Denitrification is a critical process for advanced nitrogen removal in wastewater treatment， fundamentally governed by microbially driven electron transfer and electron allocation. As research has shifted from macroscopic treatment metrics toward microscopic regulation， elucidating denitrification mechanisms from an electron-flow perspective has emerged as a major research frontier. This review systematically summarized the theoretical framework of electron flow in denitrification systems， compared intracellular electron transport pathways and energy allocation characteristics between heterotrophic and autotrophic denitrifiers， and highlighted the central role of the quinone pool in electron collection and redistribution. Furthermore， from the perspective of interspecies microbial interactions， recent advances in indirect interspecies electron transfer （IIET） and direct interspecies electron transfer （DIET） were summarized， and competitive as well as cooperative interactions among microorganisms in mixed systems during electron donor and electron acceptor utilization were analyzed. Building on this framework， the impacts of carbon source characteristics， pH， oxidation-reduction potential （ORP）， and coexisting contaminants on electron transport chains and electron allocation pathways were further discussed. Finally， in light of current limitations in the in situ quantification of electron fluxes， future research directions were proposed， including the development of multi-scale in situ characterization techniques， novel electron-conductive materials， and intelligent electron-flow regulation models.

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 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.

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.

Coastal wetland ecosystems are intrinsically linked to regional socioeconomic development. However， the internal response relationship between these two systems remains unclear. This study took Dongtai City as a study case and used systematic field sampling and multi-source data integration. Partial least squares structural equation modeling （PLS-SEM） was employed to analyze the coupled relationships among socioeconomic development， river surface water quality， and sediment carbon and nitrogen characteristics. The results indicated that over the past five years， both the socioeconomic level and urbanization rate of Dongtai City have increased steadily. Water quality exhibited significant seasonal fluctuations， while a marked declining trend in total nitrogen （TN） was observed. Meanwhile， total organic carbon （TOC） and TN contents in coastal wetland sediments showed minor fluctuations. The PLS-SEM analysis revealed that socioeconomic development indirectly regulated TOC and TN contents in coastal wetlands （path coefficient = 0.1， P < 0.05） by influencing the surface water pollution load of rivers （path coefficient = -0.33， P < 0.001）. This study elucidated the internal nexus between macro-socioeconomic drivers and micro-nutrient characteristics in coastal wetlands， providing a scientific foundation for the synergistic advancement of ecological conservation and the marine economy.

The green and low-carbon construction of river regulation projects is an important part of the green transformation of water conservancy projects under the goals of "carbon peaking and carbon neutrality". Aiming at the common problems existing in the green and low-carbon construction of traditional river regulation projects， such as excessive qualitative descriptions of strategies， insufficient life cycle assessment （LCA）， excessive process analysis， and inadequate multi-scenario guidance， this paper took the demonstration section of the Jurong River Regulation Project in Nanjing as a case study. Based on identifying the carbon emission characteristics of river regulation projects via LCA， an environment-economic dual-objective model was adopted to conduct scenario analysis for the selection of green and low-carbon construction technologies under different objectives， and corresponding combined strategies of green and low-carbon technical measures were proposed. The results showed that the carbon emission intensity during the construction period of the Jurong River demonstration section（length 8.46 km） was 2705 t CO₂eq/km， among which the raw material production stage accounted for 92.49%， followed by the engineering construction stage （5.75%）， engineering transportation （1.06%）， and engineering preparation （0.70%）. Multi-scenario analysis indicated that the application of measures including low-carbon new energy transportation， fly ash， and recycled concrete could reduce carbon emissions by 4486 t CO₂eq and achieve an optimal economic benefit of RMB 1.0814 million. The combination of fly ash， recycled aggregate concrete， and carbon capture and reduction cement （with a replacement rate of 90.32%） could reduce emissions by 7551 t CO₂eq， realizing a balance between economic and environmental performance. Implementing all carbon reduction measures could achieve a carbon reduction of 9596 t CO₂eq but would require an investment of RMB 1.1337 million. The scenarios of maximum economic benefit and economic-ecological balance present better engineering applicability and can provide a decision-making basis for the green and low-carbon construction of river regulation projects.

This study reconceptualized partial nitrification from a microbial ecological perspective by elucidating the dynamic competition between AOB and NOB across the initiation， maintenance， and destabilization phases. Continuous selection pressure was proposed as the core determinant of process stability within a community-process coupled framework. The review indicates that the initiation depends on non-steady-state disturbances that amplify AOB growth advantages， whereas the maintenance phase is characterized by a metastable state with dynamic community structure but relatively stable function， where NOB persist at low abundance or under spatial constraint. When cumulative disturbances weaken AOB competitiveness， NOB can rapidly rebound， inducing a critical shift from partial to complete nitrification. Accordingly， operational strategies centered on resource supply， niche constraint， and community feedback are outlined， emphasizing window-period management to enhance system resilience. The alignment of time-resolved community data with key operational parameters is further discussed as a basis for identifying instability thresholds and early-warning signals to support predictive control and risk management in partial nitrification processes.

Nitrogenous pollutant discharges are rising with urbanization and industrialization， and their untreated release worsens aquatic nitrogen pollution. Currently， nitrogen removal from municipal and industrial wastewater is transitioning from an energy-intensive model to strategies emphasizing pollution reduction， carbon mitigation， and synergistic efficiency. Green and sustainable nitrogen removal technologies represent a key research frontier in water pollution control. This review systematically examined nitrogen pollution in China's wastewater， characterized nitrogen-laden industrial effluents， and highlighted challenges such as wide concentration ranges， complex compositions， and treatment recalcitrance. Based on this analysis， this paper comprehensively reviewed the principles and applications of advanced nitrogen removal technologies， including physicochemical， biological， electrochemical/bioelectrochemical， and advanced oxidation processes. Their treatment efficiency， advantages， and limitations were analyzed， with special emphasis on the application of advanced oxidation processes for refractory nitrogenous pollutants. Future efforts should prioritize adopting low-energy， low-chemical-consumption biological nitrogen removal processes， integrate electrochemical and advanced oxidation processes with conventional methods， enhance overall treatment efficiency， and reduce costs. These advancements are pivotal for achieving China's Dual Carbon Goals and advancing sustainable development.