화학공학소재연구정보센터
Journal of Hazardous Materials, Vol.159, No.2-3, 567-573, 2008
Bioassessment of a combined chemical-biological treatment for synthetic acid mine drainage
In this work, ecotoxicological characteristics of synthetic samples of acid mine drainage (AMD) before and after a combined chemical-biological treatment were investigated by using Lepidium sativurn and Daphnia magna. AMD treatment was performed in a two-column apparatus consisting of chemical precipitation by limestone and biological refinement by sulphate reducing bacteria. Synthetic samples of AMD before treatment were toxic for both L sativum (germination index, G, lower than 10%) and D. magna (100% immobility) due to acid pH and presence of copper and zinc. Chemical treatment (raising pH to 5-6 and eliminating copper) generated effluents with reduced toxicity for L sativum (G=33%), while 100% immobility was still observed for D. magna. Dynamic trends of toxicity for the first and fifth outputs of the biological column denoted a gradual improvement leading to hormesis for Lepidium (after the initial release of organic excess), while a constant residual toxicity remained for Daphnia (probably due to H2S produced by sulphate reducing bacteria). (C) 2008 Elsevier B.V. All rights reserved