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961.
Xiaoqiang Gong Jinbiao Li Scott X. Chang Qian Wu Zhengfeng An Chengpeng Huang Xiangyang Sun Suyan Li Hui Wang 《Frontiers of Environmental Science & Engineering》2022,16(3):39
962.
采集并测试广州市林地土壤样品600余组,分析土壤中As、Cr、Cd、Hg、Cu、Pb、Zn、Ni和磁学性质的相关性。结果表明:土壤磁性颗粒以软磁性矿物为主,北部以超顺磁、多畴颗粒为主,南部以单畴、多畴颗粒为主。相关性分析表明:北部Cu、Ni、Cr、Cd与较粗的磁性颗粒共存,Cd与软磁性矿物共存,As与超顺磁颗粒共存且为自然源;南部相关关系不显著,Ni和As来源为人为源;不同污染程度土壤回归方程相关系数均较好,南部深〖CD*2〗浅层回归方程证明上述8种元素和磁性相关性不受自然来源或人类活动影响。 相似文献
963.
964.
光催化氧化苯甲酸时TiO2中毒机理及再生方法的研究 总被引:4,自引:1,他引:4
以苯甲酸作为模型污染物,采用强制中毒的方法研究了TiO2在悬浮光催化氧化体系中的中毒过程,并通过对中毒TiO2进行IR、SPS及XPS表征,分析了中毒后TiO2的表面性质,揭示了苯甲酸光催化降解过程中TiO2光催化剂的中毒机理.采用高温焙烧、UV光照射及超声波振荡等方法对中毒TiO2进行再生,并考察再生效果.研究表明,实验条件下,催化剂反复使用20次后将完全中毒.引起TiO2中毒的主要原因是苯甲酸及其降解中间产物,如羟基苯甲酸、顺丁烯二酸、反丁烯二酸等吸附、积累在TiO2表面,占据了TiO2的表面活性位置,使其光催化活性下降;TiO2在使用过程中出现的团聚现象也会导致其活性降低.比较了高温焙烧、UV光照及超声波清洗3种方法对中毒催化剂的再生效果的比较研究,结果表明,3种方法均能使中毒后TiO2的催化活性得到一定恢复,其中高温焙烧对中毒TiO2的再生效果较好. 相似文献
965.
966.
Gullino S 《Journal of environmental management》2009,90(6):2012-2019
This article explores the potential of a GIS-based approach to city management - Baltimore's CitiStat e-government program - for meeting the goals of sustainable urban regeneration. The argument advocated here builds on the widely held recognition that the application of ICTs in general can lead to both new forms of inclusion and exclusion of citizens. Therefore attending to the 'digital divide' is a relevant issue because cities are complex environments where outcomes of interventions are uncertain and widening participative arenas to different actors can increase the possibilities to regenerate declining urban areas in a more democratic way. 相似文献
967.
The Southeastern United States is a global center of freshwater biotic diversity, but much of the regions aquatic biodiversity is at risk from stream degradation. Nonpoint pollution sources are responsible for 70% of that degradation, and controlling nonpoint pollution from agriculture, urbanization, and silviculture is considered critical to maintaining water quality and aquatic biodiversity in the Southeast. We used an ecological risk assessment framework to develop vulnerability models that can help policymakers and natural resource managers understand the impact of land cover changes on water quality in North Carolina. Additionally, we determined which landscape characteristics are most closely associated with macroinvertebrate community tolerance of stream degradation, and therefore with lower-quality water. The results will allow managers and policymakers to weigh the risks of management and policy decisions to a given watershed or set of watersheds, including whether streamside buffer protection zones are ecologically effective in achieving water quality standards. Regression analyses revealed that landscape variables explained up to 56.3% of the variability in benthic macroinvertebrate index scores. The resulting vulnerability models indicate that North Carolina watersheds with less forest cover are at most risk for degraded water quality and steam habitat conditions. The importance of forest cover, at both the watershed and riparian zone scale, in predicting macrobenthic invertebrate community assemblage varies by geographic region of the state. 相似文献
968.
Ammonium removal by modified zeolite from municipal wastewater 总被引:4,自引:0,他引:4
Ammonium removal by modified zeolite, H-form and Na-form zeolite, were examined by batch-type methods. The adsorption of ammonium on modified zeolite was exothermic process. The saturation adsorption capacity of ammonium on H-form and Na-form zeolite were 21.23 and 41.1.5 mg/g, respectively. After ten times adsorption-desorption-readsorption cycles the standard deviations of H-form and Na-form zeolite were 6.34% and 6.59%. The zeolite adsorption process has proved cost effective and practical in reducing ammonium by H-form and Na-form zeolite in municipal wastewater from concentration 27.68 mg/L to 2.80 mg/L and 5.91 mg/L. 相似文献
969.
970.
沸石生物联合吸附再生工艺及铵沸石再生 总被引:8,自引:0,他引:8
简述了沸石生物联合吸附再生的工艺原理,重点讨论吸附了NH 4的沸石粉的生物再生.结果表明,沸石和液相之间的NH 4是一种动态的离子交换平衡,污水的电导率对吸附了NH 4的沸石粉的NH 4解吸量有明显的影响;污水中阳离子对吸附了NH 4的沸石粉的再生率可达40%-50%,在微生物的硝化作用下可达94%.沸石生物联合吸附再生工艺中,吸附了NH 4的沸石粉的再生是"化学再生"和"生物再生"相结合的过程,生物硝化作用促进了沸石相中NH 4的解吸. 相似文献