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261.
本文通过对城市公用管道工程的施工质量进行安装监检,结合发现的问题,指出了高压管道应重视材料验收和焊接施工组织;中压管道应防止对接焊缝微小缺陷的漏检;可采用先进仪器加强防腐质量检测的监检,督促安装单位在安装过程中做好防腐工作;钢套钢热水网直埋管道的安装监检应针对施工的特点来开展。从安全性和实用性的角度提出了有针对性的具体措施,具有可操作性。 相似文献
262.
城市生态安全多层次灰色综合评价 总被引:3,自引:1,他引:2
从城市生态安全的基本内涵出发,根据压力(pressure)-状态(state)-响应(response)模型,从生态系统压力、生态系统状况、生态系统响应3方面构建一个4层次的城市生态安全评价指标体系,运用灰色系统理论,构建了城市生态安全多层次灰色综合评价模型,并结合实例进行计算。评价结果与实际情况基本相符,表明该模型能有效地利用评价指标的信息,所给出的综合评价值既能用于描述所评价城市的生态安全状况,亦可对不同城市的生态安全状况进行比较,对更加科学合理地评价城市生态安全状况具有参考价值。 相似文献
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本文采用摇瓶法测定了14各甲酰苯胺类化合物的溶解度及正辛醇/水分配系数,二者之间具有较好的相关性,应用线性溶剂化相关方法获得的相关方程,能更好地预测测苯甲酰苯胺类化合物的的水溶解度和正辛醇/水分配系数。 相似文献
266.
Occurrence and distribution of polycyclic aromatic carbons in sludges from wastewater treatment plants in Guangdong, China 总被引:1,自引:0,他引:1
Xiangying Zeng Zheng Lin Hongyan Gui Wenlan Shao Guoying Sheng Jiamo Fu Zhiqiang Yu 《Environmental monitoring and assessment》2010,169(1-4):89-100
In this study, the occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs) were investigated in six sludge samples collected from Guangdong Province, China. Concentrations of PAHs varying from 2,534.1 to 6,926.6 μg kg???1 (dry sludge) were observed in three municipal wastewater treatment plants with phenanthrene (Phe), fluoranthene, and pyrene being the main compounds. In addition, 682.6 μg kg???1 PAHs were detected in one sludge sample from a food processing plant, with fluorene, Phe, and chrysene being the main components. No PAHs were detected in sludge samples obtained from two cosmetic plants. The levels and distributional characteristics of PAHs, polychlorinated biphenyls (PCBs), and polycyclic musks (PMs) from the samples were also compared. The results of this comparison indicated that petrochemical refineries and road traffic played important roles in the PAH loads in sludge, while PMs primarily originated from domestic wastewater and industrial wastewater from cosmetic plants. Finally, the presence of 98.8 μg kg???1 PCBs in sludge suggested diffusional emission sources from electrical components containing PCBs. 相似文献
267.
区域环境风险评估研究进展 总被引:3,自引:0,他引:3
简述了区域环境风险及区域环境风险评估的内涵,以及国内外区域环境风险评估研究发展进程及现状,指出了现阶段区域环境风险评估存在的问题,提出应重点开展区域环境风险发生机理、定量表征区域环境风险方法等研究的展望。 相似文献
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环境监测任务可信度评估是对整个监测任务实施的全过程进行跟踪考核并给出考核结果值的一种质量管理模式,可以在资质管理、任务招标、价格评分、合同付款等方面对第三方检测机构的管理提供量化依据。用好可信度评估可以在加强行业监管的同时,规范行业竞争。 相似文献
270.
Ma YG Cheng JP Jiao F Duo KX Rong Z Li M Wang WH 《Environmental monitoring and assessment》2008,146(1-3):127-138
Distribution and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in drinking water resources have been carried out for the first time in Henan Province, China. Water samples collected from four river systems and their tributaries, as well as groundwater resources, were analyzed according to EPA method 525.2. Total of 68 water samples were collected in 18 cities in Henan province in May, August and November, 2001. Concentrations of sum of 16 priority PAHs in water samples ranged from 15 to 844 ng/L with a mean value of 178 +/- 210 ng/L (n = 68). The spatial and temporal distribution of PAHs showed that the Huanghe and the Huaihe river systems had relatively higher concentrations of total PAHs. Higher concentrations of total PAHs were observed in August and November than in May, with respective mean values of 262, 232 and 33.6 ng/L. Ratios of Ant/(Ant + Phe) and Flur/(Flur + Pyr) were calculated to evaluate the possible sources of PAH contamination, which indicated that the coal combustion sources were the main contributors to PAHs in most drinking water resources. Some petrogenic (or pyrolytic) sources of PAHs were also found. The toxic equivalency factors (TEFs) were used to calculate benzo[a]pyrene equivalents (BaPE) for water samples. The average value of BaPE was 0.6 ng/L. The values in most stations were much lower than the guideline values in drinking water of Chinese Environmental Protection Agency (CEPA, 2.8 ng/L) and the US Environmental Protection Agency (US EPA, 200 ng/L). Overall, the drinking water resources in Henan province showed some carcinogenic potential. 相似文献