Determination of polychlorinated biphenyl congeners in sediment samples of twelve rivers in eastern China

Polychlorinated biphenyl (PCB) congener concentrations and their distributions were determined for the first time in 12 major rivers of eastern China. It was found that the PCB contamination level in those rivers was relatively low compared to the levels reported in most developing countries. Total amount of PCBs in the river sediments ranged from 10 to 22 ng/g dry weight and dichlorodiphenyldichloroethene (DDE) ranged from 0.89 to 7.62 ng/g. The PCB concentrations were basically homogeneous in different rivers; however, they consistently changed with the percent of total organic carbon (TOC). The PCB concentrations and compositions found in the 12 river sediments were very similar, with the tetra‐ and penta‐ groups as the dominants. Given that distributions and contaminant levels in sediments reflect the number of PCBs, the contamination of the 12 major rivers in eastern China is probably due to atmospheric deposition rather than the point source contamination.     

利福平废水处理的工艺实验研究

采用水解酸化-UASB(上流式厌氧污泥反应床)-接触氧化-生物活性炭工艺对利福平废水进行了生化处理。结果表明:水解酸化可以有效提高废水的可生化性,大幅度提高后续的厌氧-好氧处理效果,工艺末端的生物活性炭深度处理可以有效的去除好氧出水的COD和色度,使得出水达到GB8978-1996《污水综合排放标准》的规定标准。     

甘肃省城市节水对策研究

针对甘肃省水资源严重短缺,制约社会经济发展的事实,文章立足城市节水,从完善节水法律体系,依靠科学管理和技术进步着手,从工业、居民生活、城市公用事业3个方面提出了切实有效的节水措施,并在污水资源化、提高中水和雨水回收利用率方面提供了建议,为甘肃省城市节水工作提供了参考。     

一体式膜生物反应器膜污染影响因素研究

试验采用聚丙烯中空纤维膜,通过正交试验考察了膜通量、抽停时间、曝气量对膜过滤压力的影响,得出适合的膜通量是减缓膜污染的决定性因素。并确定了适宜的运行条件：膜通量5L／（m2·h）,抽吸时间8min,停抽时间2min,曝气量0．6m3／h;同时考察了EPS中多糖和蛋白质对膜污染的影响,得出多糖是主要的污染物质。     

物理诱变处理氧化亚铁硫杆菌的育种研究

以氧化亚铁硫杆菌作为出发菌,采用物理诱变进行处理。研究结果表明,经过微波和超声波诱变均能加快氧化亚铁硫杆菌氧化Fe2+和转化SO32-的速度。尤其是经过90 s微波处理的氧化亚铁硫杆菌进入对数期的时间比未经诱变前缩短12 h,48 h时Fe2+的氧化率达到99%,4小时后SO32-基本全部转化为SO42-。     

论包头市环境保护“十一五”规划的实施

对照包头市“十一五”国民经济和社会发展规划纲要及包头市“十一五”国民经济和社会发展规战略环境影响评价的要求,分析包头市“十一五”期间有关环境保护方面规划的完成情况,为“十二五”期间环保事业的发展重点和发展方向提供决策参考和技术支持。     

Management Model of Resources Equilibrium Distribution among Overlapping-Generations

Abstract

The overlapping generation models the western scholars have designed from various perspectives to address different kinds of issues do not reflect Chinese emerging political and economic problems, and cannot be entirely and blindly applied to Chinese practical situation. In this paper the authors endeavor to incorporate some western scholars' research results into their own research findings to present overlapping generations model theory in a new perspective through establishing an overlapping generations theory on population including articulation of concepts and theorems of biological generation, economic generation and social generation and the overlapping periods in biological generation and two overlapping periods in economic generation among three generations. This management model with equilibrium distribution of resource wealth includes overlapping generations length model (δ), equilibrium transfer model (?) and a complete model on equilibrium distribution among generations (δ-?). The model provides quantitative basis for the creation of resource management system, and fills in a theoretical gap in this discipline in China. Besides, it furnishes a new methodology and manipulate tool for Chinese government to establish a comprehensive management information bank for many sectors such as economic trade, population, science and technology, education, human resource, natural resource and environment, agriculture, forestry, industry, mining and energy.     

曝气陶粒生物滤池深度处理印染废水的研究

通过对陶粒生物滤池深度处理江苏某印染厂二级生化出水的研究表明:陶粒生物滤池在整个稳定运行阶段对本印染废水的CODcr去除率达55%左右,当进水CODcr在90 mg/L~100 mg/L之间时,出水CODcr可保持低于50 mg/L;陶粒生物滤池对于NH3-N也有很好的去除效果,当进水NH3-N浓度在8.5 mg/L~14 mg/L之间波动时,出水能够保持在1~1.5 mg/L,平均去除率基本稳定在88.5%左右;当进水色度在50~80度之间波动时,出水色度在38~62度之间,色度去率为20%。同时分析了CODcr、NH3-N去除的机理,以及导致色度去除不高的原因。     

基于归一化的地震灾区道路危险性综合评价

道路选择问题是地震灾后应急救援必须解决的问题之一.为了对救援道路进行合理的选择,需要对灾区道路危险性进行综合评价.现有的综合评价中较少考虑归一化方法的选取对评价结果的影响,该文使用EM(Entropy Method)改进TOPSIS(Technique for Order Preference by Similarit...     

CuxCe1-xO2/γ-Al2O3催化剂催化燃烧甲苯性能的研究

以γ-Al₂O₃ 为载体,以复合氧化物Cu_xCe_1-xO₂为活性组分,其中,x=0.1,0.2,0.4,0.6,0.8,通过浸渍法制备了一系列Cu_xCe_1-xO₂/γ-Al₂O₃催化剂.在固定床反应器中评价了催化剂对甲苯的催化活性,通过XRD、SEM对催化剂进行表征,并运用ICP-MS分析并计算Cu、Ce的摩尔比以及活性组分的负载量.结果表明,在Cu_xCe_1-xO₂/γ-Al₂O₃催化剂中Cu、Ce摩尔比的实际值与理论值相近,活性组分的负载量在19%以上,而且对甲苯都有较好的低温催化活性,其中当x=0.2时,即Cu_0.2Ce_0.8O₂/γ-Al₂O₃催化剂对甲苯的催化活性最高,其中T₁₀=160 ℃,T₉₀=265 ℃;当甲苯的进口浓度在700~3000 mg·m^-3时,进口浓度对Cu_0.2Ce_0.8O₂/γ-Al₂O₃催化剂的催化活性影响较小,且经过连续80 h的稳定性操作后转化率仍然保持在90%以上.