铜陵某富硫尾矿库周边土壤重金属污染特征及风险评价

铜陵某尾矿库堆积大量富硫尾矿,为研究其氧化状况及对周边土壤的污染情况,在尾矿库和周边采集尾矿及土壤样品,测试分析尾矿及土壤样品典型重金属(Hg、As、Cr、Cd、Pb、Zn)含量和赋存形态,并基于单因子污染指数法和内梅罗综合污染指数法对土壤污染状况进行了评价。结果表明:(1)尾矿中Fe_2O_3平均占比达到38.08%(质量分数,下同),S平均占比达到5.34%;(2)尾矿库周边土壤中Cd、As、Zn、Hg严重超标,分别为《土壤环境质量农用地土壤污染风险管控标准(试行)》(GB 15618—2018)风险筛选值的6.3、3.7、1.8、1.5倍;(3)土壤中重金属主要以残渣态形式存在,但Cd、Hg、Zn的非残渣态平均占比均达到25%以上,生物有效性较高,对周边环境存在潜在危害;(4)两种污染指数法评价结果表明,尾矿库周边土壤以Cd、As、Zn污染为主,该富硫尾矿库已对周边环境造成重度污染。     

Inhalation transfer factors for air pollution health risk assessment

To facilitate routine health risk assessments, we develop the concept of an inhalation transfer factor (ITF). The ITF is defined as the pollutant mass inhaled by an exposed individual per unit pollutant mass emitted from an air pollution source. A cumulative population inhalation transfer factor (PITF) is also defined to describe the total fraction of an emitted pollutant inhaled by all members of the exposed population. In this paper, ITFs and PITFs are calculated for outdoor releases from area, point, and line sources, indoor releases in single zone and multizone indoor environments, and releases within motor vehicles. Typical PITFs for an urban area from emissions outdoors are approximately 10(-6)-10(-3). PITFs associated with emissions in buildings or in moving vehicles are typically much higher, approximately 10(-3)-10(-1).     

UniTank工艺流程氨氮浓度的动态特征

利用基于ASM2D的数学模型对上海石洞口污水厂UniTank工艺内氨氮浓度的动态特性进行了仿真研究,发现该流程反应器氨氮浓度具有非稳态特征.反应器内氨氮浓度的变化规律与曝气时间设定及进水时间设定有关.增加曝气强度,能降低边池及中池的氨氮浓度,相应增大边池及中池的硝态氮浓度.     

HYDRUS-1D软件在地下水污染源强定量评价中的应用

以垃圾填埋场渗滤液中的氨氮为研究对象,利用HYDRUS-1D模型模拟其在包气带中的迁移转化规律,最终预测出氨氮到达地下水位处时的浓度值。引入折减系数的概念,通过改变填埋场渗滤液中氨氮的初始浓度及土壤包气带结构,计算不同输入条件下的折减系数值,用其综合反映包气带对于某一特征污染物的衰减能力,为地下水污染源强定量评价提供数据支持。     

Application of air pollution dispersion modeling for source-contribution assessment and model performance evaluation at integrated industrial estate-Pantnagar

Source-contribution assessment of ambient NO₂ concentration was performed at Pantnagar, India through simulation of two urban mathematical dispersive models namely Gaussian Finite Line Source Model (GFLSM) and Industrial Source Complex Model (ISCST-3) and model performances were evaluated. Principal approaches were development of comprehensive emission inventory, monitoring of traffic density and regional air quality and conclusively simulation of urban dispersive models. Initially, 18 industries were found responsible for emission of 39.11 kg/h of NO₂ through 43 elevated stacks. Further, vehicular emission potential in terms of NO₂ was computed as 7.1 kg/h. Air quality monitoring delineates an annual average NO₂ concentration of 32.6 μg/m³. Finally, GFLSM and ISCST-3 were simulated in conjunction with developed emission inventories and existing meteorological conditions. Models simulation indicated that contribution of NO₂ from industrial and vehicular source was in a range of 45-70% and 9-39%, respectively. Further, statistical analysis revealed satisfactory model performance with an aggregate accuracy of 61.9%.     

A quantitative assessment of source contributions to inhalable particulate matter pollution in metropolitan Boston

In this paper, source apportionment techniques are employed to identify and quantify the major particle pollution source classes affecting a monitoring site in metropolitan Boston, MA. A Principal Component Analysis (PCA) of paniculate elemental data allows the estimation of mass contributions for five fine mass panicle source classes (soil, motor vehicle, coal related, oil and salt aerosols), and six coarse panicle source classes (soil, motor vehicle, refuse incineration, residual oil, salt and sulfate aerosols). Also derived are the elemental characteristics of those source aerosols and their contributions to the total recorded elemental concentrations (i.e. an elemental mass balance). These are estimated by applying a new approach to apportioning mass among various PCA source components: the calculation of Absolute Principal Component Scores, and the subsequent regression of daily mass and elemental concentrations on these scores.One advantage of the PCA source apportionment approach developed is that it allows the estimation of mass and source particle characteristics for an unconventional source category: transported (coal combustion related) aerosols. This particle class is estimated to represent a major portion of the aerosol mass, averaging roughly 40 per cent of the fine mass and 25 per cent of the inhalable particle mass at the Watertown, MA site. About 45 per cent of the fine particle sulfur is ascribed to this one component, with only 20 per cent assigned to pollution from local sources. The composition of the coal related aerosol at this site is found to be quite different from particles measured in the stacks of coal-fired power plants. Sulfates were estimated to comprise a much larger percentage of the ambient coal related aerosol than has been measured in stacks, while crustal element percentages were much reduced. This is thought to be due to primary panicle deposition and secondary aerosol accretion experienced during transport. Overall, the results indicate that the application of further emission controls to local point sources of particles would have less influence on fine aerosol and sulfate concentrations than would the control of more distant emissions causing aerosols transported into the Boston vicinity.     

Engineering risk assessment for emergency disposal projects of sudden water pollution incidents

Without an engineering risk assessment for emergency disposal in response to sudden water pollution incidents, responders are prone to be challenged during emergency decision making. To address this gap, the concept and framework of emergency disposal engineering risks are reported in this paper. The proposed risk index system covers three stages consistent with the progress of an emergency disposal project. Fuzzy fault tree analysis (FFTA), a logical and diagrammatic method, was developed to evaluate the potential failure during the process of emergency disposal. The probability of basic events and their combination, which caused the failure of an emergency disposal project, were calculated based on the case of an emergency disposal project of an aniline pollution incident in the Zhuozhang River, Changzhi, China, in 2014. The critical events that can cause the occurrence of a top event (TE) were identified according to their contribution. Finally, advices on how to take measures using limited resources to prevent the failure of a TE are given according to the quantified results of risk magnitude. The proposed approach could be a potential useful safeguard for the implementation of an emergency disposal project during the process of emergency response.

     

滇池流域地下水污染风险评价及其防控研究

地下水是维系水系统良性循环和支撑生态系统协调发展的重要保障.针对滇池流域水文地质特征,选择含水层介质、地形坡度、河网距离以及硝态氮单位面积污染负荷4个评价因子对地下水污染风险进行综合评价.利用层次分析法确定4个评价因子的权重并进行图层叠加分析,将地下水污染风险划分为敏感区、易污染区和一般防控区进行分区防控.最后提出防治措施,以期为水资源的优化配置和水体保护提供参考.     

Effects of wind shear on pollution dispersion

Using an accurate numerical method for simulating the advection and diffusion of pollution puffs, it is demonstrated that point releases of pollution grow into a shape reflecting the vertical wind shear profile experienced by the puff within a time scale less than 4 h. For distances beyond several 10 s of kilometers from a release point, shear-related dispersion effects are probably the dominant mechanism affecting the area and magnitude of surface impacts. For assessing long-range pollutant dispersion, the common assumption that pollutants disperse as horizontally spherical “puffs” in the atmosphere is inherently inaccurate since shear-induced horizontal spreading of pollution is not a homogeneous “turbulent-like” diffusion process. A Lagrangian puff model can simulate an area impacted by a pollution puff only if larger shear-dependent horizontal puff dispersions are assumed. However, even if impacted areas are reasonably simulated, peak concentrations will be severely underestimated since atmospheric puffs influenced by even small amounts of wind shear are nonspherical. If horizontal dispersion coefficients in a Lagrangian puff model are adjusted so that peak concentrations are correctly simulated, then the calculated pollution impact area will be severely skewed. In shear environments, no choice of horizontal dispersion coefficients in a single-puff Lagrangian model will yield reasonable correlations with puffs that are skewed into nonspherical shapes by atmospheric wind shear.     

中压紫外/氯水处理工艺过程中氯的分解规律

在中压紫外/氯高级氧化技术应用于去除水中微量污染物的过程中,氯的浓度会由于光解作用而降低,直接影响该技术的处理效率.为解决上述问题,通过测定不同中压紫外剂量下氯浓度的变化,研究了氯的分解规律,以及氯投加量、pH、温度、腐殖酸和常见阴离子等条件对氯分解速率的影响.结果表明,氯的分解遵循一级动力学,其分解速率常数kobs随...     

Exposure and hazard assessment within the life cycle impact assessment

Environmental Science and Pollution Research -     

海浪河水环境重金属污染健康风险评价

为阐明海浪河地表水体中重金属污染物的分布特征与风险水平,对研究区域内As、Cd、Zn、Cu、Pb、Mn等重金属污染物浓度进行了分析检测,并采用美国环境保护局(USEPA)推荐的健康风险评价模型对水体中重金属引起的健康风险进行了评价。结果表明,各采样点的重金属监测数据中As、Cd、Zn 和Cu均达到Ⅱ类水质标准,符合水环境功能区划要求,Pb是海浪河主要超标污染物。海浪河重金属As和Cd的健康风险值远远大于Zn、Cu、Pb和Mn的健康风险值,风险值相差4~5个数量级。致癌物As的健康风险值最大,在S5和S6采样点分别达到了5.81×10-5和9.43×10-5a-1,均高于最大可接受风险水平5.0×10-5a-1。     

长荡湖入湖河流底泥污染特征和潜在生态风险评价

选择长荡湖入湖河流为研究对象,分析河流底泥营养盐、有机质和重金属的分布特征,采用潜在生态风险指数法评价底泥重金属的潜在污染风险水平。结果表明,长荡湖入湖河流底泥中总氮和总磷均低于流域背景的平均水平,分别为1 134.15和664.81 mg·kg⁻¹,氮、磷化学计量比 (N/P = 1.96)也低于我国不同纬度典型的湖泊底泥平均水平(N/P =3.89~9.57),且所有底泥中总磷都存在较高的污染负荷。有机质的平均质量分数为1.23%,除方洛港外,整体质量分数相对较低,与总磷和总氮强相关。入湖河流底泥中重金属的平均质量分数高于背景值,特别是新河港、方洛港和大浦港,其中Cu、Zn、Cd和Hg的平均质量分数显著高于流域背景值,分别为48.25、163.47、0.37和0.12 mg·kg⁻¹。潜在污染风险主要存在于新河港和方洛港,其风险指数分别为328.8和222.26。方洛港存在潜在污染风险的底泥主要集中在深层底泥的45 cm以下,且赋存了大量的营养盐,人为干扰可能再次释放营养盐,故不建议实施清淤工程。该研究结果可为同类湖泊水质监管与治理提供参考。     

洋河流域不同时空水体重金属污染及健康风险评价

确定水体重金属污染及健康风险时空变化趋势,对流域水环境管理具有重要指导意义。基于1995年、2005年和2015年洋河流域10个监测断面的重金属监测数据,采用健康风险评价模型,对洋河流域As、Cd、Pb、Hg 和 Cu 的浓度及其引起健康风险的时空变化进行了评价。结果表明,洋河流域重金属污染及其健康风险在时间上呈降低趋势,超过地表水质量标准三类标准的重金属由1995年的Cd、Pb和Hg变为2005年和2015年的Cd、Pb。致癌物质As和Cd所引起的个人年均风险远远高于非致癌物质 Pb、Hg 和 Cu。重金属健康风险总和在1995年所有监测断面均超过国际辐射防护委员会（ICRP）推荐的最大可接受风险水平,2005年全部在最大可接受风险水平以下,2015年只有响水铺略微高于该水平。在空间分布上,重金属污染较为严重及其健康风险较大的区域集中于南洋河下游城区段、清水河下游张家口市区段和洋河干流下游段。     

罗时江河口湿地沉积物磷的空间分布及污染风险评价

以云南洱海罗时江入湖河口湿地为典型对象,利用柱状底泥分层采样器采集罗时江河口湿地沉积物样品,0~10 cm为表层,10~30 cm为中层,30~60 cm为底层,分析了3层沉积物的总磷含量。研究结果表明,(1)从水平方向看,罗时江河口湿地各层(表层、中层、底层)沉积物总磷分布均呈现出沿2条主水道(水道Ⅰ和水道Ⅱ)向岸边递减,并在入水口处出现峰值的规律;垂直方向上看,总磷含量随着沉积深度增加而减少,表层富集明显。表层、中层和底层沉积物总磷平均含量分别为1.09、1.03和0.99 g/kg。(2)运用单因子污染指数评价法对沉积物总磷进行了评价,3层沉积物总磷总体属于中度污染,局部出现重度污染。各层污染程度从大到小依次为表层(1.81) >中层(1.72) >底层(1.65),重度污染主要集中在水道Ⅰ上。     

Regional distribution of cadmium minerals and risk assessment for potential cadmium pollution of soil in China

系统地分析和评价了中国镉矿的区域分布及长期采选冶活动所带来的土壤镉污染风险.研究结果表明,截至2005年底,中国累计探明镉资源储量约为719.47kt,保有镉资源储量约为587.37 kt,且多与铅矿、锌矿等以共、伴生形式存在.中国镉矿主要分布在中部、西南部及华东地区,这些地区的镉资源探明储量占中国累计探明总储量的88.0％,保有储量占中国总保有储量的87.1％.据统计,中国镉采出量约为136.10 kt,主要集中在西南地区,其镉采出量占中国总采出量的59.4％.镉污染事件主要发生在镉矿相对丰富及采选冶活动较密集的云南、广东、湖南、贵州等地区,大部分矿冶区及周边土壤呈现重度镉污染,农作物中含镉量超出《食品中污染物限量》(GB2762-2005)中限值.     

重庆市页岩气开采的浅层地下水污染风险评价

采用岩溶地下水评价模型的欧洲法完成重庆市浅层地下水脆弱性评价,以重庆市重点水污染行业空间分布为基础,结合区域页岩气井分布及开采量,完成重庆市浅层地下水污染源负荷评价。基于GIS设置叠置矩阵,实现重庆市页岩气开采浅层地下水污染风险评价。结果表明：重庆市浅层地下水固有脆弱性中等及以上区域面积29 065.4 km2,占全市35.27%,主要分布在渝东北大巴山及渝东南武陵山地区;重庆市页岩气开采污染源负荷中等及以上区域面积29 124.98 km2,占全市35.35%,主要分布在中部涪陵区、渝西都市区及周边;浅层地下水污染中等及以上风险区域面积12 628.07 km2,占全市总面积的15.33%,其中页岩气规划开采区内面积8 450.86 km2,占类型区面积的66.92%,占规划区18.38%,高风险区主要分布在渝中部涪陵及渝东南彭水局部、黔江局部及秀山等地,中等风险区呈分散分布。页岩气开采应尽量避开岩溶大泉、落水洞等高风险区域,强化防范地下水环境风险的措施,以保证区域地下水安全。     

成都市冬季重污染过程中挥发性有机物污染特征及来源解析

采用大气挥发性有机物(VOCs)在线监测系统对成都市冬季重污染过程的VOCs进行了连续在线观测,用正交矩阵因子分解(PMF)模型开展了VOCs源解析工作,并对重污染成因进行了分析。结果表明:观测期间成都市总VOCs(TVOCs)体积分数为21.83×10~(-9)～183.59×10~(-9),平均值为54.17×10~(-9),TVOCs中烷烃浓度最高,其次为炔烃、烯烃、芳香烃和卤代烃;成都市主要VOCs污染源为机动车排放源、液化石油气燃烧排放源、工业源、生物质燃烧源和溶剂使用源,贡献率分别为34.15%、21.57%、19.08%、15.19%、10.02%;边界层压缩和静风条件可能是导致VOCs和PM2.5浓度增加的主要原因。