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991.
本文在总结国内外自然保护区级别划分背景的基础上,根据我国自然保护区建设和管理的现状,提出保护区级别划分应遵循的原则,如以定性方法为主,与现行行政体制相一致等。根据这些原则,研究制定了我国自然保护区级别划分的标准。该标准将自然保护区划分为国家级、省级、市级和县级。并对其标准进行了详细描述和定义。此外,本文还对保护区级别划分的依据和确定保护区重要性的评价指标进行了阐述和讨论。此标准的研究对于当前我国自然保护区的建设和规范化管理具有重要的意义。 相似文献
992.
In this paper, the amount of oxygen consumption, end products and activities of microorganisms are considered as the three factors which affect the biodegradability of organic substances in water. Two integrated assessment methods for biodegradability of organic substances, fuzzy clustering integrated assessment and weighted integrated assessment, have been developed. Simultaneously, the detail steps for assessing a new organic substance biodegradability with these two integrated assessment methods are proposed. 相似文献
993.
In the present study, a hydrophilic bifunctional polymeric resin (LS-2) with sulfonic groups was synthesized, and the adsorption performance of three aniline compounds, aniline, 4-methylaniline, and 4-nitroaniline onto LS-2 was compared with that on the commercial Amberlite XAD-4. The uptake of the aniline compounds on LS-2 is a procedure of coexistence of physisorption and chemisorption and obeys the pseudo-second order rate equation, while the uptake of the compounds on XAD-4 is merely a physical adsorption and follows the pseudo-first order rate equation. All the isothermal data fit well with the Freundlich model, and the values of K(F) of the compounds adsorbing on LS-2 are much higher than those on XAD-4 suggesting the higher adsorbing capacities on LS-2 than those on XAD-4, which may be attributed to the microporous structure and the polar groups on the network of LS-2 resin. Dynamic adsorption and desorption studies for aniline on LS-2 show that the breakthrough adsorption capacity and the total adsorption capacity are 0.96 and 1.24 mmol per milliliter resin, respectively. Nearly 100% regeneration efficiency for the adsorbent was achieved by 5% hydrochloric acid. 相似文献
994.
The influence of pH on the degradation of phenol and chlorophenols by potassium ferrate 总被引:16,自引:0,他引:16
This paper presents information concerning the influence of solution pH on the aqueous reaction between potassium ferrate and phenol and three chlorinated phenols: 4-chlorophenol (CP), 2,4-dichlorophenol (DCP), 2,4,6-trichlorophenol (TCP). The redox potential and aqueous stability of the ferrate ion, and the reactivity of dissociating compounds, are known to be pH dependent. Laboratory tests have been undertaken over a wide range of pH (5.8-11) and reactant concentrations (ferrate:compound molar ratios of 1:1 to 8:1). The reactivity of trichloroethylene was also investigated as a reference compound owing to its non-dissociating nature. The extent of compound degradation by ferrate was found to be highly pH dependent, and the optimal pH (maximum degradation) decreased in the order: phenol/CP, DCP, TCP; at the optimal pH the degree of degradation of these compounds was similar. The results indicate that for the group of phenol and chlorophenols studied, the presence of an increasing number of chlorine substituent atoms corresponds to an increasing reactivity of the undissociated compound, and a decreasing reactivity of the dissociated compound. 相似文献
995.
射流曝气的气液两相流的数值模拟 总被引:7,自引:0,他引:7
射流曝气在活性污泥处理方法中起着重要的作用。采用数值模拟的方法研究自吸式单级单喷射流器中的气液两相流动状况,通过对不同长径比和喷嘴面积比的射流曝气器模型的气液两相流的计算,定量分析长径比和喷嘴面积比对射流曝气器流场和空气与工作介质流量比的影响,为进一步设计开发新型高效的射流曝气器提供参考。 相似文献
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我们于1995年3月 ̄4月调查了武汉市高位铁皮水箱的供水质量。结果表明:高层住宅水箱近年虽曾清洗消毒,但高层用户龙头水及水箱水中游离性全氯未达标比例较大,分别为73.3%和66.7%。个别底层住户水样中铁超标。高位水箱水样中细菌总数超标比例为20%。反映了高层住宅二次供水中在水的输送、贮存过程中有二次污染存在。经水样监测指标相关性和灰色关联性分析,认为游离性余氯可作为常规监测高层住宅二次供水质量的 相似文献
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