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941.
总磷是评价水质的重要指标,磷以多种形式存在,随着污水排放标准的不断更新,总磷标准的尺度不相一致。本文根据国家相关标准和规范,提出了能让已有标准内在联系更加完整和协调的建议,期待环境行政管理部门对废水中总磷排放标准做出更加明确合理的相关规定。 相似文献
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Community Structure and Quality After 10 Years in Two Central Ohio Mitigation Bank Wetlands 总被引:1,自引:1,他引:0
We evaluate two 10-year-old mitigation bank wetlands in central Ohio, one created and one with restored and enhanced components,
by analysis of vegetation characteristics and by comparison of the year-10 vegetation and macroinvertebrate communities with
reference wetlands. To assess different measures of wetland development, we compare the prevalence of native hydrophytes with
an index of floristic quality and we evaluate the predictability of these parameters in year 10, given 5 years of data. Results
show that the mitigation wetlands in this study meet vegetation performance criteria of native hydrophyte establishment by
year 5 and maintain these characteristics through year 10. Species richness and floristic quality, as well as vegetative similarity
with reference wetlands, differ among mitigation wetlands in year 1 and also in their rate of change during the first 10 years.
The prevalence of native hydrophytes is reasonably predictable by year 10, but 5 years of monitoring is not sufficient to
predict future trends of floristic quality in either the created or restored wetland. By year 10, macroinvertebrate taxa richness
does not statistically differ among these wetlands, but mitigation wetlands differ from reference sites by tolerance index
and by trophic guild dominance. The created wetland herbivore biomass is significantly smaller than its reference, whereas
detritivore biomass is significantly greater in the created wetland and smaller in the restored wetland as compared with respective
reference wetlands. These analyses illustrate differences in measures of wetland performance and contrast the monitoring duration
necessary for legal compliance with the duration required for development of more complex indicators of ecosystem integrity. 相似文献
945.
区域化工危险评价研究 总被引:2,自引:2,他引:0
为提高区域企业安全监管的科学性和有效性,采用化工厂危险程度分级法对常州市武进区69家高危化工企业进行同一标准的危险评价,确定其固有危险指数和固有危险等级。运用样本均值和标准差变异系数分析企业整体危险的趋同性,认为69家企业整体危险程度不高,物量指数、工艺系数、设备系数、环境系数、厂房系数依次是监管的重点,应加大对安全设施的督查力度。运用单侧控制图分析了高危企业和单项指标的偏移性,认为有9家企业属于超控状态,应根据超控原因实施有针对性的重点监管;在安全设施系数上超控的企业数量最多,加强对安全设施的监督力度,企业受益面最大,安全效果最明显。 相似文献
946.
Masoud Kayhanian Akshay Vichare Peter G. Green John Harvey 《Journal of environmental management》2009,90(11):3574-3580
Leachate metal pollutant concentrations produced from different asphalt and concrete pavement surfacing materials were measured under controlled laboratory conditions. The results showed that, in general, the concentrations of most metal pollutants were below the reporting limits. However, dissolved chromium was detected in leachate from concrete (but not asphalt) specimens and more strongly in the early-time leachate samples. As the leaching continued, the concentration of Cr decreased to below or close to the reporting limit. The source of the chromium in concrete pavement was found to be cement. The concentration of total Cr produced from leachate of different cement coming from different sources that was purchased from retail distributors ranged from 124 to 641 μg/L. This result indicates that the potential leachability of dissolved Cr from concrete pavement materials can be reduced through source control. The results also showed that the leachability of dissolved Cr in hardened pavement materials was substantially reduced. For example, the concentration of dissolved Cr measured in actual highway runoff was found to be much lower than the Cr concentration produced from leachate of both open and dense graded concrete pavement specimens under controlled laboratory study. It was concluded that pavement materials are not the source of pollutants of concern in roadway runoff; rather most pollutants in roadway surface runoff are generated from other road-use or land-use sources, or from (wet or dry) atmospheric deposition. 相似文献
947.
中国与世界银行对新建火电厂的环保要求对比分析 总被引:1,自引:1,他引:0
详细介绍了中国和世界银行对新建火电厂的不同环保要求,比较分析了电厂污染物排放中的大气(颗粒物、二氧化硫、氮氧化物)、工业废水和噪声的排放限值,对规划、新建火电厂的主要污染物控制具有参考意义。 相似文献
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