摘要 : To explore the feasibility of enhancing the electroactivity of coffee ground biochar (CBC)-based carbon mats through controlled incorporation of reduced graphene oxide (rGO), various carbon mats consisting of powdered activated carbon (PAC), CBC, and rGO were fabricated and applied for the removal of representative antibiotics via peroxymonosulfate (PMS) activation under continuous filtration. The effects of the operational modes, water matrices, and target pollutant types on the performance of cathodic electroactive membranes were systematically investigated under limited carbon loading. Results indicated that non-radical singlet oxygen attack and surface-confined oxidation were the dominant pathways for target pollutant removal by CBC/rGO electroactive membranes. The membranes exhibited distinct oxidative selectivity, with a higher oxidation capacity for electron-donating group-bearing sulfonamides (sulfamethoxazole: 96.2% removal) than for electron-withdrawing group-bearing fluoroquinolones (levofloxacin: 62.6% removal) over a short contact time within the carbon mats, as evidenced by the removal efficiencies of both target pollutants and dissolved organic carbon. Density functional theory calculations and liquid chromatography-mass spectrometry analysis revealed that antibiotic degradation involves hydroxylation, C–N/C–O bond cleavage, and aromatic ring opening, which are closely correlated with the structural and electronic properties of the target pollutants. Notably, Ecological Structure-Activity Relationships toxicity predictions demonstrated that several degradation intermediates posed higher developmental and mutagenic toxicity risks than their parent compounds, thereby highlighting the necessity of regulating the oxidative selectivity in electroactive membranes and developing effective post-treatment processes for filtrates to mitigate such toxic risks.

摘要 : While organic phosphorus (OP) is increasingly identified as a critical driver of eutrophication due to its high bioavailability, traditional remediation strategies predominantly target inorganic phosphate (IP). Herein, a novel calcium‐lanthanum peroxide modified halloysite nanocomposite (CLPH) was developed for the synchronous removal of IP and OP from aqueous systems. Batch experiments revealed superior adsorption capacities for both phosphate (P i, 65.29 mg-P/g) and Myo -inositol hexakisphosphate (IHP, employed as a model OP, 59.40 mg-P/g), surpassing the hydroxide-based analogue (CLH). Furthermore, CLPH demonstrated excellent selectivity in the presence of competing ions and natural organic matter. Mechanistic analysis indicated that P removal is governed by electrostatic attraction, inner-sphere complexation, and surface precipitation. Crucially, IHP removal was found to involve partial catalytic hydrolysis into P i followed by subsequent capture, validating the reactive sequestration mechanism. In real waster matrices, CLPH reduced total P in surface water to below 0.02 mg-P/L within 180 min, and lowered P concentrations in raw sewage and secondary effluent to below 0.30 and 0.05 mg-P/L, respectively, achieving over 98% removal of dissolved OP. These results position CLPH as a promising bifunctional material for mitigating eutrophication through the reactive sequestration of IP and OP.

摘要 : The practical application of the Fenton reaction is limited by the excessive generation of iron sludge, which results from the inefficient regeneration of ferrous ions during the FeIII/FeII redox cycle. A hydrogen-assisted strategy was introduced to address this issue. Pd was employed as a catalytic site to activate molecular H2, a green and sustainable reductant, thereby accelerating FeIII reduction and minimizing sludge formation. UiO-66(Zr), a highly porous metal–organic framework, was utilized as the support to anchor Pd via two distinct configurations: Pd@UiO-66(Zr), where Pd is confined within internal pores, and Pd/UiO-66(Zr), where Pd is deposited on the external surface. The effect of the active center location on the reaction performance was systematically investigated. Mechanistic investigations revealed that singlet oxygen (1O2) dominated in the confined Pd@UiO-66(Zr) system, whereas hydroxyl radicals (·OH) were prevalent in Pd/UiO-66(Zr). Under optimal conditions (2 g·L−1 catalyst, 25 μM FeII, 20 mM H2O2, 30 mL·min−1 H2, 20 mg·L−1 CBZ), the Pd@UiO-66(Zr) system achieved complete CBZ removal within 30 s, while the Pd/UiO-66(Zr) system required approximately 60 min. After six consecutive cycling tests, no obvious decline in removal efficiency was observed for Pd@UiO-66(Zr), and Pd leaching was nearly undetectable. In contrast, a gradual decrease in removal efficiency was observed for Pd/UiO-66(Zr), accompanied by noticeable Pd leaching. The superior performance of the Pd@UiO-66(Zr) system was attributed to enhanced hydrogen activation, more efficient FeII regeneration, and a distinct ROS pathway driven by spatial confinement.

摘要 : Heavy metal pollution poses persistent threats to both aquatic ecosystems and human health due to its high toxicity and potential for bioaccumulation. Environmental risk is primarily determined by the bioavailable metal fractions that organisms assimilate, rather than total metal concentrations. Whole-cell bioreporters, which directly capture the organism's physiological response to heavy metal exposure, are crucial for accurate assessment of bioavailability. However, ubiquitous inorganic cations (K +, Na +, Ca 2+, Mg 2+ ) and dissolved organic matter (DOM, represented by humic acid, HA) in aquatic environments significantly influence the bioavailability of heavy metals. This study investigated the impact of these environmental factors on the bioavailability of cadmium (Cd), nickel (Ni), and zinc (Zn) using bioreporter assays. Single-factor experiments demonstrated that Ca 2+ and Mg 2+ exert concentration-dependent inhibitory effects on all target metals, with Ca 2+ showing the strongest suppression of Zn bioavailability. Na + and K + exhibited nonlinear effects, modestly enhancing the bioavailability of Ni and Zn at low concentrations, but suppressing the bioavailability of Cd at higher concentrations. HA reduced Cd bioavailability primarily through complexation. In multi-factor tests with a fixed HA concentration (44 μmol/L), increasing Ca 2+ or Mg 2+ levels competed with HA for metal complexation sites, resulting in metal desorption and increased bioavailability (an antagonistic interaction). However, at excessive cation concentrations (Ca 2+ > 2.49 mmol/L' Mg 2+ > 6.17 mmol/L), competition shifted toward binding sites on the bioreporter cell membrane, resulting in synergistic suppression and causing significant discrepancies between bioreporter measurements and model predictions. This study elucidates the complex regulatory mechanisms governing metal bioavailability within the cation–DOM–metal ternary system, confirms the robustness of bioreporter assays in complex water matrices, and provides a theoretical foundation and technical framework for the development of precise environmental risk assessment models.

摘要 : In this study, a novel S-scheme heterojunction of Cu-doped BiVO 4 integrated with BiOI was constructed for efficient ciprofloxacin (CIP) degradation and algal inhibition in eutrophic waters. Selective doping of Cu 2+ into the BiVO 4 phase introduced abundant oxygen vacancies, optimized the electronic structure, and enhanced visible-light absorption and charge carrier separation. The heterojunction exhibited outstanding photocatalytic performance, achieving 85.1 % CIP degradation and over 60 % mineralization within 90 min under visible light. In eutrophic water, it simultaneously removed 97.7 % of CIP and inactivated Microcystis aeruginosa by 69.4 %, demonstrating strong synergistic effects. Mechanistic studies revealed that the Cu 2+ -induced oxygen vacancies and S-scheme charge transfer pathway facilitated efficient generation of •O 2 - and h + radicals, which dominated the photocatalytic process. Density functional theory (DFT) calculations further elucidated the electronic structure modifications and charge migration mechanisms, and identified key radical attack sites (Fukui indices). While Liquid chromatograph mass spectrometer (LC-MS) analysis identified possible CIP degradation pathways. Moreover, the heterojunction displayed excellent environmental adaptability, maintaining over 70 % CIP removal efficiency in various water matrices, including tap water, sewage effluent, and two distinct types of lake water with the presence of inhibitory ions (Ca 2+, HCO 3 - ). These findings demonstrate the great potential of Cu-doped BiVO 4 /BiOI heterojunction for the remediation of antibiotic- and algae-contaminated surface waters.

摘要 : Sulfide inhibition offers a potential strategy for achieving nitritation in wastewater treatment, yet its long-term feasibility and synergy with microbial stratification in continuous-flow aerobic granular sludge (AGS) systems remain unexplored. This study experimentally demonstrates that sulfide stabilizes nitritation in continuous-flow AGS reactors. Sustained high-rate nitritation was achieved under elevated sulfide loading (20-80 mg S/L) without residual ammonium control, with nitrite accumulation efficiency (NAE) > 85% and ammonium oxidation rate (AOR) > 1.46 kg N/(m 3 ·d). This performance challenges the paradigm that ammonium-based suppression is essential for suppressing nitrite-oxidizing bacteria (NOB) in granules. Sulfide appeared to directly inhibited NOB while concurrently enriching sulfide-oxidizing bacteria (SOB, primarily Thiobacillus). Correspondingly, the metabolism of these SOB is likely to have intensified oxygen consumption, exacerbating oxygen limitation in granule interiors and further restricting NOB. Granular structure enabled spatial proximity between SOB and ammonia-oxidizing bacteria (AOB), allowing SOB to potentially act as a biological shield by rapidly oxidizing sulfide and reducing toxicity to AOB. Microbial exposure experience critically modulated this response, as prior sulfide exposure shortened AOB inhibition lag by selecting for metabolically active SOB consortia and inducing physiological adaptations. Despite sulfide fluctuations (20-80 mg S/L), granules maintained structural integrity (sludge volume index at 3 min (SVI 3 ) <29 mL/g) and settling function, with increased extracellular polymeric substances (especially proteins) enhancing stability. This work demonstrates sulfide as an enabling agent-not a disruptor-for stable nitritation in AGS, facilitating integration with anammox or denitritation for energy-efficient nitrogen removal from sulfide-containing wastewaters.

摘要 : Dissimilatory iron reduction (DIR) plays a fundamental role in subsurface biogeochemical cycling, yet mechanistic understanding of how common soil components, specifically clay minerals and solid-phase organic matter, influence this process remains fragmented. This study systematically investigates the distinct mechanisms by which montmorillonite and solid-phase humic acid (SP-HA) influence ferrihydrite reduction by Shewanella oneidensis MR-1. Our results demonstrate that montmorillonite significantly enhanced the extent of ferrihydrite reduction, which can be attributed to its strong adsorption of biogenic Fe(II), thereby effectively mitigating surface passivation. SP-HA functioned as an efficient electron shuttle, substantially accelerating the initial reduction rate, producing 0.45 mM Fe(II) within 24 h compared to 0.13 mM in the HA-free system, though its overall performance was constrained in comparison to dissolved HA due to physical limitations. Both additives profoundly altered mineral transformation pathways via suppressing secondary mineralization. Crucially, they triggered adaptive microbial responses: montmorillonite reduced riboflavin secretion by 22% but increased cytochrome c by 35%, whereas SP-HA induced a biphasic shuttle synergy with endogenous mediators. These findings reveal that montmorillonite and SP-HA actively reprogram microbial electron-transfer strategies through distinct mechanisms, providing new insights into iron biogeochemical cycling in structured soil environments.

摘要 : The occurrence of antibiotics and the proliferation of harmful algal blooms in aquatic environments raise significant concerns regarding their potential risks to aquatic ecosystems and human health. Here, a novel Z-scheme heterojunction photocatalyst, BiOCl 1-x I x /CAU-17 (CAUB-x), was successfully constructed using a combined solvothermal and in situ growth strategy. An intimate interfacial contact between CAU-17 and BiOCl 1-x I x was achieved via Bi–Cl covalent bonds, which establishes a direct Z-scheme charge transfer pathway. The optimized CAUB-0.3 sample achieved a high tetracycline (TC) degradation rate of 90.87 ± 2.24 % within 90 min under UV light, demonstrating its excellent photocatalytic activity. Additionally, CAUB-0.3 acts by inducing oxidative stress through generated reactive oxygen species (ROS), effectively disrupting both the cellular structure and antioxidant system of Microcystis aeruginosa, resulting in its inactivation. This work provides a novel strategy for developing dual-purpose photocatalysts that are both efficient and stable for concurrently degrading antibiotics and controlling algal blooms.

摘要 : Polycyclic aromatic hydrocarbons (PAHs) represent a significant class of organic contaminants in soils, exhibiting long-term stability and biotoxicity. Medium- and low-ring PAHs (MLPs, 2–4 rings) exhibit higher solubility and mobility than high-ring PAHs (5–6 rings), leading to greater potential for migration in soil environments. Thus, accurately evaluating their adsorption behavior is essential for understanding environmental distribution and ecological impacts. In this study, 1408 adsorption data points from 51 publications, covering 142 soil samples and five MLPs (naphthalene, fluorene, phenanthrene, pyrene, and fluoranthene), were compiled. Soil properties (organic carbon, pH, cation exchange capacity, Clay), MLPs property (octanol–water partition coefficient), and experimental conditions (equilibrium concentration, solid-to-liquid ratio, temperature) were selected as feature variables. Six machine learning algorithms were applied to model MLPs adsorption. Among all models, the extra trees (ET) model showed the best performance ( R2 = 0.856, RMSE = 0.899). SHAP analysis revealed that equilibrium concentration and solid-to-liquid ratio were the dominant factors. The trained ET model was applied to map MLPs adsorption capacity in Chinese soils, revealing regional differences linked to organic carbon, pH, cation exchange capacity, and Clay. Overall, northwestern soils showed lower adsorption capacity, while southwestern, parts of central China, and northeastern soils were stronger. Moreover, sorption capacity increased with the number of benzene rings. The present work highlights how machine learning can be applied to forecast interaction of five MLPs with soils, providing a basis for risk assessment and remediation strategies.

摘要 : Integrated fixed-film activated sludge (IFAS) and one-stage partial nitritation-anammox (PN/A) are considered the optimal combination for wastewater nitrogen removal. However, pilot-scale studies on IFAS-PN/A processes remain scarce, which may be attributed to the lack of practically feasible control strategies. This study evaluated the potential of implementing different control strategies in a one-stage IFAS-PN/A pilot plant. The results showed that combining intermittent aeration with low dissolved oxygen (DO) was insufficient to meet ammonia-oxidation demands under mainstream conditions, while implementing an integrated control strategy that combined mixed volatile suspended solids (MLSS), pH, and DO regulation, favorable nitrogen removal efficiency of 73.1–92.8% was achieved for treating wastewater with nitrogen concentrations ranging from 100 to 5000 mg N/L. Correlation analysis and structural equation modeling revealed that controlling MLSS and the aeration coefficient is effective for ensuring adequate ammonium oxidation, whereas pH and ammonia oxidation rate (AOR)/ nitrogen loading rate (NLR), which better capture inter-parameter dynamics, serve as suitable indicators for process regulation and decision-making. Therefore, a multi-parameter control scheme integrating MLSS, aeration coefficient, pH, and AOR/NLR on top of intermittent aeration and DO control was demonstrated to achieve effective NOB suppression and enhanced performance across a wide concentration range.