Metakaolin Based Geopolymer from Thailand as an Adsorbent for Adsorption of Multi- and Mono- Cations from Aqueous Solution

Waste management and water quality are two main problems nowadays. Geopolymer material has efficiency for adsorbing the ions from wastewater. In this research, the metakaolin based geopolymer was studied and used as an adsorbent to remove heavy metal ions. Moreover, the factors which affect adsorption process of heavy metals on geopolymer materials were investigated. The kaolin as used in this research was from Thailand. The metakaolin geopolymer was synthesized by mixed raw materials with an alkaline solution. The metakaolin geopolymer was washed and sieved through 100 mesh. The produced metakaolin geopolymer powder was used as an adsorbent. The XRD results showed a highly amorphous structure in obtained metakaolin geopolymer. Moreover, the BET surface area of metakaolin and geopolymer particles were 9.83 m2/g and 20.36 m2/g, respectively. The parameters of adsorbent amount, initial pH, time of shaking, temperature and initial metal ions concentration on the removal potential of geopolymer were studied. In addition, the multi-and mono-cations solution were demonstrated to compare the efficiency of each heavy metal ions. The results showed that the amount of Pb2+, Cu2+, Cd2+, and Ni2+ ions adsorbed onto metakaolin geopolymer increased with an increasing contact time, pH, temperature and amount of geopolymer. It is concluded that Pb2+, Cu2+, Cd2+, and Ni2+ ions in aqueous solution are efficiently removed by metakaolin geopolymer which could be applied as a low cost and good alternative for wastewater treatment.