Effluent reuse potential of a dual-stage ceramic MBR coupled with RO treatment for textile wastewater

Abstract

The objective of this study was to investigate textile wastewater treatment using pilot-scale dual-stage ceramic membrane bioreactor ( MBR) and subsequent reverse osmosis (RO) system. Performance tests were carried out for 2 months using wastewater obtained from a local textile plant. Three different filtration periods (15, 30, and 45 min) with three back flushes (4, 8, and 12 s) were tested to observe flux and removal efficiencies of color, chemical oxygen demand (COD), ammonium (NH4+-N), and phosphate (PO43-P). MBR plant was operated at 500 mbar suction pressure. Mixed liquor suspended solids in the reactor was about 6.3 g/L. COD and color removal efficiencies in MBR were ranging from 83.2% to 89.1% and from 83.2% to 95.6 %, respectively. Moreover, NH4+-N, PO43--P and sulfate (SO42-) removal efficiencies in the MBR system were about 44.4%-81.7%, 60.0%-85.3%, and 21.2%-54.9%, respectively. Carbohydrate and protein concentrations of soluble microbial products and extracellular polymeric substances in the reactor were also measured. The complete removal efficiency of color, PO43--P, and SO42- was achieved with the RO system integrated into ceramic MBR. In addition, higher than 95% of conductivity, COD and NH4+-N, were removed from wastewater. The permeate quality was so high that the water could be recycled for reuse in the dying process.