Application of IFAS Process to Treat Laboratory Wastewater

Laboratory wastewater is difficult to be effectively treated due to large fluctuations in water quality and complex sources of ingredients,which may contain certain toxic and hazardous substances. In this study,the laboratory wastewater discharged from a scientific research institution was sampled as the research object,and the integrated fixed-film activated sludge（ IFAS） process treatment method was adopted to explore the characteristics of production and discharge of laboratory wastewater at different time periods. Meanwhile,the water quality and quantity of laboratory wastewater were regulated by adding septic tank sewage,the IFAS process was used to investigate the removal effect and impact resistance of experimental wastewater COD,NH₃-N and other pollutants. The results illustrated that the biodegradability,toxicity and impact load of laboratory wastewater could be improved by mixingthe lab wastewater with the septic tank wastewater in a ratio of 2∶ 1,when the laboratory wastewater COD and NH₃-N were 13. 88 ～ 766. 99 mg/L and 0. 35 ～ 5. 76 mg/L,respectively. The COD and NH₃-N concentration of the effluent after treatment by IFAS process could reach the first-level emission standards in “sewage comprehensive discharge standard”（ GB 8978-1996）. Additionally,the study also found that IFAS process had good impact load resistance.