Toxicity of herbal pharmaceutical wastewater to a freshwater crustacean Ceriodaphnia dubia.

The main objective of this study was to evaluate the acute toxicity of raw, neutralized and physico-chemically treated and biologically treated effluent of herbal pharmaceutical industry. The acute toxicity test was determined using freshwater crustacean Ceriodaphnia dubia under laboratory conditions. LC(50) values for raw, neutralized and physico-chemically treated effluent for 12, 24, 36 and 48 h ranged between 3.0-4.5%, 3.9-10.8% and 22-28% respectively. It is evident from the results that physicochemical treatment reduced the toxicity by around 25% while biological treatment reduced the toxicity completely. Results subjected to statistical evaluation depicted regression coefficient of more than 0.9 indicating good correlation between the mortality rate and effluent concentrations.