An investigation on the toxicity of sewage

In this study, the toxicity of municipal wastewater samples, taken from the second industrial zone and the general sewerage outlet were investigated by bioassays using garden cress (Lepidium sativum) and freshwater fish (Lepistes reticulatus) as test organisms. The LC50 (72-h) values of the fish in both Konya city wastewater samples, the general effluent and that of the second industrial zone, were calculated to be 41 and 47%, whereas the highest seedling percentages of garden cress were calculated to be 83 and 79%, respectively. The toxicity dilution factors of the wastewaters were found to be within the acceptable range for industrial discharge into sewerage systems and according to the industrial wastewater discharge rules of the Turkish water pollution control regulations.