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941.
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Conventional wastewater treatment simulation programs use a "lumped" approach, where process rates are calculated using bulk concentrations of biomass and microbial storage products. A recently developed distributed, or agent-based, approach, where individual bacteria are modeled to account for their potentially variable hydraulic experiences, was applied to the 5-stage Bardenpho process, a type of enhanced biological phosphorus removal (EBPR) that includes internal recycle flows, which were hypothesized to affect distributed state development. Consistent with previous results, the EBPR predicted performance was worse according to the distributed approach than the lumped approach. In addition, increasing the internal recycle rate increased the anoxic reactor nitrate concentrations, tending to decrease EBPR performance. However, in the distributed approach, differences in the state distributions in internal recycle-linked reactors decreased with increasing recycle flow, tending to improve EBPR. These phenomena tend to have simultaneous and opposite effects on EBPR. The net effect will depend largely on the specific systems and the nitrate concentration in anoxic reactors. 相似文献
944.
在地理信息系统(GIS)与遥感(RS)技术的支持下,选择多种定量指数对滇西北高原典型湿地区———碧塔海自然保护区进行了空间格局分析研究。通过分析,揭示了研究区景观空间格局的结构和特征及受扰程度,为研究区的湿地资源利用与保护提供了科学依据和决策支持。 相似文献
945.
Waste incineration is a politically sensitive issue in the UK. The major current technology is based on direct combustion of wastes in a moving-grate furnace. However, general public opinion prefers non-direct burning technologies. Waste gasification is one of those nearest technologies available. By reducing the primary air-flow rate through the grate of a packed-bed system, operation of the existing solid-waste incineration equipment can be easily converted from combustion mode to gasification mode without major modification of the hardware. The potential advantages of this are lower dust carry-over in the flue gases, lower bed temperature (and therefore lower NO(x) formation in the bed), simplified gas-treatment procedures and lower running cost, among other benefits. The major disadvantages are, however, reduced throughput of the wastes and possibly higher carbon in the ash at exit. In this study, numerical simulation of both combustion and gasification of municipal solid wastes in a full-scale moving grate furnace is carried out employing advanced mathematical models. Burning characteristics, including burning rate, gas composition, temperature and burning efficiency as a function of operating parameters are investigated. Detailed comparisons between the combustion mode and gasification mode are made. The study helps to explore new incineration technology and optimise furnace operating conditions. 相似文献
946.
混凝剂对去除不同水质污水中磷的效果分析 总被引:1,自引:0,他引:1
通过混凝试验,比较了常见的4种混凝剂对生活污水和模拟水样2种不同水质的污水中磷的去除效果,并对这2种污水中的除磷机理进行了比较分析.发现在2种水质条件不同的水样中,使用相同的混凝剂.其磷的去除效果有很大的差异.在生活污水中混凝剂的投加量达到50 mg/L时,污水中的磷去除率能达到85%以上,达到国家规定的二级排放标准.而在模拟水样中,即使混凝剂的投加量达到240 mg/L,磷的去除率依然很低.最高去除率只能达到63.7%,无法达到污水排放标准中的要求. 相似文献
947.
Mann-Kendall检验及其在河流悬沙浓度时间序列分析中的运用 总被引:1,自引:0,他引:1
探讨了Mann-Kendall非参数秩次相关检验在时间序列分析方面的应用,并以云南省文山州盘龙河为例,把它运用到河流悬沙浓度时间序列的趋势分析和突变分析研究中。结果表明:①M-K检验同样适用于河流悬沙浓度的趋势与突变分析;②盘龙河自20世纪60年代初至90年代末河流悬沙浓度一直表现为波动上升趋势,1999年后有下降的迹象;③盘龙河的河流悬沙浓度自20世纪60年代以来存在着两个明显的突变点,其一在1973年,其二在1999年。 相似文献
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950.
Qingsong Wang Jinhua Sun Xiaolin Yao Chunhua Chen 《Journal of Loss Prevention in the Process Industries》2006,19(6):561-569
With the extensive applications of lithium-ion batteries, many batteries explosion accidents were reported. The thermal stability of lithium-ion battery electrolyte could substantially affect the safety of lithium-ion battery. The C80 micro calorimeter was used to study the thermal stability of several commonly used organic solvents and electrolytes. The samples were heated in argon atmosphere and air atmosphere, respectively. The chemical reaction kinetics was supposed to fit by an Arrhenius law, then the self-accelerating decomposition temperature was calculated. It is found that most of the samples are stable in argon atmosphere while decomposing in air atmosphere, and the single organic solvent is more stable than the electrolyte generally. 相似文献