排序方式: 共有14条查询结果,搜索用时 906 毫秒
11.
Tian L Hossain SR Lin H Ho KF Lee SC Yu IT 《Environmental geochemistry and health》2011,33(6):623-630
Despite the successful reduction in roadside NO( x ) levels, no such decrease has been detected in roadside NO(2) concentration in Hong Kong. One underlying cause could be the rising primary NO(2) fraction of the total emission of NO( x ). Primary NO(2) can be particularly detrimental to Hong Kong because a large fraction of the population are exposed to the traffic-related primary pollutants in the street canyons formed by congested high-rise buildings. In this study, hourly mean concentration data for roadside nitrogen oxides (NO( x )), nitrogen dioxide (NO(2)), and background ozone (O(3)) were used to estimate the mean primary NO(2) fraction from vehicle exhausts in Hong Kong. An overall increasing trend was observed for the primary NO(2) fraction (f-NO(2)) values in all the three roadside air monitoring sites. The primary NO(2) as a fraction of total NO( x ) (f-NO(2)) increased approximately from 2% in 1998 to 13% in 2008 in Hong Kong. The two particular periods of rising f-NO(2) coincided with the two implementation periods of the diesel retrofit programs for the light-duty vehicles and heavy-duty vehicles. Future vehicle emission control strategies should target not only total NO( x ) but also primary NO(2). Health benefit or disease burden estimates should be taken into account and updated in the process of policy planning and evaluation. 相似文献
12.
13.
采用单因素试验分析了多功能复合微生物制剂MCMP处理垃圾渗滤液的反应条件,结果表明:投加MCMP能促进渗滤液COD、NH3-N、TP的去除,在反应时间72 h,间歇曝气36h,接种量(VMCMP:V水)为1/8000,进水pH值8时处理效果较好,去除率分别达到37.56%、72.74%、51.56%。MCMP技术与生物膜法联合处理垃圾渗滤液的试验表明:同单纯使用MCMP菌处理渗滤液相比,以陶粒为填料的MCMP生物膜系统,对TP的去除效果有明显提高,去除率达到65.23%,对COD和NH3-N去除率影响不显著。 相似文献
14.