The hybrid process with eco-friendly materials for the treatment of the real textile industry wastewater

Abstract The present study represents the application of a hybrid process to a pretreated real textile wastewater. Hybrid process includes electrocoagulation, adsorption, and photo Fenton- like oxidation methods. In our previous study, electrocoagulation (EC) method was investigated and the optimum conditions were determined. Nearly 35% total organic carbon (TOC), 18.6%, chemical oxygen demand (COD), 90% turbidity, and 50% color removal efficiencies were achieved by the EC step. In this study adsorption and photo Fenton- like oxidation were applied sequentially to the effluent of EC step. Walnutshell and corncob agricultural wastes were used for the preparation of the activated carbon. After adsorption step, the removal efficiency of the TOC was found to be nearly 75% and color, turbidity, and total dissolved solids achieved the standards for irrigation water. Also, the removal efficiency of the COD was found as 27%. For adsorption, Langmuir isotherm model fit better and the second order kinetic model was found to be the best model. The BiNiO3 catalyst with corncob support material was effective for the photo Fenton- like oxidation method. The optimum conditions were selected as 0.75 g/L BiNiO3/corncob based catalyst loading and pH = 7–7.5. At the end of the hybrid process, 87% TOC, 49% COD, 96% turbidity, approximately 90% color and 95–97% suspended solids removals were achieved. The hybrid system was effective to achieve the irrigation water standards except for salinity and COD. Agricultural wastes used in preparation of catalysts and adsorbents were promoted to be innovative, environmentally friendly and economical.