Textile wastewater treatment using a UF hollow-fibre submerged membrane bioreactor (SMBR).

The objective of this study was to investigate the performance of a laboratory-scale submerged membrane bioreactor (SMBR) system for the treatment of synthetic textile wastewater containing disperse red dye. The SMBR system was run aerobically in a continuous flow mode at five different hydraulic retention times (HRTs) of 24,18,14.4,11.28 and 8.4 h respectively, with an average permeate flux of 20 L/(m2 x h). The performance of the system was not adversely affected by decreased HRT and the consequent rise in the food/microorganism ratio (0.07 to 0.14 g BOD/(g SS x d)) and organic loading rate (OLR: 0.4 to 1.24 BOD kg/(m3 x d)). The average removal rate for COD, BOD and colour were 92.33%, 93.69% and 91.36%, respectively. To maintain a stable flux and prevent fouling, the membrane was covered with a cylindrical wire-mesh cage, and routine chemical backwashing and chemical cleaning procedures were adapted. Transmembrane pressure increased from 29.47 to 58.42 kPa (0.29 to 0.58 bar) during each run of HRT. The results indicated that synthetic textile wastewater could be treated very effectively by the SMBR system.