Removal of methylene blue and Congo red from the wastewater in a jet loop reactor using ozone and activated carbon

Abstract

The textile industry consumes a large amount of fresh water, resulting in colored effluent due to the incomplete fixation of certain dyes. Traditional textile wastewater treatment such as coagulation-flocculation, membrane filtration, thermal separation and electrochemical processes are expensive and pose significant environmental challenges. To address these issues an alternative technique for decolorizing textile effluent using a modified sparged loop reactor was proposed in this study. The jet loop reactor basically a multiphase reactor was utilized to treat textile wastewater with ozone. In this study, the textile wastewater containing water-soluble basic dyes such as Methylene blue and Congo red was simulated at a concentration of 50 ppm and the color removal efficiency of the reactor was analyzed. The effect of process parameters such as effluent flow rate (0.2– 0.4 Liter/min), sparger openings (2−4), adsorbent weight (0.5 – 1.5 g) and ozone dosage time (10–30 min) on the decolorization efficiency of the reactor were examined and optimized using Response Surface Methodology. In this study, a maximum color removal of 93 % and 85 % for Congo red dye and Methylene blue dye simulated wastewater was achieved. A correlation was developed using Response Surface Methodology-Box Behnken Design and the developed model was successfully interpreted with experimental values. Based on our results, we believe that it is possible to replace the energy-intensive thermal separation process with jet loop sparged reactor to treat the textile effluent. As a sustainable process, loop reactor may result in a huge reduction of freshwater consumption.