Hybrid coagulation-flocculation and anaerobic-aerobic biological treatment for industrial textile wastewater: pilot case study

Color is one of the main problems in wastewater and many techniques can be applied to remove it. In the present work, a pilot plant scale investigation was carried out to optimize treatment efficiency in order to reduce the amount of residual adsorbed dye that will be found in the waste sludge. For degradation of textile wastewater (TWW), coagulation-flocculation experiments were performed in a jar test apparatus using FeCl3, Fe(SO4), Al-2(SO4)(3) and Cu(SO4) as a coagulant agent and three bacteria (Sphingomonas paucimobilis, Bacillus sp. and filamentous bacteria) by means of biodegradation, coagulation-flocculation process and their combination. The color, COD and phenol removal were 81.82%, 76.17% and 35.69% respectively. UV-vis and nuclear magnetic resonance (NMR) spectroscopy analysis confirmed the biodegradability of the TWW by post and pre-treatment of the developed bacterial consortium. The textile wastewater phytotoxicity assessment on Sorghum bicolor and Triticum aestivum showed 80% and 60% reduction after post-treatment textile wastewater.