REMOVAL OF FLUORIDE FROM WATER USING CHEMICALLY MODIFIED JUTE

摘要

Possibility of removing fluoride present in water using inexpensive, plant-based biosorbents has been studied. The data indicate that untreated and transesterified jute could be effectively used as biosorbents for removing fluoride. In essence, the process is an endothermic and spontaneous physical adsorption driven by hydrogen bonding, protonation and van der Waals forces. Relevant batch study results indicate that up to 98 % of F~-present in distilled water spiked with 5 mg/L NaF could be removed using only 0.8 g of transesterified jute biosorbent. In comparison, untreated jute could remove only 42 % of F~-. Although the process efficiency was higher at pH of about 5, transesterified jute biosorbent was found capable of removing F~-at a pH between 3 and 8. The F~-removal efficiency of the transesterified jute was found to be 1.8 times higher than that of untreated jute and 2.3 times that of activated alumina. The biosorbents could be regenerated by washing with mild acid solution and the fluoride captured could be immobilized in a virtually insoluble solid form. The process of fluoride removal by transesterified jute is also advantageous because it does not produce sludge, increase water hardness, or release hazardous leachates.