BATCH AND COLUMN STUDIES FOR REMOVAL OF CU AND ZN USING INDUSTRIAL SOLID WASTE AS NEW ADSORBENT

Abstract:

Abstract: Chemical industries discharge both wastewater and solid waste laden with pollutants of environmental concern. This paper explores the reutilization of industrial solid waste, 'metal oxide slag' as new adsorbent for the removal of Cu and Zn from aqueous solutions through batch and column studies at fixed conditions of room temperature, acidic pH of 3.5, 8/14mesh adsorbent particle size. Through batch studies for three batch parameters of adsorbent dosage, time of contact and initial pollutant concentration, dynamics of adsorbent capacity, pollutant removal, Isomorphic ion-exchange mechanism, Langmuir and Freundlich isotherms, Lagergren rate, Weber diffusion and Elovich chemisorption were estimated. Similarly, at fixed feed flowrate, through column studies for two column parameters of bed depth and column feed concentrations, the column dynamics of breakpoint, pollutant removal, adsorptive capacity and adsorption rate were calculated. Chemically resistant PVC pipes were used in place of traditional glass columns. Standard S-shape breakthrough curves indicated the existence of constant liquid phase driving force upto bed exhaustion. Cu removal of 92.32percent and Zn removal of 74.57percent increased with increase in bed depth but decreased with increase in the feed concentration. A scale-up designed is proposed for treating large volumes of industrial effluents based on Bohrat-Adam's correlation and critical depth.

Keywords: Adsorption, industrial wastewater, Cu, Zn, heavy metal, metal oxide slag, column studies, adsorbent.