Microtox evaluation of industrial wastewaters

The main purpose of this study was to establish an inhibitory database using the Microtox assay for different wastes. The waste samples included 19 pretreated industrial wastes from two different industrial parks, 11 other industrial wastes outside industrial parks, and different treatment process effluents. The following is a brief summary of the findings from this study: (1) COD and BOD had a close relationship among different wastes; (2) Microtox data did not correlate with the conventional parameters of BOD, COD and SS; (3) many wastes did not meet the pretreatment standards and exhibited high Microtox toxicity; (4) some wastes exhibited high Microtox toxicity, although they met the pretreatment standards; (5) the mixture of the individual wastes exhibited an antagonistic effect; (6) the activated sludge process removed 60-75% of influent toxicity; and (7) the final effluent sometimes showed an increase in Microtox toxicity.