Agricultural solid wastes for the removal of heavy metals: Adsorption of Cu(II) by coirpith carbon

Adsorption studies of Cu(II) from aqueous solutions on carbonized coirpith were carried out under varying conditions of agitation time, metal ion concentration, adsorbent dose, and pH. Adsorption equilibrium was reached in 25 min for 20 – 50 mg/L concentrations of copper(II). Kinetics of adsorption obeyed a first order rate equation. The per cent removal increased from 50 to 90 with the increase of pH from 2.0 to 4.0 and remained constant to pH 10.0 for a Cu(II) concentration of 20 mg/L. Adsorption equilibrium followed both Langmuir and Freundlich isotherms.