Adsorption studies of zinc ions from wastewater using activated almond shell

Abstract

Heavy metals become major surface water and groundwater contaminants. They are discharged by various industries such as electroplating, metal finishing, textile, storage batteries, mining, ceramic and glass. Biosorption can be used for the treatment of wastewater with low heavy metal concentration as an inexpensive, simple and effective alternative to conventional methods. Biosorption is the capability of active sites on the surface of biomaterials to bind and concentrate heavy metals from even the most dilute aqueous solutions. The mechanism of biosorption is complex, and includes ion exchange, chelation, adsorption by physical forces, entrapment in capillaries and spaces of the structural polysaccharide network and diffusion through cell walls and membranes

The aim of this study is to investigate the effects of the influential parameters such as adsorbent dosage, particle size, initial metal ions concentration and initial pH on removal of Zn²⁺ ions from aqueous solutions using activated almond shell (AS). The equilibrium adsorption data were analyzed by Langmuir, Freundlich and Temkin adsorption isotherm models. The results indicate that activated almond shell are good adsorbents for Zn²⁺in aqueous solutions.