Sulfamethazine (SMT), a sulfonamide antibiotic widely used in aquaculture and animal husbandry, faced enormous challenges in terms of safe and effective disposal. Secondary iron hydroxysulfate minerals, including jarosite (Jar) and schwertmannite (Sch), were low-cost, readily available, and environmentally friendly. However, their application have been bottlenecked by the regeneration of ≡Fe2+. Herein, WS2@Jar and WS2@Sch synthesized through ball milling method was used to activate peroxymonosulfate (PMS) to degrade SMT from wastewater. The effects of anion species, humic acid, actual water sources, initial pH, and different antibiotics on the degradation performance of the two systems were systematically investigated. Notably, the WS2@Jar and WS2@Sch demonstrated superior PMS activation efficiency, achieving 100% degradation of 10 mg/L SMT within 15 and 30 minutes, respectively. The degradation of SMT in both systems involved both free radical (•OH, , and ) and nonradical pathways (1O2 and electron transfer), with nonradical pathways contributing more substantially to the degradation. Valence state changes in the ≡W4+ and ≡S2- species facilitated the conversion of ≡Fe3+ to ≡Fe2+. The rapid regeneration of ≡Fe2+ on the surface of WS2@Jar and its excellent electron transfer efficiency during the reaction made the WS2@Jar/PMS system superior to the WS2@Sch/PMS system. In this study, four possible degradation pathways for SMT was proposed, and the ecotoxicity of its intermediates was discussed. In addition, this study provided a new perspective for the efficient activation of PMS using natural iron-based catalysts to remove refractory organic pollutants from wastewater.

ObjectiveTo investigate the disruptive effects of perinatal exposure to the environmental endocrine disruptor bisphenol AF (BPAF) on hepatic lipid metabolism in prepubertal (postnatal day 21, PND21) male offspring rats, and to provide scientific evidence for assessing the obesogenic effect of BPAF.MethodsSprague-Dawley (SD) rats aged 8 weeks were used in this study. Pregnant rats were divided into BPAF dose groups (2, 10, 50 mg·kg⁻¹) and a vehicle control group (corn oil), with 6 confirmed pregnant females per group. Gavage administration started from gestational day 0 and continued until the end of lactation. At PND21, one male offspring per litter was randomly selected. Serum concentrations of glucose (GLU), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), leptin (LEP), free fatty acid (FFA), as well as oxidative stress markers superoxide dismutase (SOD) and malondialdehyde (MDA), were measured. Pathological changes in liver and adipose tissues were evaluated, and the expression levels of genes related to hepatic lipid metabolism were measured.ResultsCompared to the vehicle control group, the 50 mg·kg⁻¹ group showed significantly increased serum LEP and MDA levels in male offspring (P<0.05), and significant upregulation of hepatic lipoprotein lipase (Lpl), fatty acid synthetase (Fas), and peroxisome proliferator-activated receptor γ (Pparg) gene expression (P<0.05). The 2 mg·kg⁻¹ group exhibited a significant increase in adipocyte length (P<0.05), while the 50 mg·kg⁻¹ group showed significant increases in both adipocyte area and length (P<0.05). No significant abnormalities were observed in liver histopathological examination.ConclusionPerinatal exposure to 50 mg·kg⁻1 BPAF induced adipocyte hypertrophy, elevated leptin levels, upregulation of lipid synthesis gene expression, and enhanced oxidative stress in prepubertal male offspring, suggesting that BPAF may exert environmental obesogenic effects by disrupting lipid metabolism pathways.

Secondary iron minerals play significant roles in the immobilization of As under acidic conditions, such as acid mine drainage. However, previous research works have not clarified the effect of pH on As(III) removal through coprecipitation with secondary minerals. Therefore, in this study, we aimed to investigate the discrepancy in As(III) coprecipitation with biogenic synthesized schwertmannite (Sch) and jarosite (Jar) at different pH values. For this, concentrations of Fe2+, TFe, SO4 2-, and As(III) in shake flasks were monitored during an overall incubation period of 83 h at initial pH of 1.5, 2.0, and 2.5. In addition, the physicochemical properties of collected minerals after incubation were identified using scanning electron microscopy, X-ray diffraction, pore size distribution, and Brunauer - Emmett - Teller surface area analyses. Our results showed that almost no mineral synthesis and no As(III) removal were detected in coprecipitated schwertmannite (Co-Sch) system and coprecipitated jarosite (Co-Jar) system at an initial pH of 1.5. The TFe precipitation efficiencies and As(III) removal efficiencies increased considerably and morphologies of Co-Sch and Co-Jar improved significantly when the initial pH value increased from 2.0-2.5. The maximum TFe precipitation efficiency and As(III) removal efficiency reached 30.8% and 89.6%, respectively, for the Co-Sch system, and were 47.5% and 37.4%, respectively, for the Co-Jar system. The overall results show that pH significantly affects the formation of Co-Sch and Co-Jar and the behaviour of As(III) coprecipitation. {GRAPHICAL ABSTRACT}

Soluble iron and sulfate in acid mine drainage (AMD) can be greatly removed through the formation of minerals facilitated by seed crystals. However, the difference in the effects of jarosite and schwertmannite as endogenous seed crystals to induce AMD mineralization remains unclear. This paper intends to study the effect of Fe2+ oxidation and Fe3+ mineralization in the biosynthesis of minerals using different addition amounts and methods of jarosite or schwertmannite. The results showed that the addition amount and method of different seed crystals had no effect on the Fe2+ bio-oxidation but would change the Fe3+ mineralization efficiency. With the same amount of seed crystals added, jarosite exhibited a higher capacity to promote Fe3+ mineralization than schwertmannite. Adding seed crystals before the initiation of Fe2+ oxidation (0 h) could significantly promote Fe3+ mineralization efficiency. With the increase of seed crystals, jarosite could not only shorten the time required for mineral synthesis but also improve the final mineral yield, whereas schwertmannite could only shorten the time required for mineral synthesis. When Fe2+ was completely oxidized to Fe3+ (48 h), the supplementary of jarosite could still effectively improve Fe3+ mineralization efficiency, but the addition of schwertmannite no longer affected the final mineralization degree.

Chlorinated paraffins (CPs), which were conventionally classified into short- (SCCPs), medium- (MCCPs) and long- (LCCPs) chain CPs, have received growing attention due to their wide usage and extensive detection in environmental samples and biota. The number of studies regarding the biomonitoring of CPs in human beings increased rapidly and their health risk gained great concern. This review summarized their occurrence and homologue patterns in human matrices including blood/serum, placenta, cord serum and breast milk. As the production and usage of SCCPs was progressively banned after being listed in Annex A of the Stockholm Convention, the production of MCCPs and LCCPs was stimulated. Accordingly, the ratio of MCCPs/SCCPs in human samples has increased rapidly in the last 5 years. The current understanding of exposure routes and risk assessments of CPs was also reviewed. Oral dietary intake is the most predominant source of daily CP intake, but dust ingestion, inhalation and dermal exposure is also nonnegligible, especially for MCCPs and LCCPs. Furthermore, the reported upper bound of the estimated daily intakes (EDIs) in various risk assessment studies was close to or exceeded the tolerable daily intakes (TDIs). Considering the bioaccumulation and long-lasting exposure of CPs, their health impacts on humans and the ecosystem required continuous monitoring and evaluation. CPs are extensively existed in human samples with increased M/S ratio. Dietary intake is the main source. The reported upper bound of EDIs may be close or exceed TDIs, thus further risk assessments are required.

氧化亚铁硫杆菌(A.ferrooxidans)介导的生物矿化方法可促使酸性矿山废水(Acid Mine Drainage,AMD)中Fe离子向次生铁矿物转变.采用固定化的方式来提高A.ferrooxidans密度有助于强化Fe2+的生物矿化能力.选取流化床19孔填料、弹性填料、悬浮球填料作为挂膜对象,通过多批次的连续培养来考察3种填料的A.ferrooxidans挂膜能力及稳定挂膜所需周期,继而比较3种挂膜填料对模拟AMD中Fe2+的生物矿化能力,并估算A.ferrooxidans有效生物量.结果表明,3种填料(5.00g)的A.ferrooxidans挂膜能力依次为弹性填料(1.76 g)＞流化床19孔填料(0.90 g)＞悬浮球填料(0.78 g)(干重),且挂膜启动至稳定状态至少需要4批次.X射线衍射分析(X-ray diffraction,XRD)表明,3种填料表面含矿生物膜均为施氏矿物和黄钾铁矾的混合物.以游离态A.ferrooxidans的Fe2+氧化速率作为参比,估算出流化床19孔填料、弹性填料、悬浮球填料生物膜中A.ferrooxidans有效生物量依次为1.67×108、8.52×108、1.92×108cells·g-1(干基).研究还发现,等同Fe2+生物氧化速率下,A.ferrooxidans挂膜填料比游离态A.ferrooxidans具有更强的AMD矿化驱动能力.

Compared with the widespread and serious heavy metal contamination in soils, microplastic pollution has gained attention only recently. Little is known about how microplastics affect the distribution of heavy metals in soils, especially across soil components level. In this study, a 180-day soil aging experiment and soil density fractionation were performed to investigate the effect of polypropylene (PP) microplastics on the binding behavior of cadmium (Cd) to solid components, i.e. particulate organic matter, organo-mineral complexes (OMC), and mineral. Results showed addition of 2-10% microplastics in soils induced the decomposition of OMC fraction by 10.88-23.10%. Compared to the control, the content of dissolved organic carbon increased, and pH, humic substances, and soil organic matter decreased with microplastics. After 180d of aging, the content of Cd in OMC fraction increased by 17.92%, while microplastics made Cd contents decline by 10.01-19.75%. The impacts strongly depended on the dose and surface characteristic of microplastics. Overall, PP microplastics increased the concentration of bioavailable Cd in soils via decreasing soil retention of Cd by the OMC fraction. These findings based on the solid components level will provide a new perspective for understanding microplastics effects on soil systems and pollutants.

The impact of environmental pollution on human health has become a consensus. Based on the provincial panel data of China from 2002 to 2017, this paper analyzes the impact of industrial wastes on human health. With respect to human health, average annual frequency of physician visits per capita (AAFPV) is used as a measure for the short-term human health; all-cause mortality is used to illustrate the long-term human health. The results show that in the short term, with the level of industrial smoke dust increasing every 1 percentage, AAFPV would increase by 0.24 percentage. This effect is significant in East China and West China. Central China is affected by industrial waste water, with a rate of increasing AAFPV by 0.12 percent for every 1 percent increase of chemical oxygen demand per unit area. In the long term, water pollution is the main influencing factor of all-cause mortality.

In the field of environmental health risk assessment and management research, heavy metals in soil are a constant focus, largely because of mining and metallurgical activities, and other manufacturing or producing. However, systematic vulnerability, and combined research of social and physical vulnerability of the crowd, have received less attention in the research literature of environmental health risk assessment. For this reason, tentative design modelling for comprehensive environmental health vulnerability, which includes the index of physical and social vulnerability, was conducted here. On the basis of experimental data of heavy-metal pollution in soil and vegetables, and population and societal survey data in Daye, China, the physical, social, and comprehensive environmental health vulnerabilities of the area were analyzed, with each village as an evaluation unit. First, the polluted and reference areas were selected. Random sampling sites were distributed in the farmland of the villages in these two areas, with two sampling sites per village. Then, 204 vegetable samples were directly collected from the farmland from which the soil samples had been collected, composed of seven kinds of vegetables: cowpea, water spinach, amaranth, sweet potato leaves, tomato, eggplant, and pepper. Moreover, 400 questionnaires were given to the local residents in these corresponding villages, and 389 valid responses were obtained. The results indicated that (1) the average physical vulnerability values of the population in the polluted and reference areas were 3.99 and 1.00, respectively; (2) the village of Weiwang (WW) had the highest physical vulnerability of 8.55; (3) vegetable intake is exposure that should be paid more attention, as it contributes more than 90% to physical vulnerability among the exposure pathways; (4) arsenic and cadmium should be the priority pollutants, with average physical vulnerability value contributions of 63.9% and 17.0%, respectively; (5) according to the social vulnerability assessment, the village of Luoqiao (LQ) had the highest social vulnerability (0.77); (6) for comprehensive environmental health vulnerability, five villages near mining activities and two villages far from mine-affected area had high physical and social vulnerability, and are the urgent areas for environmental risk management. In order to promote environmental risk management, it is necessary to prioritize identifying vulnerable populations in the village-scale dimension as an innovative discovery.

The severity of environmental pollution from acid mine drainage (AMD) is increasingly garnering attention. In this study, the effects of hydraulic shear forces (achieved by regulating the shaking table’s rotation speed) on Fe2+ bio-oxidation and Fe3+ hydrolytic mineralization in an acidic 9K medium-FeSO4-Acidithiobacillus ferrooxidans system (simulated AMD) are investigated. Results reveal that a higher shaking speed favors a higher oxidation rate of Fe2+, whereas a very low or high shaking speed restricts the removal of Fe3+. Shaking table rotation speeds of 120–180 rpm were preferred for biomineralization treatment in the simulated AMD. As the initial concentration of Fe2+ in the system decreased from 9.67 to 0 g/L in 40 h, the dissolved O2 (DO) in the solution dropped to its lowest concentration after 20 h and then increased to its initial level between 40 and 120 h. However, the corresponding total Fe (TFe) precipitation efficiency increased with the increasing mineralization time after 40 h. The effect of O2 supply time on biomineralization revealed that DO was mainly used in Fe2+ bio-oxidation. After Fe2+ was completely oxidized by A. ferrooxidans, the precipitation efficiency of TFe was independent of the O2 supply.

氧化亚铁硫杆菌(A.ferrooxidans)介导的生物矿化方法促使可溶性Fe向次生铁矿物转变对酸性矿山废水(AMD)治理具有重要意义.化能自养菌A.ferrooxidans易受水流冲击而流失,常采用固定化方式来提高菌密度,从而保证较高的Fe2+氧化和成矿速率以满足实际需要.本研究在相同初始条件下(pH=2.30、Fe2+浓度4.48g/L、A.ferrooxidans密度8×106cells/mL)生物合成固定有A.ferrooxidans的施氏矿物、黄钾铁矾和黄铵铁矾,比较矿物溶解前(固定态)和溶解后(游离态)A.ferrooxidans的Fe2+氧化性能,并分析各矿物对A.ferrooxidans的固定能力.结果表明,生物成因次生铁矿物干重排序为施氏矿物(0.24g)＜黄铵铁矾(0.35g)＜黄钾铁矾(0.67g),但矿物固定A.ferrooxidans的能力却依次为施氏矿物＞黄铵铁矾＞黄钾铁矾.以游离态A.ferrooxidans的Fe2+氧化速率作为参比,推算出本研究所得施氏矿物、黄铵铁矾、黄钾铁矾固定A.ferrooxidans的有效生物量依次为5.33×107～5.33×108,5.72×106～5.72×107,6.35× 106cells/g(干基).次生铁矿物载体有效生物量不仅直接影响AMD体系中Fe2+氧化速度,也间接决定了总Fe的矿化去除效果.

From a macro perspective, the inconsistency between population distribution and economic development reflects the lag of population mobility and, at the same time, widens regions' economic disparity. China, as a socialist country, is very concerned with the regional disparities. Aiming at analyzing ways to reduce regional disparities and promote balanced and sustainable regional developments, this paper applies spatial analytical methods in econometrics, using the Yangtze River Economic Belt in China as an example, to analyze the spatial inconsistency between the distribution of population and economic development. The study also examines the influencing factors for such inconsistency and proposes countermeasures from the perspective of floating population and regional economics. The research results show that the improvement of human capital and the tilt of regional policies are conducive to population agglomeration. Furthermore, increasing the input of physical capital can promote economic agglomeration. From the spatial econometric analysis in this paper, the direct and indirect effects have opposite directions, so it is necessary to consider the indirect effects when implementing policies or programs.

股利政策是上市公司重要的财务政策之一,也是现代企业财务管理活动的核心内容之一,监管部门对公司的股利政策监管也在随着资本市场的调整而逐步发展完善.文章运用单变量分析和双重差分估计法,探究《关于修改上市公司现金分红若干规定的决定》这一政策对公司股利政策产生的影响效应.研究结果显示:存在股权再融资动机的上市公司,其发放的每股现金股利显著减少,在绝对数方面产生逆政策效应;进一步研究发现,就相对数而言,其现金股息率虽有上升的趋势,产生顺政策效应,但该效应尚不显著,政策的出台未能达到预期效应,激励企业现金股利的效果尚不明显.

本文以湖北省"十二五"环境规划的水环境保护指标为主要依据,采用压力—状态—响应(PSR)模型,从污染排放强度、水质改善效果、水资源利用和污染减排效率三个维度出发,建立湖北省"十二五"水环境保护政策评价指标体系,对政策的实施效果进行量化评估.结果表明:湖北省"十二五"期间水环境保护政策实施效果呈逐年上升趋势,从二级指标来看,政策实施在污染排放强度以及水资源利用和污染减排效率两方面均取得较好的成效,但在水质改善方面效果不明显甚至有所下降.建议湖北省在"十三五"期间以至接下来更长的一段时期内,首先要重点加强省内各局部区域的水环境承载能力评估,并依据评估结果对现有的产业布局进行有效的调整;其次应进一步强化环境监测和管理力度,以减少可能的非法排污.本文构建的指标体系对进一步促进省域水环境保护政策实施效果评价的规范化、合理化不无借鉴意义.

Acid mine drainage (AMD) is characterized typically by high acidity,soluble Fe,sulfate,and toxic metals.Thus,it is of practical significance to promote the transformation of soluble Fe and sulfate into secondary iron hydroxysulfate minerals by biomineralization ofA.ferrooxidans,which is helpful in enhancing subsequent lime neutralization efficiency of AMD due to reducing the production of ferric hydroxide and waste gypsum.In the study,we investigated that the influence of three anions (C1、NO3-、PO43-) on the pH value,bio-oxidation rate of Fe2+,total Fe deposition efficiency,and phases of secondary iron minerals in simulated AMD containing A.ferrooxidans.The results indicated that a higher concentration of monovalent cations inhibited the biological oxidation of Fe2+.The tolerance ability of A.ferrooxidans to the three anions varied significantly (PO43 ＞NO3 ＞Cl).In addition,for anion concentrations lower than those tolerated by A.ferrooxidans,Fe2+ oxidation was not affected.However,high concentration of anion can inhibited the hydrolysis and mineralization of Fe3+ indirectly by inhibiting the oxidation activity ofA.ferrooxidans,resulting in a decrease in the total Fe precipitation rate and a reduction in the secondary iron minerals production.Influenced by the decrease of Fe3+ supply rate,the synthetic pathway of secondary iron minerals was biased towards the schwertmannite.

Massive urbanization is producing large-scale urban migration in China. Based on the database of the Population Information System of the Health and Family Planning Commission, the spatial characteristics and demographic structural characteristics of migrants have been analyzed at the interprovincial, intra-provincial and city scales, using Wuhan, China as a case study. A panoramic image of the overall migration in this area has been produced, illustrating that in-migration continues to have a "squeezing" effect on low-skilled jobs with low barriers to entry. There are clear differences between in-migrants and out-migrants; the great majority of in-migrants are fertile women and floating children, and out-migrants have left their children. Moreover, basic public services are insufficient for in-migrants. This paper concludes by presenting a selection of policies to help manage migrants.

Acid mine drainage (AMD) is typically characterized by low pH, a high concentration of sulfate and dissolved heavy metals. Therefore, it is of practical significance to promote the transformation of soluble Fe and SO42- into iron hydroxysulfate minerals by biomineralization of Acidithiobacillus ferrooxidans. This enhances the lime neutralization efficiency of AMD by reducing the production of ferric hydroxide and waste gypsum. In this study, a new microbial enhanced plug-flow ditch reaction system was developed for the pretreatment of AMD on a semi-pilot scale. System stability under different hydraulic retention times (HRTs) was examined and the effects of microbe enhancement-lime neutralization technology and direct lime neutralization technology were compared. The bio-oxidation efficiency of Fe2+ (5 g L-1) reached 100% in some parts of the system when HRT was 3 and 2 days, and the time taken to reach steady state was 6 and 4 days, respectively. When the HRT was 1 day, the reaction system had operated for 4 days before the equilibrium was lost. At the optimum HRT (2 days) and after the system was stable, the average precipitation rate of total Fe was 53.62% and the average removal rate of As(III) was 17.27%. Following microbial enhanced pretreatment, the amount of lime required and waste residues generated for AMD neutralization decreased by 75.00% and 85.25%, respectively. This result supports the application of microbial enhancement-lime neutralization passive treatment technology for AMD.

Objective This study was performed to evaluate the state of heavy metal contamination in soil and vegetables and assess the health risk of inhabitants in the mine-affected area and area far from the mine (reference area) in Daye, China. Methods The heavy metal concentrations in soil and vegetable samples were detected by inductively coupled plasma mass spectrometry. Residents’ exposure parameters were obtained through a questionnaire survey. A health risk assessment model recommended by the United States Environmental Protection Agency was used to evaluate the residents’ risk of oral exposure. Results The copper, lead, cadmium, and arsenic concentrations in soil and in vegetables were higher in the mine-affected area than in the reference area. The health risk of residents in the reference area was within the acceptable range (hazard index < 1, carcinogen risk < 10 −4 ). In the contaminated area, however, the mean hazard index was 2.25 for children and 3.00 for adults, and the mean carcinogen risk was 4.749 × 10 −4 for children and 0.587 × 10 −4 for adults. Conclusions Potential health risks exist for inhabitants near the mine area. Cadmium and arsenic should be paid more attention as risk sources.

Five trace elements including Zn, Cu, Cd, Cr and As were investigated in surface water from ten typical sampling sites in Honghu Lake. The consequence indicated that all of the detected trace element levels were within the allowed standard of China’s safe water guideline. The hazard quotients (HQ) and the hazard index (HI) value levels of all the five heavy metals in all sampling sites did not exceed the acceptable risk limits of non-carcinogenic value through the selected assessment method. Pearson’s correlation analysis and principal component analysis (PCA) indicated that Zn and Cu mainly originated from the natural alluviation and non-point agricultural sources, whereas Cr and As were mainly derived from industrial effluents. Moreover, Cd mainly originated from both non-point agricultural and industrial pollution sources. In addition, cluster analysis (CA) implied that cluster 1 (including S3, S5, S6 and S10) was considered the set of high pollution sites and cluster 2 (including S4 and S9) was identified as the set of moderate pollution sites.

Acid mine drainage is highly acidic and contains large quantities of Fe and heavy metal elements. Thus, it is important to promote the transformation of Fe into secondary iron minerals that exhibit strong heavy-metal removal abilities. Using simulated acid mine drainage, this work analyzes the influence of monovalent cations (K+, NH4+, and Na+) on the Fe2+ oxidation and total Fe deposition efficiencies, as well as the phases of secondary iron minerals in an Acidithiobacillus ferrooxidans system. It also compares the Cr(VI) (K2Cr2O7) and As(III) (As2O3) removal efficiencies of different schwertmannites. The results indicated that high concentrations of monovalent cations (NH4+ ≥ 320 mmol/L, and Na+ ≥ 1600 mmol/L) inhibited the biological oxidation of Fe2+. Moreover, the mineralizing abilities of the three cations differed (K+ > NH4+ > Na+), with cumulative Fe deposition efficiencies of 58.7%, 28.1%, and 18.6%, respectively [n(M) = 53.3 mmol/L, cultivation time = 96 h]. Additionally, at initial Cr(VI) and As(III) concentrations of 10 and 1 mg/L, respectively, the Cr(VI) and As(III) removal efficiencies exhibited by schwertmannites acquired by the three mineralization systems differed [n(Na) = 53.3 > n(NH4) = 53.3 > n(K) = 0.8 mmol/L]. Overall, the analytical results suggested that the removal efficiency of toxic elements was mainly influenced by the apparent structure, particle size, and specific surface area of schwertmannite.