Studies on Defluoridation of Water by Tea Ash:An Unconventional Biosorbent

Abstract

Residual part of tea as a household waste was effectively used for removal of fluoride from aqueous medium. The variable operating parameters such as pH, initial fluoride concentration, sorbent particle size, agitation time and temperature. The defluoridation capacity increases with increasing adsorbent dose and contact time but decrease with initial concentration of fluoride solution. Moreover, acidic pH (6) showed the highest removal of fluoride. Further defluoridation follows second order kinetics and Langmuir and Freundlich adsorption isotherm. The surface and sorption characteristics were analyzed using FTIR and SEM techniques. For domestic and industrial applications, defluoridation with 100% achievement and subsequent regeneration of adsorbent was performed with a household water filter and fixed bed column respectively.