A novel adsorption process for the removal of salt and dye from saline textile industrial wastewater using a three-stage reactor with surface modified adsorbents

Abstract

Handling wastewater generated from textile industries is strenuous due to various xenobiotic and hazardous pollutants, which includes multi-category carcinogenic dyes. The existing conventional treatment methods adopted in developed nations are cost-intensive which leads to identify suitable alternative to achieve sustainable development and economic affordability. A befitting explication has been identified for treating textile wastewater using unmodified (UM), H2SO4 modified (M-H2SO4), and chitosan-coated banana fiber (M-CHI) as adsorbents in three stage reactors. The surface area of M-CHI, M-H2SO4, and UM was 4.808, 1.247, and 0.964 m²/g, respectively. The experimental findings bring about an effective adsorption process achieved at the optimal adsorbent dosage 25 g/L, contact time 10 mins, temperature 25 °C, and pH 5. A three-stage reactor was designed based on the results of single stage reactors where maximal dependable results were are achieved in the reactor with M-CHI. The three-stage reactor achieved a maximum of 95.1% dye, 99.56% turbidity, 27.83% TDS, 95.75% carbonate, 88.17% bicarbonate, 95.71% total hardness, 91.69% sulfate, 70.94% chlorides, and 96% COD removal. The FTIR, XRD, and HRSEM/EDX results indicates that M-CHI seems to be more efficient than others. Moreover, the adsorption isothermal analysis and column kinetic model are favorable towards the adsorption treatment processes. Overall, the efficiency order of the adsorbents was found to be M-CHI > M-H2SO4 > UM. However, as per the LCMS and GCMS analysis, a combined adsorption process of all the adsorbents is required to treat the textile wastewater effectively.