Application of Appopolite in Adsorption of Heavy Metals (Co and Ni) from Waste Water

Abstract

The optimum conditions for adsorption/ion exchange by using a batch method were evaluated by changing various parameters such as adsorbent amount, initial pH of the solution, mixing temperature and initial metal ions. The influence of the temperature on the ion-exchange/adsorption process was also examined. The Langmuir and Freundlich adsorption isotherm equations were derived from the basic empirical equations, and used for calculation of ion exchange parameters. Adsorption isotherms of Co²⁺ & Ni²⁺ ions could be best modelled by the Langmuir equation. The influences of contact time, metal initial concentration, adsorbent dosage concentration, and temperature have been studied. The adsorption efficiencies are found to be contact time dependent, increasing the contact time in the range of 20 180 min. The sorption equilibrium has attained between 60 and 180 min.

Keywords - Adsorption, Freundlich adsorption isotherm, ion exchange, Langmuir equation, sorption equilibrium