Simultaneous removal of cadmium and turbidity in contaminated soil-washing water by DAF and electroflotation
Park, J.; Jung, Y.; Han, M.; Lee, S.
Water Science and Technology a Journal of the International Association on Water Pollution Research 46(11-12): 225-230
2002
ISSN/ISBN: 0273-1223 PMID: 12523758 Document Number: 542388
The removal of cadmium and turbidity from contaminated soil-washing water was studied by dissolved air flotation (DAF) and electroflotation at laboratory scale by using sodium lauryl sulfate (SLS) as an anionic surfactant, and calcium hydroxide (Ca(OH)2) as a coagulant. Using DAF, and in the presence of SLS or Ca(OH)2, the maximum recovery rate of cadmium obtained at a stoichiometric cadmium to collector and coagulant ratio of 1:4.5 was 51.1% and 80.8%, while the removal rate of turbidity was 18.4% and 19.2%. However, satisfactory cadmium and turbidity removal was not obtained by DAF. Much more significant removal of cadmium (100%, not detected in the residual) and turbidity (95.7%) was obtained by electroflotation using an aluminium metal plate as electrode, which generated hydroxide and aluminum ion. As a consequence, electroflotation is considered an effective method to separate cadmium and turbidity from contaminated soil-washing water. The electroflotation process may have practical applications for the removal of other hazardous metals from contaminated soil-washing water.