期刊名称:African Journal of Environmental Science and Technology
电子版ISSN:1996-0786
出版年度:2010
卷号:4
期号:4
页码:234-249
DOI:10.5897/AJEST09.183
语种:English
出版社:Academic Journals
摘要:Despite the overwhelming advantages of mechanic villages, their heavy metal pollution of soil due to poor waste management is causing serious ecological and public health concerns. Analytical results show that heavy metal concentrations (mgkg-1) above background levels in the upper 100 cm soil profiles of the Okigwe, the Orji and the Nekede mechanic villages in the Imo River basin, collectively range from 748 - 70,606 (± 23021) for Fe; 99-1090 (± 176.8) for Pb; 186 - 600 (± 49.7) for Mn; 102 - 1001(± 208) for Cu; 8 - 23 (± 6.3) for Cd; 4 - 27 (± 4.2) for Cr; and 3 - 10 (±2.2) for Ni. The most abundant metals of environmental concerns are Pb, Mn and Cu, in the order of Pb > Mn > Cu. For proper waste management and environmentally friendly mechanic villages, mechanic villages should have emission testing facilities, concrete floor workshops, toilet facilities, tarred roads and drainage channelled to one or more three-phase storm water treatment facilities. We recommend infiltration method in the sandy areas, and detention method in the shale areas. A combination of the two methods can be used in the transition zones of the basin. The infiltration method is not applicable at Okigwe due to the high clay/silt content (47 - 64%) and presence of an underlying clay bed, despite the initially high infiltration rate (38.1 cm/h). Weathered layer (0 - 7.4 m) across Orji and Nekede, and (0 - 4 m) at Okigwe is the most implicated in the soil pollution process. We further recommend: extended producer responsibility (EPR) for used motor oil, the use of local phyto - remediation plants sensitive to Pb, Mn and Cu, installation of groundwater monitoring wells, comprehensive waste management plan, standard guidelines for establishment of mechanic villages, code of practice, and continuous education for the mechanics.
关键词:Soil contamination; storm water treatment; emission testing; EPR; heavy metals