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The Defluoridation Technology Project was called upon to survey existing water resources by three different institutions lying in fluorotic Tanzania: 1) The Ngongongare Secondary School. 2) The St Constantine International School and 3) The Minjingu Church Project. In case 1), due to low affordability, an open dug well was proposed. In case 2) a defluoridation system was installed and could be used to estimate essential design parameters, as Operation Period (1 Year), Removal Efficiency (93 %) and Removal Capacity (3-4 mg/g of Bone Char). In case 3) the water was deadly toxic because of high fluoride concentrations, but, fortunately, unpalatable due to high contents of Alkalinity/Salinity. The salinity renders the defluoridation process useless. A system of combined rain water harvesting and defluoridation of brought water sources was proposed. [ABSTRACT FROM AUTHOR]

A rational management of defluoridation works must include surveillance of defluoride filters, estimation of individual operation periods, and on-time recharge of saturated filters. This is done best in a database, where all necessary information is included, i.e., about the client, the site, the raw water, the water analyses, the filter, its recharges, and, most importantly, its first expected date of exhaustion and recharge. Automatically, the database would produce up-to-date lists of installed filters that would need recharge and further merge E-mails to clients indicating to them the length of time their filters have been operating, offering them new recharges on time, and stating to them the prices and conditions. Our experience shows that the database and the E-mail reminders made the maintenance and the surveillance of the filters more efficient and this has contributed to a higher sustainability of defluoridation works. The principles and setup of the Defluoridation Technology Project database are explained further. It is concluded that defluoridation works can only be sustainable if managed efficiently through a database system. [ABSTRACT FROM AUTHOR]

Africa, with its Great Rift Valley, accommodates the world's most severe fluoride belt. Here fluorosis has been prevalent for as long as history can convey. Spot wise in the Rift Valley, fluorosis has been considered as a part of normal human countenance. In spite of the fact that using alum in water treatment was known in ancient Egypt in 1500 BC, defluoridation of water by means of alum was only reported in Ethiopia and Tanzania in the 1980s. Both countries, learning from the defluoridation experiences in USA in the 1930s and then the Indian experiences, led in the late 1970s-1980s by the National Environmental Engineering Research Institute (NEERI), a research institute created and funded by the Government of India, counted the Nalgonda technique as the process of choice in the mitigation of fluorosis in some of their severe fluorotic areas. However, many experiences with the Nalgonda technique led to frustrations, disappointments, and finally the total abandonment of the process. In recent years, Tanzania, Kenya, and Ethiopia have been the leaders in the implementation in Africa in the defluoridation of water and they all consider the bone char process as the process of choice for the mitigation of fluorosis in the affected parts of the Rift valley. Some of the experiences that led to this African U-turn in defluoridation policy are presented. [ABSTRACT FROM AUTHOR]

The standard defluoridation capacity procedure was utilised to quantify the differences between the differently coloured bone chars, that are obtained in the charcoal packed furnace used in large scale production in Tanzania and Kenya. The highest defluoridation capacities were obtained with black and brown coloured bone char, while grey and white bone chars were the result of poor charring, with a deteriorated defluoridation capacity. Maintaining the bone char in black and brown may however introduce problems of discoloration, objectionable taste and smell, and elevated salinity. Post-treatment by means of mild acidification and water wash alleviated these side-effects, making it possible to produce a high quality bone char with respect to both the defluoridation capacity and the quality of the treated water. [ABSTRACT FROM AUTHOR]

The ability of defluoridation media to up-take fluoride (F) from water solutions is best described by both the intensity sorption constant and the capacity sorption constant in the best fitting of the two sorption models: Freundlich and Langmuir. However, when it comes to defluoridation of water for drinking purposes, the focus has to be constrained to initial F concentrations that are comparable with the waters that often occur in fluorotic areas and are likely to be considered as raw water sources for drinking and, furthermore, to residual F concentrations that are considered safe for cooking and drinking. This paper defines a "standard defluoridation capacity" for defluoridation media as the capacity in mg of removable F per g of the used medium in a batch experiment, where the initial F concentration is 5 mg/L and the residual concentration is about 1 mg/L. A procedure for the determination of the standard F removal capacity of media is described. The simplicity of the test makes it useful for comparing the defluoridation capacities of large numbers of media and in the routine quality control of the same processed medium, as in factory production. Examples are shown where the standard defluoridation capacity is either determined by this test or derived from literature data. In addition, the standard defluoridation capacity procedure may be a useful tool to standardize the quality check of the defluoridated waters. [ABSTRACT FROM AUTHOR]

Photographs taken during a conference with oral health organization Intercountry Centre for Oral Health (ICOH) that was held in Chiang Mai, Thailand in 2014 are presented.