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.

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.

Oxidative potential (OP) is a crucial indicator for evaluating the capacity of PM_2.5 to trigger oxidative stress. Therefore, this study employed dithiothreitol (DTT) method to measure the OP of PM_2.5. During the observation period, the results indicated that the daily average concentration of atmospheric PM_2.5 in Taiyuan severely exceeded the standard, with a maximum concentration reaching 150.91µg/m³, signifying severe air pollution. The daily average values for volume-normalized (DTT_v) and mass-normalized (DTT_m) DTT activity were (2.90±1.07)nmol/(min·m³) and (38.34±18.91)pmol/(min·µg), respectively. Meanwhile, a significant positive correlation was observed between PM_2.5 mass concentration and DTT_v (r=0.916, P<0.01), while a negative correlation was found with DTT_m. Furthermore, DTT_v exhibited significant correlations (P<0.05) with organic carbon (OC), elemental carbon (EC), metallic elements (Fe, Mn, Zn, Pb), and ionic components (K⁺, Cl^-, etc.) within PM_2.5. These phenomena suggested that DTT activity primarily depends on specific components of PM_2.5. The study further integrated the positive matrix factorization (PMF) model with the multiple linear regression algorithm. Quantitative analysis revealed that solid fuel combustion sources, such as coal combustion, were the most important sources of OP in Taiyuan, contributing 54.7%, followed by motor vehicle sources (23.3%) and dust sources (22.0%).

This study focuses on five typical lakes in cold-arid areas, analyzing the phosphorus pool capacity and phosphorus migration dynamics of sediments using methods such as phosphorus fractionation, diffusive gradients in thin films (DGT), and the DGT Induced Fluxes in Sediments model (DIFS). Partial least squares path modeling (PLS-PM) was further employed to identify the key driving factors for the endogenous phosphorus pool capacity and migration dynamics in these lakes. The results showed that the average values of total phosphorus (TP_w), total nitrogen (TN_w), and nitrogen-to-phosphorus ratio (TN_w/TP_w) in the water of the five lakes were (0.81 ± 1.31)mg/L, (3.40 ± 1.87)mg/L, and (26.13 ± 22.75), respectively, indicating that these were phosphorus-limited lakes. The average total phosphorus (TP_s) content in surface sediments was (763.48 ± 563.70)mg/kg, with calcium-bound phosphorus (Ca-P) accounting for 51.09% of the TP_s. The comprehensive pollution index (FF) values for sediments indicate a severe pollution level. The biologically available phosphorus (BAP) dissolved active phosphorus (C_DGT-P), and distribution coefficient (K_d) average (193.54 ± 55.94)mg/kg, (0.19 ± 0.14)mg/L, and (11.34 ± 9.29)cm³/g, respectively. All three indicators of phosphorus pool capacity were lower than those in lakes of the eastern plains, reflecting a relatively low phosphorus reservoir capacity in cold and arid lakes. The DIFS model shows that the reaction time (T_c) of the five lakes ranges from 0.004 to 74, 170s, lower than that of lakes in the eastern plains, indicating slower phosphorus migration dynamics and a relatively lower supply rate to the water body. PLS-PM analysis reveals that the primary factor influencing phosphorus reservoir capacity in these lakes was sediment properties (0.64,P<0.05). The main factor influencing phosphorus migration dynamics (0.95, P<0.05) was the environmental conditions of the water bodies, with limited influence from lake trophic state and phytoplankton.

To address the co-contamination of phthalic acid esters (PAEs) and cadmium (Cd) in agricultural soils of Guangxi province, a novel approach using immobilized functional microbial agent has been proposed. A composite microbial consortium, composed of three functional bacterial strains including Gordonia sp., Rhodococcus sp., and Bacillus sp., was developed with the ability to tolerate Cd and degrade PAEs. The microbial agent was immobilized on a thiol-modified montmorillonite-biochar composite carrier with optimized preparation conditions to enhance their remediation capabilities. The synergistic remediation efficacy of the agent on PAEs-Cd co-contaminated soils and the underlying mechanisms were elucidated. The results demonstrated that the composite microbial consortium achieved a degradation rate of 92.7% for total PAEs within 5days, while the carrier material exhibited a Cd saturation adsorption capacity of 15.2mg/kg. The optimal immobilization conditions were determined to be 30℃, with a bacteria-to-carrier ratio of 1:20 (V/M) for 1day. Under these conditions, the immobilized microbial agent achieved a degradation rate of 95.4% for ΣPAEs within 5days. When applied at a dosage of 1% to PAEs-Cd co-contaminated soils, the immobilized microbial agent resulted in 54.14% PAEs elimination and 37.06% decrease of exchangeable Cd after 50days. The immobilized microbial agent exhibited favorable synergistic remediation efficacy for PAEs-Cd co-contamination. The research findings provided a theoretical basis for the remediation of PAEs-Cd co-contamination in farmland soil of Guangxi and filled the theoretical gap in the control and remediation of PAEs-Cd co-contamination.

To investigate the effects of water flow disturbances on the growth and aggregation characteristics of Microcystis blooms, this study conducted controlled indoor experiments in a flume, with disturbance frequencies set at 30, 40, 50, and 60min^-1. The growth dynamics and size variation of Microcystis colonies were systematically analyzed under varying disturbance conditions. The results showed that low-intensity water flow disturbances (frequency<40min^-1 or velocity<0.026m/s) significantly promote the secretion of extracellular polymeric substances (EPS) in Microcystis, with a strong correlation observed between Chlorophyll-a and EPS concentrations (r²>0.85). Conversely, high-intensity disturbances (frequency>50min^-1 or velocity>0.034m/s) inhibited EPS secretion, leading to a weakened correlation between Chlorophyll-a and EPS concentrations (r²<0.8). Within the experimental ranges of flow velocity (0~0.08m/s) and turbulent kinetic energy (0~0.004m²/s²), the size of Microcystis colonies exhibited minimal variation (ranging from 0.4~0.6mm). Furthermore, low-intensity disturbances facilitated the formation of surface blooms with shorter durations, whereas higher-intensity disturbances suppressed bloom aggregation while extending algal survival periods.

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.

The study used humic acid (HA) to drive the potassium permanganate/persulfate (PM/PMS+HA) system to investigate the removal of small molecule organic pollutants and the effectiveness of membrane fouling control. The experimental results showed that the PM/PMS+HA system exhibited excellent removal performance for different small molecule organic compounds, including Atrazine (ATZ), Phenol (Phenol), Diclofenac Sodium (DCF), Carbamazepine (CBZ), Ibuprofen (IBP) and Sulfamethoxazole (SMX). The first-order kinetic constants of the PM/PMS+HA system were all higher than 18×10^-2min^-1, far higher than the PM/PMS system, PM system, and ultrafiltration system alone. At the same time, the PM/PMS system has a good membrane fouling alleviation effect. When HA was used as the pollutant, the effluent specific flux of the PM/PMS system only decreased to 0.919 within 15 minutes, much higher than the 0.393 obtained by HA filtration alone. Meanwhile, when using the PM/PMS system for membrane cleaning, the membrane flux recovery rate reached 98.51%. The mechanism of the PM/PMS+HA system was explored through capture experiments and measurements using a UV spectrophotometer. The experimental results indicate that during the filtration process of PM/PMS+HA, it is mainly the rich electronic HA in the system that triggers the decomposition of the composite oxidant (PM-PMS). The decompositionof composite oxidants produces reactive oxygen species (^•OH、SO₄^•-、¹O₂) and reactive manganese(Mn(V)and Mn(VI)). The generated reactive oxygen species and reactive manganese oxidize pollutants, leading to the removal of new pollutants and a decrease in the molecular weight of membrane pollutants, thereby achieving the removal of new pollutants and the control of membrane pollution. The PM/PMS system driven by pollutants has achieved the coupling of ultrafiltration membranes with advanced oxidation technology, providing new ideas for the removal of small molecule organic compounds and membrane fouling control in ultrafiltration technology.

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.

This paper used the multi-region input-output model to calculate the embodied carbon and its industrial structure of China's inter-city industrial trade based on the perspective of value-added trade, depict the structural characteristics of the embodied carbon transfer network, and the mechanism of the embodied carbon transfer network is revealed through the exponential random graph model (ERGM). The study found that: The inter-city industrial trade embodied carbon transfer network is dense but without scale, with small world structure and miscompatibility. Resource-intensive and capital-intensive industries contribute more than 90% of the embodied carbon transfer. Cities with high embodied carbon net outflow are mainly resource-based and industrial cities in the Yellow River Basin and the Bohai Rim region, while cities with high embodied carbon net inflow are mainly the national and regional central cities east of Hu Huanyong Line. Large-scale embodied carbon transfer mainly occurs among the cities within the provinces, and the inter-city embodied carbon transfer network has a certain provincial boundary effect. The embodied carbon transfer of provincial cities presents the "core-edge" structure around the provincial central cities. The embodied carbon transfer of inter-provincial cities shows the radial structure from the resource-based cities and industrial cities in the Yellow River basin and the Bohai Rim region to Beijing, Shanghai, Hangzhou, Ningbo, Suzhou, Chongqing, Guangzhou, Guangzhou and Shenzhen and other central cities. In the mechanism of inter-city embodied carbon transfer network, mutualism and preference dependence effect are important endogenous mechanisms. Cities with developed economy, dense population, high per capita consumption level and advanced industry are more inclined to flow into the embodied carbon. Cities with higher comparative advantages and low energy efficiency in resource-based industries are more inclined to outflow embodied carbon. Policy proximity and geographic proximity have a positive impact on the inter-city embodied carbon transfer network, and technical proximity has a negative impact.