Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202604011
Reverse osmosis (RO) membrane fouling remains a critical bottleneck in reclaimed water production, yet its spatial heterogeneity over extended operation is poorly understood. This study investigated fouling characteristics and microbial community dynamics on RO membranes after 3.5 years of operation in a full-scale microfiltration-reverse osmosis (MF-RO) system treating reclaimed water. Long-term monitoring showed stable effluent quality (turbidity <0.1 NTU, conductivity <400 μS/cm), but RO inlet pressure exhibited seasonal fluctuations of 15%–22% between summer and winter, attributed to water viscosity changes. Membrane autopsies revealed distinct fouling layers at the inlet (RO1) and outlet (RO2) ends. RO1 featured a dense bio-inorganic composite fouling layer with CaSO4 crystals and rod-shaped microbial aggregates (5–10 μm), dominated by Proteobacteria (77.11%), particularly Alphaproteobacteria (71.49%) and Xanthobacteraceae (35.29%), which secreted extracellular polymeric substances (EPS) to form biofilms. In contrast, RO2, exposed to higher salinity, showed reduced microbial abundance (Proteobacteria decreased to 64.79%) and a shift toward halotolerant taxa, including Microbacteriaceae (23.73%) and Actinobacteriota (24.76%), with EPS secretion increased by 42%. Alphaproteobacteria relative abundance dropped by 19.3%, while Gammaproteobacteria rose to 12.54%. These findings elucidate salinity-driven microbial succession and spatial heterogeneity of fouling, providing a basis for targeted antifouling strategies and 'zonal-graded' cleaning protocols in reclaimed water plants.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605010
The underwater light environment is a critical limiting factor for the colonization of submerged macrophytes and the ecological restoration of shallow lakes. Previous studies rarely quantified the contribution of aquatic environmental factors to the water quality–underwater light–macrophyte relationship, nor did they comprehensively consider factor correlations or establish thresholds for macrophyte colonization. This study, conducted in a typical national wetland nature reserve (Hongze Lake), measured photosynthetically active radiation, light attenuation coefficient (Kd), euphotic depth (Zeu), water transparency (SD), total suspended solids (TSS), chlorophyll-a (Chl-a), total nitrogen (TN), and total phosphorus (TP). A simulation model for Kd was developed, spatial distributions of environmental factors were analyzed, and contribution rates to light attenuation were quantified. Results showed that the mean Kd was 10.31±3.76 m⁻¹, and the mean Zeu (0.53±0.24 m) was lower than the mean water depth (0.94±0.29 m), with a spatial pattern of shallower Zeu in the west and deeper in the east. TSS and Chl-a were the primary direct influencing factors, while TN acted mainly indirectly. To achieve effective macrophyte colonization under average water depth conditions, thresholds were determined: Zeu ≥ 0.94 m, SD ≥ 0.41 m, Kd ≤ 4.95 m⁻¹, and Chl-a ≤ 3.8 μg/L. These findings provide quantitative guidance for lake restoration and water quality management.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605009
Reservoir CO2 emissions are a critical component of the global carbon cycle, yet existing prediction models often neglect reservoir size stratification, mixing data from large, medium, and small reservoirs. This study addresses this gap by constructing a training dataset exclusively for large and medium reservoirs in China and developing a neural network-based CO2 flux prediction model. The model revealed significant latitudinal zonation, with CO2 fluxes in southern low-latitude basins (e.g., Yangtze, Pearl) substantially higher than in northern high-latitude basins (e.g., Yellow, Songliao). Statistical analysis identified total phosphorus (TP) content as the strongest driver, exhibiting a positive exponential correlation with CO2 flux (p < 0.01). Reservoir age and latitude showed significant negative correlations, while physical parameters such as reservoir area, pre-impoundment submersion ratio, and average water depth showed no significant national-scale correlation. The study underscores the heterogeneity of dominant drivers across basins and proposes differentiated carbon mitigation strategies: for southern high-emission basins, controlling phosphorus inputs through wastewater treatment and restricting aquaculture; for northern basins, enhancing soil conservation to reduce carbon-rich sediment influx; and for new reservoirs, implementing vegetation clearance before impoundment and optimizing flood discharge schedules. These findings provide a theoretical basis for carbon emission characterization and support low-carbon management of large and medium reservoirs in China.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605006
Military ecological and environmental protection is a critical component of national ecological and environmental protection. Military activities and operations, such as training and drills, weapons and equipment testing, and combat, are prone to triggering a series of ecological and environmental problems, including greenhouse gas emissions, deterioration of water resources and water quality, vegetation destruction, land degradation, and typical physical and chemical pollution, which have attracted extensive global attention. This study systematically analyzed the eco-environmental impacts of military activities on multiple environmental media (atmosphere, water, and soil) across different periods, and conducted pollution source tracing in multi-media and representative regions. It reviewed the current status of ecological and environmental protection technologies for the three major environmental media, i.e., atmosphere, water, and soil, and summarized the characteristics and constraints of military ecological and environmental research. Finally, it proposed the research trends and key development directions for military ecological and environmental protection from four dimensions: data monitoring and sharing, research and development of in-situ remediation technologies for military-civilian integrated combined pollution, green construction practices for military facilities, and optimization of management systems.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605008
Vegetable production is a significant source of greenhouse gas emissions, yet national-scale assessments comparing cultivation modes remain scarce. Using life cycle assessment (LCA) and provincial statistical data from 2018–2022 across 27 provinces, we quantified the carbon footprint (CF) per unit yield for 10 typical vegetables under open-field and facility farming. Results show annual average CFs range from 65.5 to 293.8 g CO2-eq/kg, with open-field radish lowest and open-field green bean highest. Spatial heterogeneity is pronounced, especially for facility eggplant and open-field green bean. CF exhibits distinct clustering: fruit vegetables emit more in central-southern open-field and northern facility systems, while leafy vegetables follow a 'south-high, north-low' pattern. Fertilizer production and field N2O emissions dominate, contributing up to 80.4% of total CF. In facility systems, irrigation electricity and agricultural film inputs become significant, reaching 57.87% contribution. These findings support region- and crop-specific mitigation strategies for China's agricultural dual-carbon goals.