Treatment of textile wastewater in combined granular activated carbon- membrane bioreactor (GAC-MBR)

Abstract

In recent years, the membrane bioreactor (MBR) process has been seen as a promising technology for the treatment of both municipal and industrial wastewater, including textile wastewater which has the potential to generate high levels of pollution in the receiving environment. However, membrane fouling during MBR operation is seen as one of the most important drawbacks due to the reduction of membrane flux. In this study, granular activated carbon MBR (GAC-MBR) technology was investigated to treat real textile wastewater. In this context, conventional MBR (R1) and GAC-MBR (R2) with GAC (300 mg) were operated for 48 days. A flat-plate ceramic membrane module was used in both reactors. The chemical oxygen demand (COD) and color removal efficiencies were found to be 87 +/- 3% and 73 +/- 7% in conventional MBR, whereas these pollutant removal efficiencies were determined as 89 +/- 6.4% and 78 +/- 4.8%, respectively, in the GAC-MBR process. According to the results obtained, while conventional MBR required physical cleaning every other day, GAC-MBR did not require any cleaning after the addition of GAC. It was also observed that GAC had no direct effects on the excretion of soluble and loosely-bound or tightly-bound extracellular polymeric substances, however, reduced the transmembrane pressure, capillary suction time, and membrane fouling propensity.