The treatment of pre-treated real textile industry wastewater by application of combined physical, chemical and biological methods in the presence of corn cob and walnut shell based materials

In this study, the hybrid application of physical, chemical and biological methods were tested for the treatment of in-situ treated textile wastewater in order to meet irrigation water standards for agricultural purposes. For this purpose, adsorption, photo-Fenton like oxidation and microbial fuel cell methods were applied to textile wastewater consecutively. Corn cob and walnut shell based materials were used as adsorbents. Similar TOC removal efficiencies were obtained with both activated carbons. However, corn cob based adsorbent has more consistent. For this reason, corn cob based material was used as catalyst support in Fenton-like oxidation method. In the Foto-Fenton like oxidation method, the best result was obtained with BiNiO3 catalyst on activated carbon. When the results of the experiments with microbial fuel cells, which are the third and last step of the hybrid process are evaluated, it is concluded that this step is not very effective. At the end of the hybrid process, approximately 90% Total Organic Carbon, 50% Chemical Oxygen Demand, 96% turbidity, 90% color and 96% suspended solids removal were achieved. With respect to irrigation water standards, total organic carbon, turbidity, color, pH and suspended solids are met, however chemical oxygen demand and salinity are not satisfied. Four different adsorption isotherm models were investigated and Langmuir and Freundlich equations were found to be better compared to other isotherm equations. The second order kinetic equation could best describe the adsorption.