Abstract
Dried and ground material of the brown alga Ecklonia maxima and the waste product from the manufacture of Kelpak, a seaweed concentrate used in agriculture, have previously been shown to be effective biosorbents of heavy metals. The recovery of bound cadmium and the subsequent reuse of the biosorbents were investigated. Acids (HCl, HNO3 and H2SO4) and the chloride salts (NaCl and CaCl2) were more effective at desorbing cadmium ions than the carbonate salts (NaHCO3 and K2CO3) and the chelator Na2EDTA. The optimum concentration of the acids for desorption was between 0.01M–0.1M. Depending on the acid and concentration used for desorption, optimum time for desorption ranged from 30 min to 2 h. The sorbent derived from ground Ecklonia maxima could be used for more than four adsorption-desorption cycles whereas the sorbent derived from the Kelpak Waste could only be used effectively for up to three adsorption-desorption cycles.
Copyright © 2002 by Walter de Gruyter GmbH & Co. KG
