Microcystis aeruginosa, which is widely acknowledged as a dominant taxon in cyanobacterial blooms, also poses a significant threat to aquatic biodiversity and human systems. In this study, the Chlorella-based biochar-supported nano zero-valent iron (BC/nZVI) composite material was prepared, in which the biochar stabilized the nano zerovalent to prevent agglomeration, achieving a high removal efficiency of 92.27 % for Microcystis aeruginosa. The reactive oxygen species (ROS), including 1O2, O2 center dot-, and center dot OH, were generated through intercellular Fenton reaction driven by the released Fe2+ and in-situ generated H2O2 by BC/nZVI. The generated ROS caused the damage of enzymatic proteins, reduced the activity of superoxide dismutase and catalase, and impaired the antioxidant system, leading to the reduction of physiological metabolism in Microcystis aeruginosa cells. Meanwhile, the BC/nZVI also led to damage of the cell membrane due to lipid peroxidation by ROS. These led to the cell lysis of M. aeruginosa through membrane damage and metabolic collapse. This study proposed a novel nanomaterial that combines safety and stability, offering a promising strategy for the efficient in-situ control of cyanobacterial blooms, thereby advancing the development of water environment quality control.

Harmful algal blooms (HABs) caused by Microcystis aeruginosa (M. aeruginosa) threaten freshwater ecosystems and human health globally, necessitating efficient and sustainable remediation strategies. Here, we demonstrate a heterogeneous photo-Fenton system using an iron-based metal-organic framework (MIL-88A(Fe)) for simultaneous M. aeruginosa inactivation and secondary pollutant degradation. Under low-power LED light, MIL-88A(Fe) catalyzed near-complete (>99.9 %) algal removal within 180 min, achieving irreversible damage to extracellular polymers (EPS), cell membranes, photosynthetic apparatus (e.g., chlorophyll-a and phycobiliproteins), and antioxidant systems (e.g., superoxide dismutase). Reactive oxygen species (HO• and O2•-) generated in the system further degraded the released algal organic matters (AOM) including microcystin-LR (MC-LR), thereby reducing secondary pollution risks. Notably, a pilot-scale trial using immobilized MIL-88A(Fe) on expanded perlites under real solar light confirmed the feasibility of this approach for real-world water treatment, with comparable efficiency to lab-scale tests. This work provides a scalable, MOF-enabled photo-Fenton strategy to address HABs and their toxic byproducts, bridging the gap between mechanistic understanding and practical application.

Cyanobacterial outbreaks seriously affect drinking water safety. Therefore, developing effective algal removal technologies is urgently needed. The study aims to investigate the effects of pH, electrode distance, current density, and initial algal concentration on electrochemical algae collection. Consequently, we loaded nanoscale zero-valent iron (nZVI) on activated carbon fiber/nickel foam (ACF/Ni) to form an ACF/nZVI/Ni composite cathode using the liquid phase reduction method and used titanium-based platinum plating (Pt/Ti) as the anode to construct a novel Pt/Ti- ACF/nZVI/Ni electrochemical system. The results showed that on pH of 6.0, the electrode distance was 10 mm, the current density was 75 mA/cm(2), and the initial algal concentration was OD680 = 0.100; the algal cell removal rate was 94.20% after electrolysis for 30 min. This paper provides an efficient and environmentally friendly electrochemical algal removal technology for protecting the safety of drinking water and dealing with cyanobacterial outbreaks.

Contaminated mining soils could lead to heavy metal pollution of surrounding farmlands under rainfall conditions. With the aids of sequential extraction, batch leaching, and dynamic leaching experiments, this study was carried out to investigate the characteristics of heavy metals in contaminated mining soils, understand their leaching behavior under different rainfall conditions, and evaluate the potential effects on surrounding farmlands. The results indicated that the concentrations of heavy metals (Cr, Ni, Cu, Zn, As, Cd, and Pb) in the contaminated mining soils were several or even twenty times higher than their corresponding background values, and Cd, Zn, Cu and Pb had considerable proportions (>50 %) in mobile forms. The leaching amounts of heavy metals from the contaminated mining soils had positive correlation with their contents in acid soluble form, and showed strong dependence on rainfall pH conditions. Acid rainfalls (pH = 4.32) can greatly increase the average annual release of Cd, Zn, Cu and Pb from mine soils in the study area, with increments ranging from 72.4 % (Pb) to 85.9 % (Cd) compared to those under alkaline conditions (pH = 7.42). The leaching of heavy metals was well fitted by two-constant, pseudo second-order and parabolic equations, indicating that their multi-layer sorption/desorption behavior on soil surface was dominated by chemical processes and their release was controlled by the diffusion within the soil pore channels. The two-column leaching experiment showed that the metal-rich leachate can lead to obvious increments of heavy metals in non-residual fractions (in particular Cd in acid soluble form) in surrounding farmlands, which would significantly raise the potential ecological risk associated with heavy metals. These findings indicate the importance of contaminated mining soils as a long-term source of heavy metals and the needs for mitigating the releases of toxic elements, especially in areas with heavy acid precipitation.

The aim of this paper was to effectively reduce environmental pollution and further improve the enzymatic hydrolysis rate of corn straw. Thus, a pretreatment method for activating cellulose by using ionic liquid to treat metal ion solution was developed. By investigating the effects of the three factors of substrate mass fraction, reaction temperature, and reaction time, and the interaction between the factors on the pretreatment effect, the response surface design method was used to optimize the conditions of ionic liquid (1-butyl-3-methylimidazolium chloride) treatment of corn straw after activation, and the physicochemical structure and enzymatic hydrolysis efficiency before and after treatment were compared and analyzed. The experimental results showed that the yield of reducing sugar was increased by 157.85% and 150.41%, respectively, compared with the untreated corn straw. The analysis of chemical composition and structure showed that the cellulose content of the material increased significantly by 68.11% and 60.54%, respectively, after ionic liquid treatment. The results of the scanning electron microscope (SEM) observation and X-ray diffraction (XRD) showed that the relative crystallinity of the material decreased after ionic liquid treatment, which was more conducive to the enzymatic hydrolysis of cellulose.

Soil pollution is a global environmental problem. Nanoscale zero-valent iron (nZVI) as a kind of emerging remedial material is used for contaminated soil, which can quickly and effectively degrade and remove pollutants such as organic halides, nitrates and heavy metals in soil, respectively. However, nZVI and its composites can enter the soil environment in the application process, affect the physical and chemical properties of the soil, be absorbed by microorganisms and affect the growth and metabolism of microorganisms, thus affecting the ecological environment of the entire soil. Because of the potential risks of nZVI to the environment and ecosystems, this paper summarizes the current application of nZVI in the remediation of contaminated soil environments, summarizes the various factors affecting the toxic effects of nZVI particles and comprehensively analyzes the toxic effects of nZVI on microorganisms, toxic mechanisms and cell defense behaviors to provide a theoretical reference for subsequent biosafety research on nZVI.

To investigate the treatment effect of algae biosorbent on heavy metal wastewater, in this paper, the adsorption effect of M. aeruginosa powder on heavy metal ions copper, cadmium and nickel was investigated using the uniform experimental method, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and TG-DSC comprehensive thermal analysis. The experimental results showed that the initial concentration of copper ion solution was 25 mg/L, the temperature was 30 °C, the pH value was 8 and the adsorption time was 5 h, which was the best condition for the removal of copper ions by algae powder adsorption, and the removal rate was 83.24%. The initial concentration of cadmium ion solution was 5 mg/L, the temperature was 35 °C, the pH value was 8 and the adsorption time was 4 h, which was the best condition for the adsorption of cadmium ion by algae powder, and the removal rate was 92.00%. The initial nickel ion solution concentration of 15 mg/L, temperature of 35 °C, pH value of 7 and adsorption time of 1 h were the best conditions for the adsorption of nickel ions by algae powder, and the removal rate was 88.67%. The spatial structure of algae powder changed obviously before and after adsorbing heavy metals. The functional groups such as amino and phosphate groups on the cell wall of M. aeruginosa enhanced the adsorption effect of heavy metal ions copper, cadmium and nickel. Additionally, M. aeruginosa adsorption of heavy metal ions copper, cadmium, nickel is an exothermic process. The above experiments show that M. aeruginosa can be used as a biological adsorbent to remove heavy metals, which lays a theoretical foundation for the subsequent treatment of heavy metal pollution by algae.

At present, research on the influence of human activities (especially urbanization) on the microbial diversity, structural composition, and spatial distribution of rivers is limited. In this paper, to explore the prokaryotic community structure and the relationship between the community and environmental factors in the Jialing River Basin of Chongqing, so as to provide a basis for monitoring microorganisms in the watershed. The V3–V4 region of the 16 S rRNA gene was analyzed by high-throughput sequencing and the microbial community of the waters of the Jialing River was analyzed for the diversity and composition of the prokaryotic community as well as the species difference of four samples and correlations with environmental factors. The main results of this study were as follows: (1) The diversity index showed that there were significant differences in the biodiversity among the four regions. At the genus level, Limnohabitans, unclassified_f_Comamonadaceae, and Hgcl_clade were the main dominant flora with a high abundance and evenness. (2) A Kruskal–Wallis H test was used to analyze the differences of species composition among the communities and the following conclusions were drawn: each group contained a relatively high abundance of Limnohabitans; the Shapingba District had a higher abundance of Limnohabitans, the Hechuan District had a wide range of unclassified_f_Comamonadaceae, and the Beibei District had a higher Hgcl_clade. (3) Through the determination of the physical and chemical indicators of the water—namely, total nitrogen, total phosphorus, chemical oxygen demand, chlorophyll A, and an analysis by an RDA diagram, the results demonstrated that the distribution of microbial colonies was significantly affected by the environmental factors of the water. Chemical oxygen demand and ammonia nitrogen had a significant influence on the distribution of the colonies. Different biological colonies were also affected by different environmental factors.

调研长三角典型城市213家重点行业企业398套废气处理系统的基础上,分析了吸附、吸收、冷凝、光解/光催化、低温等离子体、燃烧法和生物处理技术在不同行业的应用情况,同时分析了以上处理技术的不同组合工艺在不同行业的应用情况以及实际的VOCs净化效果.结果 表明:吸附是最常用的VOCs处理技术,具有广谱性,应用占比为47.49％,吸附再生与燃烧和冷凝等末端处理技术结合时可以达到90％的净化效率,同时废吸附剂产生量降低90％以上,实现VOCs废气处理的资源化和能源化;吸收、冷凝、光解/光催化、低温等离子体和生物法处理工艺则具有一定的选择性和偏好性.选择合理的组合处理技术,可以发挥不同处理技术的优势,保证处理系统的高效性和稳定性.

为了探讨绿肥配施减量化肥对土壤固氮菌的影响,以开展八年的紫云英配施减量化肥的长期定位试验站为平台,选取不施肥（CK）、单施化肥（NPK）、紫云英配施80%化肥（MF80）、紫云英配施60%化肥（MF60）和紫云英配施40%化肥（MF40）共5个处理,于水稻分蘖期采集土样,采用荧光定量PCR和Illumina Miseq高通量测序技术,分析了不同施肥制度下土壤固氮菌nif H基因丰度和多样性的变化规律。结果表明:与单施化肥相比,翻压紫云英的减量施肥处理水稻产量与其无显著差异,从化肥用量和产量综合考虑,MF60处理是一种适宜的施肥制度。翻压绿肥处理土壤全氮明显增加;碱解氮含量（除MF60处理）与NPK处理无显著差异。翻压紫云英配施减量化肥的施肥处理（除MF40处理）土壤固氮菌丰度明显高于NPK处理,且固氮菌丰度与土壤碱解氮、硝态氮和p H呈显著正相关。翻压紫云英后土壤固氮菌Shannon指数明显低于NPK处理,各施肥处理间OTU指数差异不明显。各施肥处理的土壤固氮菌均以变形菌门为绝对优势菌门,翻压紫云英的减量施肥处理变形菌门丰度显著低于单施化肥处理。主坐标分析表明,翻压紫云英配施减量化肥的3个施肥处理与CK、NPK处理的土壤固氮菌的群落结构差异较明显。研究表明,紫云英配施减量化肥有利于提升土壤肥力和固氮菌的数量,紫云英的施用和化肥用量都是影响土壤固氮菌群落结构的重要因素。

To understand greenhouse gas (GHG) flux in reclaimed water intake area impact on urban climate, 'static chamber' method was used to investigate the spatio-diurnal variations and the influence factors of GHG fluxes at water-air interface from Jian River to Chaobai River. Results showed that the average fluxes of CO2 from the Jian River and the Chaobai River were 73.46 mg(m(2).h)(-1) and -64.75 mg(m(2).h)(-1), respectively. CO2 was emitted the most in the Jian River, but it was absorbed from the atmosphere in the Chaobai River. Unary linear regression analyses demonstrated that Chlorophyll a (Chl a) and pH variation controlled the carbon source and sink from the Jian River to the Chaobai River. The diurnal variation of CO2 fluxes was higher at night than in the daytime in the Jian River, and it was the inverse in the Chaobai River, which highly correlated with dissociative CO2 and HCO3- transformation to CO32-. The average fluxes of CH4 from the Jian River and Chaobai River were 0.973 mg(m(2).h)(-1) and 5.556 mg(m(2).h)(-1), respectively, which increased along the water flow direction. Unary and multiple linear regression analyses demonstrated that Chl a and total organic carbon (TOC) controlled the increase of CH4 along the flow direction. The diurnal variation of CH4 fluxes was slightly higher in the daytime than at night due to the effect of water temperature.

采用三级厌氧柱串联形成的递进式强化厌氧处理工艺协同Fenton氧化工艺处理某印染厂的印染废水(COD 1 418 mg/L、色度400倍).三级厌氧柱的运行参数为:以陶粒为填料,进水pH为7.0,3个厌氧柱的HRT均为16h,柱温(33±2)℃.厌氧柱2的强化条件为投加280mg/L钙离子和30 mg/L PAM,厌氧柱3的强化条件为投加350mg/L煤质活性炭.三级厌氧柱强化前后的COD去除率分别为70.38％和84.13％,色度去除率分另为50.00％和62.50％.Fenton氧化处理的最佳条件为H2O2投加量450 mg/L、FeSO4投加量450 mg/L、反应pH 3.5、反应时间0.5 h.整个工艺的总COD去除率达96.12％、总色度去除率达78.75％,处理后出水的COD为55 mg/L、色度为85倍,满足GB 4287--2012《纺织染整工业水污染物排放标准》中的直排标准.

The pH is a primary index reflecting water quality in rivers. The Jian River and Chaobai River are two reclaimed water intake areas which have elevated pH. This elevated pH has a marked effect on both the phytoplankton, species in water and vegetation on the shore. Understanding the main reasons causing pH elevation in river water has important implications for river ecosystem management and the improvement of water quality and can provide a theoretical basis for the direction of water quality improvement. For this reason, each biogeochemical and physical process influencing pH changes in water was quantified along the flow direction in the Wenyu to Chaobai reclaimed water diversion project, in which proton consumption and production by such processes were monitored and calculated at five monitoring sections. The calculations indicated that photosynthesis and denitrification were the primary reasons for the increase of pH in the Jian River and Chaobai River. Oppositely, carbonate precipitation and sediment decomposition restricted the increase of pH in both rivers. In addition, CO2 emission to the air also promoted a increase of pH in the Jian River, while CO2 absorption from the air restricted the increase of pH in the Chaobai River. NO3- nitrogen in reclaimed water was not efficiently removed and the reclaimed water flow condition in the intake area created favorable conditions for photosynthesis of algae breeding and denitrification by microorganisms. Therefore, biogeochemical and physical processes that promoted the increase of pH were greater than inhibiting processes and the pH gradually increased along the flow direction. The contribution rates of photosynthesis and denitrification for the increase of pH were 55.48 and 27.09%, respectively, in the Jian River and 78.08 and 21.92%, respectively, in the Chaobai River. In addition, CO2 emission contributed 17.43% of the increase in pH in the Jian River.

As a new style fertilizer, slow-control release fertilizer had been an important subject in recent years, but few researches were about soil microbial community structure diversity. Phospholipid fatty acid method was used to determined the microbial community structure diversity of acid soil and slight alkaline soil applied with slow-release compound fertilizer (SRF), chemical fertilizer (CF) and common compound fertilizer (CCF) at the 10th, 30th, 60th and 90th day under the constant temperature incubation condition. Results indicated that various bacteria (i. e 13:0, i14:0,14:0, i15:0, a15:0, i16:0, 16:12OH, 16:1w5c,16:0, i17:0, a17:0, cy17:0, 17:02OH, i18:0, 18:0 and cy19:0w8c), two actinomycetes (10Me17:0 and 10Me18:0) and only one fungus (18:1 w9c) were detected in two soils after applying slow-release compound fertilizer and other fertilizers during the whole incubation period. SRF could significantly increase the fungi PLFA content by 8.3% and 6.8% at the early stage (the 10th day and 30th day) compared with CF, as well as significantly increase by 22.7% and 17.1% at the late stage (the 60th day and 90th day) compared with CCF in acid soil. SRF significantly increased bacteria, fungi and gram positive bacteria compared with CF and CCF in incubation period (except at the 30th day) in slight alkaline soil. SRF could significantly improve the ratio of normal saturated fatty acid and monounsaturated fatty acid at the 30th day and 90th days in acid soil compared with no fertilizer (CK), CF and CCF, while as to slight alkaline soil, SRF was significantly greater than that of CK, CF and CCF only at the 60th day. SRF could significantly decrease the ratio of iso PLFA and anteiso PLFA in acid soil (in 30-90 days) and slight alkaline soil (in 10-60 days). For two soils PLFA varieties, contents and ratios of microbial community, slow-release compound fertilizer increased soil microbial PLFA varieties and contents, and decreased the influence to microbial survival environment, especially for the acid soil. Through the research of slow-release compound fertilizer on soil microbial community structure diversity, it could provide a scientific basis for widely application of slow-release compound fertilizer in agricultural production.

Trichloroethylene (TCE), a widely used solvent, is often determined in groundwater and is one of biologically refractory organic contaminants. The aim of the study is to use a new chemical oxidation method to degrade TCE source pollution in groundwater. Fenton-like reactions (hydrogen peroxide catalyzed by iron minerals generates hydroxyl radicals) and sodium persulfate activation (sodium persulfate activated by heat/iron minerals to produce sulfate radicals) have strong oxidative capacity to degrade a wide range of organic contaminants. In this work, hydrogen peroxide and/or sodium persulfate catalyzed by siderite (designated as STO, SO, PO systems, respectively) degrading TCE in groundwater were investigated. Removal rates of TCE in STO, SO, and PO systems were 100%, 57%, 20%, respectively. The order of TCE removal rates is in agreement with that of hydroxyl radicals generated in the systems, indicating that hydroxyl radicals play a critical role in removing TCE. No by-product except CO2, Cl− and H2O generated as final products in the STO system suggests that TCE was near completely mineralized. The results show that the STO is an effective method to treat TCE contaminated source in groundwater.