An Efficient Removal of Disperse Dye from Wastewater Using Zeolite Synthesized from Cenospheres

Abstract

In the present work, cenospheres were modified to synthesize zeolite in order to improve their adsorption capacity. The synthesized zeolite was characterized by attenuated total reflectance-Fourier transform infrared (ATR-FTIR), scanning electron microscope (SEM), energy dispersive X-ray (EDX), laser particle size analyzer (CILAS), and Brunauer-Emmett-Teller (BET) method to confirm the desired modifications in cenospheres. Batch adsorption study was conducted to optimize physical parameters such as pH, adsorbent dosage, dye concentration, agitation speed, and contact time at 25, 35, and 45°C for the removal of Disperse Orange 25 (DO) and Disperse Blue 79∶1 (DB) dyes from wastewater. Maximum 93 and 89% removal has been achieved in 100 and 120 min contact time having 0.6 and 0.8 g/L adsorbent dosage in case of DO and DB dyes, respectively, at optimized pH 6, dye concentration 40 mg/L, and agitation speed 140 rpm at 45°C. Monolayer adsorption capacity was found to be 125.0 mg/g for DO and 109.8 mg/g for DB. Adsorption of dyes on zeolite followed Langmuir isotherm and pseudo-second order kinetic. Thermodynamics data suggest conclusively exothermic and spontaneous adsorption of dyes. Synthesized zeolite was regenerated after dye recovery in organic media. Moreover, zeolite has been applied for treatment of textile mill effluent and analyzed through ultraperformance liquid chromatography (UPLC) to confirm the removal of dye.