Removal of Disperse Orange and Disperse Blue dyes present in textile mill effluent using zeolite synthesized from cenospheres

Abstract

In this research, an efficient, ecofriendly method of using coal fly ash in the form of zeolite to treat wastewater containing dyes was studied. Response surface methodology involving Box–Behnken design was applied to a batch process to evaluate the effect of process parameters such as contact time, dye concentration, agitation speed, pH, and adsorbent dosage onto zeolite. Disperse Orange 25 (DO) dye showed a maximum of 96% removal under optimal conditions of contact time of 119 min, dye concentration of 38.00 mg/L, agitation speed of 158 rpm, pH of 6.10, and adsorbent dosage of 0.67 g/L, whereas 95.23% of Disperse Blue 79:1 (DB) dye removal was observed at adsorbent dose of 1.05 g/L, dye concentration of 26.72 mg/L, agitation speed of 145 rpm, pH of 5.68, and contact time of 122 min. It was concluded that cenosphere-derivatized zeolite adsorbent is efficient, ecofriendly, and economical and has high potential for the removal of DO and DB dyes from aqueous solutions. Highlights Modified cenosphere-based zeolite used for dye removal from wastewater.; Box–Behnken design used to optimize the optimum conditions for dye removal from wastewater.; Maximum Disperse Orange 25 and Disperse Blue 79:1 removal was 96% and 95.23%, respectively.; Derivatized zeolite is ecofriendly and economical for dye removal from wastewater.;

Keywords

• box–behnken design
• cenospheres
• disperse dyes
• response surface methodology