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991.
The biological toxicity of aquatic ecosystems should be considered when assessing the effects of toxicity on the water environment. The aim of this study was to identify the main pollutants in the Baiyangdian (BYD) and the factors that contribute to biological toxicity. We determined various physical and chemical indicators in the surface water of the BYD, including nutrients and heavy metals, and the biological toxicity. We also explored the sources of the main pollutants and how the pollutants contributed to toxicity in the lake, using correlation analysis and an index of the biological toxicity. The results showed that total nitrogen (TN), ammoniacal nitrogen (NH4+-N), chromium (Cr), and zinc (Zn) were the main pollutants in the BYD surface water. The average concentration of Cr was 2.3 times greater than the Class V threshold, and the concentrations at about 65% of the sampling points, mainly those in the southern part of the BYD, exceeded the threshold standard. The average concentration of Zn was 1.25 times higher than the Class V threshold, with the concentrations of about 35% of the samples greater than the threshold concentration. The integrated toxicity of the surface water to luminescent bacteria ranged from 0.51% to 58%, and averaged 24.07%, which was within the range of moderate toxicity. The inhibition rates were high near Diantou (59%) and Duan (51.6%). The pollutant levels in the BYD tend to be related to the population density, with pollution mainly caused by sewage and domestic garbage, with little influence from local industries. Cr and TN were strongly correlated, but the biological toxicity was not correlated with any of the individual environmental indicators, which suggests that the toxicity in the surface water of the BYD reflected the combined effects of the environmental factors, rather than a single factor. The information from this study, about the main pollutants and the relationships between the physical and chemical properties of the surface water in the BYD, can be used to support plans for restoring the BYD. 相似文献
992.
通过建立3个不同导气管管径(Ф25 mm,Ф50 mm,Ф75 mm)的准好氧生物反应器填埋场,探究了导气管管径对其碳氮污染物转化的影响.研究表明,准好氧生物反应器填埋场渗滤液总氮、氨氮、CODCr、TOC的降解均符合线性-指数复合模型,且当导气管管径由25 mm增大至50mm时,可明显提高其降解速率,分别由0.00323、0.00474、0.01177、0.0059 d-1提高至0.01921、0.02267、0.01617、0.01253 d-1;由50 mm进一步增大至75 mm时,渗滤液碳氮污染物的降解速率也有小幅提高.导气管管径的增大有利于填埋体内碳氮污染物的去除,由Ф25 mm增大至Ф50mm时,碳氮污染物去除率明显提高,且只有很少部分转移至液相中,同时氮污染物和碳污染物的气化率分别提高了33.42%和10.74%;进一步增大至Ф75 mm时,碳氮污染物去除率也有一定程度提高.导气管管径越大,固相中碳氮物质剩余率越低,液化率越低,气化率越高. 相似文献
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995.
Shan Weidong 《中国人口.资源与环境(英文版)》2013,11(2):58-62
Abstract This paper analyses redounded profits of cooperation and non-cooperation among cities in urban agglomerations based on game theory. It discusses the problems of economical development among cities with feeble cooperation, and deduces the conclusion that only cooperation of cities produces the maximum profits and realizes Pareto efficiency for cities and urban agglomerations. The paper states that cooperation is the cornerstone of economic sustainable development in urban agglomerations in profits produced by cooperation among cities. Some suggestions to accelerate cooperation among cities are proposed. 相似文献
996.
掘进巷道风流温度分布规律的数值模拟 总被引:6,自引:0,他引:6
根据紊流状态下的守恒原理 ,导出了描述掘进巷道风流紊流流动和温度分布的微分方程。通过对矿内风流流动及热力过程的理论分析及现场实测 ,系统地开展矿内风流流场和风流温度场的分布规律及其耦合作用机理的理论分析与研究 ,并利用PHOENICS程序进行数值模拟 ,初步得出了矿井掘进巷道风流温度与各种参数的变化规律。掘进巷道风流温度随风速提高呈负幂函数规律降低 ,随入风流温度升高而线性升高。 相似文献
997.
中国环境政策矩阵的构建与分析 总被引:2,自引:0,他引:2
可持续发展战略要求对已有的环境政策手段进行重新评估。由世界银行提出的环境政策矩阵则是进行这种评估的成功之举。本文利用政策矩阵这一模式探讨了我国环境政策手段的构成与特点,并进而提出了创新我国环境政策手段的几点建议,以促进我国可持续发展战略的实施。 相似文献
998.
黑河流域水资源可持续利用对策 总被引:6,自引:0,他引:6
水资源私有制和生态环境恶化已成为黑河流域面临的严重问题。本文分析了黑河流域水资源开发利用中存在的问题,在结合大量翔实数据的基础上,以水资源可持续利用为原则,提出了黑河流域水资源可持续利用的途径与措施。 相似文献
999.
The river ecosystem in the Hai River Basin(HRB), an important economic region in China, is seriously degraded. With the aim of river restoration in the HRB, we developed a method to assess the river's ecological status and conducted a preliminary application of the method.The established method was a predictive model, which used macroinvertebrates as indicator organisms. The river's ecological status was determined by calculating the ratio of observed to expected values(O/E). The method included ecoregionalization according to natural factors, and the selection of reference sites based on combinations of habitat quality and macroinvertebrate community. Macroinvertebrate taxa included Insecta,Crustacea, Gastropoda, and Oligochaeta, with 39 families and 95 genera identified in the HRB. The HRB communities were dominated by pollution tolerant taxa, such as Lymnaeidae, Chironomus, Limnodrilus, Glyptotendipes, and Tubifex. The average Shannon–Wiener index was 1.40 ± 0.5, indicating a low biodiversity. In the river length of 3.31 × 10~4 km, 55% of the sites were designated poor, with a bad ecological status. Among nine secondary river systems, Luan and Zi-ya had the best and worst river conditions,respectively. Only 17 reference site groups were selected for river management in the 41 ecoregions examined. This study lays the foundation for river restoration and related research in the HRB, and we anticipate further developments of this novel method. 相似文献
1000.
以大连市为研究区域,构建人文因素对区域生态系统影响的指标体系、评估模型及评估标准,基于状态空间法,从区域资源、区域环境、人文因素三个维度对大连市2002-2012期间47个指标,评价人文因素对生态环境的影响。结果表明:近十二年来,大连市人文因素对生态环境的影响综合指数几乎都在临界值以下,即处在影响适度范围内,总体上达到了可持续发展的要求,但是与青岛市相比,大连市还应该加强生态环境保护的力度,避免在以后的发展中受到环境的制约。 相似文献