Advanced Treatment of Textile Wastewater for Reuse by Ozonation-Biological and Membrane Processes

摘要

Ozone and biological aerated filter (BAF) were combined as a pre-treatment of membrane filter for an advanced treatment of textile wastewater. It was found that adding ozone into BAF directly, forming an integrated system, allowed a higher CODcr and color reduction in this study. The optimal ozone dosage in the integrated unit was 20～30 mg/L. After the pre-treatment, the water qualities were CODcr 27.4 mg/L, turbidity 4.2 NTU, SS 3.0 mg/L, ammonia nitrogen 0.7 mg/L and color 2 times on average. In the final stage of the membrane process, the permeate water quality was the following: pH value 7.4～7.9, conductivity 50～200 μs/cm, total hardness 2～10 mg/L, total alkalinity 25～60 mg/L.