Abstract:
Chitosan was derived from crab shells through deacetylation process using 50% NaOH. The
obtained chitosan was used for adsorption studies. Adsorption parameters such as pH, contact time,
metal concentration, adsorbent dosage, and temperature were investigated. It was observed that
optimum pH for nickel was pH 5 and optimum pH for copper was also pH 5. Maximum adsorption
for both metals was at 120 minutes. Evaluation of the effect of temperature on adsorption showed
that metal removal decreases with increase in temperature. The adsorption process was exothermic
and this was reflected -in the –ve values of ΔH o obtained. Isotherm studies showed that the
adsorption process obeyed Freundlich model with high R 2 values.
