Removal of Some Metal Ions from Aqueous Solution Using Coconut Coir Dust and Modified Coconut Coir Dust Extract Resins

Coconut coir dust and its modified (carboxylated and sulphonated toluenediisocynate) extract resins (CTR and STR) have been used to remove Pb, Cu, Zn and Ni ions from aqueous solution. The coconut coir dust removed more of these metal ions than the CTR and STR. The adsorption of the metal ions decreased in descending order of Pb>Ni>Cu>Zn for the coir dust, Cu>Pb>Ni>Zn for the CTR while that for STR followed the Cu>Pb≈Ni>Zn. The efficiency of the adsorbents depended on their cation exchange capacities and pH(pzc). The higher the Cation Exchange Capacity (CEC) and pH(pzc) the higher the rate of adsorption of the metal ions. The functional groups on the adsorbents are responsible for metal ion removal include the carboxylic, hydroxyl and sulphonic groups as revealed by their infra-red spectra. Hence, coconut coir dust and its modified extract resins are efficient for the removal of metal ions from aqueous solution.