daphnia pulex toxicity testing of ethylenediaminetetraacetic acid tetrasodium salt dihydrate and the wastewater effluent from extraction of rhodium using emulsion liquid membranes

ecotoxicity of rhodium (rh) from the model of mining waste water side stream was examinedin this paper. rh was extracted from the model of the mining waste water using an emulsion liquid membrane(elm). the extractions were done at ph of 1.87 and ph 2.92 and 41.6 % and 46.2 % of rh was extractedrespectively. the side streams of ph of 1.87 and ph 2.92 after the extractions were examined for ecotoxicityusing daphnia pulex in the acute toxicity testing. all test organisms died after 48 hours of exposure to the sidestream effluent with the original ph = 1.87, while 10-60 % survival rates were observed at the mining spenteffluent with original ph of 2.92 if the strength of the effluent ranged from 12.5 to 62.5 %. results forethylenediaminetetraacetic acid tetrasodium salt dehydrate (edta) showed that an increase in concentrationof edta in the test concentrations lead to the death of d. pulex. it was concluded that the very dilute waterside streams are toxic hence the discharge of the spent rh side-stream should thus be discouraged andprevented at all costs.