农产品产地土壤重金属外源污染来源解析及防控策略研究

分析了工业生产排放、污水灌溉、矿产资源开发、农业投入品施用、大气颗粒物降尘及固体废弃物堆放等农产品产地土壤重金属主要外源污染来源,在此基础上构建了包括工业过程源、固定燃烧源、灌溉水源、废弃物堆放源、流动源和农业投入品源的来源清单,并从建立健全源头预防和强化过程控制2个方面,提出了加强农产品产地土壤重金属污染监管的相关建议。     

桂林市细颗粒物部分典型排放源的粒径谱及成分分析

采用在线单颗粒气溶胶质谱技术源解析方法,对桂林市PM2.5典型排放源的粒径和化学成分进行质谱分析,采集燃煤/燃气源、工业工艺源、扬尘源、油烟源4类共计7个典型排放源。结果表明,桂林市4类排放源细颗粒物的粒径分布为0.25~1.25μm,80%以上的细颗粒分布在0.2~1.0μm的小粒径范围,峰值约0.68μm。细颗粒物离子成分含有Na~+、Mg~+、K~+、NH~+4、Fe~+、Pb~+、Cd~+、V~+、Mn~+、Li~+、Al~+、Ca~+、Cu~+、Zn~+、Cr~+、CN~-、PO_3~-、NO_2~-、NO_3~-、Cl~-、SO_4~(2-)、SiO_3~-等成分,桂林市细颗粒物为元素碳、有机碳元素碳、有机碳、富锰颗粒、富铁颗粒、富钾颗粒、矿物质、左旋葡聚糖以及其他金属等9类。     

基于源流域水量水质模型研究小流域营养物管理方案

采用澳大利亚源流域水量水质模型模拟东山小流域内2001-2010年9种不同土地利用类型产生的降雨径流及总氮和总磷的污染负荷,模拟结果为:流域内多年平均径流量为6 150万m3/a,总氮输出负荷为270 t/a,总磷负荷为22 t/a。模拟结果表明:水产养殖塘和高地茶果树是东山地区主要的营养物来源。通过三个情景方案的模拟,说明当地环境管理方案可以有效地削减入湖的营养负荷,其中第二个情景方案的削减量最大,总氮和总磷负荷分别削减了18%和25%。     

Biomagnetic monitoring of industry-derived particulate pollution

Clear association exists between ambient PM₁₀ concentrations and adverse health outcomes. However, determination of the strength of associations between exposure and illness is limited by low spatial-resolution of particulate concentration measurements. Conventional fixed monitoring stations provide high temporal-resolution data, but cannot capture fine-scale spatial variations. Here we examine the utility of biomagnetic monitoring for spatial mapping of PM₁₀ concentrations around a major industrial site. We combine leaf magnetic measurements with co-located PM₁₀ measurements to achieve inter-calibration. Comparison of the leaf-calculated and measured PM₁₀ concentrations with PM₁₀ predictions from a widely-used atmospheric dispersion model indicates that modelling of stack emissions alone substantially under-predicts ambient PM₁₀ concentrations in parts of the study area. Some of this discrepancy might be attributable to fugitive emissions from the industrial site. The composition of the magnetic particulates from vehicle and industry-derived sources differ, indicating the potential of magnetic techniques for source attribution.     

Distribution, source and risk assessment of polychlorinated biphenyls (PCBs) in urban soils of Beijing, China

The concentration of PCBs in urban soils of Beijing across six land types including business districts (BD), cultural and educational areas (CE), classical gardens (CG), public green (PG), residential areas (RA), and roadsides (RD) was investigated. The total concentrations of PCBs ranged from below method detection limit (M.D.L.) to 37.11 × 10⁻³ mg kg⁻¹ dry weight (mean: 11.70 × 10⁻³ mg kg⁻¹; median: 13.28 × 10⁻³ mg kg⁻¹), which was at a medium level compared with other cities around the world. In general, the levels of PCBs decreased from the center of Beijing city to the suburb, suggesting the increasing PCBs concentrations with the age of the urban area. For different types of land use, the highest level of PCBs was observed in CG soils which have the oldest age, and the homologue profiles were similar, which were predominated by lowly chlorinated congeners including di-, tri- and tetra-CBs. Principal component analysis indicated that local sources such as Aroclor 1016, 1242, and 1248 were important sources in addition to long-range transport of PCBs all over the world. Although the toxic equivalency (TEQ) concentrations of dioxin-like PCBs in all soil samples of Beijing were higher than those in other urban areas of China, they met the Canadian soil quality standard.     

Enrichment of polycyclic aromatic hydrocarbons (PAHs) in mariculture sediments of Hong Kong

Surface and core sediments collected from six fish farms in Hong Kong and from reference sites were investigated for the enrichment and sources of polycyclic aromatic hydrocarbons (PAHs). Moderately high ∑PAH₁₆ levels (123-947 ng g⁻¹, mean: 450 ng g⁻¹) were found in the surface aquaculture sediments. In comparison with the sediments from the reference sites, the average enrichment percentage of total organic carbon (TOC) and PAHs in surface sediments were 21.4 and 43.8%, respectively, and in the core sediments, 24.6 and 73.7%, respectively. Mathematical source apportionment analyses (i.e. isomer ratios, hierarchical cluster analysis, principal components analysis with multiple linear regression analysis) suggested a higher percentage of petrogenic sources in aquaculture sediments. The fish feeds might be the main source of the enriched PAHs in the aquaculture sediments. To our knowledge, this is the first study showing that PAHs in aquaculture sediments could be attributed to human aquaculture activities.     

Comparison of receptor models for source apportionment of volatile organic compounds in Beijing, China

Identifying the sources of volatile organic compounds (VOCs) is key to reducing ground-level ozone and secondary organic aerosols (SOAs). Several receptor models have been developed to apportion sources, but an intercomparison of these models had not been performed for VOCs in China. In the present study, we compared VOC sources based on chemical mass balance (CMB), UNMIX, and positive matrix factorization (PMF) models. Gasoline-related sources, petrochemical production, and liquefied petroleum gas (LPG) were identified by all three models as the major contributors, with UNMIX and PMF producing quite similar results. The contributions of gasoline-related sources and LPG estimated by the CMB model were higher, and petrochemical emissions were lower than in the UNMIX and PMF results, possibly because the VOC profiles used in the CMB model were for fresh emissions and the profiles extracted from ambient measurements by the two-factor analysis models were "aged".     

Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments of rivers and an estuary in Shanghai, China

Concentrations, spatial distribution and sources of 17 polycyclic aromatic hydrocarbons (PAHs) and methylnaphthalene were investigated in surface sediments of rivers and an estuary in Shanghai, China. Total PAH concentrations, excluding perylene, ranged from 107 to 1707 ng/g-dw. Sedimentary PAH concentrations of the Huangpu River were higher than those of the Yangtze Estuary. The concentration of the Suzhou River was close to the average concentration of the Huangpu River. PAHs source analysis suggested that, in the Yangtze Estuary, PAHs at locations far away from cities were mainly from petrogenic sources. At other locations, both petrogenic and pyrogenic inputs were significant. In the Huangpu and Suzhou Rivers, pyrogenic input outweighed other sources. The pyrogenic PAHs in the upper reaches of the Huangpu River were mainly from the incomplete combustion of grass, wood and coal, and those in the middle and lower reaches were from vehicle and vessel exhaust.     

浅议工业污染源全面达标试点中的环境监测工作

本文简要介绍了中山市在国家环保总局“十五”环境规划期间做为第一批工业污染源全面达标试点城市,环境监测部门发挥出的重要职能和作用。对工业污染源全面达标验收工作做了全面而客观的总结和评估,为日后开展此项工作的兄弟单位提供了有益的经验和启示。     

Statistical approach for the source identification of boron in leachates from industrial landfills

Boron has been found in high concentrations in leachates from landfills located throughout Japan. However, the source(s) of boron in the leachates, i.e., what kind of waste(s) releases this element into the leachate, has not been clarified. In this study, boron concentrations in leachates from 48 industrial landfills were evaluated, in relation to the categories of waste constituting the landfill in each of the sites, by multiple regression analysis. The multiple regression analyses were carried out using the log-transformed boron concentration as a dependent variable and each of 19 categories of industrial waste (according to the Japanese Waste Disposal and Public Cleansing Law) as independent variables. Stepwise variable selection was employed in the analyses. Although the significant variable(s) selected varied according to the data sets analyzed (viz., data sets from least controlled landfill sites, from controlled landfill sites, and from both), cinders, slag, and waste plastics emerged as wastes with positive partial regression coefficients that significantly explained the boron levels in the leachates. These results indicated that cinders, slag, and waste plastics were the sources of high concentrations of boron in the leachates. The results of the present exploratory statistical analyses warrant a systematic survey of the boron contents of, and leachability from, cinders, slag, and waste plastics. Received: January 17, 2000 / Accepted: July 24, 2000