PERFORMANCE EVALUATION OF HYBRID BIOLOGICAL REACTORS FOR TEXTILE WASTEWATER TREATMENT USING POWDERED ACTIVATED CARBON

Abstract

Due to the population growth, urbanization, change in human life style and lacking natural water resources, the need and demand of water has become ever greater. To overcome water scarcity problem, wastewater can be treated efficiently by advanced technologies. In Pakistan textile industry has got much importance and is the most attractive sector. The discharge of dye containing effluents from such industry is undesirable for environment. MBR technology is highly promising technique nowadays for biodegrading organic matter in general and dyes in textile wastewater in particular. Bench scale Hybrid Membrane Bioreactor (H-MBR), Hybrid Sequencing Batch Reactor (H-SBR) and Conventional Sequencing Batch reactor (C-SBR) treating synthetic textile wastewater under similar operating conditions were evaluated for removal of color, Chemical Oxygen Demand (COD) and nutrients at 12 hr hydraulic retention time (HRT) and 30 days solids retention time (SRT). Synthetic textile wastewater was based upon the characterization of real wastewater from Crescent Textile Mill Faisalabad, Pakistan. Treatment of synthetic textile wastewater through H-MBR and H-SBR was supplemented with powdered activated carbon (PAC) as an adsorbent for the removal of dye color and soluble organic and inorganic substances in the reactor. PAC was efficient in removing chemical oxygen demand (COD) and color from textile wastewater. It facilitated in membrane fouling control and reduced soluble extracellular polymeric substances (EPS) in H-MBR. The optimized dose of PAC was observed in the range of 100-150 mg/L. Results showed an improved COD removal of 93% and color removal of 99% in H-MBR as compared to 89% COD and 92% color removal efficiencies in H-SBR.