A review on the sorptive elimination of fluoride from contaminated wastewater

Biosorption is considered to be one of the favourable remediation techniques for fluoride removal from aqueous solutions. Other conventional techniques such as precipitation, reverse osmosis, ion exchange, nanofiltration etc, have several demerits such as huge initial costs, higher electricity consumption, generation of sludge, etc. The process of biosorption has become an economically feasible and environmentally benign alternative technique in the treatment of water and wastewater industries owing to the disadvantages associated with above-mentioned techniques. In this regard, numerous biosorbents have been developed for their successful implementation on defluoridation. Due to various technical barriers in the biosorption process which hinder its commercialization, there has been a steadily growing interest in this area of research. Of late more attention is being paid towards the development of cost-effective adsorbents using various agricultural wastes, plant biomass, bacteria, algae and fungi. This review paper highlights the use of various biosorbents, sorption isotherm, and kinetics. Literature review indicates the potentiality of such wastes as biosorbents for fluoride removal. Maximum fluoride removal of 91% was obtained by lanthanum-modified bone waste with a biosorption capacity of 8.96 mg/g which is reportedly the highest fill date. However, it is important to determine whether these biosorbents could be used on the commercial scale which, in turn, might result in controlling pollution.