THE TOXICITY EVALUATION OF WASTE-WATER FROM THE CHEMICAL-INDUSTRY

The purpose of our investigation was the acute and chronic toxicity evaluation of the wastewater from the chemical industry, while the previous study had indicated high toxicity of the receiving streams far away from the point of wastewater inflow. The luminescent bacteria Photobacterium phosphoreum and invertebrate Daphnia magna were used for toxicity tests. The results of the toxicity tests showed that the investigated wastewater contained toxic substances, which caused acute and chronic toxicity to test organisms. Daphnia magna were more sensitive than Photobacterium phosphoreum. The acute toxicity of the wastewater on daphnids disappeared after dilution to 1:420, but the chronic toxicity did not disappear earlier than 1:1350.