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.

This review summarizes the synthesis and regulation mechanisms of quorum sensing (QS) systems in Gram-negative and Gram-positive bacteria, focusing on key signalling molecules including acyl-homoserine lactones (AHLs), autoinducing peptides (AIPs), and autoinducer-2 (AI-2), as well as their applications in environmental remediation. The results demonstrate that QS-mediated regulation of bacterial collective behaviors primarily involves two critical processes: synthesis/release of signalling molecules and subsequent recognition-triggered behavioral responses. Notably, S-adenosylmethionine (SAM) serves as a common substrate for multiple QS signal biosynthesis pathways, potentially reflecting co-evolutionary adaptation between QS systems and bacterial coordination. Certain signalling molecules exhibit cross-kingdom functionality, not only adjusting conspecific bacterial behaviors but also mediating communication between phylogenetically unrelated bacteria and plants. Microbial communities leverage QS to synchronize population-level activities, optimize community architecture, and modulate synthesis of key degradation enzymes, thereby enhancing biofilm-mediated remediation efficiency. Finally, the development directions of QS-based microbial remediation technologies are discussed. The research results provide theoretical foundations and practical insights for studies on microbial remediation technologies.

In this study, a method for control of humic acid-cadmium composite pollution using MXene/PMS process in the presence of trace Fe(III) was proposed. The results showed that the removal efficiency of Cd²⁺ by MXene material in the presence of humic acid decreased from 70% to 48%, and addition of 0.5µmol/L Fe(III) and 50µmol/L peroxymonosulfate increased the removal efficiency of Cd²⁺ to above 60%. too much or less PMS inhibited the removal of Cd²⁺. Reducing Fe(III) from 1.0µmol/L to 0.3µmol/L promoted the removal of Cd²⁺. The strong reducing property of MXene material and its strong interaction with metal ions triggered the Fe(III)/Fe(II) cycle and inhibited the hydrolysis of iron ions, realizing the efficient removal of humic acid-cadmium composite pollution under neutral conditions. The reactive species generated in the reaction system were mainly hydroxyl radicals and sulfate radicals. Under the background condition of Xijiang river, this technique maintained good removal effect.

A multi-phase extraction technology was implemented to reduce the source of pollutants within a large retired chemical area in Shanghai, prevent further diffusion, and lower the health and ecological risks associated with the pollutants, while simultaneously analyzing the characteristics of NAPLs under the influence of multi-phase extraction. Through monitoring pollutants in the shallow groundwater across the site, changes in the spatial distribution of pollutants in the aquifer under extraction influence were characterized and ecological risks were assessed. The study indicated that the one-year multi-phase extraction project was significantly effective, with removal rates of pollutants in heavily contaminated areas reaching 64.56% to 99.26% at varying depths. A high degree of homogeneity and spatial autocorrelation was maintained among NAPLs prior to extraction, with correlation coefficients ranging from 0.26 to 0.72. The extraction process influenced the distribution and concentration of pollutants, resulting in changes in the correlations among them. The content and depth of DNAPLs in the site maintained a significant positive correlation, while LNAPLs exhibited a negative correlation. Under the extraction influence, the spatial distribution fitting of pollutants showed a substantial reduction in the central area and surrounding contamination halo, with the range of 1,4-dichlorobenzene pollution experiencing the largest decline, reducing the contaminated area by 91.98%. The assessment indicated that the proportion of high ecological risk points within the site significantly decreased post-extraction, and the multi-phase extraction comprehensively reduced the ecological risk of the site. However, some points of medium to high ecological risk still exist (primarily related to total petroleum hydrocarbon pollutants), which should be monitored and addressed in future remediation efforts.

In order to clarify the interference effect of multiple coexisting pollutants on the degradation of target pollutants during the irradiation treatment process of complex wastewater, a multivariate pollution model was constructed according to the composition of typical antibiotic wastewater, and radiolytic degradation experiments under different conditions were designed. The results showed that ionizing irradiation could effectively improve the water quality of cephalosporin antibiotic wastewater. After irradiation at 5kGy, the COD and TOC of the pollution model decreased by 15.4% and 13.9%, respectively. The degradation percentage of the target pollutant cefotaxime sodium (CTX) in pure aqueous solution reached more than 93%. The coexisting compounds in the pollution model all have a certain degree of interference effect on the radiolytic degradation of CTX, and there is no significant correlation between the intensity of the interference effect and the relative concentration. After irradiation at 5kGy, the degradation percentage of CTX in the pollution model was 11.8% lower than that in pure water. There were differences in the interference modes of CTX degradation when the coexisting substances existed alone (binary model) and at the same time (multivariate model). Benzothiazole, thiourea and MIBK had the greatest influence on the degradation of CTX when existing alone, of which the interference effects Δk_p were 0.18, 0.14 and 0.12, respectively; while thiourea, benzothiazole and xylene had the greatest interference effect on the degradation of CTX when existing simultaneously, the de-interference effect Δk_n were 0.22、0.17 and 0.03, respectively. The sequence of the reaction between different compounds and free radicals and the interaction between the coexisting substances have a significant effect on the degradation of CTX.

We systematically investigated the effects of two model foulants, sodium alginate (SA) and bovine serum albumin (BSA), on the efficiency of the PRO process and organic fouling behavior on both sides of the membrane when natural seawater was used as the draw solution. The presence of foulants in the feed solution led to the flux reduction caused by the fouling within the support layer, in which the fluxes of SA and BSA decreased by 42.54% and 30.99%, respectively. When filtering BSA with smaller particle size instead of SA, it led to a more significant membrane fouling due to the blockage of internal pores in the support layer. The flux was 10.08% lower in SA filtration compared to BSA in the presence of model foulants in the draw solution, with fouling behavior primarily existed on the membrane surface. According to the XDLVO theory, the interfacial energy barrier of SA towards the feed solution side was lower than that towards the support layer side, leading to less repulsion with the active layer side of the membrane and increased membrane fouling. Conversely, BSA showed lower repulsion towards the membrane support layer side, suggesting that BSA existed on the feed solution side lead to more significant membrane fouling behavior, resulting in greater flux loss.

This study analysed the spatiotemporal characteristics of dissolved oxygen (DO) concentrations upstream and downstream of sluices during dry and wet years, using data from three automated water quality monitoring stations and field measurements along the Huangjiang River in Guangdong Province. Multiple statistical methods were employed to identify the relative contributions of key influencing factors to DO variability across years under different precipitation conditions. Upstream DO concentrations were generally higher in dry years ((8.02±0.10) mg/L) than in wet years ((7.26±0.08) mg/L). In contrast, DO levels in the downstream tidal section increased from (4.45±0.10) mg/L (dry year) to (7.33±0.09) mg/L (wet year), primarily due to improved water quality. Periodic fluctuations were observed in both years, with higher DO levels during the flood season and lower levels during the non-flood season throughout the river channel. Influenced by the gate control and different external inputs, DO fluctuations upstream and downstream were driven by different factors. Rainfall and water temperature explained 44% to 87% of the DO variability upstream. While ammonia nitrogen, and COD_Mn were the most influential factors downstream, accounting for 53% to 75% of the variability. Furthermore, the “lacustrine” upstream section was especially sensitive to climate variations. In this area, the loss of phytoplankton biomass caused by stormwater runoff was a major factor contributing to DO difference during dry and wet years. While DO downstream is more easily influenced by water pollutants, especially the significant decrease in oxygen-demanding substances.

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.

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.

To systematically assess the environmental risks of natural steroidal estrogens in vegetables, there is an urgent need to establish an efficient, reliable, universal, and convenient extraction and detection system for these estrogens. This study demonstrated that the three natural steroidal estrogens showed a strong linear relationship, with a correlation coefficient greater than 0.9995. The detection limits for estradiol, 17β-estradiol, and estrone were found to be 0.36~3.23μg/kg, 0.76~3.67μg/kg, and 13.97~20.12μg/kg, respectively. The average recoveries for these substances ranged from 104.9% to 130.5%, while the relative standard deviations were between 4.9% and 18.7%. In root samples, the average recoveries were between 80.5% and 129.9%, with relative standard deviations ranging from 4.2% to 38.8%. This method detected natural estrogens in vegetable samples randomly collected in Nanjing city. The results indicated that natural estriol was detected in all vegetable samples, with a 100% detection rate in both the ground and root parts. The detection rate for 17β-estradiol was 75% in the ground part and 100% in the root. In contrast, the detection rate for estrone was 43.8% in the ground part and 18.8% in the root. Further studies are needed to assess the potential risks associated with estrone. Overall, The method exhibits high accuracy and precision, fulfilling the requirements for analysis and determination. Consequently, it provides scientific evidences for effectively assessing and control the environmental risks associated with natural steroidal estrogens in vegetables.