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.     

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     

清洁生产、生态工业和循环经济

清洁生产、生态工业和循环经济是当今环保战略的3个主要发展方向,三者有共同之处,又有各自明确的理论、实践和运行方式.笔者在对三者的内涵作了简单介绍之后,着重从理论上探讨环境管理延伸到企业、企业群落和国民经济一切相关领域的必然性和合理性,提出并论述了生态工业与循环经济的前提和本质是清洁生产,从优质资源、生态和环境总量保有量的角度探讨了循环经济对我国国际竞争力的重要性.      

PM2.5 chemical source profiles for vehicle exhaust, vegetative burning, geological material, and coal burning in Northwestern Colorado during 1995

PM_2.5 (particles with aerodynamic diameters less than 2.5 μm) chemical source profiles applicable to speciated emissions inventories and receptor model source apportionment are reported for geological material, motor vehicle exhaust, residential coal (RCC) and wood combustion (RWC), forest fires, geothermal hot springs; and coal-fired power generation units from northwestern Colorado during 1995. Fuels and combustion conditions are similar to those of other communities of the inland western US. Coal-fired power station profiles differed substantially between different units using similar coals, with the major difference being lack of selenium in emissions from the only unit that was equipped with a dry limestone sulfur dioxide (SO₂) scrubber. SO₂ abundances relative to fine particle mass emissions in power plant emissions were seven to nine times higher than hydrogen sulfide (H₂S) abundances from geothermal springs, and one to two orders of magnitude higher than SO₂ abundances in RCC emissions, implying that the SO₂ abundance is an important marker for primary particle contributions of non-aged coal-fired power station contributions. The sum of organic and elemental carbon ranged from 1% to 10% of fine particle mass in coal-fired power plant emissions, from 5% to 10% in geological material, >50% in forest fire emissions, >60% in RWC emissions, and >95% in RCC and vehicle exhaust emissions. Water-soluble potassium (K⁺) was most abundant in vegetative burning profiles. K⁺/K ratios ranged from 0.1 in geological material profiles to 0.9 in vegetative burning emissions, confirming previous observations that soluble potassium is a good marker for vegetative burning.     

饮用水水源保护区划分问题探讨

阐述了国内外划定饮用水水源保护区的方法和原则,并举例说明了辽宁省水库水源保护区的划分情况以及相关的技术发展趋势、法律程序等。     

Modeling of a cryogenic liquid pool boiling by CFD simulation

A boiling model is developed by Computational Fluid Dynamics (CFD) code to calculate the source term of a cryogenic liquid spill. The model includes the effect of the changing ground temperature on the vaporization rate of the cryogenic liquid. Simulations are performed for liquid nitrogen. The model can describe different boiling regimes (film, transition and nucleate). The heat flux calculated for each boiling regimes are compared to the experimental data from literature. The developed numerical model seems to have a good ability to predict the heat flux for the film boiling stage. Model development is still necessary to improve the prediction of the nucleate boiling regime. Overall, the approach shows very promising results to model the complex physical phenomena involved in in the vaporization of cryogenic liquid pool spilled on ground.