Various low cost biodegradable and synthetic adsorbents for defluoridation of drinking water
A comprehensive review of the literature reveals that fluoride removal through adsorption onto various materials is most promising in terms of cost of the medium and running costs, ease of operation, adsorption capacity, potential for reuse, number of useful cycles, and possibility of regeneration. Adsorption processes involve the passage of the water through a contact bed where fluorideis removed byion-exchange or surface chemical reaction with the solid bed matrix. In the past few years, surface adsorption is the most interesting area of research for removing fluoride from water. This method is frequently used in large scale by many water treatment plants as it can operating flow rates, can produce high quality of water without the generation of sludge, and removes contaminant from water very effectively. Several adsorbent material shave been tried in the past to identify an efficient and economical de fluorinating agent. Activated alumina, activated carbon, activated alumina-coated silica gel, calcite, activated saw dust, activated coconut shell carbon-activated fly ash, groundnut shell, coffee husk, rice husk, magnesia, serpentine, tricalcium phosphate, bone charcoal, activated soil sorbent, carbon, defluoron-1, defluoron-2, etc. are different adsorbent materials reported. The most commonly used adsorbents are activated alumina and activated carbon. The fluoride-removing efficiency of activated alumina gets affected by hardness, pH, and surface loading (the ratio of total fluoride concentration to activated alumina dosage). The adsorption process can remove fluoride up to 90%, and the treatment is very cost-effective. Regeneration is required after every 45 months as effectiveness of the adsorbent for fluoride removal is reduced after each regeneration cycle. Recent analysis of edulabad ground water performed at our Engineering Lab revealed that the fluoride concentration is 3.9ppm which is far greater than the WHO limit of < 1.5ppm. As social responsibility of suggesting economical and simple techniques of defluoridation for the residents, we have taken up the project of defluoridation techniques using natural, biodegradable and synthetic adsorbents.
Vustelamuri Padmavathi. Various low cost biodegradable and synthetic adsorbents for defluoridation of drinking water. International Journal of Advanced Research and Development, Volume 6, Issue 6, 2021, Pages 1-5