This study focuses on regions characterized by complex traffic environment area and its background environment, exploring the contamination profiles of six heavy metals（As, Hg, Cu, Ni, Pb, and Cd）at two spatial scales. Through modeling analysis, this study examined the patterns of dust resuspension and the associated health risks resulting from the movement of a single traffic source. The results indicate that the levels of Cd, Pb, and Cu contamination in traffic intensive area, as well as their ecological risks, exceed those found in background area, with Cd showing the highest contamination, 70% of which poses a high ecological risk. During the movement of a single traffic source, the severity of changes in dust concentration is positively correlated with velocity, with dust accumulation occurring at heights of 0.3m and 0.6m above ground level. The primary exposure pathway for key heavy metals is hand-to-mouth ingestion; although both non-carcinogenic risk and carcinogenic risks are generally low, at a vehicle speed of 60km/h and a height of 0.6m, the non-carcinogenic hazard quotient for inhalation（HQ-inh）is elevated. Therefore, protective measures are recommended for individuals active within this range.

A metal polyphenol-modified TiO₂ photocatalytic membrane（（TA-Fe³⁺）/TiO₂-PVDF）was prepared by a layer-by-layer self-assembly method using polyvinylidene difluoride（PVDF）membranes as the substrate, and an in situ photocatalytic membrane filtration system was constructed to degrade tetracycline in water. The structures of the photocatalytic membranes were characterized by SEM, EDS, XRD, FTIR and contact angle meter, and all the characterization results proved the successful coating of（（TA-Fe³⁺）/TiO₂-PVDF）and the enhanced hydrophilicity of the membrane surfaces; and tetracycline as a representative of the antibiotics was selected for the study of the degradation performance, which was achieved at a low dosage（50mg/L）of peroxydisulfate（PMS）, a transmembrane pressure of 5 kPa, and an in situ photocatalytic membrane filtration system to degrade tetracycline in water. 250 mW/cm²visible light intensity, the tetracycline degradation rate was always maintained at 80% during 1h operation, the average removal rate of tetracycline was 7.34g/h, and the water flux only decreased by 6% compared with that of the original PVDF membranes, which is suitable for neutral and weakly acidic conditions, and basically unaffected by common ions in the water column and natural organic matter; finally, the mechanism of tetracycline degradation by（TA-Fe³⁺）/TiO₂-PVDF membranes was investigated by active species capture assay and EPR, and it was found that photocatalysis synergistically with PMS oxidation produced ¹O₂, h+, O₂^-· and SO₄^·- as the main active species, and degraded tetracycline by both the free radical and non-free radical pathways.

In this study, zebrafish were used as a model organism to investigate the effects of combined exposure to polyamide microplastics（PA MPs）and triclosan（TCS）on lipid metabolism in larval zebrafish. The findings demonstrated that PA exhibited a strong adsorption capacity for TCS, with an adsorption rate reaching 74% at 168h. Exposure to PA and TCS from 6hpf to 120hpf resulted in pronounced morphological abnormalities in larval zebrafish, including pericardial edema, swim bladder closure, yolk sac edema, and spinal curvature, with a malformation rate of 13%. Moreover, combined exposure induced the accumulation of reactive oxygen species within the larvae, triggering oxidative stress responses. In the hepatic region, significant lipid accumulation was observed, accompanied by elevated levels of T-CHO and TG. These changes were further correlated with aberrant expression of genes involved in lipid metabolism, confirming that combined exposure to PA and TCS disrupted lipid metabolic processes in zebrafish. Mechanistic investigations revealed that combined exposure led to a reduction in mitochondrial membrane potential and decreased expression of ATP synthase genes, resulting in impaired energy supply and subsequent energy metabolism disruption. Notably, the presence of PA significantly amplified the disruptive effects of TCS on lipid and energy metabolism compared to exposure to either PA or TCS alone.

In a sequencing batch reactor with alternating anaerobic/aerobic operation, activated sludge from an oxidation ditch was used as the inoculated sludge for culturing poly-phosphate biofilm enrichment. The potential functions of GAOs in the biofilm phosphorus enrichment system were investigated by examining the effects of the changes in the abundance of glycogen-accumulating organisms（GAOs）in the biofilm on the phosphorus enrichment performance and the metabolic characteristics of the microbial community. The results showed that GAOs became the dominant organisms in the enrichment culture of phosphorus-accumulating biofilm, but they did not adversely affect the phosphorus removal and enrichment of the biofilm system. Due to the significant increase of PHA metabolic activity and poly-P metabolic activity in individual cells of phosphorus-accumulating organisms（PAOs）, the biofilm community as a whole was dominated by the phosphorus accumulating metabolism（PAM）. GAOs as a dominant bacterial genus in the system, might obtain the reducing power（NADH）required for synthesizing PHA through EMP metabolism, which could provide sufficient energy reserve for the absorption of phosphorus by the PAOs in aerobic conditions, and thus stimulate the phosphorus removal and enrichment effect in the biofilm system. The inorganic phosphorus transport system（pst）and poly-P synthesizing genes（ppk）were up-regulated, so that the biofilm system showed good phosphorus removal and enrichment ability, and the GAOs（Candidatus Competibacter）, as a potential denitrifying bacterium, could synchronize with the aerobic denitrification in the biofilm phosphorus-enrichment system.

In order to explore the resistance mechanism of polymer ultrafiltration membranes to ozone, polyvinyl chloride（PVC）membranes and polyvinylidene fluoride（PVDF）membranes as representatives were used, and systematically evaluated the effects of ozone on the water permeability, pollutant retention capacity and mechanical properties of the membranes by simulating 0.1mg/L ozone exposure for 0.5 years, and analyzed the changes in chemical properties. The results showed that the water permeability of the PVC membrane significantly increased under the action of ozone for 36 hours, up to more than 4times that of the new membrane, while the retention capacity of humic acid（HA）decreased by about 27.6%. The water permeability and retention performance continued to decrease with the extension of exposure time. The water permeability of PVDF membranes increased significantly in the initial stage, with the HA retention performance decreasing by about 40.2% after 36hours of aging. However, the performance tended to stabilize after 1 hour of aging. Ozone aging led to a decrease in the hydrophilicity of the two membranes, but the hydrophilicity of PVC membranes decreased to a lesser extent, showing their relative advantages in maintaining hydrophilic properties. The analysis of the membrane structure mechanism showed that ozone mainly damaged the membrane performance through oxidation and the loss of the hydrophilic additive polyvinyl pyrrolidone（PVP）, and the membrane matrix itself remained intact, which was also confirmed by SEM observations. The mechanical properties of the two membranes decreased after aging, but the PVDF membrane showed relatively high mechanical strength. A comprehensive comparison of the ozone resistance of PVC, and PVDF, showed that PVC had relative advantages in ozone aging resistance in terms of retention, anti-pollution, hydrophilic, and mechanical properties, followed by PVDF. These findings provide an experimental basis and theoretical reference for the application and optimization of polymer ultrafiltration membranes in ozone-containing water treatment environment.

In view of the accumulation of nitrite in the effluent of denitrification biofilter in water recycling plant, nitrite accumulation in denitrification filter units of 4recycled water plants was investigated. Two denitrification filter process units of recycled water plant, G（with nitrite accumulation）and W（without nitrite accumulation）, were selected as research objects to explore the causes of nitrite accumulation under the condition of low carbon to nitrogen ratio influent. The results showed that operating parameters such as backwashing cycle and mode of filter had little effect on nitrite accumulation. The sludge denitrification rates of plants G and W were 0.51 and 0.92 mgNO₃/（mgVSS·d）, respectively. The accumulation of nitrite in the effluent from the filter of Plant G was due to the weak denitrification ability of microorganisms in the filter. When nitrate nitrogen was present in the denitrification process, the denitrification rate of nitrite in the sludge of Plant G was 75% lower than that of plant W, and it was easier to produce nitrite accumulation. When the sludge biomass of Plant G was increased to twice the concentration of plant W, the maximum nitrite denitrification rate still couldn’t reach the level of plant W, so the biomass was not the main reason for the accumulation of nitrite in Plant G. The results of microbial community structure analysis showed that the abundance of Methylotenera in the filter of W plant was 12.9% higher than that of G plant. The denitrification process was mainly completed by denitrifying bacteria using methyl type nutrition, which was the cause of nitrite accumulation happening or not, and it was not necessary to consider the influence of bacteria species using other organic types on nitrite accumulation.

This study taken Wuliangsuhai Lake as the research object to reveal the microbial community structure of lake sediments, elucidated the representative iron-reducing microorganisms and their abundance, investigated the seasonal differences in the impact of iron-reducing microorganisms on As-P migration and transformation during the ice-bound period and the summer, and the impact of P on As migration and transformation, with the aim of providing a basis for deepening the understanding of the environmental geochemical behavior of As in cold and arid regions and As pollution remediation, and providing reference for the water environmental protection of As pollution and eutrophication risks in dual-risk lakes. The results showed that the relative abundance of iron-reducing microorganisms during the ice-bound period was higher than that in summer. There were seasonal differences in the representative iron-reducing microorganisms. Bacillus and Geobacter were the dominant genera of iron-reducing microorganisms during the ice-bound period and summer, but Geothrix was also one of the representative iron-reducing microorganisms in summer, and Shiwanella was one of the representative iron-reducing microorganisms during the ice-bound period. The correlation analysis and PLS-SEM model results showed that the representative iron-reducing microorganisms that play a major driving role in As-P migration and transformation and their impact on As-P migration and transformation exist significant seasonal differences. In summer, although the abundance of Thermoanaerobium was small, the iron-reduction process driven by Thermoanaerobium（path coefficient=0.178）would affect the release of As and P from sediments to water to a certain extent. In addition, Bacillus could also promote the iron-reduction process（Path coefficient=0.115）and was the main driver of As-P mobility and transformation. During the ice-bound period, the more abundant Geobacter was an important driver（path coefficient=0.530）of As mobility, which had an important effect on the mobility and transformation of As-P, and the effect of Thermoanaerobium on iron reduction (Path coefficient=0.284）and As-P mobility and transformation was greater than in summer（path coefficient=0.178）.

A CN-supported Mn₃O₄（Mn₃O₄-CN）composite was synthesized as a catalyst for the catalytic ozonation of 2,3-dimethylpyrazine degradation in wastewater. The catalytic efficiencies of 2, 3-dimethylpyrazine were investigated under various ozone dosages, catalyst dosages, pH and temperature conditions. The results showed that under the conditions of an ozone dosage of 3mg/L, a catalyst dosage of 0.02g/L, pH =7 and a temperature of 10℃, the degradation rate of pollutants reached 100% within 20 min. Scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and other characterization methods were used to analyze the properties of the prepared Mn₃O₄-CN. It was confirmed that Mn₃O₄ and CN were successfully bonded, and the valence states of Mn were mostly +2 and +3. The reactive oxygen species analysis demonstrated that the surface hydroxyl groups and oxygen vacancies were identified as the main active sites, and ⋅OH was the main active oxygen species generated in the reaction system. The cyclic experiments showed that the Mn₃O₄-CN has good stability and reusability.

In this study, carbonic anhydrase-producing bacteria were selected and introduced into short-term experiments involving sandstone-CO₂-water interactions. The chemical properties of the solution, the dissolution-precipitation process of rock minerals, and the changes in bicarbonate ion concentration were analyzed and detected. The results showed that after 20days of reaction under conditions of 50℃ and 10MPa, the pH of the system increased, and the microbial group pH was slightly higher than that of the control group. The participation of bacteria significantly accelerated the dissolution and precipitation processes of rock minerals, reducing the core porosity from 15.02% to 13.27%. In a 1-liter solution with a solid-to-liquid ratio of 1:5, the effective CO₂ sequestration amounts for the control group and the microbial group were 0.207g and 0.726g, respectively. The addition of microorganisms resulted in better carbon fixation, demonstrating that carbonic anhydrase-producing bacteria have a certain promoting effect on CO₂ geological sequestration.

The present study was aimed to quantitatively estimate the odor emission of municipal solid waste landfills in the loess area of Northwest China and investigate the technical feasibility of using loess soil as covering material for odor pollution control. For this purpose, the study was conducted in field and chose four types of landfill surface sources representing different periods and different coverage states in this region. The surface odor release rates were determined as follows: 5915µg/(m²·h) for newly formed landfill surface without cover, 122µg/(m²·h) for newly formed landfill surface with loess cover 757µg/(m²·h) for loess-covered surface after 5months, and 14057µg/(m²·h) for re-exposed landfill surface. The results indicated that the loess cover reduced odor emissions by more than 94% at two periods and effectively controlled various odor compounds. The analysis on the loess microbial community structure after 5 months of coverage showed that Actinobacteria had the highest relative abundance, potentially participated in the degradation of volatile organic compounds, and had a stronger effect on the surface. The experimental results demonstrated the effectiveness of loess cover in controlling odor emissions, proving that the application of loess as a landfill cover layer is feasible in the northwest region.