Vivianite crystallization is recognized as an efficient and environmentally friendly approach for phosphorus recovery in wastewater resource utilization. However， in practical phosphorus recovery processes， the dissolved organic matter （DOM） present in the supernatant of sludge anaerobic fermentation may interfere with vivianite crystallization， thereby affecting both the phosphorus recovery efficiency and the product properties. In this study， polysaccharides， proteins， acetic acid， propionic acid， and humic substances were selected as representative organic matter to systematically assess how their types and concentrations affect vivianite crystallization， and to elucidate their impacts on crystal morphologies and structure as well as the associated interaction mechanisms. The results showed that the inhibitory effects of different types of organic matter on phosphorus recovery via vivianite crystallization followed the order of humic substances > proteins > propionic acid > acetic acid > polysaccharides. The presence of humic substances significantly reduced the phosphorus recovery rate and crystal size， and led to the formation of irregular surface deposits on the crystals. This study provides a theoretical foundation for clarifying the interference mechanism of DOM in vivianite crystallization within fermentation broth and offers insights for its regulation. These findings are of great importance for guiding the optimization of the efficient phosphorus recovery processes in real wastewater systems.

This study， conducted at the Haikou Jiangdong Water Plant， applied a direct ultrafiltration process to treat the Nandu River water for potable use. Pilot-scale experiments were performed to optimize key operational parameters， including filtration cycle， backwash regime， and chemical-enhanced backwash （CEB） dosing and frequency. Under the optimized condition， the study comprehensively evaluated treatment performance， membrane-fouling characteristics， and techno-economic outcomes. The results showed that with a filtration cycle of 90 min and a high-intensity， short-duration backwash regime （170 L/（m²·h） flux， 150 s air scouring， 10 s combined air-water top backwash， 10 s combined air-water bottom backwash）， together with CEB using 500 mg/L sodium hypochlorite at a frequency of 7 days， the system exhibited robust adaptability and stable performance across varying raw-water qualities. The system maintained regulatory-compliant effluent even when raw-water COD_Mn reached 7.01 mg/L during high-turbidity periods （≥50 NTU）. However， when raw-water COD_Mn approached 3.6 mg/L during low-turbidity periods （<50 NTU）， there was a potential risk of the effluent COD_Mn exceeding the applicable drinking-water standard. Over 42 days of operation， the transmembrane pressure increased by a cumulative 8.48 kPa but stabilized following a short-term high-turbidity perturbation. Membrane-fouling analyses confirmed that the optimized operating conditions effectively limited fouling and identified siliceous-aluminous inorganic residues as the primary irreversible foulant fraction. A techno-economic assessment indicated water production costs of RMB 0.226/m³ （low-turbidity） and RMB 0.243/m³ （high-turbidity）， both lower than the RMB 0.261/m³ estimated for a conventional coagulation-sedimentation-filtration-disinfection process. The operational-parameter framework established in this study provides experimental evidence and technical support for applying direct ultrafiltration as a primary pretreatment unit in engineering practice.

This study proposed a hybrid Long Short-Term Memory （LSTM）-Transformer model integrated with wavelet denoising for water quality prediction. Using hourly monitoring data （water temperature， turbidity， pH， conductivity， and dissolved oxygen） collected from two municipally controlled river cross-sections in South China from 2021 to 2024， the discrete wavelet transform was first applied for noise reduction. Subsequently， a predictive model combining LSTM and Transformer architectures was constructed. Experimental results demonstrated that the proposed model achieved outstanding performance in predicting dissolved oxygen （DO） concentrations for the next four hours at both sites （Site 1： coefficient of determination （R²）=0.8015， mean absolute error （MAE）=0.5169 mg/L， root mean square error （RMSE）=0.8494 mg/L； Site 2： R²=0.8873， MAE=0.4456 mg/L， RMSE=0.7143 mg/L）， significantly outperforming standalone LSTM and Transformer models （the R² of the proposed model increased by 5.7%， while MAE and RMSE decreased by 20.2% and 10.4%， respectively）.Furthermore， the SHAP interpretability method was employed for feature importance analysis and global impact interpretation， revealing that the key water quality factors influencing DO and their complex nonlinear relationships exhibited significant site-specific heterogeneity. This underscores the necessity of incorporating specific environmental contexts （e.g.， geographical features， hydrological conditions， and pollution source distribution） for mechanistic interpretation. The findings of this study provide an effective and interpretable technical reference for high-precision real-time prediction and intelligent management of regional river water quality.

Iron-dependent autotrophic denitrification （IDAD） is a promising biological technology for nitrogen removal from wastewater with a low C/N ratio. While significant differences in community structure among IDAD consortia from different studies have been reported， the underlying reasons remain unclear. Hypothesizing that the anion type of ferrous salts could be a key contributing factor， this study enriched two IDAD consortia （R1 and R2） using FeCl₂ and FeSO₄ as respective electron donors under identical inoculum sludge conditions. Their nitrogen removal performance， extracellular polymeric substance （EPS） composition， iron oxidation product properties， microbial community structure， and functional gene distribution characteristics during long-term operation were systematically compared. The results showed that R1 exhibited higher denitrification efficiency and Fe（Ⅱ） oxidation activity. Key iron-oxidizing bacterial genera such as Gallionella showed a significantly higher relative abundance in R1 than in R2， and R1 also maintained higher community diversity. Metagenomic analysis further revealed a higher abundance of functional genes related to iron oxidation and denitrification in R1. In contrast， R2 was enriched with more genera associated with sulfate metabolism and complex organic matter degradation. Distinct differences were also observed in EPS composition and iron mineral surface properties between the two consortia. This study confirms that the type of ferrous salt significantly regulates the structural assembly and metabolic functions of IDAD consortia， providing a theoretical basis for optimizing their application in practical wastewater treatment.

This study took a large municipal wastewater treatment plant （WWTP） in northern China as the research object， and systematically investigated the influence characteristics and response mechanism of abnormal influent shock load on the structure of activated sludge microbial community. The results showed that influent shock caused drastic changes in the structure of activated sludge microbial community： the abundances of core functional flora such as Proteobacteria and Bacteroidetes decreased significantly by 55.30% and 44.35%， respectively； the community diversity was reduced， the nitrification function was weakened， and the concentration of effluent ammonia nitrogen increased. Meanwhile， shock-resistant flora such as the genus SJA-28 within Chlorobi proliferated rapidly， showing a 5.68‑fold increase in relative abundance compared to the normal period， which helped sustain the pollutant removal capacity of the system to some extent. These findings confirmed that the activated sludge system has strong shock resistance and self-recovery capacity. The implementation of regulatory measures such as shortening sludge retention time （SRT） and increasing the dosage of sodium acetate and phosphorus removal chemicals was shown to be conducive to the rapid recovery of functional flora. Based on these findings， it is suggested that in practical operation， SRT adjustment strategies should be flexibly adjusted according to influent quality characteristics and temperature conditions， so as to improve the stability and resilience of the wastewater treatment system in responding to shock loading.

In the context of global carbon neutrality goals and energy transformation，it is urgent to develop new technologies that efficiently convert CO₂ into renewable energy carriers such as CH₄. Microbial electrolysis cells （MECs）， which couple electrochemistry with microbial metabolism for CO₂ conversion， exhibit performance that is heavily dependent on the electron transfer capabilities and biocompatibility of the cathode.Therefore，Nafion was employed to load nanoscale Fe₃O₄ and carboxylated multi-walled carbon nanotubes onto nickel foam （NF）. The electrochemical performance of the modified NF was characterized using techniques such as electrochemical impedance spectroscopy （EIS），cyclic voltammetry （CV），and linear sweep voltammetry （LSV）. The results indicated that the modified NF exhibited lower internal resistance，a larger electrochemical active surface area，and enhanced hydrogen evolution capabilities.Ultimately，this modified cathode was employed in a constant current dual-chamber anaerobic methanogenic MECs for the electrochemical reduction of CO₂ to CH₄.The results demonstrated that under a constant current of -0.1 A，the CH₄ concentration of the nanoscale Fe₃O₄ and carboxylated multi-walled carbon nanotube-modified NF group could reach 90%，surpassing the 80% CH₄ concentration of the NF group. Moreover，the daily CH₄ production of the modified group was 295 mL，higher than the 260 mL daily methane production of the NF group，reflecting an increase of 13%. It was found that the modified NF exhibited higher hydrogen production and lower internal resistance， creating a more favorable environment for the growth and enrichment of hydrogenotrophic methanogens， thereby facilitating the electrochemical reduction of CO₂ to CH₄. Subsequent microbial community analysis also indicated that the relative abundance of the hydrogenotrophic methanogen Methanobacterium in the reactor with the modified NF was higher than that in the NF group，further facilitating the process of H₂ serving as an electron donor for CO₂ reduction to CH₄. This research provides new ideas and experimental evidence for the development of novel non-precious metal composite cathode materials in bioelectrochemical systems.

As global plastic production continues to rise， the quantity of plastic waste has also increased dramatically. Effectively addressing plastic pollution while achieving the resource recovery and recycling of plastic waste has become a global challenge. Compared with conventional recycling methods， the photothermal catalysis process， which integrates photocatalysis and thermocatalysis， offers significant advantages such as high conversion efficiency and mild reaction conditions. Herein， this review outlines the research progress of photothermal catalysis technology in the treatment and resource recovery of plastic waste. It first elaborates on the mechanism of photothermal conversion， including plasmonic localized heating， non-radiative relaxation of semiconductors， and molecular thermal vibration. Based on the roles of light and heat in photothermal catalytic reactions， photothermal catalysis is classified into three categories： thermal-assisted photocatalysis， photo-driven thermocatalysis， and photo-thermal co-catalysis. The type of catalytic material plays a crucial role in regulating catalytic performance during the photothermal catalytic conversion of plastics. This review summarizes the catalytic properties of three typical photothermal catalytic materials： plasmonic metal nanoparticles， metal oxide semiconductors， and carbon-based materials， providing material design directions for efficient plastic upcycling. Furthermore， starting with the upcycling mechanisms of two representative plastics， polyethylene and polyester， the review summarizes the reaction pathways for plastic upcycling to produce liquid fuels and organic acids. Finally， based on the current research status， this review also highlights the technical challenges of using photothermal catalysis for plastic upcycling. This review aims to provide technical support for the chemical recycling of plastic waste and offer new perspectives for its upcycling.

In response to the severe global challenge of increasing microbial resistance， developing efficient and environmentally friendly antibacterial materials has become an urgent demand in the field of materials science. This research used natural dolomite from a region in Hunan as the raw material and investigated the controllable preparation process of antibacterial magnesium oxide （MgO） via the dolomite carbonation method， focusing on the regulation mechanisms of the microstructure of the product through heavy magnesium hydrolysis methods （spray pyrolysis and vacuum pyrolysis） and precursor calcination conditions. By systematically optimizing the process parameters， the optimal calcination conditions for dolomite were determined to be 1000 °C for 180 minutes， with a carbonation endpoint pH of 7.5， under which the magnesium recovery efficiency achieved the highest. Spray pyrolysis at a feed rate of 30 mL/min and 220 °C produced well-shaped hollow spherical MgCO₃·3H₂O precursors； when this precursor was calcined at 600 °C with a heating rate of 10 °C/min for 3 hours， high-activity MgO with a high specific surface area （49.43 m²/g）， nanoscale particle size （d₅₀=222.47 nm）， and a hierarchical porous structure was successfully obtained. Antibacterial tests showed that this MgO material achieved a 100% sterilization efficiency against Escherichia coli， with a minimum bactericidal concentration of 0.5 mg/mL， demonstrating excellent antibacterial efficacy. By constructing a "process-structure-performance" regulation system， this study provides reliable theoretical guidance and technical support for the preparation of high-performance， environmentally friendly nanostructured antibacterial materials based on natural dolomite.