Distribution,risk evaluation,and source analysis of the heavy metals in the sediment deposition of the lower Shichuanhe River,Shaanxi,China

In this study, 30 sediment samples were collected from the lower reaches of the Shichuanhe River in Xi’an, Shaanxi Province, China, to test the distribution of heavy metal elements in this area and for an analysis of the pollution levels of this area, hope to provide guidance on agricultural production activities in this region. The results show that the heavy metal elements in this area are mainly concentrated at the Qinghe River and Shichuanhe River confluences. Furthermore, the element contents are higher than that of the background levels of the continental crust(UCC) and close to the background levels of the soil from Shaanxi Province;the two most enriched elements are Cd and As, with contents of 0.79 and 22.7 mg·kg-1, respectively, and their contents are 3.8 and 1.72 times higher than that of the background values. Herein, the heavy metal pollution assessment methods applied indicated that Cd and As are the two most abundant pollutant elements in the area’s soils. As has a peak geo-accumulation index value of 3, and the pollution level is high, while Cd exhibits high potential ecological risks due to its high toxicity(potential risk index of 143) and an active fraction of more than 64%.In addition, a principal component analysis and hierarchical cluster analysis study showed that there are two sources of the heavy metals in this area. The Zn, As, Ni, Cu, Pb,and Cr are mainly from natural sources, and the Cd likely comes from a discharge of untreated agricultural wastewater in the region. The Cd which poses a high potential risk and mainly results from human activities, needs to be further monitored.

Multi-hierarchical fuzzy judgment and nested dominance relation of rough set theory-based environmental risk evaluation for tailings reservoirs

Environmental risk assessment of tailings reservoir assessment system is complex and has many index factors.In order to accurately judge surrounding environmental risks of tailings reservoirs and determinate the corresponding prevention and control work,multi-hierarchical fuzzy judgment and nested dominance relation of rough set theory are implemented to evaluate them and find out the rules of this evaluation system with 14 representative cases.The methods of multi-hierarchical fuzzy evaluation can overall consider each influence factor of risk assessment system and their mutual impact,and the index weight based on the analytic hierarchy process is relatively reasonable.Rough set theory based on dominance relation reduces each index attribute from the top down,largely simplifies the complexity of the original evaluation system,and considers the preferential information in each index.Furthermore,grey correlation theory is applied to analysis of importance of each reducted condition attribute.The results demonstrate the feasibility of the proposed safety evaluation system and the application potential.

Environmental risk assessment of the middle route of south－to－north water transferring source project in China

This paper focused on the environment risk of the middle route of south-to-north water transferring source project in China. Analytic hierarchy process was applied to risk identification,fuzzy probability-fault tree analysis to risk probability assessment,statistics and analogy process to risk consequences assessment, lastly, grey relevant analysis and comprehensive index process to risk impact evaluation. The main environment risk accident of the project is dam failure, the main causative factors of the accident are catastrophic flood and wrecking earthquake. The flash flood, due to dam failure, will impact on nature, society and economy. The major environment risk areas are Jingzhou and Xiangfan,Hubei Province. The environment risk management measures should be adopted in order to ensure the safety of the project-environment complex system.

Risk forecasting and evaluating model of Environmental pollution accident

Environmental risk(ER) factors come from ER source and they are controlled by the primary control mechanism(PCM) of environmental risk, due to the self failures or the effects of external environment risk trigger mechanism, the PCM could not work regularly any more, then, the ER factors will release environmental space, and an ER field is formed up. The forming of ER field does not mean that any environmental pollution accident(EPA) will break out; only the ER receptors are exposed in the ER field and damaged seriously, the potential ER really turns into an actual EPA. Researching on the general laws of evolving from environmental risk to EPA, this paper bring forwards a relevant concept model of risk forecasting and evaluating of EPA. This model provides some scientific methods for risk evaluation, prevention and emergency response of EPA. This model not only enriches and develops the theory system of environment safety and emergency response, but also acts as an instruction for public safety, enterprise's safety management and emergency response of the accident.

Risk-based evaluation on geological environment carrying capacity of mountain city - A case study in Suide County, Shaanxi Province, China

With the rapid development and expansion of the cities in China, the carrying capacity of resource and environment has become a huge concern for local governments. From the perspective of geological environment, geological disasters are the main restraining factor of the development in mountain cities. This study was conducted in Suide County of Shaanxi Province with a risk-based approach as followed: a hazard analysis on geological disasters based on a slope geological survey at a scale of 1:10,000; a consequence analysis based on unmanned aerial vehicle(UAV) aerial survey data; integrating the results of hazard analysis and consequence analysis, a risk zonation and analysis of geological disasters in urban areas were completed considering urban planning, land use planning and the safety of infrastructure and major engineering. Subsequently, taking the acceptable levels of human life and property risks incurred by landslides as the criteria of the evaluation of geological environment carrying capacity, a comprehensive assessment of current and future urban carrying capacity was conducted based on the results of the risk analyses. Accordingly, the prior development zone, the restricted development zone and the prohibited zone were delineated, with corresponding suggestions for future urban development. The technological and methodological system used in the study can be applied to geological environment carrying capacity evaluation of other important mountain cities, which can provide scientific basis for the optimization of land and space.

Characteristics and Evaluation of the High-Quality Source Rocks of Cretaceous Continental Shale Oil in Tonghua Basin, China

The presence of shale oil in the Cretaceous Hengtongshan Formation in the Tonghua Basin, drilled by the well TD-01, has been discussed in this geological investigation for the first time. To evaluate the high-quality source rocks of Cretaceous continental shale oil, the distribution characteristics and the evolution of the ancient environment, samples of shale were systematically analyzed in terms of sedimentary facies, organic geochemistry, and organic carbon isotopic composition. The results demonstrate that a TOC value of 1.5% represents the lower-limit TOC value of the high-quality source rocks. Source rocks have an aggregate thickness of 211 m and contain abundant organic matter, with TOC values of 2.69% on average and a maximum value over 5.44%. The original hydrocarbon-generative potential value(S_1+S_2) is between 0.18 mg/g and 6.13 mg/g, and the Ro is between 0.97% and 1.40%. The thermal maturation of the source rocks is relatively mature to highly mature. The δ^(13)C value range is between -34.75‰ and -26.53‰. The ratio of saturated hydrocarbons to aromatic hydrocarbons is 1.55 to 5.24, with an average of 2.85, which is greater than 1.6. The organic types are mainly type Ⅱ_1, followed by type Ⅰ. The organic carbon source was C_3 plants and hydrophytes. The paleoclimate of the Hengtongshan Formation can be characterized as hot and dry to humid, and these conditions were conducive to the development of high-quality source rocks. A favorable paleoenvironment and abundant organic carbon sources provide a solid hydrocarbon generation base for the formation and accumulation of oil and gas in the shale of the Tonghua Basin.

Considerations on Research of Environmental Risk Prevention and Control in “12th Five-Year Plan” Period

Along with the environmental pollution causes complexity and diversity increases ceaselessly, “national environmental protection” Twelfth Five “planning” (hereinafter referred to as “planning”) will be the environmental risk prevention as the “12th Five-Year Plan” one of the important tasks, including advancing environmental risk management in the whole process, key areas the environmental risk prevention measures. The whole process environmental risk management covers a risk source recognition, receptor vulnerability assessment, environmental risk characterization, risk decision and risk assessment of accident loss. This article from the environmental risk source classification, environmental risk classification management, environmental emergency response and environmental risk and insurance environment four aspects put forward the “12th Five-Year Plan” whole process environmental risk management content, to further reduce our country environmental pollution accident risk and policy makers to provide some decision support.

Spatial distribution, environmental risks, and sources of potentially toxic elements in soils from a typical abandoned antimony smelting site

The rapid development of the smelting industry increases the release of antimony(Sb)into the soil environment,which threatens human health and ecosystems.A total of 87 samples were collected from an abandoned Sb smelting site to evaluate pollution characteristics and environmental risks of the potentially toxic elements(PTEs).The contents of As,Cu,Ni,Pb,Sb,and Zn in the fresh soils determined by P-XRF were 131,120,60,145,240,and 154 mg/kg,respectively,whilst following drying,grinding,and sieving pretreatments,the corresponding contents increased to 367,179,145,295,479,and 276 mg/kg,respectively.There was a significant correlation between the data obtained by P-XRF and ICP-OES in the treated samples,which showed the application feasibility of P-XRF.The average contents of Sb and As were 440.6 and 411.6 mg/kg,respectively,which exceeded the control values of the development land in GB 36600-2018.The ecological risk levels of the six PTEs decreased in the following order:As>Sb>Pb>Zn>Ni>Cu.Non-carcinogenic risk revealed that As,Pb,and Sb posed health risks for children,whilst for carcinogenic risk,the risk values for As and Ni were higher than the limit values for both children and adults.Anthropogenic sources accounted for more than 70.0%of As,Pb,and Sb concentrations in soils,indicating a significant influence on PTEs accumulation.The findings provide a basis for quick determination of the contamination characteristics and risk control of PTEs at Sb smelting sites.

Judicial Typification of Human Rights Protection Amid Climate Risks:Legal Analysis and Path Choice

In accordance with the canonical sources of the right of legal claim,the targets of judicial review,and the intensity of judicial review intervention policies,lawsuits that directly and indirectly activate the function of human rights protection amid climate risks can be divided into the following categories:climate change lawsuits based on international human rights law,climate change lawsuits based on the domestic constitution,and judicial review of administrative procedures.Due to the singularity of the legal status and force of international human rights law,its“direct applicability”and“explanatory applicability”limit its function in protecting human rights;Climate change lawsuits based on domestic constitutions have the identification of basic right of claim,the judgment of basic rights and function,and the scope of state obligations as the judgment process.Factors such as the difficulty in right typification caused by the integration of climate law and interests,the expansion of discretionary and administrative power in legislation under the context of risk prevention,and the functional boundary of the judicial system cause the dysfunction of the dichotomous review standard of positive rights and negative rights.Procedural rights represent an important dimension of climate-related human rights.With the standardization of administrative procedures on addressing climate risks,the courts are gradually reinforcing decision-making authorities’obligation of due diligence through judicial review of risk decision-making procedures,thus indirectly guaranteeing the realization of tangible human rights.

基于不同评价方法的小浪底水库水质分析及来源解析

水质评价是水生态系统保护和水污染治理的重要基础。为探究小浪底水库不同水期水质特征,于2021年对3个断面的15个水质指标进行监测与分析。采用三种方法对研究区水环境质量进行评价,厘清水质变化规律,确定最佳的评价方法,探讨不同水期影响水质的关键环境因子并解析其来源。研究表明:库区水质总氮浓度超出地表水Ⅴ类标准,其他水质指标均达到Ⅲ类标准及以上;三种方法受指标权重影响,评价结果存在差异,综合比较与分析,确定基于TOPSIS的信息加权和排序法更适用于评价研究区水质状况;相关性分析表明,不同水期影响水质的环境因子及其来源不同,枯水期受人类活动影响,平水期水质变化与上游输入有关,丰水期受降水和水动力条件影响显著。研究结果可为小浪底水库的水环境治理提供科学依据,为库区水质评价提供新的思路。

磷指数模型在美国的应用和发展

磷是植物生长必需的营养元素之一,在农业生产中起着关键作用。然而,长期过量的磷肥投入导致土壤磷素水平增加,进而加大了土壤磷素流失风险,造成农业非点源磷污染,同时这也成为导致水体富营养化的主要因素之一。因此,识别和管理农业非点源磷的流失风险关键区,成为面源污染亟待解决的关键问题。磷指数模型起源于20世纪90年代,是评估农田磷流失潜力和指导磷管理决策的重要工具之一。根据研究区特点,美国众多学者在各州设立了不同的磷指数指标体系,优化了磷指数的组成因子、计算方法和分级标准。本文对美国各州磷指数模型评价体系进行了综述和评价,指出了磷指数模型的局限性,提出了改进方向,以期为我国磷素管理方法提供借鉴。

多指标融合赋权综合预警的冲击危险评价方法

为了进一步丰富工作面冲击危险评价方法,完善冲击地压防治体系,结合理论分析与工程实践,建立了融合4项评价指标的冲击危险综合评价指数W,用于工作面开采期间的冲击危险评价,联合震源定位及波速层析成像技术实现了对各开采区域冲击危险的综合预警。研究结果表明:(1)地质条件复杂及不规则煤柱区域震源聚集,波速高值异常;(2)融合多指标赋权建立的冲击危险综合评价指数W与震源数量及能级成较好的耦合关系,能适用于工作面冲击危险评价;(3)综合震源定位、波速层析成像和多指标融合赋权的冲击危险评价方法,可实现对高应力集中区的识别、冲击危险区域的定位、冲击危险等级的判定和卸压效果的检测。研究结果可为煤矿动力灾害的防治提供参考。

基于LEC法的磷矿矿山作业岗位水患风险评价

在地下矿山建设和生产时期,水患从始至终都是影响正常生产及人员安全的重要因素。为有效评价地下磷矿矿山开采作业中遇到水患风险情况,基于地下磷矿矿山掘进作业活动、工作步骤和场所部位,选取透水作为主要事故类型,并对涉及水患的作业岗位进行识别判定,运用增加修正系数后的作业条件危险性分析法对其进行评价,得出了相对前一个风险评价时期的风险等级,以及涉及水患岗位面临透水事故三个重要参数-事故发生的可能性变化、暴露于危险环境频繁程度和危险性相较于前期变化,然后确定使得风险的等级变化的影响要素,使得各个责任部门、岗位以及管控层级明确自身防控重点,落实安全责任。

焦化污染区春季VOCs的污染特征及其控制策略

在对介休焦化区和方山对照区春季大气挥发性有机化合物(VOCs)污染特征进行分析的基础上,利用等效丙烯浓度(PEC)法和最大增量反应活性(MIR)法量化了VOCs的臭氧生成潜势(OFP),利用分数气溶胶生成系数(FAC)法和二次有机气溶胶(SOAP)法计算了VOCs的二次有机气溶胶生成潜势(SOAFP),采用健康风险评价法对可能会威胁人体健康的VOCs组分进行了风险评估.在此基础上,结合熵值法和正定矩阵因子(PMF)源解析模型对VOCs的优先控制物种和优先控制污染源进行了判别.结果表明,介休焦化区VOCs污染严重,总VOCs(TVOCs)浓度是方山的2.7倍.介休焦化区VOCs组成具有明显的烷烃占比低而芳香烃和烯烃占比高的特点.介休的OFP、SOAFP与健康风险都远高于方山,分别是方山的3.0、8.9和8.8倍,对介休OFP、SOAFP和健康风险影响最大的物种分别为乙烯、甲苯和苯,削减烯烃和芳香烃的排放是控制介休二次生成与健康风险的有效途径.焦化源(32.4%)是介休VOCs的主要来源,其次为汽油型尾气源(29.0%)和溶剂使用源(16.9%),其中焦化源是介休一级控制污染物苯和乙烯的主要来源,贡献高达74.1%和98.9%,汽油型尾气源(52.0%)和溶剂使用源(31.3%)是一级控制污染物甲苯的主要来源.

滇东典型煤矿区土壤重金属生态风险及来源解析

【研究目的】研究区地处滇东重要煤炭和农业产区,弄清煤矿区土壤重金属空间分布特征、潜在生态风险和污染来源,对煤矿区生态环境保护治理和确保农业安全具有重要现实意义。【研究方法】基于网格布点法于2021年6月在典型煤矿区采集土壤样品497件,分析了土壤pH、SOM、As、Cd、Cr、Cu、Hg、Ni、Pb和Zn,运用污染负荷指数法和潜在生态风险指数法对重金属污染状况和潜在生态风险进行评价,通过主成分分析和正定矩阵因子分析(PMF)模型分析了重金属潜在来源。【研究结果】土壤pH平均值为5.39,以酸性为主,SOM含量平均值是云南省土壤背景值的1.20倍,Cr、Cu、Cd、Ni、Zn和Hg含量平均值和中位数均超过云南省土壤背景值,绝大部分采样点Cd、Cu、Cr、Ni含量超过风险筛选值,分别占94.97%、93.96%、91.35%、79.28%,少部分采样点As、Cd含量超过管制值,分别占0.20%、1.41%。污染负荷指数法评价结果显示,研究区整体呈现轻微污染。潜在生态风险指数法评价结果显示,研究区整体呈现中等风险。主成分分析和PMF模型解析结果显示,研究区土壤重金属主要来源于地质背景,其次为农业活动和大气沉降。【结论】煤矿区土壤中Cd、Hg潜在生态风险较高,土壤重金属主要来源于地质背景,其次是农业活动和大气沉降,建议加强相关污染土地的监测和管理,减少农家肥不合理施用,强化煤炭工业污染排放监管。

河南省氮素农业面源污染风险评价与关键管控区识别

农业面源污染是我国水环境保护面临的重要问题,风险评价对于农业面源污染防治具有重要意义。本研究以河南省为研究区域,采用层次分析法的分级赋值方法,基于熵值法和专家打分确定各影响因子权重,构建河南省氮素农业面源污染风险多因子综合评价模型,计算河南省氮素农业面源污染风险指数并在流域尺度上进行验证,划分氮素农业面源污染的风险等级并识别关键管控区。结果表明:种植源、养殖源和生活源分别贡献河南省31.52%、38.47%和30.01%的氮素流失负荷,流失负荷呈现为西低,中、东部高的特点。河南省有39 429 km^(2)的区域存在中风险,约占河南省总面积的23.61%,有17 318 km^(2)的区域存在高风险,约占总面积的10.37%;划定距河流2 km以内的中、高风险区为一般管控区和重点管控区,面积分别为10 982 km^(2)和9 285 km^(2)。通过与同期水质自动监测数据进行相关分析,决定系数为0.82,表明模型模拟结果具有较高的精准度。综合结果表明,建立的多因子综合评价模型具有科学性和准确性,可用于氮素农业面源污染风险的识别。

广西近岸海水和沉积物中有机氯农药的分布及生态风险

通过对广西近岸水体和沉积物中2类有机氯农药(OCPs,包括HCHs和DDTs)的大面调查,评估了广西近岸海域OCPs的分布特征、污染状况和生态风险。结果显示:广西近岸海域的海水中所有站位都未检出HCHs和DDTs,所有站位的沉积物中也未检出HCHs, 43个沉积物站位中DDTs的检出率为11.6%,沉积物中DDTs含量范围为nd~3.7 ng/g。研究表明:广西近岸水体及沉积物中OCPs的污染水平很低,沉积物中DDTs具有较为明显的空间分布规律,呈现出渔港附近含量高,以及TOC (有机碳)含量较高的河口附近含量高的特征。船舶防污漆可能是造成渔港附近DDTs含量较高的主要原因,部分河口站位主要受河流输入污染物影响,DDTs主要来源于历史残留,沉积物中TOC含量是影响DDTs残留分布的重要因素,DDTs易与悬浮物中的有机质通过吸附络合结合而沉积。生态风险评价结果显示:广西近岸海水的HCHs和DDTs生态风险极低,沉积物的HCHs生态风险也极低,沉积物中DDTs的潜在生态风险总体很低。

城市型石化企业大气环境风险防护区域划定研究

随着城市化进程日益加快,城市用地范围由中心城区向外扩张,原本位于郊区的石化企业开始与城市融合,石化企业周边的空地被开发成住宅区、商业区和生活区等人员密集的场所,导致城市型石化企业的出现。城市型石化企业与周边居民的矛盾日益突出,因此城市型石化企业急需设置足够的风险防护区域。本研究以华北某石化企业新建120 t/h酸性水汽提装置为例,依据《建设项目环境风险评价技术导则》(HJ 169—2018)的环境风险模拟程序和要求,对该项目环境风险进行预测。根据预测结果,以半径为960 m的范围作为大气环境风险防护区域进行重点防护。本研究可为城市型石化企业的风险防范措施落实、应急预案编制及生态环境部门的风险管理提供参考。

豫西典型工业区周边农田土壤重金属污染特征、生态风险与来源解析

为探究豫西典型工业区(1个钢铁厂、6个工业园、5个冶炼厂)周边农田土壤重金属污染特征与生态风险,采集并测定研究区109个土壤样品中镉(Cd)、铅(Pb)、砷(As)、锌(Zn)、铜(Cu)、铬(Cr)和镍(Ni)的含量,运用一系列指数法、形态分析、主成分分析和聚类分析等方法进行了重金属元素空间分布特征分析、污染与生态风险评价、形态和来源解析。结果表明,研究区域农田土壤重金属的污染程度与累积效应密切相关,Pb的污染程度最高,且地累积效应最强。Cd、Pb和As为引起土壤环境风险的主要因子,其对综合潜在生态风险指数的贡献率分别达到了48.26%、18.81%、15.58%。Pb和Cd的有效态含量分别高达92.49%、79.54%;Zn的铁锰氧化物结合态和Cu的有机结合态占比相对其他重金属较高,分别为33.07%、24.25%;而Cr、Ni迁移转化生态风险相对较低,在土壤中的赋存形态主要为残渣态,占比分别为91.00%、64.63%。冶炼厂(S1、S3)与周围的冶炼厂(S2、S4)、钢铁厂SW和工业园(IP1、IP2、IP3)对研究区域西北片区农田土壤重金属Pb、Cd和Zn的综合潜在生态风险产生了协同影响。Zn、Pb、Cu主要来源于工业源(冶炼厂、钢铁厂等工业生产活动);Cd和As来源于工业源(冶炼厂)和农业源;Cr、Ni主要来源为自然源。此外,Zn、Pb、Cu、Cd容易受自然淋溶、成土过程和农业活动的影响,增加迁移转化的生态风险。

大气多环芳烃的浓度水平、来源与健康风险评价综述

多环芳烃(PAHs)主要源于有机材料的不完全燃烧,具有生物蓄积性和毒性(致癌、致畸形和致突变),是一类持久性有毒物质。本文综述了大气PAHs的分类、排放特征、时空分布特征、来源解析和健康风险评价,根据不同相对分子质量、存在形式、化学结构进行PAHs分类。指出了PAHs浓度呈现季节性变化,变化趋势由高到低为:冬季、春季、秋季和夏季。比较了分子诊断比率(DRs)和受体模型,包括主成分分析(PCA)、化学质量平衡模型(CMB)、正矩阵分解(PMF)和多变量受体模型(Unmix)等多种PAHs源解析方法的优缺点。来源解析表明:DRs和PCA是应用最广泛的方法,但是其来源解析结果的准确性受到诸多因素的影响;PMF和Unmix相结合来解析PAHs来源,能仅根据受体部位的测量浓度来分配源,提供了PAHs源贡献的时间序列并且弥补了需要人为解读的局限性。文中展示了如何利用终身癌症风险增量(ILCR)模型将PAHs的来源分配用于评估健康风险,并在此过程中,确定了影响ILCR准确性的关键因素。以期为进一步开展大气PAHs污染相关研究提供参考。