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901.
A fuzzy analytic hierarchy process (FAHP) approach to eco-environmental vulnerability assessment for the danjiangkou reservoir area,China 总被引:4,自引:0,他引:4
The Danjiangkou reservoir lies in the upper Hanjiang basin and is the source of water for the Middle Route Project (MRP) under the South-to-North Water Transfer Scheme (SNWT) in China. The eco-environment of water resource areas plays an important role in water conservation and purification and would have significant implications for the economic prosperity in Hanjiang basin as well as for the SNWT. Focusing on the Danjiangkou Reservoir Area (DRA), this study established an environmental information system database. Based on the database, an eco-environmental vulnerability assessment method using integrated fuzzy AHP (FAHP) and GIS was developed for the DRA. According to eco-environmental conditions and anthropic effects, vulnerability was classified into five levels: potential, light, medium, heavy and very heavy. The eco-environmental vulnerability distribution and major problems of the eco-environment were analysed and discussed. The results indicated that eco-environmental vulnerability in the DRA was moderate overall. Regions with lower eco-environmental vulnerability were located in Qinling Mountain area in the northwest, Daba Mountain area in the south and the area immediately surrounding Danjiangkou Reservoir in the east. Two regions with very high eco-environmental vulnerability were located in the north of Danjiangkou Reservoir in Henan province and in the western part of Shanxi province. On the basis of analysis of distribution of the different factors of eco-environmental vulnerability, different environmental protection measures were proposed for different areas. This study demonstrated that the proposed method was an effective approach for the assessment of environmental vulnerability. The results gained closely reflected the reality of the eco-environmental vulnerability of the DRA. 相似文献
902.
903.
生物质吸附剂处理活性艳红X-3B废水 总被引:2,自引:0,他引:2
采用城市污水处理厂二沉池的剩余活性污泥为原料,以浓度为3mol/L的ZnCl2溶液浸泡污泥,采用水蒸气为活化气和保护气,在600℃下活化污泥3h,制备出性能良好的生物质吸附剂,其碘吸附值为388.95mg/g,比表面积为447.79m^2/g,平均孔径为4.39nm,孔体积为0.31cm^3/g,微孔体积为0.09cm^3/g。实验结果表明,用该生物质吸附剂处理活性艳红X-3B废水,在废水(10mL)中活性艳红X-3B质量浓度为300mg/L、生物质吸附剂加入量为0.20g、吸附时间为30min的条件下,废水脱色率可达99.7%。活性艳红X-3B在生物质吸附剂上的吸附行为遵循Lagergren二级动力学规律,同时也可用一级吸附动力学方程描述。 相似文献
904.
初始环境评审中环境因素的识别和评价方法 总被引:3,自引:0,他引:3
初始环境评审是组织建立和实施环境管理体系的基础,而环境因素的识别和评价是这一过程的关键。探讨了识别和评价环境因素的准则,介绍了几种环境因素的识别和评价方法。 相似文献
905.
906.
Bioaccumulation, depuration and oxidative stress in fish Carassius auratus under phenanthrene exposure 总被引:7,自引:0,他引:7
In this study, laboratory experiment was carried out to determine phenanthrene bioaccumulation, depuration in whole fish and oxidative stress in the liver of freshwater fish Carassius auratus. Fish were exposed to 0.05 mg/l phenanthrene for different periods, while one control group was designated for each exposure group. Some fish after 7 days of exposure were transferred to diluted water. The concentrations of phenanthrene in fish were analyzed by HPLC. Twenty-four hours after the exposure, reactive oxygen species (ROS) were trapped by phenyl-tert-butylnitrone and detected by electron paramagnetic resonance (EPR). The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione-s-transferase (GST) were also determined. The concentrations of phenanthrene in fish increased rapidly shortly after the start of the exposure, reached a maximum level at the 2 days, and then it declined quickly to low-level-steady state. The elimination process of phenanthrene could be divided into two periods-a fast elimination period following a slower loss period. The elimination curve could be fitted mathematically as the sum of two exponential functions according to two-compartment model: C(t)=2.72e(-1.065t) + 0.68e(-0.0364t). The PBN-radical adducts were detected in fish liver samples following the exposure 24h. The hyperfine splitting constants for the PBN-radical adducts were aN = 13.5 G, aH = 1.77 G and g value was 2.0058, which were consistent with those of PBN/()OH. The results indicated that the hydroxyl radical was probably significantly induced during the exposure of phenanthrene, as compared to the control group. The changes of activities of the antioxidant enzymes also were observed. In addition, after fish were removed from phenanthrene exposure, the recovery status of these antioxidant indices was explored. These results clearly indicated phenanthrene could be accumulated in fish and similar redox cyclings were produced, resulting in the changes of the activities of the antioxidant enzymes and the production of ROS with the oxidative stress. 相似文献
907.
908.
殷嵩 《安全.健康和环境》2014,14(4):44-46
对雅克拉凝析气田单井集输系统腐蚀状况进行分析,得出该腐蚀主要是CO_2腐蚀和冲刷腐蚀综合作用的结论,提出并实施相应的防腐对策。 相似文献
909.
一株碱性果胶酶高产细菌的分离、系统发育分析和产酶条件的初步优化 总被引:27,自引:0,他引:27
从腐烂的苹果表皮筛选到一株碱性果胶酶的高产菌株,命名为WSHB04-02.分离菌株为革兰氏阳性细菌,有芽孢,菌落颜色为乳白色.分离菌株WSHB04-02的16SrDNA全序列分析表明,该菌株与Bacillussubtilus具有99%的相似性,并与其他13株产碱性果胶酶菌株的16SrDNA结果进行同源性分析,并构建系统发育树.发现菌株WSHB04-02在不含果胶类物质与Mg2 的培养基上能高产碱性果胶酶,在优化的培养条件下,碱性果胶酶的酶活达到34U/mL,在国内还未见报道.图6表2参15 相似文献
910.
构建复合塔式生态滤池进行污水处理实验,对含氮污水通过系统各处理单元前后4种氮形态变化和浓度分布进行探讨。比较各单元进出水水质变化,研究各单元总氮和硝氮的去除效果以及对系统总去除率的贡献。结合装置构造特点,系统分析了氮素在复合塔式生态滤池中的迁移转化规律及除氮机制,并创新性应用δ15N-NO3-方法加以佐证。研究结果表明,复合塔式生态滤池工艺对总氮和硝氮均有很好的去除作用,实验污水中氮污染以硝氮为主,总氮去除主要取决于硝氮的去除;复合塔式生态滤池中硝化-反硝化交替作用明显,为不同形态氮的相关转化以及氮的去除创造了优越的条件。 相似文献