Separation of divalent metal ions using Pandanus Amaryllifolius Roxb (Pandanus)leaves: desorption study

Desorption by dead biomass has been studied on Pandanus Amaryllifolius Roxb (Pandanus leaves) by conducting batch experiments. The recovery of heavy metals such as lead and copper ions from biomass was examined using a variety of desorbing chemicals. This study aims to discover the best chemical which is able to leach the metal effectively with highest desorbing capacity. The results showed that HCl at pH 2 and 3.0mM EDTA at pH 4.58 were effective in desorbing the copper and lead ions from the biomass. The recovery of copper is very feasible since over 90% of copper was removed from the biomass. The percentage of lead recovery is about 70%. In contrast, Na2CO3 and NaOH are not effective in desorbing both of the metals. The results indicated that low pH is preferable for desorbing the metal ions. The binding ability of HCl is explained using ion-exchanging principle. More concentrated protons are able to replace those ions thus regenerating the biomass. EDTA is functioning as polydentate ligands, which appear to grasp the metal between the six donor atoms. It was suggested that recovery of metal ions is mainly due to the strength of bonding between the fraction of functional group of biomass and metal ions. Recovery of the deposited metals can be accomplished because they can be released from the saturated biomass in a concentrated wash solution, which also regenerates the biomass for reuse. Desorbing chemicals such as HCl and EDTA have proved successful for desorbing the metal ions. Thus, biosorption of heavy metals by biomass will be emerged as one of the alternative technology in removing the heavy metals.