Textile wastewater treatment in anaerobic reactor: Influence of domestic wastewater as co-substrate in color and COD removal

Abstract

Treatment of textile wastewater with domestic wastewater as co-substrate was investigated in this study. Combined textile and domestic wastewater at different mixing ratios (100:0, 80:20, 60:40) was treated under anaerobic reactor. The influence of residence time, textile wastewater fraction and initial pH were determined in view of COD and color removal. Response Surface methodology (RSM) with Box–Behnken design (BBD) was employed to determine conditions for higher simultaneous removal of COD and color. The highest simultaneous removal of COD and color were satisfied at initial pH of 8.6, residence time of 9 days while textile and domestic wastewater ratio was 77:23. The highest removal efficiencies realized were 70% and 72% for color and COD respectively. In general, longer residence time and higher initial pH favored higher simultaneous removal of COD and color. Furthermore, textile wastewater fraction in range of 0.65 – 0.8 favored simultaneously high COD and color removal. Therefore, co-digestion of textile and domestic wastewater at specific ratio is a novel finding that can be further developed for treating textile wastewaters. Moreover, this technology is a promising approach to enhance biological treatment of textile wastewater.