Removal of Fe and Mn From Polluted Water Sources in Lesotho Using Modified Clays

This paper reports the use of unfunctionalized and phenylalanine functionalized clays as an alternative cost effective, environmental friendly and efficient sorbent for the removal of Mn and Fe from polluted drinking water sources in Lesotho. The Mn and Fe metals were adsorbed on two different clays (clay Aa black clay and clay Ba yellow clay) collected from Ha-Teko in Maseru (clay A) and Phoqoane in Mafeteng district (clay B). Comprehensive batch test studies were performed to assess the effect of pH, stirring time and initial concentration of Mn and Fe. The adsorption of the metals was greater at higher pH and equilibrium was reached at pH 8 after 30 min of stirring. The phenylalanine functionalized clays displayed improved adsorption efficiency of up 100% (Fe adsorption using clay A in 30 min) while the unfunctionalized clays gave relatively low adsorption of up to 70% (Fe and Mn adsorption using clay A). The clays, which are present in abundance in Lesotho, can be effectively used for the removal of Fe and Mn from drinking water sources.