Sorption Equilibrium of fluoride onto Phyllanthus emblica activated carbon

Abstract

Groundwater contaminated with excess fluoride (above 1.5 mg/L) posed some risks to the public health in India. Methods available for fluoride contaminated water treatment are cogaulation– filtration using alum+lime+bleaching powder (Nalgonda technique), adsorption using activated alumina, coagulation, nanofiltration, etc. Use of aluminium compounds for water treatment purpose needs replacement on neurological health problem. Objective to this, the preparation and fluoride adsorption behavior of Phyllanthus emblica is reported here. It is seen that fluoride adsorption density varies as a function of contact time, adsorbent dose, temperature and adsorbent particle size at neutral pH. The data indicate that the prepared adsorbent surface sites are heterogeneous in nature and that fits into a heterogeneous site-binding model. Commonly used isotherms namely Freundlich, Langmuir, Redlich-Peterson and Temkin models were studied. The present system followed the Redlich–Peterson isotherm as well as Langmuir adsorption isotherm model. The results supported that the Phyllanthus emblica based bioadsorbent can be used to remove the excess fluoride from its contaminant sources.