秋季南通近海大气气溶胶水溶性离子粒径分布特征

2012年10~11月在南通近海设立观测点,利用Anderson分级采样器采集大气气溶胶样品,用离子色谱仪(Metrohm IC)分析其中10种水溶性离子组成.结果表明,南通秋季近海PM10和PM2.1中水溶性离子浓度分别为59.70,45.96mg/m3.PM2.1中主要离子质量浓度排列依次为SO42->NO3->NH4+>Ca2+. SO42-,NO3-和NH4+占PM10中离子浓度的80%以上,二次离子为近海区域气溶胶的主要成分.SO42,NH4+和NO3-均表现出单峰型分布,峰值区间均为0.43~1.1mm,Ca2+,Na+和Cl-表现为双峰型.Ca2+高浓度峰值出现4.7~5.8mm粒径段内;Na+和Cl-峰值出现在0.43~1.1mm和3.3~5.8mm内,但最大峰值浓度区间不一致.PM10中nss-SO42-/SO42-比值均高于90%,陆地源对近海硫酸盐的影响显著.nss-SO42-/NO3-的比值在<2.1μm的粒径段内均大于1,表明该区域固定源是大气细粒子中离子的重要贡献源,但移动源对粗粒子的影响值得重视.个例分析显示,稳定的天气系统,高污染排放内陆地区的污染物传输,是造成10月27日的严重污染过程的主要原因.     

A mathematical approach for retrofit and optimization of total site steam distribution networks

This paper presents a generic mathematical model for retrofitting the steam power plants in an industrial site. The industrial sector under review consists of one steel mill, one oil refinery, and several petrochemical plants, where only small-scale steam integration has been implemented before this study. The relevant unit models in a typical steam power plant are established, and the steam plant retrofit problem is formulated as a mixed-integer nonlinear program (MINLP). Feasible retrofit alternatives suggested by experienced field engineers are investigated in sequence to examine the revenue of those possible modifications. The first scenario examines operational optimization of existent plants; the second option allows installation of one new turbine and replacement of several boilers and turbines with lower efficiency; the third scenario considers using a steam ejector to upgrade the disqualified import steam in the oil refinery. The significant merits from these three retrofit alternatives show that the proposed MINLP formulation has been a great help to enhance the inter-plant steam integration in an industrial sector.     

基于潜在生命损失的危险化学品仓储区规划选址和安全布局方法研究

在现有基于风险的土地使用安全规划方法的基础上,通过引入潜在生命损失这一综合风险评价指标,建立了基于移动危险源潜在生命损失的危险化学品仓储区规划选址模型和基于固定危险源潜在生命损失的仓储区安全布局优化模型。在此基础上,提出了危险化学品仓储区规划选址和安全布局优化方法,并通过案例分析验证了该方法的适用性和可行性。采用该规划选址和安全布局优化方法可提高区域土地使用安全规划的效率,为进行城市重大危险源的规划选址和安全布局提供了新的思路。     

The status of heavy metal levels in a Ramsar site,Kuala Gula bird sanctuary: the impact of the anthropogenic inputs

Distributions of Cd, Cu, Pb, and Zn in the surface sediments from two sites of the Kuala Gula Bird Sanctuary, Malaysia were monitored for a period of 6 months from October 2006 to March 2007. In December 2006, the concentration of Zn in one location was significantly (p??1) than the other metals at both sites, but in the oxidizable organic fraction it was highest at both sites during October; with mean concentrations of 18?mg?kg^?1 at both locations. In the acid-reducible fraction, high concentrations of Pb (2.3?mg?kg^?1) were detected at station 2 in February 2007, being highest among all four metals at both stations. The acid-reducible fraction found in Pb ranged from 0.10% to 3.1% in both stations. Percentages ranging from 51% to 96% were observed for all four metals in the resistant fraction throughout the sampling period. These results indicate low contributions from anthropogenic sources. The findings constitute a baseline data archive for future reference.     

Polycyclic aromatic hydrocarbons in surface sediments held in experimental mesocosms

Sediment was collected from three locations along a pollution gradient in Narragansett Bay and transplanted to controlled mesocosms. Total hydrocarbons and eleven individual polycyclic aromatic hydrocarbons (PAHs) were measured in these sediments over a period of 394 days. Total hydrocarbon concentrations increased in the “relatively uncontaminated”; (Rhode Island Sound) sediment that was held in the mesocosms, but did not change in the two other sediments. The concentrations of four PAHs: naphthalene, 2‐methyl naphthalene, 1‐methyl naphthalene and biphenyl, decreased in the “contaminated”; (Providence River) sediment during the experiment and the calculated half‐lives for these compounds were 287, 353, 321 and 333 days, respectively.     

典型电子废物焚烧区水生生物多溴联苯醚累积特征

对广东清远某电子废物焚烧区封闭水体中水生生物体PBDEs(多溴联苯醚)的累积特征进行了研究. 结果表明,草虾、田螺、河蚌、鲫鱼、鲤鱼、黄鳝和乌鳢等水生生物体内w(∑₂₁PBDEs)(以脂肪质量计)为0.2487~24.50μg/g. 该电子废物焚烧区水生生物PBDEs污染较严重,较我国其他地区开放性水体的水生生物体w(PBDEs)高出1~3个数量级. 其中,底栖动物河蚌和田螺体内PBDEs累积最高,w(∑₂₁PBDEs)分别为11.38和4.968μg/g. 不同同系物在水生生物体内累积差异较大,BDE209是水生生物体PBDEs累积的主要组分,占49.83%~91.48%,八溴代和九溴代BDE也发生了高累积. 营养级是电子废物焚烧区水生生物PBDEs累积的最主要控制因素,但捕食和生活习性对生物体尤其是软体动物PBDEs累积也产生了较大影响.      

Physicochemical properties of non-living water hyacinth (Eichhornia crassipes) and lesser duckweed (Lemna minor) and their influence on the As(V) adsorption processes

Eichhornia crassipes (Ec) and Lemna minor (Lm) are aquatic plants. They are considered as weeds of the water and approach being a scourge in many parts of the world, choking waterways and hindering transport upon them. At the same time they are known to readily remove heavy metal ions from water. This paper considers the use of non-living plants as novel and inexpensive biosorbent for the removal of As(V) from watersheds. In the first place they were conditioned and characterised to determine their physicochemical and surface properties and in the second place their adsorption properties for As(V) from aqueous solution were evaluated considering the toxicity of this metalloid in the environment. It describes the methodology to prepare the non-living biomasses; the physicochemical characterisation by SEM, XRD, FTIR, TGA analyses and surface characterisation of Ec and Lm by specific surface, hydration kinetic, point of zero charge determination by mass titration, active site density and XPS analysis are described. Both studied biomasses were found to be potential bio-sorbents for arsenic ions from aqueous solution. According to their efficiency to remove arsenic, they can be used in a very low cost metalloid ions removal system.     

Temporary site selection and decision‐making methods: a case study of Tehran,Iran

Decisions on selecting an appropriate site for temporary shelter used to be taken in a limited amount of time after a disaster. The need for a systematic method in this area inspired the MADM (multi‐attribute decision making) for complex disaster management decisions. This research proposes a model for appropriate and systematic site selection for temporary shelters, before an earthquake, using a geographical information system and MADM based on an earthquake damage assessment. After the effective criteria for site selection of temporary shelters are determined, the geographical layers of these criteria are prepared for Municipal District No.1 of Greater Tehran, the capital of Iran. Given these attributes and the required shelter area (415–610 hectares), 14 zones are proposed initially. Various MADM methods are used for the final selection. The mean of the aggregated ranking results are determined, and 10 of the 14 initial zones are ranked.     

简易生活垃圾填埋场综合治理工程设计

随着越来越多标准化生活垃圾填埋场的建成和投入运行,原有简易生活垃圾填埋场的环境综合治理被各级环境管理部门日益重视,成为改善环境急需解决的问题。以西北某市简易生活垃圾填埋场综合整治工程为例,通过分析简易垃圾填埋场存在的主要环境隐患,有针对性地提出了解决垃圾渗沥液、填埋气、边坡安全等环境和安全问题的具体工程措施,尽量将简易垃圾填埋场对周围环境的影响降到最低程度。     

RBCA、CLEA及CalTOX模型在苯并[a]芘污染场地健康风险评估中的应用比较

为探讨不同模型对污染场地健康风险评估结果的影响,以苯并[a]芘为例,采用RBCA、CLEA和CalTOX模型对某工业污染场地表层土壤进行健康风险评估,分析了评估结果的差异和原因,同时对模型的主要暴露参数进行了敏感性分析,并推导出基于风险概率分布的土壤修复限值。结果表明,RBCA、CLEA和CalTOX模型计算的苯并[a]芘致癌总风险分别为2.40×10-4、6.32×10-4和7.04×10-6,且经口摄入和皮肤接触2个途径对人体健康造成的危害最大。降解作用是影响CalTOX模型风险评估结果不同于RBCA和CLEA模型的重要因素,3个模型间参数取值及方法学的差异也会导致风险评估结果不同。各模型暴露参数的敏感性排序也有差异。采用基于风险概率分布的方法推导土壤修复限值,RBCA、CLEA和CalTOX模型所得结果分别为0.18、0.08、0.13(不考虑降解作用CalTOX模型)和10.74(考虑降解作用CalTOX模型)mg·kg-1,为各模型直接推导值的1.5～2.6倍。基于风险概率分布的方法可有效降低风险评估过程中参数不确定性的影响,为工业污染场地土壤修复值的制定提供参考。