offers a substantial addition to our understand of the process underlying heterojunction photocatalysis as well as the development of superior heterojunction composite photocatalyst. [ABSTRACT FROM AUTHOR]

The degradation of two textile dye molecules was studied using photochemical processes, both in the absence and presence of light. Various methods were employed, including photolysis/UV, combined H2O2/UV photolysis, Fe2+/UV treatment, Photo-Fenton/UV at 350 nm and Photo-Fenton with solar irradiation. The decolorization efficiency of dyes in aqueous solution was evaluated for two specific dyes: Bromothymol Blue (BTB) and Methyl Green (MG). These experiments were carried out in batch mode. The results demonstrated a synergy between light irradiation and the presence of Fenton's reagents, such as hydrogen peroxide and divalent iron. In addition, it was demonstrated that direct solar irradiation can be used without specific devices to achieve high efficiency at low cost. In the first part, we checked the impact of the various operating parameters. Reaction efficiencies were compared for the same system in the dark and under the assistance of an artificial or solar light source. In the second part, we studied the parameters of the Photo-Fenton process, such as the initial pH of the solution, the initial concentrations of oxidant, iron catalyst, and dye under irradiation from either light source. Whereas the mere photolysis without Fenton's reagents allowed decolorization yields below 26 %, addition of the oxidant (H2O2) or the catalyst (Fe(II) species amplified the treatment efficiency. However, the presence of both H2O2 and Fe(II) under light irradiation was shown synergetic with yields ranging from 72 to 85 % depending on the dye worked and the light source: because of its broader spectrum in the UV domain, solar irradiation led to the highest decolorization yields. The above results were obtained for well-defined proportions of dye and reagents: for a 20 mg/l dye solution, Fe(II) catalyst concentration equal to 10−3 M, peroxide concentration of 5.10−2 M and a pH of 3. These conditions allowed optimal production of OH· radicals, allowing high efficiency in systems using solar irradiation. [ABSTRACT FROM AUTHOR]

Copyright of Textile Industry / Tekstilna Industrija is the property of Union of Textile Engineers & Technicians of Serbia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technology of Water Treatment is the property of Technology of Water Treatment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technology of Water Treatment is the property of Technology of Water Treatment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • The iron-based catalyst Fe-N/O@C with Fe-N 2 O 2 coordination was prepared by a simple pyrolysis process. • The Fe-N/O@C + PMS system achieves the degradation of BPA primarily through non-radical pathways dominated by 1O 2 and high-valent iron species. • The doping of O causes a change in the charge distribution of Fe-N. • DFT calculations were used for further analysis to understand the reasons behind the differences in the degradation pathways of Fe-N/O@C and Fe-N@C. Iron-nitrogen co-doped carbon materials as heterogeneous catalysts have attracted much attention in advanced oxidation processes involving peroxymonosulfate (PMS) due to their unique structure and enormous catalytic potential. However, there is limited research on the influence of different coordination structures on the central iron atoms. Through simple pyrolysis, we introduced oxygen atoms into the Fe-N coordination structure, constructing Fe-N/O@C catalysts with Fe-N 2 O 2 coordination structure, and achieved efficient degradation of bisphenol A (BPA). Quenching experiments, electron paramagnetic resonance, and electrochemical analysis indicate that compared to the free radical activation pathway of Fe-N@C, high-valent iron-oxo species (≡Fe(Ⅳ) = O) are the main reactive oxygen species (ROS) in the Fe-N/O@C/PMS system. Meanwhile, we compared the differences in the oxidation states of Fe atoms and electron density in different coordination structures, revealing the formation of high-valent iron-oxo species and the mechanism of interfacial electron transfer. Therefore, this study provides new insights into the design and development of Fe-N co-doped catalysts for resource-efficient and environmentally friendly catalytic oxidation systems. [ABSTRACT FROM AUTHOR]

The confined W 18 O 49 nanowires with Co-Vo-W asymmetric active center are constructed by surface-rich Vo coupled with single-atom cobalt. The adsorption and activation of PMS were enhanced, leading to the generation of more active free radicals (SO 4 •-, •OH, •O 2 –) and non-free radicals (1O 2) for the decomposition of micropollutants. Notably, the degradation rate of bisphenol A by Co-W 18 O 49 is 32.6 times faster than that of the W 18 O 49 monomer, significantly surpassing other transition-metal-doped W 18 O 49 composites. [Display omitted] • The Co-W 18 O 49 catalyst with Co-Vo-W asymmetric active center induced by Vo coupled with single-atom Co was synthesized. • The Co-Vo-W asymmetric active center effectively enhances PMS adsorption and activation, leading to the generation of more active free radicals and non-free radical. • The degradation rate constant of endocrine disruptors by Co-W 18 O 49 is 32.6 times faster than W 18 O 49 monomer. Enhancing the activation of peroxymonosulfate (PMS) is essential for generating more reactive oxygen species in advanced oxidation process (AOPs). Nevertheless, improving PMS adsorption and expediting interfacial electron transfer to enhance reaction kinetics pose significant challenges. Herein, we construct confined W 18 O 49 nanowires with asymmetric active centers containing Co-Vo-W (Vo: oxygen vacancy). The design incorporates surface-rich Vo and single-atom Co, and the resulting material is employed for PMS activation in water purification. By coupling unsaturated coordinated electrons in Vo with low-valence Co single atoms to construct an the "electron fountainhead", the adsorption and activation of PMS are enhanced. This results in the generation of more active free radicals (SO 4 •-, •OH, •O 2 -) and non-free radicals (1O 2) for the decomposition of micropollutants. Thereinto, the degradation rate of bisphenol A (BPA) by Co-W 18 O 49 is 32.6 times faster that of W 18 O 49 monomer, which is also much higher than those of other transition-metal-doped W 18 O 49 composites. This work is expected to help to elucidate the rational design and efficient PMS activation of catalysts with asymmetric active centers. [ABSTRACT FROM AUTHOR]

Sulfate radical-based advanced oxidation processes exhibit great potential for the degradation of organic pollutants. In this study, P-doped biochar (PBC500) was successfully synthesized by the pyrolysis of H3PO4-impregnated cow manure waste and was employed to activate peroxymonosulfate (PMS) for the elimination of 17β-estradiol (E2). The characterization results showed that the surface area, defective structure, and functional groups (C=O and phosphorus-containing groups) of biochar increased after H3PO4 modification. PBC500 exhibited high PMS activation activity and excellent E2 degradation capacity; 97.91% of 3 mg/L E2 can be removed within 90 min using 0.2 g/L PBC500 and 1 mM PMS. Based on the quenching experiments and X-ray photoelectron spectroscopy (XPS) analysis, defective structures, C=O, and P-C groups on biochar act as active sites to promote the catalytic oxidation of E2 by generating O2− and 1O2. In addition, PBC500 displayed excellent reusability, achieving 65.15% E2 degradation after three reuse cycles. Overall, this study presented a new technique that supports a high efficiency, environmentally friendly, and low cost treatment method for E2 wastewater and simultaneously provided a new option for the resource utilization of livestock waste. [ABSTRACT FROM AUTHOR]

The breakdown of dyes, which are environmentally hazardous substances and notoriously difficult to degrade, presents the main treatment challenge for wastewater from textile industries. Most advanced oxidation processes (AOPs) for dye degradation usually use costly decolorizing agents, whose residue from Wastewater Treatment Plants may be hazardous to the environment. The present study aimed to apply ultrafine bubbles (UFBs) for water AOPs to degrade textile dyes. Our most recent innovation, ultrafine bubbles, enables the production of reactive oxygen species recently introduced as oxidants in AOPs. First, the disc diffuser was optimized by introducing various flow rates of 1–5 L Per Minute (LPM) to generate UFBs with unique characteristics observed from Zeta Potential, pH, Dissolved Oxygen (DO), and Oxidation–Reduction Potential (ORP). The air UFBs using a disc diffuser with 3 LPM were selected to degrade the Navacron Ruby S-3B dye solution (1000 Pt-Co). The treatment was optimized on the coagulant dosage (0.25, 0.5, 0.75, and 1 ppm) and bubbling times (0–120 min). As a result, the UFBs were successful in degrading the Navacron Ruby S-3B dye solution, resulting in a 45% reduction in Pt-Co color scale with a bubbling time of only 120 min and minimal coagulant dosage (0.5 ppm) compared to the Navacron Ruby S-3B dye solution treatment commonly using a coagulant dosage of 1.5 ppm without UFBs. Based on FTIR, XRF, and PL analysis, we propose the AOP mechanism of hydroxyl radicals for the Navacron Ruby S-3B dye solution. It is emphasized that UFB water AOPs (UFBs–WAOPs) represent a promising alternative technology for treating textile wastewater without chemicals or decolorizing agents. Thus, the UFBs-WAOPs are economical and environmentally benign textile wastewater treatment methods. [ABSTRACT FROM AUTHOR]

Single-atom catalysts (SACs) with atomic dispersion active sites have exhibited huge potentials in peroxymonosulfate (PMS)-based Fenton-like chemistry in water purification. However, four-N coordination metal (MN4) moieties often suffer from such problems as low selectivity and narrow workable pH. How to construct SACs in a controllable strategy with optimized electronic structures is of great challenge. Herein, an innovative strategy (i.e., the "4 + 1" fabrication) was devised to precisely modulate the first-shell coordinated microenvironment of FeN4 SAC using an additional N (SA-FeN5). This leads to almost 100% selective formation of high-valent iron-oxo [Fe(IV)-O] (steady-state concentration: 2.00 × 10-8 M) in the SA-FeN5/PMS system. In-depth theoretical calculations unveil that FeN5 configuration optimizes the electron distribution of monatomic Fe sites, which thus fosters PMS adsorption and reduces the energy barrier for Fe(IV)-O generation. SA-FeN5 was then attached to polyvinylidene difluoride membrane for a continuous flow device, showing long-term abatement of the microcontaminant. This work furnishes a general strategy for effective PMS activation and selective high-valent metal-oxo species generation by high N-coordination number regulation in SACs, which would provide guidance in the rational design of superior environmental catalysts for water purification. [ABSTRACT FROM AUTHOR]