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911.
设计了异波折板水解酸化-A2O一体化反应器,进行生活污水处理的实验研究。10个月的实验结果表明,系统的最佳水力停留时间(HRT)为8 h时,最适COD进水浓度为240-100mg/L,最佳混合液回流比(r)-污泥回流比(R)为250%-100%。控制反应器于以上运行参数下,25±2℃所对应的COD、TN和TP去除率分别为96.84%、67.55%和81.92%。当温度降至7℃时,其COD、TP和TN分别降至86.35%、50.25%和65.68%。基于实验分析结果,阐明了一体化反应器高效性的机理在于异波折板水解酸化段具有高效传质特性和A2O段具有复合式活性污泥-接触氧化好氧池的特点。 相似文献
912.
Rui Wu Guangyi Li Zongyi Zhang Yulong Ren Weijian Han 《Frontiers of Environmental Science & Engineering》2007,1(3):292-298
Road transport produces significant amounts of emissions by using crude oil as the primary energy source. A reduction of emissions can be achieved by implementing alternative fuel chains. The objective of this study is to carry out an economic, environmental and energy (EEE) life cycle study on natural gas-based automotive fuels with conventional gasoline in an abundant region of China. A set of indices of four fuels/vehicle systems on the basis of life cycle are assessed in terms of impact of EEE, in which natural gas produces compressed natural gas (CNG), methanol, dimethylether (DME) and Fischer Tropsch diesel (FTD). The study included fuel production, vehicle production, vehicle operation, infrastructure and vehicle end of life as a system for each fuel/vehicle system. A generic gasoline fueled car is used as a baseline. Data have been reviewed and modified based on the best knowledge available to Chongqing local sources. Results indicated that when we could not change electric and hydrogen fuel cell vehicles into commercial vehicles on a large scale, direct use of CNG in a dedicated or bi-fuel vehicle is an economical choice for the region which is most energy efficient and more environmental friendly. The study can be used to support decisions on how natural gas resources can best be utilized as a fuel/energy resource for automobiles, and what issues need to be resolved in Chongqing. The models and approaches for this study can be applied to other regions of China as long as all the assumptions are well defined and modified to find a substitute automotive energy source and establish an energy policy in a specific region. 相似文献
913.
全氟辛酸(perfluorooctanoic acid,PFOA)和全氟辛烷磺酸(perfluorooctane sulfonate,PFOS)是2种备受关注的持久性有机污染物,具有生物积累性和生物毒性,危害生态环境和人类健康.近年来,世界范围内严格管控PFOA和PFOS,导致PFOA和PFOS替代品在工业生产中大量使用.研究表明,PFOA和PFOS替代品在各环境介质中普遍存在,但其安全风险尚未充分研究.本文概括了近年来较受关注的几类PFOA和PFOS替代品的来源与分布,综述了在大气、地表水、地下水和土壤中的污染现状,总结了替代品的毒性效应,并展望了在PFOA和PFOS替代品研究中有待解决的问题. 相似文献
914.
915.
Madeleine E. Hardus Han de Vries David F. Dellatore Adriano R. Lameira Steph B. J. Menken Serge A. Wich 《Behavioral ecology and sociobiology》2013,67(3):429-437
The diet of great apes consists of several hundred plant species. The factors determining diet differences have been examined between populations but not within a population, probably due to the confounding effect of seasonal fluctuations on fruit availability. In Sumatran orangutans (Pongo abelii), fruit availability appears to be sufficiently high year round to have little influence on diet composition, which in turn allows for addressing this question. We examined the diet of eight adult female orangutans at Ketambe, Sumatra, and investigated whether fig and non-fig fruit availability, association time, and/or home range measures influenced dietary overlap between female dyads. Between most pairs, females’ diets were different: 16 out of 23 pairs had a significantly low diet species overlap. Only fig diet overlap was influenced (negatively) by the availability of non-fig fruit. Association time only influenced (positively) fig diet overlap. Hence, orangutans gathered in fig trees when non-fig fruit availability was low. Home range measures did not influence overall diet overlap. To our knowledge, this is the first study showing that, while controlling for confounding factors, individuals with similar energetic requirements, from the same population and sharing the same area, make different dietary choices relatively to their preferred (non-fig) fruit constituting the majority of their diet. Social transmission, with putative matrilineal diet traditions, suitably explains these results. We discuss the implications of the findings for orangutan conservation, namely on reintroduction and the felling of fig trees. 相似文献
916.
Guoliang Zhang Liang Zhang Xiaoyu Han Shujun Zhang Yongzhen Peng 《Frontiers of Environmental Science & Engineering》2021,15(2):32
917.
Yunping Han Lin Li Ying Wang Jiawei Ma Pengyu Li Chao Han Junxin Liu 《Frontiers of Environmental Science & Engineering》2021,15(3):38
918.
嗅觉标准液是可使人的嗅觉阈值测试标准化,科学化,数量化,应用嗅觉标准液对人群的嗅觉阈值测试,可以了解我国人群嗅觉状及特点,以便应用标准液筛选嗅觉试验员和鼻科临床无创伤检验等方面。 相似文献
919.
920.
Wenjuan Zhang Bo Han Ramato Ashu Tufa Chuyang Tang Xunuo Liu Ge Zhang Jing Chang Rui Zhang Rong Mu Caihong Liu Dan Song Junjing Li Jun Ma Yufeng Zhang 《Frontiers of Environmental Science & Engineering》2022,16(4):46