This study analyzed the carbon reduction effect of national green data centers on cities and its mechanism. Then, based on the pilot and construction work of national green data centers, a quasi-natural experiment was constructed. Using the difference-in-differences method and panel data of 283 cities from 2011 to 2022, the carbon reduction effect of national green data centers was empirically analyzed, and its mechanism and heterogeneity were explored. The pilot of national green data centers has a significant carbon reduction effect, with a coefficient of -0.013, which is significant at the 5% statistical level. The pilot of national green data centers significantly reduces the carbon emission intensity of cities. This result remains valid after multiple robustness tests, including parallel trend tests, placebo tests, exclusion of selection bias, exclusion of the impact of other policies, and exclusion of the impact of the epidemic. The pilot of national green data centers can reduce the carbon emission intensity of cities by promoting the development level of the digital industry and the green technological innovation level of the region. The impact of the pilot of national green data centers on the development level of the digital industry and the green technological innovation level is significantly positive at the 1% statistical level, with coefficients of 0.039 and 0.061, respectively. The carbon reduction effect of national green data centers is more significant in non-energy-rich cities, cities with high environmental protection levels, and cities with high information levels. The impact of the pilot of national green data centers on these three types of cities is significantly at least at the 10% statistical level, with coefficients of -0.016, -0.017, and -0.016, respectively. Therefore, efforts should be made to promote the green transformation of data centers and expand the scope of the pilot of national green data centers.

This study establishes a carbon emission reduction measurement model for the secondary ash recycled ceramsite project from the perspective of carbon footprint, combined with the National Certified Voluntary Emission Reduction (CCER) methodology. Taking the 40000 tons/year secondary ash recycled ceramsite project as an example, empirical analysis is conducted to evaluate the project's carbon emission reduction. Based on the analysis of key carbon emission factors, the carbon emission reduction potential of the secondary ash recycled ceramsite project is optimized and evaluated. The results show that the total CO₂e emission reduction of the 40000 tons/year secondary ash slag regenerated ceramsite project in 2023 is 32600 tons, of which the ceramsite production stage contributes to 95% of the emission reduction. From the perspective of carbon footprint analysis, the total annual CO₂e emissions of the project are about 64900 tons, and the processing, production, and raw material acquisition stages are key links in the carbon emissions of the ceramsite project. From the analysis of CO₂ emission source categories, the substitution of solid waste materials such as secondary ash and sludge is the key to carbon reduction in the ceramsite industry. In addition, the priority order of adding solid waste materials is secondary ash, sludge, and waste soil. Regarding the optimization of carbon emission reduction potential, under four low-carbon scenarios of green raw materials, clean power grid, low-carbon transportation, and recycling, the secondary ash regenerated ceramsite project achieved CO₂e emission reductions of 69300, 34200, 35600 and 32800 tons, respectively. Under the green raw material scenario, the ceramsite industry has a carbon emission reduction potential of 9million tons.

This study centers on environmental regulatory policies, employing a two-way fixed effect model to scrutinize their impact, underlying mechanisms, and theoretical implications on new quality productivity enhancement. A U-shaped correlation exists between environmental regulations and the enhancement of new quality productivity. Beyond a critical turning point, a 1% escalation in vertical environmental regulation intensity correlates with a 124.42% augmentation in high-quality economic development. Environmental regulations significantly bolster the advancement of new quality productivity levels in both eastern and western provinces of China. Environmental regulations serve as a catalyst in amplifying the mechanisms fostering new quality productivity, particularly by influencing the "new labor tools" and "new infrastructure" subsystems.

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 systematically investigated the synergistic interactions between biochar and the model electroactive microorganism Shewanella oneidensis MR-1 in electron transfer processes through comprehensive electrochemical analyses, kinetic modeling, and electron pathway characterization using chromium(VI)-contaminated soil as the experimental matrix. The biochar-based microbial agents demonstrated effective Cr(VI) bioremediation, with biological reduction mediated by MR-1identified as the predominant mechanism following dual-process kinetics. Optimal remediation performance (96.30% Cr(VI) reduction efficiency) was achieved under conditions of 25mg/kg Cr(VI) contamination, 5% (w/w) biochar-based microbial agents dosage, and 30% soil moisture content. Comparative analysis revealed distinct temporal remediation patterns: adsorption-based biochar-microbial composites exhibited rapid initial Cr(VI) sequestration but limited long-term stability, whereas encapsulation-based formulations showed gradual but sustained reduction capacity. Mechanistic studies demonstrated that biochar functioned as an effective microbial carrier, simultaneously enhancing MR-1proliferation and facilitating extracellular electron transfer from microbial cells to Cr(VI) contaminants through its conductive carbon matrix. Notably, the immobilized system maintained 60.44% reduction efficiency after three operational cycles, highlighting its potential for sustainable in situ remediation of chromium-contaminated soils.

This article constructed a multidimensional urban sprawl measurement index system from the structural dimension, morphological dimension, density dimension, and efficiency dimension. Based on map visualization, standard deviation ellipse, and cold and hot spot analysis, it explored the spatiotemporal characteristics and migration evolution patterns of China's urban comprehensive sprawl from 2005 to 2020. The spatiotemporal geographically weighted model (GTWR) was used to empirically examine the spatiotemporal heterogeneity of the impact of multidimensional urban sprawl on carbon emission intensity. Research shows that: (1) The comprehensive urban sprawl in China exhibited a spatial difference of "high in the east and low in the west", but the urban sprawl in the eastern coastal and northeastern regions has declined in the later stage of the sample. The standard deviation ellipse shows a trend of centripetal clustering, and the center of gravity of the distribution shifts towards the southwest as a whole. The analysis of hot and cold spots presents regional differences of "hot in the east and cold in the west". (2) The overall urban sprawl has a significant impact on carbon emissions, and over time, it plays a positive promoting role in an increasing number of cities. The positive promotion area is mainly concentrated in the central and western regions and coastal areas, while the negative inhibition area is mainly the North China Plain and the Pearl River Delta. (3) There is significant spatiotemporal heterogeneity in the influencing factors of each dimension. In terms of temporal trends, the structural dimension promotes carbon emissions in most cities and its influence increases year by year; The form dimension has shifted from a promoting effect to a inhibiting effect on carbon emissions in most cities; The density dimension and efficiency dimension suppress carbon emissions in most cities, but the density dimension shows a polarization trend year by year, while the influence of the efficiency dimension weakens overall. In terms of spatial distribution, the influence of structural dimension and density dimension is stronger in the southeastern, western, and northeastern regions, while the significant effect of morphological dimension is in the northeastern border and central western regions, and the significant effect of efficiency dimension is in the central and western regions.

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 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 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.

Sulfate radical (SO₄^•−)-based advanced oxidation processes (SR-AOPs) are characterized by in situ generation of SO₄^•− with strong oxidation capacity, which can effectively degrade a variety of organic pollutants. However, SO₄^•− can transform nitrite (NO₂⁻) and bromide (Br⁻) into toxic nitrated byproducts and halogenated byproducts, respectively. In this study, the mechanisms underlying the formation of nitrated and brominated byproducts on the reaction system in which NO₂⁻ and Br⁻ coexist were systematically investigated. Results showed that three nitrated byproducts, including 2-nitrophenol, 4-nitrophenol, and 2,4-dinitrophenol were produced during the heat-activated persulfate nitrification process. It was observed that nitrophenols accounted for approximately 34.5% of the phenol transformed under reaction conditions of [phenol]= 50µmol/L, [NO₂⁻]=100µmol/L,[PDS]=2mmol/L and temperature of 60℃ C. Once NO₂⁻ was co-present, the formation rate of nitrophenol was significantly accelerated. The conversion rate increased to 46.0% under the same conditions. Br⁻ can be oxidized by SO₄^•− to form reactive bromine species, which rapidly react with NO₂⁻ to form a strong oxidizing agent, nitryl halide. Then nitryl halide reacts with the phenol and plays a key role in promoting the formation of nitrophenol. Note that, Br⁻ is eventually released and acts as a catalyst equivalent. Meanwhile, the presence of NO₂⁻ results in an inhibition of the rate of formation of brominated byproducts, such as dibromoacetic acid. Therefore, the transformation mechanisms of NO₂⁻ and Br⁻ influence each other in SR-AOPs. When they coexist, promote the formation of nitrophenol byproducts but inhibit brominated byproducts.