The practical application of the Feammox for nitrogen removal is challenging in the presence of high amounts of oxygen and organic carbon. This study presents a novel approach to address this issue which involves enhancing biological nitrogen removal in a magnetic zeolite modified intermittently aerated sequential biological reactor (MZeo-IASBR). The MZeo-IASBR demonstrated excellent performance, achieving 99.09% NH₄⁺-N and 89.12% TN removal efficiencies. The relative abundances of Proteobacteria, Planctomycetota, and Chloroflexi at the phylum level and Delftia and Pirellula at the genus level increased with the addition of NZ@Fe₃O₄, when compared to the microbial community analysis results of the IASBR with no addition of supplements and Zeo-IASBR with the addition of natural zeolite. The genera Acinetobacter and Bdellovibrio were mainly observed in the MZeo-IASBR system, and Acinetobacter may be related to the Feammox process. The combination of NZ@Fe₃O₄ and intermittent aeration under low oxygen levels promoted the aggregation of aerobic denitrifying bacteria and iron-reducing bacteria, which predominately removed nitrogen through the integration of simultaneous nitrification and denitrification (SND), Feammox, anammox, and NDFO processes. The MZeo-IASBR represents a promising strategy for advanced nitrogen removal in wastewater treatment, offering considerable supports for the practical application of Feammox processes.

Per- and poly-fluoroalkyl substances (PFASs), a class of synthetic chemicals with exceptional chemical and thermal stability, have emerged as persistent environmental contaminants with significant bioaccumulative potential, posing substantial risks to ecosystems and human health. Although the production of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) has been phased out across the world, these compounds persist ubiquitously in all kinds of environmental compartments, with marine ecosystems serving as their ultimate sink. Through a search process, this review identified 420 articles published from September 2004 to September 2024 that systematically examined the distribution patterns and ecotoxicological effects of PFOA and PFOS in marine environments, particularly focusing on their bioaccumulation and ecotoxicity through marine trophic webs. While numerous physico-chemical approaches for remediation of PFAS have been proposed, their practical implementation is limited by substantial economic costs, excessive energy requirements, and low mineralization efficiency. In this context, microbial degradation emerges as a promising, eco-friendly alternative for mitigation of PFAS. Recent advancements in microbial degradation pathways and mechanisms for PFOA and PFOS are critically assessed, while emphasizing the current limitations and prospects of bioremediation strategies in marine environments. Furthermore, potential solutions and outline future research directions are proposed to enhance the efficacy of biological approaches for management of marine PFAS contamination.

Clogging of zero-valent iron (ZVI) is among the most prominent technical bottlenecks limiting its application in long-term groundwater remediation. In this study, three ZVI species with different oxygenated anion modifications on the surface—micron ZVI (mZVI), oxalated mZVI (OX-mZVI), and phosphorylated mZVI (P-mZVI)—were selected to conduct a comparative study on the clogging problem during remediation of nitrobenzene-contaminated groundwater. The clogging degree (Φ_C) was innovatively employed to quantify ZVI clogging, and the clogging mechanisms of influencing factors were uncovered by analyzing changes in Φ_C, reactivity, volume expansion, iron valence state, and iron corrosion product (FeCP) species. Results revealed that the clogging resistance of ZVI decreased in the following order: P-mZVI > OX-mZVI > mZVI. The reduction process of nitrobenzene controlled the increase of Φ_C, and the reduction of NO₃⁻—a groundwater background ion—served as an indicator for clogging stage changes. Surface chemistry analysis revealed that the increase of Φ_C originated from the volume expansion effect of FeCPs. Iron corrosion increased the Fe(III) content, producing Fe₃O₄ and FeOOH, which roughened the ZVI surfaces and formed dense agglomerates via crystal expansion, causing chemical clogging by occupying pore space. Overall, enhancing the electron selectivity and surface hydrophobicity of ZVI using surface modification methods can enhance its anti-clogging performance.

Ozone (O₃) has become a major air pollutant worldwide, posing an alarming threat to public health. However, whether the exposure to O₃ induces liver and lung damage remains unclear, alongside the underlying mechanisms. In this study, the mice were exposed to environmentally-relevant concentrations of O₃ for 30 d, alongside the systemic analysis of the injuries in lungs and livers. The results revealed that O₃ exposure could reduce weight gain and induce histopathological damage in both lungs and livers, accompanied by dysregulated oxidative stress-related genes and elevated pro-inflammatory factors. Additionally, the lung microbiome analysis demonstrated that the microbial abundance was decreased and community structure was altered, and it was indicated by the network analysis that the complexity of the microbial network was diminished. Besides, the aspartate aminotransferase (AST) activity, malondialdehyde (MDA), and Fe²⁺ levels were found to be elevated after O₃ exposure by the hepatic profile assessment, accompanied by depleted glutathione (GSH) both in liver and plasma. These alterations were associated with a ferroptosis process in the liver, and it was confirmed by lipidomics that the most significantly impacted processes were ferroptosis-related. Additionally, multi-omics mediation analysis demonstrated that lung injury could mediate liver lipid dysregulation through lung microbiota. These findings provide novel mechanistic insights into the toxicological mechanism of O₃ via the lung-liver axis.

Understanding the characteristics of O₃ precursor contributions over multiple years is crucial for designing effective O₃ control strategies over the Pearl River Delta (PRD) region of China. In this study, a deep learning-based response surface model (DeepRSM) was developed and applied over the PRD (DeepRSM-PRD) to identify and quantify the main features of O₃ regimes and regional contributions in the core PRD over multiple years (2019–2021). The Out-of-Sample (OOS) validation results indicated that DeepRSM-PRD effectively predicted the nonlinear response of O₃ to emission controls, maintaining validity across non-training periods. Our study revealed that O₃ generation was sensitive to volatile organic compounds (VOC) in the core PRD in 2019, with nitrogen oxides (NO_x)-limited regimes emerging in most major cities in 2020 and 2021. Further investigation into source contributions showed that in our model domain, O₃ formation in central cities of the PRD was primarily driven by local contributions and was susceptible to influence from nearby cities. With small emission reductions, VOC contributions predominantly drive O₃ production in Guangzhou and Shenzhen. However, NO_x emissions were identified as the primary contributors in all central city receptors when anthropogenic emissions were removed, sharing 59.5%–69.3% in 2019, 64.4%–72.3% in 2020, and 62.75%–73.2% in 2021. Our results highlight the need for a high focus on NO_x emissions control in the core PRD. In addition, for Guangzhou and Shenzhen, VOC reduction also plays a crucial role in the initial stages of modest emission reductions.

Coking wastewater is complex and highly toxic, with conventional treatment technologies often struggling with low degradation efficiency, long treatment durations, high costs, and limited resilience to variable wastewater characteristics. Three-dimensional electrochemical system (3DES) has emerged as a promising alternative for treating coking wastewater. By incorporating particle electrodes, 3DES expands the reaction surface area, enhancing mass transfer and improving pollutant degradation efficiency. Although previous studies have focused on the treatment performance of 3DES, a comprehensive analysis covering its mechanisms, electrode materials, operational parameters, and hybrid treatment strategies for coking wastewater treatment is still lacking. This review aims to fill that gap by systematically examining the advantages of 3DES in improving degradation efficiency, enhancing biodegradability through electrochemical-microbial interactions, and addressing current limitations. Additionally, it highlights future research directions, including optimizing particle electrode materials, exploring underlying mechanisms, developing kinetics models, and scaling up industrial applications. This review offers valuable insights into the sustainable and effective treatment of industrial wastewater from the coking industry.

Controlling pollution from per- and polyfluoroalkyl substances (PFAS) is a global challenge due to their toxicity, chemical stability and environmental persistence. Persulfate-based advanced oxidation processes (PS-AOPs) have emerged as a promising technology for degrading these persistent contaminants. However, the distinct physicochemical properties of PFAS lead to significant differences in the efficacy and mechanisms of PS-AOPs for PFAS removal, necessitating in-depth classification studies. This review critically examines the environmental fate and accumulation patterns of PFAS, focusing on PS-AOPs as a viable remediation strategy. Key contributions include: 1) Sorting out the migration and transformation patterns of PFAS in the environment; 2) Demonstration of PS-AOP’s superiority over the advanced reduction process (ARP) for PFAS degradation; 3) A systematic analysis of recent advancements in various PS-AOPs, encompassing their mechanisms, influencing factors, and system characteristics; 4) An in-depth evaluation of how PFAS structure, particularly chain length and functional groups, affects degradation efficiency; 5) Three integrated AOPs/ARPs strategies providing actionable insights to address PFAS contamination. Collectively, this review offers actionable insights for optimizing AOPs and ARPs, with implications for advancing PFAS remediation technologies.

Chemical absorption with amine-based solvents was treated as a promising route approach for carbon dioxide (CO₂) capture from industrial flue gases. The heat-stable salts (HSS) degraded from amine species is unavoidable and detrimental for CO₂ capture. To solve this problem, 17 porous materials, including anion-exchange resins, macroporous adsorption resins, and activated carbon, were selected for the purification of the hazardous HSS to regenerate the biphasic solvents. The purification performance was thoroughly assessed through experimental tests that examined the effects of various factors, including temperature, flow rate, and pH. Among the materials tested, the macroporous adsorption resin (NKA-9) demonstrated the highest purification efficiency, achieving an adsorption efficiency 92.0% for NO₃^-, and an overall efficiency of 51% for HSS removal. The experimental tests showed that pH was the most significant factor. The decreasing pH value was detrimental to HSS purification. Additionally, a multi-step purification process combining anion exchange resin, activated carbon, and macroporous adsorption resin was evaluated. The multi-stage process effectively removes 82.98% HSS and 62.44% Fe³⁺ ions. The presented work holds significant importance for controlling the HSS concentration in amine-based solvent and maintaining the long-term efficient operation of CO₂ capture process.

The extensive use of antibiotics causes the abundant antibiotic residuals in the environment, further accelerating the transfer of antibiotic resistance genes (ARGs). ARGs pose a high risk to public health and environmental ecosystems. Pollutants and ARGs coexist in various environments such as livestock farms, landfills, constructed wetlands, etc. As a sink of various pollutants, wastewater treatment plants cannot completely remove antibiotics and ARGs, as well as provide a habitat for ARGs accumulation and transfer. In addition to antibiotics, numerous non-antibiotic pollutants, such as nanomaterials, disinfectants, non-antibiotic pharmaceuticals and microplastics, have also been reported to drive ARGs dissemination, especially their conjugative transfer. These non-antibiotic pollutants could induce bacterial oxidative stress, redistribute energy for metabolic pathways and upregulate the expression of plasmid-related genes. To fully understand the fate and risk of ARGs in ecosystems, it remains urgent to emphasize and fill the gap in the role and mechanism of non-antibiotic pollutants in facilitating ARGs transfer. Therefore, this review systematically summarizes the contribution of non-antibiotic pollutants to the accumulation and spread of ARGs and their regulatory mechanisms. More efforts could be paid to microbial behaviors and interactions under the stress of multiple non-antibiotic pollutants. It provides a holistic insight into the potential ecological risks of non-antibiotic pollutants and their resulting ARGs transfer, which probably facilitates the development of effective control strategies for resistance.

This study investigated the effects of biochar (BC), H₃PO₄-modified biochar (BP) and KH₂PO₄-modified biochar (BK) on heavy metals (HMs) passivation and the distribution of antibiotic resistance genes (ARGs) and metal resistance genes (MRGs) during anaerobic digestion (AD). Characterization results revealed that the application of BK significantly decreased the mobility of Cr, Cu, and Pb, attributing to metal phosphate precipitation formation. EEM-PARAFAC and 2D-FTIR-COS analysis showed that the C–O stretching, polysaccharide-like structures, N-contain substance or carboxylic reacted faster after adding biochar. Biochar addition promoted the synthesis of fluorescent and humic-like components, and accelerated humification process, thus showing a greater complexation ability for HMs. In BK treatments, most detected ARGs abundance were reduced with efficiencies of 85%–96%, and MRGs abundance, such as phrT, yieF, chrR, etc., were significantly declined by more than 90%. Biochar addition directly reduced MRGs abundance by improving the immobilization degree of HMs. Biochar addition inhibited horizontal gene transfer (HGT) facilitated by mobile genetic elements (MGEs) and reduced co-selective pressure by HMs, thereby decreasing ARGs abundance. Biochar stimulated growth of HMs tolerant bacteria, such as Bacillus, Romboutsia, Clostridiales, etc., which functioned well in HMs immobilization. P-loaded biochar as additive is recommended in AD to mitigate ARGs distribution and reduce HMs risks.

A multiobjective optimization (MOP) control method for integrated urban drainage systems (UDSs) was proposed to mitigate the impact of overflow pollution on ecosystems. Existing research often targets single rainfall events, individual objectives, or isolated facilities, lacking a comprehensive, long-term strategy. To address this, the proposed method incorporates long-term rainfall data to optimize performance across key system components in the UDSs, including drainage pipelines, pumping stations, detention pipelines, intelligent diversion wells (IDWs) and sewage treatment plants (STPs). This MOP approach dynamically coordinates infrastructure to reduce combined sewer overflows (CSOs) and pollutant loads while balancing operational costs and facility performance. Applied to a case study of Yuhang District, Hangzhou, China under a six-month rainfall sequence, the method achieved average CSOs reduction rates of 47.87% under moderate rain and 33.60% under heavy rain, with corresponding pollutant discharge reductions of 77.55% and 71.37%. The optimization also improved pumping stations efficiency, reducing operating hours by 13.76%. Key IDWs influencing system performance were recognized, with IDWs 9, 10, and 14 being the most critical. These results indicate that this approach can significantly improve the long-term hydraulic and environmental performance of UDSs, offering theoretical insights and practical guidance for sustainable urban water management.

Urban composite non-point source (UCNPS) pollution has become a considerable source of basin pollution. Its control can generally be approached at the source and process levels; however, source and process control facilities face challenges in achieving high-efficiency control. To optimize the layout of source control facilities, two methods were developed in this study: 1) a Storm Water Management Model (SWMM)–group decision-making method for small-area basins and 2) a multi-objective optimization method for large-area basins. For process control of combined sewer overflow (CSO) pollution, methods based on the SWMM and ideal point theory were developed to determine the optimal CSO storage tank volume and the optimal interception ratio of the combined drainage systems. For process control of first-flush runoff (FFR) pollution in separate drainage systems, methods integrating SWMM simulations with empirical design formulas were proposed to determine the optimal volume and layout of FFR storage tanks. These methods were applied to develop high-efficiency source and process control schemes in two representative urban areas—Yongchuan and Jintan—in the Yangtze River Basin, China. The results indicated that by optimizing the layout of source control facilities, 12.44%–22.07% of the pollution load was intercepted at the source level. Furthermore, the rational deployment of process control facilities intercepted 29.6%–44.9% of CSO pollution and 22%–33% of FFR pollution at the process level, achieving efficient UCNPS pollution control with limited resources. The proposed methods and cases studies provide valuable references for UCNPS pollution control in other basins.

The prevalence of quinolone antibiotics as emerging contaminants in wastewater necessitates urgent remediation strategies due to their recalcitrant nature and ecological risks. This study demonstrates an innovative Ag-nZVI/BC composite synthesized through silver-modified nZVI immobilized on coconut shell biochar, which effectively activates H₂O₂ for levofloxacin (LVF) degradation. The composite’s exceptional performance (91.2% LVF removal at 0.3 g/L dosage) stems from its 238 m²/g specific surface area and abundant oxygen-containing functionalities that facilitate electron transfer. Systematic parameter optimization revealed pH 3.0, 10 mmol/L H₂O₂, and 0.3 g/L catalyst as optimal conditions, while coexisting anions showed differential inhibition effects. Radical quenching experiments coupled with EPR spectroscopy confirmed ·OH and ·O₂⁻ as dominant reactive species. Through LC-MS analysis, we identified three primary degradation pathways involving piperazine ring cleavage and defluorination. Notably, eco-toxicity assessment using ECOSAR indicated 62.7% reduction in acute aquatic toxicity after treatment. The regenerable catalyst maintained 83.4% efficiency after five cycles, demonstrating a sustainable approach for antibiotic-contaminated wastewater remediation.

Evidence on the lagged effects of long-term exposure to fine particulate matter (PM_2.5) components is limited. Data on air pollution, meteorology, population health and socioeconomic status were collected from 237 major cities in China between 2015 and 2019. The differences-in-differences model was established to analyze the lagged effects of the annual mean concentration of PM_2.5 components on mortality. The PM_2.5 component-mortality associations exhibited long-term lag patterns, with statistically significantly at lag 2 and lag 3 yr. During the cumulative lags of 0–3 yr, each inter-quartile range increase in exposure to EC, OC, SO₄^2–, NO₃^–, and NH₄⁺, total mortality risk increased by 9% (RR=1.09; 95%CI: 1.02, 1.16), 8% (RR=1.08; 95%CI: 1.01, 1.15), 16% (RR=1.16; 95%CI: 1.07, 1.25), 22% (RR=1.22; 95%CI: 1.08, 1.38), and 16% (RR=1.16; 95%CI: 1.04, 1.29), respectively. Additionally, the observed associations between PM_2.5 components and mortality risks were much stronger among the high-longitude (eastern) regions, as well as areas with high air pressure and high GDP per capita. These findings may help provide critical implication for formulating a multi-domain cooperative control strategies on PM_2.5 components.