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31.
危险废物填埋场的安全选址是销毁日本遗弃在华化学武器工作中的一项重要的技术工作。本文依据我国环境保护的法律法规及标准,并采用科学的方法对危险废物填埋场址的选择进行了论述和评价,即:首先通过分析场址选择的影响因素,制定出科学、合理、可行的场址选择技术方案;然后再按优劣顺序对拟选的5个填埋场进行科学评价;最后选出最优的填埋场。  相似文献   
32.
All the regulations that define a maximum concentration of metals in the receiving soil are based on total soil metal concentration. However, the potential toxicity of a heavy metal in the soil depends on its speciation and availability. We studied the effects of heavy metal speciation and availability on soil microorganism activities along a Cu/Zn contamination gradient. Microbial biomass and enzyme activity of soil contaminated with both Cu and Zn were investigated. The results showed that microbial biomass was negatively affected by the elevated metal levels. The microbial biomass-C (Cmic)/organic C (Corg) ratio was closely correlated to heavy metal stress. There were negative correlations between soil microbial biomass, phosphatase activity and NH4NO3 extractable heavy metals. The soil microorganism activity could be predicted using empirical models with the availability of Cu and Zn. We observed that 72% of the variation in phosphatase activity could be explained by the NH4NO3-extractable and total heavy metal concentration. By considering different monitoring approaches and different viewpoints, this set of methods applied in this study seemed sensitive to site differences and contributed to a better understanding of the effects of heavy metals on the size and activity of microorganisms in soils. The data presented demonstrate the relationship between heavy metals availability and heavy metal toxicity to soil microorganism along a contamination gradient.  相似文献   
33.
As a remedial option, the natural attenuation capacity of a petroleum contaminated groundwater at a military facility was examined. Hydrogeological conditions, such as high water level, permeable uppermost layer and frequent heavy rainfall, were favorable to natural attenuation at this site. The changes in the concentrations of electron acceptors and donors, as well as the relevant hydrochemical conditions, indicated the occurrence of aerobic respiration, denitrification, iron reduction, manganese reduction and sulfate reduction. The calculated BTEX expressed biodegradation capacity ranged between 20.52 and 33.67 mg/L, which appeared effective for the reduction of the contaminants levels. The contribution of each electron accepting process to the total biodegradation was in the order: denitrification > iron reduction > sulfate reduction > aerobic respiration > manganese reduction. The BTEX and benzene point attenuation rates were 0.0058-0.0064 and 0.0005-0.0032 day-1, respectively, and the remediation time was 0.7-1.2 and 2.5-30 years, respectively. The BTEX and benzene bulk attenuation rates were 8.69 × 10-4 and 1.05 × 10-3 day-1, respectively, and the remediation times for BTEX and benzene were 7.2 and 17.5 years, respectively. However, most of the natural attenuation occurring in this site can be attributed to dilution and dispersion. Consequently, the biodegradation and natural attenuation capacities were good enough to lower the contaminants levels, but their rates appeared to be insufficient to reach the remediation goal within a reasonable time frame. Therefore, some active remedial measures would be required.  相似文献   
34.
传统有机磷、有机氯农药具有高毒性、持久性和环境激素效应,处于痕量和超痕量浓度水平都可能给人类生命健康和生态环境带来严重威胁和风险。由于农药及其副产物的历史残留、累积及跨界迁移和分布,农药厂搬迁厂址用于房地产开发场地环评具有很大困难。结合南方某市一大型农药厂搬迁厂址用于房地产开发项目的案例,探讨了该类场地评价中基础资料的搜集方法和环评中应遵循的理念和原则。  相似文献   
35.
根据环境影响评价监测的要求,提出了环评监测中方案的细化、点位布设方面存在的问题,阐述了如何合理设置监测点位、准确把握采样方法、科学选择分析方法等问题。  相似文献   
36.
文章通过黑岱沟露天煤矿排土场不同植被配置土壤水分垂直动态研究,阐述了不同植被配置类型对土壤水分的影响。结果显示:9种植被配置类型的土壤台水量随土层深度的增加而减小,但变化幅度有差异;原生植被处的土壤水分利用层厚度大于人工植被。  相似文献   
37.
污染场地修复决策支持系统的几个关键问题探讨   总被引:6,自引:0,他引:6  
廖晓勇  陶欢  阎秀兰  赵丹  林龙勇  李尤 《环境科学》2014,35(4):1576-1585
场地土壤和地下水环境污染问题已成为近年来我国环境保护领域关注的焦点和热点.污染场地修复决策支持系统是在场地勘察与风险评估基础上,筛选最佳的修复技术,以制定经济高效的场地污染治理方案.本文探讨与分析修复决策系统的框架、模型、方法等关键环节,评估与总结了国际上现有40多种修复决策软件的模块及功能.针对我国场地污染问题,综合国际前沿的思想与理念,提出适合我国现阶段经济社会发展水平的决策支持系统开发思路.  相似文献   
38.
An evaluation method that can express the local leakage of leachate from joint sections in steel pipe sheet pile (SPSP) cutoff walls is discussed in this study. In particular, the evaluation of environmental feasibility (containment of leachates containing toxic substances) considering a three-dimensional arrangement and hydraulic conductivity distribution of the joint sections in the SPSP cutoff wall is compared with an evaluation that uses the equivalent hydraulic conductivity. This equivalent hydraulic conductivity assumes that the joint section and the steel pipe are integrated; therefore, the hydraulic conductivity is substituted with a uniform permeable layer. However, in an evaluation that employs the equivalent hydraulic conductivity, it is difficult to consider the local leakage of leachate containing toxic substances from the joint sections in the SPSP cutoff wall. It was established that evaluations of the environmental feasibility of SPSP cutoff walls with joint sections must take into account the local leakage of leachates containing toxic substances from the joint sections. Also, it was clarified that technologies that lower the hydraulic conductivities of joint sections in SPSP cutoff walls and also facilitate the use of sparser joint arrangements contribute significantly to increasing the environmental feasibility of SPSP cutoff walls at landfill sites.  相似文献   
39.
基于层次分析法的秦皇岛市垃圾填埋场选址评价   总被引:1,自引:0,他引:1  
城市垃圾填埋场场址的选择,受到当地经济、交通、气候条件,自然地理条件,环境保护条件,水文地质工程地质条件等诸多因素影响,是一项十分复杂的工程。本文总结了秦皇岛市现有垃圾填埋场的基本情况、存在问题及其产生原因。鉴于层次分析法在多目标决策分析方面的成效,将其运用到秦皇岛市垃圾填埋场选址评价中,对研究区进行适宜性分区,依次划分为最佳场地区、适宜场地区、较适宜场地区、不适宜场地区。  相似文献   
40.
针对风电机组选址与民爆企业安全管理的突出矛盾,研究分析了风电机组和民爆危险品建筑物间安全距离设定的原则和方法,深入剖析了重大危险影响因素,并结合现行标准规范和国外相关规定及经验做法,估算了安全距离值,探讨了安全距离设定的可能性、合理性和适应性,提出了安全距离设定的建议和参照依据。  相似文献   
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