Rice Husk Ash Derived Zeolite Blended with Water Hyacinth Ash for Enhanced Adsorption of Cadmium Ions

Abstract

In order to helpcurtail or imposesustained control to the offensive water hyacinth plant,it is essential to explore ways of generatingwater remediation materials from it. In the current study, the capacity and efficacy of water hyacinth ash (WHA),its insoluble residue (WHAR) and rice husk ash (RHA)to remove cadmium ionsand methylene blue from contaminated water was investigated. Mixtures of the two ashes were used to formulatezeolitic materialsby hydrothermal reactions. Material A, ZMA was prepared by using rice husk ash and the soluble portion of WHA while for material B, ZMB a mixture of equal amounts the two ashes including the insoluble fraction of WHA were used. Batch experiments was carried out to determine the effect of metal ion concentration, initial PH, contact time (t), temperature (T), shaking speed and adsorbent dose on percentage removal of Cd2+ and methylene blue by the ashes and their zeolitic products. The data obtained for adsorption of Cd2+ on RHA, ZMA, and ZMB was found to best fit in the Langmuir isotherm model while WHA and WHAR data best fitted in theFreundlich model. Adsorption capacities for cadmium on RHA, WHA, WHAR, ZMA and ZMB adsorbents ions were 3.745, 52.00, 56.89, 11.24 and 22.22mg/g respectively.The findings showed that incorporating the WHAR during synthesis of the zeolitic material enhanced its adsorption capacity and efficiency for Cd (II) ions and methylene blue.