Goswami, Aparajita2015-09-212023-10-192015-09-212023-10-192013ROLL NO. 09610710https://gyan.iitg.ac.in/handle/123456789/439Supervisor: Mihir Kumar PurkaitaScarcity of drinking water is a major problem in present world. Although lots of water sources are available, source of drinking water is very limited due to contamination of water. The most harmful contaminant present in water includes fluoride, arsenic, iron and nitrate/ nitrite. The fluoride contamination covers almost all parts of the world. India is also affected severely by this contaminant. Seventeen states of India are affected by fluorosis, which is a fluoride bearing disease. Small amount of fluoride is important for the development of teeth and bone. But its excess content may cause several diseases to human as well as animals. Therefore researcher focused on their research for efficient defluoridation techniques. Various techniques like adsorption, chemical coagulation - precipitation, membrane separation, ionexchange and hybrid techniques were investigated in detail. Unfortunately the performance of all the processes remains unsatisfactory due the unique properties of fluoride. Considering the fundamental aspect of fluoride removal, the present work is focused on few defluoridation techniques. Three different techniques viz., adsorption, chemical precipitation and chemical precipitation followed by microfiltration were investigated for effective removal of fluoride from water. Adsorption study was carried out with four different adsorbents like pyrophyllite, acidic alumina, schwertmannite and nanomagnetite aggregated schwertmannite. The adsorbents were characterized by XRD, BET, FTIR, FESEM and VSM to know its structure, surface area, functional groups present, morphology and magnetic property respectively. Several parameters like contact time, initial fluoride concentration, adsorbent dose, pH, ..enCHEMICAL ENGINEERINGThesis