膜生物反应器在废水处理中的研究及应用

膜生物反应器(MBR)是近年来发展起来的一种新型的水处理技术,现就膜生物反应器类型、特点、对污染物的去除效果进行阐述,并系统介绍了近年来国内外利用膜生物反应器处理废水的研究成果以及膜生物系统在实际废水处理中的应用.简要阐述了膜污染的成因和膜清洗的方法以及建议,展望了未来膜生物技术在中国广阔的发展前景.     

水相中CCl4和CHCl3的紫外光解机理

利用瞬态吸收光谱技术研究水体污染物CCl4 和CHCl3 在紫外光照条件下的转化和归宿 ,表明在 2 4 8nm激光作用下 ,CCl4 解离为CCl3 和Cl自由基 ;CHCl3 在此条件下不解离 ,但加入少量的苯后即发生明显解离 ,产生CHCl2 和Cl自由基 .在有氧条件下 ,光解产生的CCl3 和CHCl2 自由基均与O2 反应分别生成CCl3O2 和CHCl2 O2 ;在无氧条件下 ,CCl3 和CHCl2 则发生偶合反应分别生成C2 Cl6和C2 H2 Cl4 .本研究还得出了一些微观速率常数 .     

西藏甲马铜多金属矿床的岩浆热液交代成因:地质与地球化学证据

西藏甲马铜多金属矿床的成因前人已提出了很多种观点。根据野外地质特征的观察 ,并结合矿区和区域岩矿石的微量元素、常量元素和稀土元素的分析与对比 ,作者认为该矿床的成因属于岩浆热液交代矽卡岩型矿床 ,推测其成矿时代为喜山早期。     

沈阳市能源需求预测及潜力分析

本文采用逐步回归分析法预测能源需求，结果表明能源消费量与国民生产总值显著相关，预测到２０００年，沈阳市短缺能源达２００万吨标煤．为此，文中进一步提出了提高能源开发、利用潜力的途径和措施及其环境效益．     

公路桥面伸缩装置及其对桥梁静动力性能影响综述∗

桥梁伸缩装置(以下简称伸缩缝)使用环境恶劣、受荷形式复杂,易出现多种病害。伸缩缝病害会造成桥梁耐久性降低,车致桥梁动力响应加重等不利现象。因此,伸缩缝病害机理及其处置方法和考虑伸缩缝参数影响的车-桥耦合动力响应规律研究受到了广泛关注。本文综述了桥梁伸缩缝力学性能,常见病害及其影响,病害机理及其处置方法等的发展现状;重点讨论了考虑伸缩缝参数及其变化影响的桥梁动力响应的研究进展及存在的问题;展望了未来桥梁伸缩缝研究中有待解决的关键问题。     

微生物在环境污染治理中的应用

本文介绍了近年来微生物在气体污染、水污染的处理等方面的应用。     

水相中CCl4和CHCl3的紫外光解机理

利用瞬态吸收光谱技术研究水体污染物CCl₄和CHCl₃在紫外光照条件下的转化和归宿,表明在248nm激光作用下,CCl₄解离为CCl₃和Cl自由基;CHCl₃在此条件下不解离,但加入少量的苯后即发生明显解离,产生CHCl₂和Cl自由基.在有氧条件下,光解产生的CCl₃和CHCl₂自由基均与O₂反应分别生成CCl₃O₂和CHCl₂O₂;在无氧条件下,CCl₃和CHCl₂则发生偶合反应分别生成C₂Cl₆和C₂H₂Cl₄.本研究还得出了一些微观速率常数.     

Research on the anti-interference capability of the tourism environment system for the core stakeholders of semi-arid valley-type cities: analysis based on the multi-scenario and time series diversity perspectives

Environmental Science and Pollution Research - Given the relatively harsh natural environment in semi-arid valley areas, the attraction and radiation functions of semi-arid valley cities have...     

The role of lime in dredged mud dewatered by a plate and frame filter press and potential substitutes

Environmental Science and Pollution Research - Dredged mud is a kind of construction material that can be reused as waste. It needs to be dehydrated before it is used. At present, plate and frame...     

Biodegradation of triazine herbicide metribuzin by the strain Bacillus sp. N1

By enrichment culturing of soil contaminated with metribuzin, a highly efficient metribuzin degrading bacterium, Bacillus sp. N1, was isolated. This strain grows using metribuzin at 5.0% (v/v) as the sole nitrogen source in a liquid medium. Optimal metribuzin degradation occurred at a temperature of 30ºC and at pH 7.0. With an initial concentration of 20 mg L^?1, the degradation rate was 73.5% in 120 h. If the initial concentrations were higher than 50 mg L^?1, the biodegradation rates decreased as the metribuzin concentrations increased. When the concentration was 100 mg L^?1, the degradation rate was only 45%. Degradation followed the pesticide degradation kinetic equation at initial concentrations between 5 mg L^?1 and 50 mg L^?1. When the metribuzin contaminated soil was mixed with strain N1 (with the concentration of metribuzin being 20 mg L^?1 and the inoculation rate of 10¹¹ g^?1 dry soil), the degradation rate of the metribuzin was 66.4% in 30 days, while the degradation rate of metribuzin was only 19.4% in the control soil without the strain N1. These results indicate that the strain N1 can significantly increase the degradation rate of metribuzin in contaminated soil.