The reed biochar was chemically modified using hydrochloric acid, dicyandiamide, and magnesium chloride as activators. This study investigated the effects of varying pH values, addition amounts, and initial solution concentrations on the nitrate nitrogen adsorption capacity of four types of biochar. Additionally, the adsorption kinetics and thermodynamic characteristics of the biochars for nitrate nitrogen removal were analyzed. When reed straw is pre-carbonized at 500℃ for 2hours and subsequently activated with modified materials at 700℃ for 2hours, the resultant dicyandiamide-modified biochar (DBC) exhibits the best adsorption performance, achieving a removal efficiency of 75.5%. Compared to unmodified biochar (BC), the surface morphology of the modified biochars becomes more concave, with denser pores, increased functional groups, and a specific surface area enhanced by 7 to 10 times. When the potassium nitrate concentration is 500mg/L, the optimal dosages are 1g for BC, DBC, and magnesium chloride-modified biochar (MBC), and 0.8g for hydrochloric acid-modified biochar (HBC). The nitrate nitrogen adsorption performance of DBC is favorable in a slightly alkaline environment, with the highest adsorption capacity observed at a pH of 9. The nitrate nitrogen adsorption behavior of all four biochars aligns well with the pseudo-second-order kinetic model, and their isothermal adsorption curves fit the Langmuir equation, suggesting predominantly monomolecular layer adsorption. Overall, DBC demonstrates excellent nitrate nitrogen adsorption performance and offers a promising solution for mitigating nitrate pollution in aquatic environments.

A typical urban lake (Xinghu Lake) in the Guangdong Hong Kong Macao Greater Bay Area was selected as the study area, and the density flotation method was used to extract microplastics from surface sediments. The spatiotemporal occurrence characteristics of microplastic were presented, and the potential ecological risks of microplastic were revealed, and the spatial autocorrelation of microplastic abundance was analyzed. The results showed that the average abundances of microplastic in surface sediments of Xinghu Lake were (637±392) and (1765±883) particles/kg during the wet and dry seasons, respectively. Here, the colors of microplastic were mainly blue and black, lines were the dominant microplastic shapes, and the size of microplastic was concentrated in the range of 100 to 2000µm. Rayon, polypropylene, and polyethylene terephthalate were the main polymer types of microplastic in surface sediments of Xinghu Lake during the wet and dry seasons. The abundances of microplastic in surface sediments of Xinghu Lake showed a strong spatial autocorrelation during different seasons, and the sampling interval for microplastic should be less than 435m here. Meanwhile, the average comprehensive potential ecological risk indexes of microplastic in surface sediments of Xinghu Lake were 53.0 9and 344.08 during the wet and dry seasons, which were the slight and very strong risk levels, respectively. Furthermore, the potential ecological risks of rayon microplastics were relatively high.

This study implemented an integrated precipitation-air stripping-electrochemical oxidation process to treat limestone wet desulfurization wastewater, systematically investigating the effects of operational parameters on chloride removal, nitrogen elimination, and organic pollutant degradation. The removal mechanisms of multiple contaminants were comprehensively elucidated. Through response surface methodology (RSM) optimization, the salt precipitation achieved 66.9% chloride ion removal efficiency under optimal conditions (Ca/Al/Cl molar ratio of 6.8:1.9:1, operational temperature 37.5℃). Air stripping was conducted under alkaline condition, which attained 76.5% ammonia nitrogen removal efficiency. Finally, after 180min electrochemical oxidation, the effluent ammonia nitrogen and COD concentrations were significantly reduced to 7mg/Land 165mg/L, respectively. Mechanistic analysis revealed that the introduction of calcium-aluminum salts facilitated the transformation of tetrahedral Al(OH)₄^- into Ca-O-Al octahedral under high Ca/Al ratios and appropriate thermal conditions. Cl^- were immobilized through adsorption or ion exchange by calcium-aluminum bimetallic layered hydroxide, then the Ca₄Al₂(OH)₁₂Cl₂•10H₂O was formed and precipitated from the water. After precipitation-air stripping process, the residual Cl^- concentration in the effluent was high, enabling its participation in electrochemical activation, and generating reactive species such as •Cl, •OH and ¹O₂, Thus those pollutants such as ammonia nitrogen and organic matters in the effluent was efficiently purified by direct anodic oxidation and indirect oxidation of active substances.

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.

Per-/polyfluoroalkyl substances (PFASs) and pharmaceuticals and personal care products (PPCPs) were selected as the typical emerging contaminations to investigate the pollution characteristics in the atmospheric particulate matter (APM) of Chengdu. Concentration levels of 25PFASs and 9PPCPs in the APM of Chengdu were analyzed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and source analysis was carried out on the PFASs, and the concentrations of the PFASs were correlated with total suspended particulate matter(TSP). The results showed that 10PFASs and 1PPCPs were detected in the APM. ∑₁₀PFASs concentrations ranged from 4.58 to 647.59pg/m³, with a mean value of 140.81pg/m³, and the highest level was found in PFBA (mean value of 133.18pg/m³). The concentration of ∑PPCPs ranged from 34.98 to 474.00pg/m³, with a mean value of 189.88pg/m³, among which cotinine (CTN) was the only detected PPCP. The principal component analysis indicated that the atmospheric PFASs in the atmosphere of Chengdu were mainly originated from the surfactants, textile and leather industries. Except for 6:2 Fluorotonous Sulfonic Acid (6:2FTSA) and perfluorobutanoic acid (PFBA), all the other PFASs showed a significant positive correlation with TSP(P<0.05), which is related to the presence of Fe₂O₃ oxides and organic matter in atmospheric particulate matter discussed.

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.

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.

In order to analyse the response of bacterial community structure to the abundance of nitrogen (N) and phosphorus (P) metabolic functions in different water depths of lakes, this paper presents a characterization of the spatial distribution and correlation of bacterial community structure and the abundance of N and P related metabolic functions in the surface, middle and bottom waterbodies by high-throughput sequencing technology, with Lake Dali as the object of the study. The results showed that the composition of the dominant bacterial communities in the surface, middle and bottom water layers varied significantly with the changes in the physical and chemical properties of the water. Based on the ecological network, the dominant and important genera under the first five dominant phyla were analysed under the screening criteria of degree and abundance values, and the dominant genera in the different depths of Lake Dali were significantly changed, such as three genera in the surface and middle water, and two genera in the bottom water. Comparatively, CL500-29_marine_group and Thermus in the surface water, Synechococcus and norank_o__NB1-n in the middle water, and Synechococcus、norank_o__NB1-n、norank_f__CK06-06-Mud-MAS4B-21 in the bottom water, remained consistent with the two screening criteria. Further PICRUSt2 prediction of the functional composition of the bacterial community yielded 6 primary functions and 12 secondary metabolic functions. In particular, although Pseudomonas,Paracoccus and Synechococcus showed significant positive correlation with the abundance of N and P metabolic functions, the correlation with the N and P content of different forms was different, such as Pseudomonas showed positive correlation with the change of N and P content, Paracoccus showed negative correlation with the N and P content, and Synechococcus showed negative correlation with N and positive correlation with P elements. Overall, the differences in N and P contents caused by changes in water depth had significant effects on N and P metabolism and the dominant genera.

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.

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.