Start
Jan 21, 2010 - 16:00
End
Jan 21, 2010 - 18:00
Venue
P C Saxena auditorium
Event Type
Speaker
Prof. K. Kesava Rao ChE Department IISc Bangalore
Title
Excess fluoride in drinking water: health effects estimation and removal
Abstract: Prolonged consumption of water containing excess fluoride (F–) by people leads to fluorosis. The geographical extent and adverse effects of fluorosis provide a strong motivation for our work on two aspects: (i) estimation of F– at the field level: a colorimeter had been developed in our group some years ago but was plagued by problems related to the replication of the device. An accidental observation led to the development of a modified circuit that overcame these problems. The cost of the device is about Rs. 300 and its performance is roughly comparable to that of the conventional uv-visible spectrophotometer; and (ii) defluoridation: the combined process for defluoridation is similar in spirit to the alum-activated alumina process of Mjengera and Mkongo (2003). Water having a fluoride concentration of about 5 mg/L (a value typically encountered in some areas in India affected by fluorosis) can be treated by the present process. However even after four cycles of regeneration of the alumina pellets the cost of treatment is high (50 paise/L). Proper disposal of the regeneration effluent remains a problem but solar distillation offers a ray of hope. Based on work in progress some modifications that may reduce the cost of treatment will be discussed.About the Speaker: K. Kesava Rao received his B.Tech. degree in chemical engineering from IIT Madras in 1977 and his M.S. and Ph.D. degrees in chemical engineering from the University of Houston in 1979 and 1982 respectively. After spending a year as a post-doctoral fellow/half-time lecturer at Princeton he joined the Department of Chemical Engineering at IISc Bangalore where he is now a Professor. His research work was in the area of granular flow and heat transfer in honeybee swarms but he has recently shifted to the defluoridation of drinking water. He is a Fellow of the Indian Academy of Sciences Bangalore. This talk is the inaugural lecture as part of the Institute Distinguished Lecture Series in Chemical Engineering in the Memory of Prof. C V Seshadri.