不同植物人工湿地净化效果及基质微生物状况差异分析

为研究不同植物对人工湿地污染物净化效果和基质微生物状况的影响,采用序批式运行的沙培模拟人工湿地,探讨了菖蒲、香蒲、千屈菜、芦苇和白鹤芋5种湿地植物在不同HRT(水力停留时间,分别为1,3和5 d)下对模拟废水中TP,NH₄+-N和COD_Cr去除效果的影响,比较了不同植物类型模拟人工湿地中基质微生物的数量差异. 结果表明,不同植物系统对污染物的去除随HRT延长逐渐提高,HRT为5 d时各植物系统对污染物的去除效果最佳.TP,NH₄+-N和COD_Cr的最高去除率分别达90.4%,61.7%和96.4%.相对于其他试验系统,菖蒲系统对各污染指标均具有最优的去除效果. 植物种类对基质微生物数量的影响无显著差异.研究还发现,各系统中亚硝酸细菌数量与NH₄+-N去除率之间呈显著相关.      

THE MEANING AND EFFICACY OF SOCIAL WITHDRAWAL AS A STRATEGY FOR COPING WITH CHRONIC RESIDENTIAL CROWDING

Two studies examined whether the previously documented coping strategy of social withdrawal in response to chronic crowding is related to changes in social information processing. In both studies we found evidence that individuals residing in crowded homes in comparison to uncrowded homes were less cognizant of personal information about strangers in an incidental encounter under naturalistic, uncrowded conditions as well as under highly crowded conditions, occurring in the laboratory. Furthermore, we show in the experimental study that interference with this social withdrawal process has significant effects on social information processing. In study 2 we also demonstrate that social withdrawal in response to acute crowding is an effective coping strategy for reducing short-term stress for those who have learned to employ this strategy while living under chronically crowded conditions. All of these results occur independently of income levels.