This study investigated the effects of raw water turbidity variation on the stable flux, pollutants removal, and bio-cake layer of gravity flow ultrafiltration (GDM) system. The results showed that the increase of raw water turbidity led to a significant decrease in the flux of GDM system, but a new stable flux can be achieved in 17~30 days. Compared to control GDM with low influent turbidity (1.8~3.7NTU), the increase of raw water turbidity to 10, 50 and 100 NTU reduced the stable flux of GDM system by 15%, 36% and 61%, respectively. The macromolecular organic matter carried by particles was degraded by microorganisms in the bio-cake layer to low molecular weight organic matter, which passed through the membrane and resulted in increase of dissolved organic matter in the effluent with the increase of raw water turbidity. The ammonia removal rate of GDM system reached more than 80% after 9days of start-up, and the temporary decrease in ammonia nitrogen removal capacity occurred due to the increase of raw water turbidity. However, it recovered after 7~11days of adaptation period. With the increase of raw water turbidity, the thickness of bio-cake layer increased by 1.8 to 7.9 times and the microbial extracellular polymeric substances increased by 37 to 98%. Meanwhile, the microbial community structure underwent certain changes. This study shows that GDM system has certain adaptability to increase of raw water turbidity.

The transmission of prions can induce the largely spread of transmissible spongiform encephalopathies, which pose a serious threat to animal and human health. Soil is a natural reservoir for prions. Prions can enter the soil through animal excretion, carcass decomposition, and bind to soil components. The binding of prions to different soil components varies significantly, and their effects are simultaneous and mutual, jointly influencing the spread of prions in the soil. On the one hand, the adsorption of soil particles and humic substances enhances their stability and persistence in the soil, reduces their bioavailability, and thus inhibits the spread of prions. On the other hand, montmorillonite and manganese ions can increase their activity and infectivity to a certain extent, thereby contributing to the spread of prions. The control of prions in the soil can be achieved through biotechnologies such as environmental prevention and control, enzyme treatment and composting technique, based on the improvement of their detection methods. In the future, the research on prions in the soil environment should take more into account the influence of the characteristics of soil compounds and native microorganisms on prions, so as to promote the development of in-situ prion degradation methods to control their spread. This work will provide theoretical support for the development of new technologies for soil prions control.

The removal efficiency of glyphosate may be affected due to the quenching process of radicals by in-situ produced inorganic phosphorous. To address the problem, we have developed a novel approach to achieve the direct electron transfer between glyphosate and PMS by adding NaOH to adjust the pH values. The effectiveness and mechanisms of glyphosate degradation in various NaOH concentration were evaluated by several experiments: optimizing the concentrations of reactants, radical trapping tests, and electron paramagnetic resonance (EPR) characterization. Varying pH could change the morphologies of glyphosate and PMS, as a result, accompanied the various glyphosate removal rate. Under alkaline condition, the mechanisms of glyphosate degradation depended on the direct electron transfer process, and insignificant contribution of hydroxyl and sulfate radicals. Thus, it effectively prevented the negative effects on radical oxidation by produced inorganic phosphorous during glyphosate removal processes. As a result, glyphosate (10mg/L) was completely decomposed after five minutes with the addition of 5mmol/L PMS and 6mmol/L NaOH.

To address the problems of traditional methods lacking the characterization and assessment of internal environmental risks in chemical industrial parks, having single assessment indicators, and not considering the factor of risk prevention and control capabilities, a refined assessment method for sudden environmental incidents at the scale of chemical industrial parks was proposed based on the grid-based risk analysis method for sudden environmental incidents in administrative regions. This method refines the risk unit grid, optimizes the environmental risk field intensity model, improves the vulnerability standards for environmental risk receptors, and introduces a correction factor representing the level of environmental risk prevention and control. Taking a certain fine chemical industrial park along the Yangtze River in Jiangsu Province as an example, environmental risk assessments were conducted and compared using the original assessment method and the refined assessment method. Compared with the original assessment method, the refined assessment method better characterized the distribution of atmospheric and water environmental risks within the park. The number of people involved in the high-risk and medium-risk areas of the atmospheric environment in the study area increased by 17,000, and the areas of high-risk and high-medium-risk areas of the water environment increased by 0.91% and 9.45% respectively. This method can effectively establish the connection between environmental risk assessments at different scales such as chemical industrial parks and environmental risk enterprises, more accurately identify high-risk enterprise units and environmental receptors, and ensure the safety of the internal population and key water bodies in the park.

This study aimed to investigate the influencing mechanism of polystyrene nanoplastics (PS-NPs) in aerobic granular sludge (AGS) systems. The addition of 20mg/L PS-NPs had a negligible impact on the removal of organic matter and phosphorus in the AGS systems. However, it exerted a pronounced inhibitory effect on nitrogen removal, with ammonia nitrogen removal and total nitrogen removal exhibiting a reduction of 21.98% and 41.31% compared to the control group, respectively. Additionally, PS-NPs inhibited the secretion of extracellular polymeric substance (EPS) and altered the EPS structure, making it looser by affecting the secondary structure of proteins. Further studies demonstrated that PS-NPs caused intense oxidative stress within microorganisms by inducing excessive reactive oxygen species (ROS) production, which resulted in lactic dehydrogenase (LDH) levels rising to 151.27% and compromised cell membrane integrity. The long-term presence of PS-NPs led to changes in microbial community structure, inhibiting the growth of denitrifying bacteria, such as the classes Gammaproteobacteria and Alphaproteobacteria. In contrast, the proliferation of the classes Flavobacteria and Chitinophagia was promoted by PS-NPs. Moreover, KEGG database analysis indicated that PS-NPs not only significantly inhibited the pathways related to quorum sensing and metabolic activity, particularly the metabolic pathways of aromatic amino acids, but also reduced the relative abundance of genes encoding denitrifying functional enzymes. This ultimately posed a negative impact on the denitrification performance and the long-term stability of AGS systems.

This study evaluated the short-term, acute impacts of elevated Cu(II) and Cr(VI) concentrations on the nitrogen-removal efficiency, microbial community composition, and predicted metabolic responses of anammox granular sludge. Results showed that 12mg/L Cu(II) induced a temporary inhibition of anammox activity. In contrast, 8mg/L Cr(VI) caused a near-complete cessation of nitrogen removal. High concentrations of Cu(II) and Cr(VI) decreased the relative abundance of Candidatus Kuenenia by 4.86% and 2.88%, respectively, indicating that heavy metals likely impair anammox performance by directly inhibiting key anammox bacteria. Functional-prediction analysis (PICRUSt2) suggested that, under Cu(II) and Cr(VI) stress, the anammox community upregulated pathways associated with cell motility, energy metabolism, chemotaxis, signal transduction, and xenobiotic biodegradation—presumably as adaptive responses to mitigate toxicity.

A novel catalytic membrane (AC-MgO@PVDF) was fabricated by loading activated carbon (AC) and MgO onto a poly (vinylidene fluoride) (PVDF) membrane using a vacuum filtration method. The as-prepared catalytic membrane (AC-MgO@PVDF) was employed to activate persulfate (PS) for the oxidation of ammonia nitrogen (NH₄⁺-N) in aqueous solution. The structure and elemental composition of the catalytic membrane were characterized by SEM, Raman and XPS. The efficiency and mechanism of NH₄⁺-N oxidation by the AC-MgO@PVDF/PS system were investigated. The results showed that under the conditions of a flow rate of 1mL/min, a PS dosage of 8g/L and an AC loading of 4.8mg/cm², the removal rate of 30mg N/L NH₄⁺-N and the nitrogen gas (N₂) selectivity of the NH₄⁺-N oxidation products reached 100% and 91.7%, respectively, after 25min of operation. The system exhibited a broad pH tolerance range (3~12) and was barely affected by common anions and natural organic matters in water body. Even after 240min of continuous operation, the system could still achieve a removal rate of over 60% for NH₄⁺-N. Quenching experiments, EPR measurements, and electrochemical tests revealed that f NH₄⁺-N was primarily oxidized through a non-radical pathway, with direct electron transfer being the main mechanism for its oxidation to N₂.

This study involved the collection and analysis of bacteria and fungi samples in water and sediment from ten typical sub-lakes of Poyang Lake. A hydrological connectivity index system for sub-lakes was established to quantitatively assess the effect of hydrological connectivity on microbial community structure. The results indicate significant differences in the α-diversity of water bacteria, sediment bacteria, and fungal communities during different stages of the dry season, sediment bacteria and fungi showed higher α-diversity during the mid-dry season. The difference in β diversity of water bacterial community was more obvious in different periods, and the β diversity of sediment bacterial and fungal communities showed spatial differences. With the increase of hydrological connectivity, the similarity of sediment bacterial and fungal communities was lower. The water area ratio (WSP) and water depth (WD) were the main hydrological connectivity variables affecting the water bacterial community structure. Lake basin elevation (LE) and WD were the main hydrological connectivity variables affecting sediment bacteria and fungi community structure. Hydrological connectivity explained less variation in water bacterial community structure (7.6%) compared to sediment bacteria (33.3%) and fungal (29.7%) community structures. The co-interpretation rate of hydrological connectivity and physicochemical factors on bacterial community structure in water was only 2.4%, and the co-interpretation rates of bacterial and fungal community structure in sediments were 9.7% and 6.2%, respectively. Sediment bacterial and fungal communities were predominantly shaped by stochastic and deterministic processes, respectively, while both processes jointly influenced water bacterial communities. Under moderate hydrological connectivity, water bacterial communities showed stronger stochastic processes, whereas as connectivity increased, stochastic processes in sediment bacteria and fungi weakened.

The scientific prevention and effective control of environmental health risks are essential to achieving the vision of a‘Beautiful China’. However, China currently lacks comprehensive guidelines for medium and long-term environmental health risk management. This study discusses the ideal levels of environmental health risk management required to meet key milestones of a‘Beautiful China. Through the review of previous management efforts, we identify several critical challenges: insufficient risk prevention and control system, inadequate regulatory standards for conventional pollutants, and limited research base and understanding of emerging pollutants. In the end, this study concludes by proposing a future management system that prioritizes public health protection through systematic prevention and control of both conventional pollutants and emerging pollutants.

Box-Behnken response surface methodology (BBD-RSM) and back propagation artificial neural network (BP-ANN) algorithms were used to model and predict the process parameters (contact time, initial concentration, temperature, pH) of activated carbon adsorption of total phosphorus (TP), and the reaction conditions in the BP-ANN model were optimized in combination with genetic algorithms (GA). The results showed that in the BBD-RSM model, the P<0.0001, which could better predict the TP removal process, and contact time was the most significant parameter for TP removal, with the relative influence order of the factors in the TP adsorption process being: contact time > pH > temperature > initial concentration. The BP-ANN model was used for optimization, and the optimal network structure was 4-8-1. Sensitivity analysis showed that the factors affecting the TP removal rate were ranked as contact time (34.05%) > pH (28.67%) > temperature (19.56%) > initial concentration (17.72%). Based on the BP-ANN model, the GA was used to optimize the operating conditions of the artificial percolation system, and the optimization results for the TP removal process were: contact time of 720.53min, initial concentration of 2.75mg/L, temperature of 30.62℃, and pH value of 5, achieving the optimal removal rate (99.63%). Experimental validation analysis showed that BP-ANN-GA had a higher R² (0.9939) and lower RMSE (1.2851) compared with BBD-RSM when predicting against the experimental values, indicating that this model had better predictive ability and could better describe the TP removal process in the constructed rapid infiltration (CRI) system.