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261.
周贵忠  许硕  姚倩  银钗 《环境科学》2017,38(7):2972-2977
通过逐渐提高SBR反应器中活性污泥的盐度,探索不同盐度下活性污泥的活性、性质及其微生物群落变化,并研究结晶紫废水以及纳米四氧化三铁对微生物群落的影响.结果表明,随着盐度的增加,活性污泥的COD、氨氮去除率以及污泥体积指数SVI值均降低,在质量分数2%的盐度下,COD、NH_4~+-N的去除率为80%和75%,SVI值不足35 mL·g~(-1);随着盐度的增加微生物的多样性逐渐减少,系统中革兰氏阴性菌优势菌种的位置逐渐被真菌和放线菌取代,而革兰氏阳性菌依然为优势菌;加入结晶紫染料的活性污泥与盐度为2%的活性污泥样品相比发现:红细菌属、丽水菌属含量有所增加,产黄杆菌、农杆菌属含量减小.加入MNPs的结晶紫-活性污泥与不加MNPs的结晶紫活性污泥对比:酸胞菌属、产黄杆菌含量增加,红细菌属、农杆菌属含量减小.  相似文献   
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The SO2 emission sources of the Chengdu-Chongqing economic zone were divided into 556 emissions units according to four different categories, which are city, industry, point sources, and area sources. The CALPUFF model was used to calculate the contribution of each unit, and consequently obtain an influence-transferring matrix. To ensure that the SO2 concentrations of 46 cities and counties in the Chengdu-Chongqing economic zone meet air quality standards, an emission optimization model was developed to calculate optimal emissions of each emission unit under different development scenarios. The result showed the optimal emissions of SO2 by different provinces and industries. To achieve the target of restricting and optimizing development, corresponding planning programs were developed for every district.  相似文献   
264.
以陕南燃煤型砷中毒病区的5个自然村为调查采样点,通过现场流行病学调查和环境样品的分析测定,分析砷暴露人群的砷暴露途径,估算各暴露途径(呼吸、饮水和食物)的暴露剂量及对总暴露的贡献率,探讨引发燃煤型地方性砷中毒发病的最低有效暴露剂量。研究结果表明,除对照村外,采暖季各村的烤火间和卧室空气砷含量均有不同程度的超标,水和粮食未受燃煤砷污染。在采暖季,高砷煤燃烧污染的空气是人群砷暴露的主要来源;在非采暖季消化道砷暴露是各村的主要摄砷途径;提示消化道暴露对累积砷暴露的贡献不容忽视。结合问卷调查和流行病学调查结果,估算陕南病区引发燃煤型砷中毒的最低累积暴露剂量在1 712 mg左右。  相似文献   
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266.
分析了石化销售企业施工现场安全管理的现状以及产生的原因,针对上述问题提出了加强工程施工安全监管的建议和相关管理措施。  相似文献   
267.
一元有机酸的络合萃取研究   总被引:8,自引:2,他引:6  
柴金岭 《环境化学》1998,17(3):264-270
本文考察了不同稀释剂中磷酸三丁酯(TBP)和甲基异丁基酮(MIBK)的甲酸,乙酸,丙酸,丁酸及氯乙酸,二氯乙酸和三氯乙酸等一元有机酸的萃取,萃取反应属中性络合萃取机理,有机相中生成1:1的萃合物,同时,探讨了各因素(有机酸种类、稀释剂性质、温度和无机盐)对萃取的影响,得到了萃取反应的平衡常数,热力学函数和萃取性能与有机酸性质间的关系方程等。  相似文献   
268.
重点介绍了邯钢新建2000m^3高炉(7^#高炉)出铁场和槽下上料系统粉尘污染治理方面的成功经验,并对应用电除尘器处理粉尘的技术进行了简要分析。  相似文献   
269.
As part of our efforts to find effective methods to the drinking water risk management, the health risk assessment of arsenic and cadmium in groundwater near Xiangjiang River was analyzed. The results suggest that although the arsenic and cadmium concentrations in 97% of groundwater sources are less than the requirement of Water Quality Standards for Drinking Water (GB5749-2006) in China, the residents served by almost all of the investigated centralized drinking water sources have a significant potential health risk by consumption, especially cancer risk. It is justified through analyses that risk assessment is an effective tool for risk management, and the maximum permissible concentration of arsenic and cadmium in drinking water (0.01 and 0.005?mg L-1, respectively) is suitable for China at present, considering the current economic status of China. Risk managers develop cleanup standards designed to protect against all possible adverse effects, which should take into account highly exposed individuals, effects of mixtures of toxic substances, attendant uncertainties, and other factors such as site-specific (or generic) criteria, technical feasibility, cost?Cbenefit analyses, and sociopolitical concerns.  相似文献   
270.
To elucidate the influence of landfill gas (LFG) emission on environmental factors, an ecological investigation that was primarily concerned with the characteristics of vegetation, cover soil, and solid waste in the landfill was carried out. Temporal and spatial variations in vegetation diversity and coverage and their effects on reducing the emission of methane in the landfill were investigated. The results showed that both vegetation coverage and diversity increased with elapsed landfill closure time. The transition trend of the vegetation species was from perennial plant (Phragmites australis) to annual plants. Perennial vegetation was the dominant type of vegetation during the early closure period, and annual vegetation coverage increased with closure time. Vegetation preferentially appeared in areas of comparatively high depth of cover soil, which was characterized by high moisture retentiveness that enabled vegetation growth. The concentrations of methane and carbon dioxide in the cover soil significantly decreased with increasing closure time. The concentrations of methane and carbon dioxide from bare cover soil were higher than those from vegetated cover soil whereas the CO2 flux of bare cover soil was less than that of vegetated cover soil.  相似文献   
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