Biological Treatment of Post-Nanofiltration Concentrate of Real Textile Wastewater

Abstract

The paper evaluates the different bioreactor systems in the treatment of real textile wastewater containing Reactive Red 120 dye concentrated in nanofiltration processes as well as real textile wastewater taken from a working factory. The two-stage sequential semi-fed batch bioreactors and the continuous system with activated carbon used as support material in the anaerobic fixed film bioreactor combined with an aerobic bioreactor, after an acclimatisation period, were very efficient in colour removal, which achieved 95%. The aromatic amine ( orthanilic acid) released as a result of the azo bond cleavage was traced both in anaerobic (accumulation) and aerobic (degradation) conditions. Biogas production in both systems was very low. Nevertheless indirect biogas production assessment showed some biogas production potential in nanofiltration concentrate without an additional car bon source. Furthermore the nanofiltration concentrate did not inhibit biogas production from synthetic wastewater. Scanning electron microscope visualisation allowed for investigation of biofilm on activated carbon which consisted of at least two layers.