Olive oil waste as a biosorbent for heavy metals

The sourcing of novel, inexpensive biowastes such as olive mill waste (OMW) from the two-decanter olive-oil-production system offers potential for the removal of metal ions by biosorption. OMW can be used in repeated regeneration cycles for the adsorption of heavy metals from aqueous solutions. The metal ions sequestered can be released in an acid solution until the concentration of these metal ions reaches a level where conventional methods can be used to provide economic metal recovery and potential revenue generation. The ability of this biomass to adsorb more than one metal ion from solution may increase its potential for application in the wastewater industry since the majority of industrial effluents contain more than one metallic species. Metal ion adsorption was found to increase with the speed of agitation and at an optimum pH value of between 4 and 7. (c) 2006 Elsevier Ltd. All rights reserved.