公路两侧土壤中铅和镉污染以及存在形态分布的分析

测定了土壤中铅、镉总量,并采用五级连续浸提法和石墨炉原子吸收分光光度法对北京市3条典型公路两侧的土壤样品中铅和镉的存在形态分布进行了测定.结果表明,所选3条公路出京方向右侧的土壤铅和镉污染严重,其铅、镉总量分别是北京地区土壤铅和镉含量背景值的1.62～6.69、5.97～18.74倍.土壤中铅主要以铁锰氧化物结合态、碳酸盐结合态、有机结合态和残渣态等形式存在,镉主要以铁锰氧化物结合态和残渣态形式存在,而活性强的离子交换态浓度均较低.不容忽视的是,铅和镉的碳酸盐结合态在碱性条件下稳定,但是具有遇酸释放的隐患.     

Biomarker responses and reproductive toxicity of the effluent from a Chinese large sewage treatment plant in Japanese medaka (Oryzias latipes)

The present study was conducted to assess the potential toxicity of the effluent from a large sewage treatment plant (GBD-STP) in Beijing. Japanese medakas (Oryzias latipes) at reproduction active period were exposed to a serial of graded concentrations of the effluent or 100 ng l-1 of 17-alpha-ethinylestradiol (EE2, positive control). Growth, gonadosomatic index (GSI), hepatosomatic index (HSI), reproductive success, induction potency of vitellogenin (VTG) in male fish and that of 7-ethoxyresorufin-o-deethylase activity (EROD) in male fish liver were used as test endpoints. The growth suppression of fish was observed in a dose-dependent manner, resulting in significant differences in both body length and body weight of medaka above 5% effluent. This effluent can inhibit the growth of gonad of medakas and are more sensitive to male than to female. At exposure concentration of 40% and higher, there was an unexpected decrease of HSI values, which may be resulted from sub-lethal toxicity of effluent to fish liver. VTG of plasma in males were induced in all exposure concentration levels, but not in a dose-dependent manner. The concentration of 5% effluent would be the lowest observed adverse effect level (LOAEL) affecting reproductive success when examining fertile individuals, fecundity and fertilization rate. The overt CYP1A response and higher reproductive toxicity may be indicative of low process efficiency of this STP.     

Cytotoxicity and DNA damage of five organophosphorus pesticides mediated by oxidative stress in PC12 cells and protection by vitamin E

Previous studies have demonstrated that pesticides could induce cytotoxicity and genotoxicity in vivo and in vitro, and that oxidative stress may be an important factor involved. However, investigations comparing the capability of different organophosphorous (OP) compounds to induce cytotoxicity, genotoxicity and oxidative stress are limited. Hence, the aim of this paper was to access the cytotoxic and genotoxic effects of five OPs or metabolites, Acephate (ACE), Methamidophos (MET), Chloramidophos (CHL), Malathion (MAT) and Malaoxon (MAO), and to clarify the role of oxidative stress, using PC12 cells. The results demonstrated that MET, MAT and MAO caused significant inhibition of cell viability and increased DNA damage in PC12 cells at 40 mg L^?1. MAO was more toxic than the other OPs. ACE, MET, MAT and MAO increased the levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), and decreased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) at 20 mg L^?1 and 40 mg L^?1 to different degrees. Pre-treatment with vitamin E(600 μM)caused a significant attenuation in the cytotoxic and genotoxic effect; pre-treatment reversed subsequent OP-induced elevation of peroxidation products and the decline of anti-oxidant enzyme activities. These results indicate that oxidative damage is likely to be an initiating event that contributes to the OP-induced cytotoxicity.     

CO2捕集回收技术研究

主要介绍了常用的胺化合物吸收法、钙基吸收剂法、金属氧化物法等CO2捕集回收技术的最新研究进展及存在的问题,综合对比了各种方法的优缺点:胺化合物吸收法吸收速率快,但再生能耗较高,因此开发"高效低耗"的复合吸收剂成为研究的重点;钙基吸收剂法在高温环境下对CO2的吸收有较好的效果,但吸收剂的碳酸化转化率及热稳定性是有待解决的关键问题;金属氧化物法具有高的CO2吸收效率,但成本较高.在此基础上,探索了CO2捕集回收技术改进工艺,提出改善吸收剂性能、开发高效低耗的CO2选择性吸收剂将成为今后CO2捕集回收技术的研究方向.     

Optimization of sprayed lime amount in the semi-dry scrubbing system of MSWI

This paper reports the characterization of residues collected from air pollution controlling devices (APCDs) at seven large-scale municipal solid wastes (MSW) incineration plants. The amount of lime being sprayed in plants is a function of free CaO content in scrubber residues; a higher free CaO content in scrubber residue causes more leaching of lead. The proper amount of lime in the semi-dry scrubbing system was found to be 5kg/ton of MSW waste. Under these conditions, both the free CaO content and lead leaching became extremely low in scrubber residue.     

Analysis of patterns and ecological security trend of modern oasis landscapes in Xinjiang, China

Ecological security has become so important that it will affect the national security and social sustainable development. In this paper, a case study on the ecological security indexes of modern oasis landscapes in Beitun Oasis, Xinjiang, was carried out. The spatial neighbouring parameters, such as the contiguous length, measure of area and patch quantity of oasis landscape patches, affected by desert landscape patches were calculated by using GIS-based buffer analysis, the method of calculating ecological security indexes of oasis landscape was developed, and the dynamic changes of patterns and ecological security indexes of the oasis landscapes since recent 30 years were analyzed. The results showed that soil salinization or alkalization and paludification were major factors affecting the ecological security in Beitun Oasis. Therefore, measures should be taken actively to prevent and control secondary salinization and paludification. The ecological security indexes of the oasis landscape in 1972, 1990 and 2005 were 78.91, 82.28 and 83.86, respectively, which showed the degree of security is improving, and the environment was developing harmoniously between human and nature. The methods of evaluating ecological security based on the spatial neighbouring relations between landscape patches can be used to reflect preliminarily the ecological security patterns of landscapes.     

UASB反应器处理染料及印染废水的研究进展

综述了国内外UASB反应器处理染料及印染废水的研究概况.分析了UASB反应器处理废水存在的问题,并给出了相应的建议.展望了UASB反应器处理染料及印染废水的发展趋势,指出厌氧UASB-好氧法组合工艺是目前处理染料及印染废水的一种经济而有效的方法.     

环境民事法律责任与环境损害赔偿

环境民事责任是环境法律责任的一种形式,是解决和处理环境损害赔偿中重要的法律依据。     

生物膜填料塔净化有机废气研究

为在国内开展生物化学法净化低浓度有机废气的研究工作,采用国内现有微生物菌种挂膜接种的生物膜填料塔净化低浓度甲苯废气,结果表明,在入口气体甲苯浓度0.183～1.803mg/L及气体流量86.4～190.8L/h（停留时间6.2～13.6s）的实验范围内,增加入口气体甲苯浓度和气体流量,可使甲苯的生化去除量增大,每升体积的生物膜填料对甲苯的生化去除量最大可达157.13mg/h。由实验结果推断,生物膜填料塔对废气中甲苯的净化去除过程属于传质控制过程。对比结果表明,本研究建立的动力学模式对实际过程有很好的适用性,计算值与实验值之间的相关系数R＝0.98。     

浅谈防机械伤害手套标准的制定

据国际上有关机构统计，在各种工伤事故中。手伤害事故占25％。我国产业人口庞大。手伤害事故相应也多，因此积极制定防机械伤害手套标准用来检验控制手套的质量，对减少手伤害事故的发生至关重要。