The natural, ground as well as surface waters in the Northern Tanzania are highly contaminated with fluoride, resulting in severe prevalence of dental and skeletal fluorosis in people. Over the last three decades Prof Eli Dahi has studied and developed the bone char process in cooperation with the Ministry of Water and the University of Dar es Salaam.

This process not only removes the fluoride from water, it also improves the water quality by removing other water physical and microbial contaminants and by adding essential minerals to the water. It is based on locally available cattle bone, installed in filters built with locally available materials. More than 600 units have been installed and much work remains to evaluate and further develop the technology, including applied research on how to upscale and develop the production technically, socio-economically as well as business wise.


The following tasks can be discussed depending on candidate interests and qualifications:

• Evaluation of performance of installed units and client support mechanisms

• Design and manufacture of household and community systems

• Research into mechanisms of fluoride removal and effect of water matrix