Evaluation of the Acute Toxicity of Pharmaceutical Wastewater to Luminescent Bacteria

Acute toxicity of wastewater from 5 nodes of technological process in the pharmaceutical factory sewage treatment station was studied by luminescent bacteria tests. The EC 50,TUa and LID of the wastewater in underground regulating tanks was 3. 44%,29 and 625,respectively,indicating the water was extremely / highly toxic; for the wastewater in surface regulating tanks,the EC 50,TUa and LID was 2. 46%,41 and 244,respectively,also extremely / highly toxic; for the wastewater in middle sediment tanks,the EC 50 100% and LID was 10,which was moderately toxic; for the wastewater in secondary sediment tanks and the final effluents,the EC 50 was above 100% and LID was 1,with no observed toxicity. The results indicated that the existing treatment process effectively reduced the acute toxicity of the pharmaceutical wastewater to luminescent bacteria,the effluents showed no observed toxicity to luminescent bacteria,which was lower than the relative effluent limits of pharmaceutical wastewater. The wastewater in lower concentration did not inhibit the luminosity,but enhanced the luminosity.