Search Results (491)

Antimicrobial resistance (AMR) constitutes a growing global threat, facilitated by the dissemination of antibiotic resistance genes (ARGs) through wastewater treatment plants (WWTPs). This systematic review, conducted following the PRISMA guidelines, compiles the risks associated with ARGs, as well as the factors that promote horizontal gene transfer (HGT) and the technologies applied for their removal. The literature shows that WWTPs act as reservoirs, where biological treatment conditions and the presence of sub-inhibitory contaminants (antibiotics, metals, and pharmaceuticals) accelerate HGT. Although conventional methods (chlorination, ozonation, UV) are effective at eliminating antibiotic-resistant bacteria (ARB), their ability to degrade persistent genetic material is insufficient. Therefore, advanced oxidation processes (AOPs) emerge as a key solution, with the photo-Fenton process standing out due to efficiently generating hydroxyl radicals, achieving the degradation of ARGs, an essential step to mitigate the spread of AMR into the environment. Full article

The rapid development of the aquaculture industry has led to increasing discharges of hypersaline and nutrient-enriched maricultural wastewater. Functional ceramic membranes have garnered significant advantages due to their exceptional chemical stability and high tailorability through surface and interface engineering. This research reviewed recent advances including the functionalization of ceramic membranes and hybrid systems coupled with advanced oxidation processes (AOPs) for enhancing degradations of nutrients and organics in maricultural wastewater treatment. Catalytic ceramic membranes enhanced removal of micropollutants including antibiotics and heavy metals. This review further systematically classified categorization of established functional ceramic membranes and synthesizes cutting-edge modification approaches for membrane fouling mitigation. Finally, this review evaluated the application prospects, challenges for scaled implementation, and proposed future research directions of functional ceramic membranes in the treatment of maricultural wastewater. Full article

Developing efficient and sustainable catalysts for advanced oxidation processes (AOPs) to remove endocrine-disrupting compounds remains a critical challenge. In this study, a defect-engineered MnFe₂O₄@SBC composite was synthesized by loading spinel MnFe₂O₄ onto sewage sludge-derived biochar (SBC) prepared at different calcination temperatures, and applied for efficient periodate (PI) activation toward bisphenol A (BPA) degradation. The catalytic performance exhibited a volcano-type dependence on calcination temperature, with MnFe₂O₄@SBC-750 achieving the highest BPA removal efficiency (98.6% within 30 min). Structural characterization revealed that MnFe₂O₄@SBC-750 possessed an optimized carbon structure with a balance between defect sites and graphitized domains. Mechanistic investigations demonstrated that multiple reactive oxygen species, including ^•OH, O₂^•−, IO₃^• and ¹O₂, were involved in BPA degradation. LC-MS analysis identified key transformation intermediates and proposed degradation pathways, while toxicity assessment confirmed reduced ecological risks after treatment. Density functional theory (DFT) calculations indicated that MnFe₂O₄@SBC significantly enhanced PI adsorption and activation by promoting interfacial electron transfer and elongating the I-O bond in IO₄⁻. Notably, MnFe₂O₄@SBC-750 exhibited the strongest electron transfer capability, attributed to the optimal regulation of defect density and graphitization degree, which facilitated π-d electronic coupling at the MnFe₂O₄-SBC interface. Overall, this work elucidates the critical role of defect regulation in spinel biochar-based catalysts for oxidant activation and provides a sustainable strategy for converting sewage sludge into high-performance catalysts for water purification. Full article

Continuous discharges from diverse industrial activities have severely degraded the water quality of the Lerma River, turning it into a major environmental, social, and public health concern. Conventional wastewater treatment processes are often insufficient for eliminating persistent and refractory organic pollutants; therefore, the implementation of advanced oxidation processes (AOPs) is increasingly required to restore water quality. In this context, the present study systematically evaluated the individual and combined effects of ozonation and electrochemical oxidation using boron-doped diamond (BDD) electrodes for the treatment of contaminated river water. Ozonation alone achieved an 89% reduction in turbidity and a 19% decrease in total organic carbon (TOC), while electrochemical oxidation reduced turbidity by 82% and TOC by 57%. Remarkably, the simultaneous application of both treatments resulted in a 98% reduction in turbidity and an 80% decrease in TOC, clearly demonstrating a strong synergistic effect. Regarding true color at 436 nm, associated with yellow chromophore compounds, removal efficiencies of 98.9%, 94.7%, and 67.3% were obtained for the combined process, electrochemical oxidation, and ozonation, respectively. Phytotoxicity tests with Lactuca sativa seeds showed no statistically significant difference in toxicity in water treated with the O₃–EO System compared to raw water. These results highlight, for the first time under real river water conditions, the superior performance of the integrated O₃–EO system as an effective strategy for the intensified degradation and partial mineralization of persistent organic contaminants, thereby underscoring its strong potential for advanced remediation of heavily polluted surface waters. Full article

Conventional wastewater treatment systems cannot effectively eliminate micropollutants such as contaminants of emerging concern (CECs). These compounds, even at trace levels, are persistent or pseudo-persistent, bioaccumulative, and potentially harmful to ecosystems and human health. Advanced oxidation processes (AOPs), based on the in situ generation of highly reactive oxygen species, have emerged as promising solutions. Peroxyacetic acid (PAA) has gained attention due to its strong oxidizing capacity, broad antimicrobial activity, environmentally benign by-products, and compatibility with different activation methods. This review provides an updated and integrated synthesis of recent advances in PAA-based AOPs for the degradation of major CEC groups, including pharmaceuticals, personal care products, pesticides, and industrial chemicals, as well as for the oxidative modification of microplastics (MPs). The review discusses several strategies for PAA activation and critically discusses removal efficiency, underlying mechanisms, and current limitations, emphasizing the gap between pollutant transformation and complete mineralization. Furthermore, the article highlights a key research need, which is the assessment of the toxicity of transformation products and their validation under realistic conditions. Overall, this review provides insight into the potential and challenges of PAA-based AOPs for sustainable water treatment. Full article

In recent years, accelerated industrialization has made water pollution a major challenge, bisphenol pollutants being one of the most typical examples. Advanced oxidation processes (AOPs) based on peroxymonosulfate (PMS) activation have been applied in environmental remediation due to their broad applicability and high pollutant removal efficiency. The key to AOPs lies in developing low-cost, highly active catalysts. This study utilized waste biomass of baijiu distillers’ grains (DSGs) as precursor to prepare biochar materials for bisphenol pollutant removal. Through high-temperature pyrolysis at 900 °C for 2 h in the presence of NaCl and KCl as activator, biochar-based materials (BC-x) were prepared, which possessed advantageous features of large specific surface area and high nitrogen doping content. When applied for typical bisphenol pollutant removal, the selected BC-900 biochar exhibited almost 100% bisphenol AF (BPAF) removal efficiency after a 30 min adsorption and following a 5 min PMS activation process under reaction conditions of 200 mg L⁻¹ of BC-900, 200 mg L⁻¹ of PMS, and 20 mg L⁻¹ of BPAF. Reactive species of sulfate radicals (SO₄⦁⁻), hydroxyl radicals (⦁OH) and singlet oxygen (¹O₂) were responsible for BPAF degradation, among which ¹O₂ played the major role. Further toxicity prediction of the BPAF degradation intermediate products implied the low ecological risk of the constructed BC-900/PMS catalytic system for BPAF removal. The findings in this study may provide useful guidance for waste biomass conversion and organic contamination remediation in water. Full article

Agricultural pesticide wastewater represents a significant environmental and public health challenge, highlighting the need for scalable and resource-efficient treatment strategies. This review adopted a PRISMA-based methodology using the Scopus and Web of Science databases, leading to the analysis of 176 peer-reviewed studies published between 2014 and 2025. The selected literature was critically examined to assess pesticide wastewater treatment technologies, including adsorption, membrane filtration (MF), advanced oxidation processes (AOPs), biological treatments, and hybrid configurations. Particular attention was given to their treatment performance, scalability from farm to district level, resource recovery potential, economic feasibility, and life-cycle assessment (LCA) implications. Among the evaluated systems, hybrid configurations combining biological processes with AOPs or MF generally showed higher removal performance, often achieving more than 80% pesticide residue removal, while offering greater adaptability and compatibility with circular biorefinery frameworks. The review identifies key opportunities for resource recovery, including methane and hydrogen production, nutrient recycling, water reuse, and chemical reclamation, thereby supporting circular bioeconomy objectives. Overall, this review proposes an integrated, multiscale circular biorefinery perspective for sustainable pesticide wastewater management and identifies research priorities for developing resilient, safe, and resource-efficient agricultural water treatment systems. Full article

Petroleum refinery wastewaters are highly recalcitrant and recognized as one of the most challenging industrial effluents requiring advanced treatment strategies. This study aims to investigate the synergistic performance of a sequential electrocoagulation (EC) and electro-Fenton (EF) process for the mineralization of this complex effluent. The EC pretreatment was optimized using response surface methodology via Doehlert design, establishing optimal conditions at pH 6.0, 0.8 A, and a 75 min electrolysis time. Under these conditions, 39% of total organic carbon (TOC) and 56% of chemical oxygen demand (COD) were removed. The quadratic polynomial model developed for the EC stage presented an excellent fit with the experimental data (R² = 0.99, R²_adj = 0.97, p < 0.05), confirming its strong predictive robustness. In order to degrade the remaining recalcitrant organic pollutants, the pretreated effluent underwent EF oxidation (0.01 M ferrous ion, 0.8 A, pH 3), leading to TOC and COD removal rates of 68% and 76%, respectively, after a 360 min electrolysis time. The integrated EC-EF process achieved an overall mineralization of 81% and an oxidation efficiency of 89%. Finally, a comprehensive evaluation of the system’s energy consumption and economic viability established a solid techno-economic baseline for this sequential approach, indicating a competitive total operating cost of USD 0.036 per gram of TOC removed. Full article

Phthalate acid esters (PAEs) are persistent organic pollutants (POPs) widely prevalent in industrial wastewater, posing significant threats to both ecological environments and human health. Although Advanced Oxidation Processes (AOPs) are recognized as efficient technologies for PAE degradation, conventional synergistic systems typically employ a simultaneous dosing mode. This approach often leads to the instantaneous quenching of excess radicals, low oxidant utilization, and imbalanced degradation kinetics. Despite its critical role in determining efficiency and costs, the dosing strategy remains an overlooked factor in current research. In this study, dimethyl phthalate (DMP) was selected as the target pollutant to evaluate a synergistic FeSO₄/H₂O₂/K₂S₂O₈ system. An innovative continuous dosing strategy was implemented to optimize radical utilization. A laboratory-scale continuous flow apparatus was developed to simulate industrial onsite conditions, enabling a systematic comparison of degradation kinetics, mineralization characteristics, and radical evolution between the two dosing modes. Results indicated that the degradation rate constant for the continuous dosing system reached 0.659 h⁻¹, representing a 21.1% increase over the simultaneous dosing system (0.544 h⁻¹). Electron Paramagnetic Resonance (EPR) analysis confirmed that the continuous dosing mode maintains a sustained and stable radical flux (^•OH and SO₄^•−) during the critical mid-stage of the degradation, effectively mitigating radical–radical quenching. When applied to real industrial wastewater (salinity: 2083 mg/L), the continuous dosing system achieved a Total Organic Carbon (TOC) removal efficiency of 86.0% at ambient temperature and initial raw water pH, outperforming the simultaneous dosing system (82.0%). GC-MS analysis further confirmed the thorough mineralization of complex organic compounds, especially those containing ester groups and aromatic rings. This research addresses a critical gap in dosing strategy studies, providing an efficient, cost-effective, and industrially viable solution for recalcitrant wastewater treatment while establishing a theoretical foundation for large-scale continuous dosing applications. Full article

Fe–carbon catalysts (FCCs) are extensively used for persulfate activation in advanced oxidation processes (PS-AOPs), an approach regarded as an efficient and cost-effective strategy for removing emerging contaminants (ECs). However, the quantitative structure–activity relationship between the degradation efficiency of ECs with diverse molecular characteristics and the microstructure of FCCs has not been clearly elucidated. This hinders the widespread practical implementation of FCCs. Herein, density functional theory (DFT)-derived molecular-descriptor-assisted machine learning models were employed to accurately predict the reaction rate constants for EC degradation in FCC-PS AOPs, mainly focusing on three aspects: performance prediction, operating condition optimization and mechanism interpretation. Additionally, DFT-derived descriptors are integrated with fabrication and operational parameters to facilitate the generative design of FCCs. The excellent fitting performance of the overall XGB model in predicting the reaction constants for EC degradation (Test R² = 0.813) highlights the notable advantages of customized hyperparameter tuning for improving predictive accuracy. Subsequently, the submodels trained using different EC clusters (derived from t-SNE and K-means clustering methods) can offer specific strategies for selecting optimal parameters of FCC-PS AOPs that target ECs with distinct properties. The interpretability of the model was improved by using SHAP values and partial-dependence plots to clarify the internal relationships of the ML “black box”. Overall, a feasible and generalizable ML model is proposed to facilitate a paradigm shift in the inverse design of FCCs for the degradation of specific ECs. Full article

Acid Black 1 (AB1), a recalcitrant disazo dye from the textile industry, poses a severe threat to aquatic ecosystems owing to its resistance to biological treatment. Although ferrate(VI) (${\mathrm{K}}_2\mathrm{Fe}{\mathrm{O}}_4)$ and plasma-based advanced oxidation processes have shown promise for dye remediation, the effect of treatment sequence on synergistic mineralization remains largely unaddressed. Nano-ferrate(VI) (nano-Fe(VI), ${\mathrm{K}}_2\mathrm{Fe}{\mathrm{O}}_4$) synthesized via the Solution Plasma Process (SPP) was integrated with Gliding Arc Plasma (GAP) in a sequential hybrid system, with nanoscale morphology and ${\mathrm{K}}_2\mathrm{F}\mathrm{e}{\mathrm{O}}_4$ composition confirmed by FE-SEM and EDS. pH, molar ratio, and temperature were systematically optimized for the standalone nano-Fe(VI) process, and synergistic performance was evaluated via Synergy Effect Factor (SEF) analysis. Optimization identified pH 7.0, [AB1]:[Fe(VI)] = 1:0.9, and 45 °C as optimal, achieving 90.24% decolorization within 12 min. The sequential nano-Fe(VI)–GAP configuration achieved the highest mineralization efficiency of 58.7%, outperforming standalone nano-Fe(VI) (36.0%), standalone GAP (16.0%), and simultaneous application (37.8%), with SEF values of 1.3 and 1.2 for mineralization and decolorization. This is the first study to quantify treatment sequence effects in a nano-Fe(VI)–GAP system via SEF analysis. The proposed system eliminates intermediate pH adjustment while achieving superior mineralization, offering a practical AOP framework for refractory textile wastewater treatment. Full article

Pollution by persistent organic pollutants (POPs) constitutes an environmental and public health crisis of planetary scale due to their toxicity, persistence, and capacity for bioaccumulation in ecosystems. Given the limitations of conventional methods, which are often costly or generate hazardous byproducts, advanced oxidation processes (AOPs) have emerged as critical alternatives for the terminal destruction of these compounds. However, a persistent gap remains between laboratory-scale innovations and their real industrial application. To address this issue, the study employs a systematic and quantitative bibliometric analysis of the scientific literature produced between 2000 and 2026. A total of 5911 documents indexed in Scopus were analyzed using specialized tools such as R Studio (bibliometrix) 2026.04.0+526 and VOSviewer (1.6.20) to map productivity, impact, and the intellectual structure of the field through co-occurrence networks and international collaboration. The results demonstrate exponential growth in research, with an annual rate exceeding 18%. China leads scientific production with 109 publications, while Spain and France record the highest impact per article, with averages of 217.5 and 213.5 citations respectively, underscoring the influence of their researchers as theoretical and methodological benchmarks. Authors such as Malato (Spain) and Oturan (France) act as central nodes of international collaboration, accumulating thousands of citations in areas such as solar photocatalysis and electro-Fenton processes. The analysis confirms that solar photocatalysis and electrochemical processes are the most effective AOP families, consistently reporting degradation efficiencies above 85–90%. Wastewater treatment is identified as the primary research driver, while advanced catalyst design has evolved into a niche technical specialization. Journals such as Chemosphere and Science of the Total Environment have consolidated as the main dissemination channels for this research. Full article

Biochar (BC)-activated peracetic acid (PAA)-based advanced oxidation processes (AOPs) were increasingly considered as cost-efficient and eco-friendly water treatment technologies for the removal of organic pollutants. However, the specific role of intrinsic carbon, nitrogen species and structure properties played in activation mechanism is still vague. In this study, the waste tea residues-based biochar (WTBC) was prepared by thermal carbonization and applied to activate PAA for the degradation of bisphenol A (BPA). The product carbonized at 800 °C (WTBC800) possessed larger specific surface area (342.57 m²/g), more abundant porous structure and massive defects state (I_D/I_G = 3.53), and exhibited a superior activation performance with 83.7% BPA removal within 120 min. Adsorption and non-radical oxidation pathways [e.g., the mediated electron transfer process (ETP) and singlet oxygen (¹O₂) generation] were evidenced to play the dominant roles in the BPA degradation through the formation of metastable complex WTBC-PAA*. The graphitic carbon, functional nitrogen species, defects structure and persistent free radicals (PFRs) in WTBC were proposed to contribute to the activation of PAA. Overall, relatively higher dosages of WTBC (0–0.5 g/L) and PAA (0–1.5 mM) facilitated the BPA degradation. The solution pH and water matrix (e.g., Cl⁻, NO₃⁻, HCO₃⁻ and SO₄²⁻) presented a negligible effect on the BPA degradation in WTBC/PAA system. This study not only proposes a sustainable approach for organic pollutants removal in wastewater, but also promotes the resource re-utilization of agricultural waste. Full article

This study investigates a combined advanced oxidation process (AOP) utilizing UVA-LED irradiation (365 nm) for the degradation of sucralose (SUC), a complex artificial sweetener that poses a challenge for wastewater treatment due to its resistance to conventional methods. A sequential treatment strategy was employed. The initial step utilized UVA-activated persulfate (PS) at varying dosages (0.12–0.5 g/L) and UVA fluence rate (ranging from 20 to 100% of nominal output). The influence of natural water components (bicarbonate, chloride, sulfate, and nitrate) on PS activation was systematically analyzed. Notably, the substantial pH decrease during oxidation opened the possibility of replacing an amount of PS with the less expensive and more environmentally friendly hydrogen peroxide (H₂O₂) in the subsequent Fenton reaction. This second step employed a stoichiometric dosage of H₂O₂ (2.12 g/g COD) and varying Fe²⁺ concentrations (0.05–0.2 g/L), achieving a 95% overall mineralization within 60 min. The combined process incurred an approximate cost of 2.5€ per m³. This research contributes to the development of more effective and environmentally friendly wastewater treatment strategies for emerging contaminants. Full article

This study evaluates the pH-dependent ozonation of 2,6-dichloro-1,4-benzoquinone to optimize sustainable oxidation strategies for water treatment. Experiments were conducted over a wide pH range under controlled temperature and ozone dosage. DCBQ was fully degraded within minutes following first-order kinetics, regardless of pH. Acidic to neutral systems experienced a progressive pH decrease due to the formation of oxygenated transformation products, whereas strongly alkaline conditions remained stable due to buffering effects. Aromaticity removal followed a second-order kinetic and increased with pH, reflecting enhanced aromatic ring cleavage under alkaline conditions. Color was rapidly eliminated for all tested pH values, while turbidity remained low at pH ≤ 10 but increased under extreme alkalinity due to colloidal aggregation. While previous studies have examined the influence of pH on ozone reaction pathways, its combined effect on ozonation performance and gas–liquid mass transfer remains largely unexplored. Dissolved ozone measurements enabled estimation of the gas–liquid mass transfer coefficient, which decreased linearly with increasing pH, revealing a direct coupling between pH-controlled ozone reactivity and transfer efficiency. Overall, pH 9–10 was identified as the optimal operational range, balancing effective aromaticity removal, ozone stability, and minimal turbidity, thus providing practical strategies for the treatment of chlorinated quinones in water. Full article