Hybridization of Biological Systems to Treat Real Textile Wastewater

Abstract

Wastewater reclamation from textile industrial sector using hybrid biological technology of anaerobic CSTR - aerobic SBR is considered to be a feasible option to adopt in developing countries. Microbial consortium in anaerobic process has the ability to degrade persistent and complexly degradable compounds resulting into the production of biogas energy in addition to the removal of biodegradable organics and decolorisation from textile wastewater. This study evaluates the performance of lab scale hybrid anaerobic-aerobic biological treatment technology for real textile wastewater on the basis of system evaluation and optimization by running system with synthetic industrial wastewater. In Phase I, system was optimized at laboratory scale on synthetic wastewater and later real textile wastewater was treated in Phase II. The study was conducted for 242 days for studying real textile wastewater treatment. Activated sludge used in the process was obtained from NUST Membrane Bioreactor (MBR) Plant and acclimatized anaerobically to synthetic and real textile wastewater over a period of 120 days. The experimental results showed that for textile wastewater of variable composition, an individual application of conventional aerobic treatment technologies is not sufficient and effective. By application of hybrid anaerobic-aerobic system, removal efficiencies of 95.6% dyes, 99.5% COD and 78.4% TKN were achieved. The anaerobic treatment technology plays the key role in treatment efficiency in addition to the generation of sustainable energy source, biogas. Study inferred that aerobic treatment is required to enhance treatment level by providing final polishing to the anaerobically treated effluent. Implication of this work to the industrial scale would be a sustainable solution for reclaiming the treated wastewater for agricultural sector and textile processing operations.