Dear Raju Thapa: even if the above mentioned page contains many papers concerning managemnet of fluoride in groundwater, there is not one describing use of bioremediation for that purpose. Bioremediation of fluoride, according to my opinion, is not good idea, because fluoride cannot be microbiologically removed from groundwater.
I agree with you Dr. Vit Mateju. But now a day in-situ (treating fluoride with anaerobic bacteria in aquifer itself) for various other pollutants like nitrate is on trend. Are such management practice applicable in case of Fluoride?
Dear Mr. Raju Thapa: I agree that several inorganic substances can be biologicaly treated (nitrate, nitrite, sulphate, sulphite, arsenic oxides and many more) and removed or transformed. But all these compounds can be biologically transformed. It is not a case of fluoride, uinfortunately.
I am affraid that PhD Thesis recommended by Mr. Mushtaq Ahmad has nothing to do with bioremediation of fluoride even if it is stated in the abstract. The method studied fluoride sorption by hydrous ferric oxide as a way of defluoridation. The further study was aimed to investigation of bacteriogenic iron oxides. Not to direct bioremediation of fluoride. It means that the main aim of the recommended work above was aimed to biological formation of iron oxides which where used as a sorption material for fluoride, NOT TO BIOREMEDIATION OF FLUORIDE.
Several in-situ techniques have been explained in the article "Ex-Situ vs. In-Situ Defluoridation of the Contaminated Aquifers: A State-of-the-Art Review.
I am sorry Asit Kumar Batabyal, but in the thesis attached by Dr. Mushtaq Ahmad is nothing about bioremediationb of fluoride, as I explained above. Biological process mentioned and studied in the thesis is aimed to biological formation of iron oxides which where used as a sorption material for fluoride, NOT TO BIOREMEDIATION OF FLUORIDE.
"........ the biologically formed iron oxides can be used as a sorption material for fluoride" - So, one kind of biological removal of fluoride. May be called 'bioremediation' in indirect way.
Of course, by definition 'bioremediation' a process where living organisms such as microbes and bacteria are used to remove contaminants.
In an earlier comment, you stated ...."Bioremediation of fluoride, according to my opinion, is not good idea, because fluoride cannot be microbiologically removed from groundwater".
May I ask you, when biological removal of some inorganic substances like nitrate, sulphur etc. are found to be effective, why it is not possible in case of fluoride. I have also not read any literature on this aspect.
Mr. Asit Kumar Batabyal: all mentioned inorganic pollutants like nitrate, sulphate (not sulphur as you say), dihydrogen sulphide are biologically transformed: nitrate to nitrogen gas, sulphate to sulphide, sulphide is oxidized to sulphate etc. This is not the case of fluoride. It is not biologically transformed at all. Best regards Vit