Application of the rescue number to the evaluation of remediation technologies for contaminated ground

An improved rescue number, RN_SOIL, which is an indicator for evaluating remediation technologies for contaminated ground that is based on both the risk and the remediation cost, is proposed as a tool of risk communication. The risk posed by contaminated ground is indicated by the figure of treatment priority at time t, FTP(t), which represents the human health risk as the number of people affected by the contaminated ground at time t during the remediation process. The calculation of the value of FTP(t) is based on exposure to contaminants that have migrated through environmental media from the contaminated ground, and is estimated by using a CalTOX model and the Monte Carlo method. The integration of FTP(t) with time, which represents the cumulative number of people affected by the contaminated ground, is used to estimate the performance of individual remediation technologies in risk reduction. The figure of unprocessibility for waste (FUW), which represents difficulties in remediation, is expressed as the remediation cost. FUW is estimated by using actual costs per unit volume of remediated soil. As an overall performance value, the rescue number for each remediation technology for contaminated ground (RN_SOIL) is calculated by multiplication of the integral FTP(t) by FUW. Smaller values of RN_SOIL are judged to indicate a better technology. The rescue index (RI), calculated as the ratio of the reduction of the integral FTP(t) to FUW, indicates the cost-effectiveness of the remediation technologies. Successful estimation of the indices (FTP(t), integral FTP(t), FUW, RN_SOIL and RI) demonstrate the usefulness of these indices in risk communication.Part of this paper was presented at 13th meeting of Japan Society of Waste Management Experts (2002)     

Is risk associated with drinking water in Australia of significant concern to justify mandatory regulation?

Presently in Australia there are no mandatory drinking water standards. Here we argue that the risk associated with drinking water in Australia is of a dimension discernible to warrant mandatory regulations. The catchments that supply the major metropolitan areas of Sydney and Adelaide, and the groundwater for the city of Perth have been seriously compromised by the encroachment of development and activities. Melbourne in the past has generally relied on a closed catchment reservoir system; however, population growth in the near future will sequester the full online operation of additional reservoirs, which have multiple land use catchments. In addition to the current landscape circumstances, the management of a water system in itself proposes significant issues of risk. Two critical assumptions that are unique to a mass medium substance like water and dramatically alter the appraisal of risk are: (1) very large numbers of people are potentially exposed, and (2) small changes in contaminant levels may have adverse population outcomes. It is also known that water reticulation systems frequently suffer from contamination problems caused solely by the distribution system, and optimal management of these facilities would best be served by statutory protected transparency and dedicated water quality programs. In 1979, an Australian parliamentary committee stated that an “uncontaminated water supply is” a “basic requirement for the obtainment of good health”; however, recent surveys of Australian water systems show many are not meeting basic water quality criteria, and many communities are not receiving regular monitoring or testing as required by government authorized Australian drinking water guidelines. Exacerbating this situation is the lack of reporting and statutory endorsed standardized procedures to ensure information is properly and promptly recorded and that data are centralized for maximum benefit. The evaluation of risk associated with drinking water in Australia is often hampered by inadequate or incomplete data. Lastly, regional and rural water supplies face a vast array of contemporary problems and experiences that include widespread usage of pesticides and agricultural chemicals. In recent years, the Darling River has experienced the worst algal bloom known to man, and this river system not only supplies a number of regional and rural towns with water, but eventually connects with the River Murray, which supplies the State of South Australia with approximately 50% of its water requirements.     

Determination of volatile organic sulfur compounds in contaminated groundwater

A practical method for the quantification of total purgeable organic sulfur (POS) in highly contaminated groundwater is described. Volatile organic sulfur compounds (VOSC) are purged from the water samples by a stream of oxygen and combusted. The emerging sulfur dioxide is absorbed in H₂O₂ and converted to sulfate which is quantified by ion chromatography and reported as mass sulfur equivalent. The overall limit of quantification is 0.03 mg l⁻¹. The content of POS is balanced with the total VOSC determined by GC-AED after liquid–liquid extraction. Separate determination of the non-volatile organic sulfur compounds by direct combustion of the water sample and adsorption to charcoal yielded a mass balance of the total sulfur content. Semi-quantitative GC-MS after purge & trap accumulation revealed that the VOSC mixture is composed of C₁–C₄ alkyl sulfides. The implementation of the developed methodology for the quantification of VOSC as potential catalyst poison in a cleaning plant for groundwater contaminated with volatile haloorganics (VOX) is presented.     

连云港春季PM2.5中主要水溶性无机离子污染特征及来源解析

于2017年3月1日—5月31日监测分析了连云港市大气PM_(2.5)中主要水溶性无机离子质量浓度的日变化规律,以及与气象因子、PM10、PM_(2.5)相关性。结果表明,水溶性无机离子质量浓度与环境空气中NO_2、CO、PM_(10)、PM_(2. 5)显著相关,与气温、风速、能见度等呈负相关;日变化呈明显单峰型,峰值出现在08:00左右;水溶性无机离子季度均值为27. 2μg/m~3,占ρ(PM_(2.5))平均50%左右,ρ(NO_3~-)、ρ(SO_4~(2-))和ρ(NH_4~+)占ρ(水溶性无机离子)总85%以上;指出,SO_4~(2-)主要受远距离传输的影响,NO_3~-和NH_4~+主要受局地源的影响。     

Particle size distribution and characteristics of heavy metals in road-deposited sediments from Beijing Olympic Park

Due to rapid urbanization and industrialization, heavy metals in road-deposited sediments(RDSs) of parks are emitted into the terrestrial, atmospheric, and water environment, and have a severe impact on residents' and tourists' health. To identify the distribution and characteristic of heavy metals in RDS and to assess the road environmental quality in Chinese parks, samples were collected from Beijing Olympic Park in the present study. The results indicated that particles with small grain size(150 μm) were the dominant fraction. The length of dry period was one of the main factors affecting the particle size distribution, as indicated by the variation of size fraction with the increase of dry days. The amount of heavy metal(i.e., Cu, Zn, Pb and Cd) content was the largest in particles with small size(150 μm) among all samples. Specifically, the percentage of Cu, Zn, Pb and Cd in these particles was 74.7%, 55.5%, 56.6% and 71.3%, respectively.Heavy metals adsorbed in sediments may mainly be contributed by road traffic emissions. The contamination levels of Pb and Cd were higher than Cu and Zn on the basis of the mean heavy metal contents. Specifically, the geoaccumulation index(I geo) decreased in the order:CdPbCuZn. This study analyzed the mobility of heavy metals in sediments using partial sequential extraction with the Tessier procedure. The results revealed that the apparent mobility and potential metal bioavailability of heavy metals in the sediments, based on the exchangeable and carbonate fractions, decreased in the order: CdZn≈PbCu.     

特别选题:环境微界面过程与污染控制序

长期以来,人们主要关注的是污染物的均相环境过程,这一点在大气污染化学和水污染化学的研究中尤其明显。然而近年来,人们开始关注环境中的非均相反应过程,从相对微观的尺度思考和探索环境的微界面问题,并从不同的视角不断认识和揭示这一过程在环境污染及其控制中的作用和意义。1997年,由荷兰科学家L.K.Koopal教授发起设立了Interfaces Against Pollution两年一次的系列国际会议,形成了全球范围内有关科学研究组织和科学家探讨和交流环境界面问题的重要平台。中国科学院生态环境研究中心汤鸿霄院士在我国首次提出环境微界面的概念,并于2003年主编了《环境科学学报》之“环境微界面过程研究论文专辑”,为该专辑作序并发表了“环境纳米污染物与微界面水质过程”的研究论文,对环境纳米微界面问题给出了全面和准确的内涵,进而开启了我国在此方面的系统性研究工作。基于汤鸿霄院士提出的环境微界面内涵和思想,2006年中国科学院生态环境研究中心组织了“环境微界面过程与污染控制”创新研究群体,得到国家自然科学基金委员会的资助。群体的研究目标是深入探索污染物在环境微界面的转移转化机制与控制原理,力争在复杂条件下微界面的定量化表征、污染物在环境微界面的转移转化规律及复合效应、基于微界面原理的环境过程调控等方面取得科学与技术突破。该研究群体的建立及深入开展相关的研究工作,将有力推动我国环境微界面理论和技术的研究进展,也将不断培养本研究方向的专业化高级人才。在过去的2年里,该研究群体在不同环境微界面特征及过程表达、污染物在典型介质和界面变化行为的原位观测、水/气/土/生物微界面上污染物的转移转化规律、基于微界面过程的水、气、固等环境的污染控制等方面取得预期研究进展。本专栏所组织的稿件,即试图从不同角度反映我们所关注的环境微界面研究领域,并通过前期研究所获得的一些具体的科学数据和结果,对环境微界面过程给出进一步的认识。然而,由于本群体的研究工作还不够深入,这样一个专栏所发表的内容不论是对环境微界面的概念与内涵,还是在探索与创新上,都还是初步的和不成熟的。或者说,本专栏所反映的只是一个有待发展和完善的科学思路。由于本专栏作者水平有限,这些论文定有不少谬误之处,敬请读者批评指正。 衷心感谢《环境科学学报》编辑部为我们提供这样一个重要的平台和机会,感谢他们为本专栏组稿、编辑和出版所做出的辛苦努力！     

Arsenic fractionation and contamination assessment in sediments of thirteen lakes from the East Plain and Yungui Plateau Ecoregions, China

Arsenic（As） fractions in the sediments of seven lakes from East Plain Ecoregion and six lakes from Yungui Plateau Ecoregion, China, were investigated. Results indicated that the total As concentrations in sediment samples of lakes of the East Plain Lake Ecoregion are higher than those of Yungui Plateau Lake Ecoregion. Residual As is the main fraction in sediment samples of lakes from both ecoregions, followed by reducible As and soluble or oxidizable As. The total As is correlated to oxidizable As and residual As in sediment samples from both lake ecoregions. As distribution in sediment samples of lakes of the East Plain Ecoregion appears to be affected by human activity, while the As origin mainly comes from natural sources in sediment samples of lakes in the Yungui Plateau Ecoregion. The potential ecological risk index and geoaccumulation index values suggest ＂low to moderate＂ risk degree and ＂unpolluted to moderately polluted＂ for As in the studied lake sediments.     

特高压电场下RTV绝缘子积污规律研究

RTV涂料表面特性与瓷、玻璃表面不同,积污的规律存在差异,对涂覆RTV涂料的特高压线路进行绝缘子积污规律的研究,有助于更好地开展特高压输电线路防污闪工作。通过仿真研究,分析了特高压输电线路电场的分布,并以四支±800 k V线路带电运行的绝缘子进行积污规律的研究,通过分别测试绝缘子上下表面的等值盐密(ESDD)、灰密(NSDD),分析了特高压RTV绝缘子的积污规律。研究发现电场影响RTV绝缘子的积污,电场强度大的位置污秽度高一些,自然环境和涂料自洁性对特高压电场下RTV绝缘子的积污其主要作用,风吹和雨水清洗对积污量的影响更大。     

Groundwater Vulnerability Assessment for Organic Compounds: Fuzzy Multicriteria Approach for Mexico City

This study was based on a groundwater vulnerability assessment approach implemented for the Mexico City Metropolitan Area (MCMA). The approach is based on a fuzzy multicriteria procedure integrated in a geographic information system. The approach combined the potential contaminant sources with the permeability of geological materials. Initially, contaminant sources were ranked by experts through the Analytic Hierarchy Process. An aggregated contaminant sources map layer was obtained through the simple additive weighting method, using a scalar multiplication of criteria weights and binary maps showing the location of each source. A permeability map layer was obtained through the reclassification of a geology map using the respective hydraulic conductivity values, followed by a linear normalization of these values against a compatible scale. A fuzzy logic procedure was then applied to transform and combine the two map layers, resulting in a groundwater vulnerability map layer of five classes: very low, low, moderate, high, and very high. Results provided a more coherent assessment of the policy-making priorities considered when discussing the vulnerability of groundwater to organic compounds. The very high and high vulnerability areas covered a relatively small area (71 km² or 1.5% of the total study area), allowing the identification of the more critical locations. The advantage of a fuzzy logic procedure is that it enables the best possible use to be made of the information available regarding groundwater vulnerability in the MCMA.