Current development of geopolymer as alternative adsorbent for heavy metal removal

Abstract

The deterioration of water quality is becoming serious due to continuous development. One of the major factors is heavy metal contamination, which is an extremely deleterious to the environment and human being. This work reviews current development of a potential alternative adsorbent, namely geopolymer, in removing heavy metal pollutants from water via adsorption techniques. Geopolymer adsorbent can be regarded as a sustainable material as it can be synthesized by utilizing waste material and by-products. Fabrication process, removal capability and factors governing the removal ability of geopolymer have been highlighted as well. As binding site is a salient criteria for the adsorption technique, enhancement in porosity of adsorbent, i.e. in porous and pervious geopolymer as well as different shapes of geopolymer, of which will influence the available binding sites, is also reviewed. The intention of this review is to provide some state-of-the-art of geopolymer technology in eliminating heavy metal pollutants from water.