TECHNO-ECONOMIC EVALUATION OF DEFLUORIDATION PLANTS IN RAJASTHAN

Abstract

Most natural waters contain traces of fluoride. Occurrence of fluoride in waters was reported from several states in India. Fluoride although beneficial when present in concentration of 0.5-1.2 mg/I, has been associated with mottled enamel of the teeth, when present in potable waters in concentrations in excess of 1.5 mg/I. Skeletal effects has been observed at concentration beyond 3.0 mg/I. This thesis provides a review of scientific literature on occurrence and distribution of fluorides, its metabolism, excretion and effect of ingestion in human systems. The effect of dental enamel and mottled enamel are also presented. Fluoride level in ground waters of Rajasthan is briefly reviewed. Defluoridation methods used in other countries and their applicability under Indian condition have been assessed. The work of defluoridation at NEERI is discussed in details. The various defluoridating materials studied included Ion Exchange Resins, Activated Carbon, Activated alumina, Magnesium and Aluminium salts. Only those that shows an encouraging trend on bench scale are studied in details. A method which is most reliable for defluoridation of water, known as "Nalgonda Technique" had been evolved by NEERI. Nalgonda Technique is simple, cheaper and easily adopted even by a layman. The capacity of various defluoridation media, problems in operation and maintenance and their limitations in applications have made the edifice of the dissertation. IEC package is the basic cruck of the acceptability of defluoridation techniques amongst the villagers and therefore total success of catering fluoride free water to the sufferers lies in IEC. To study the practicability, acceptability of the plants by the users, 0 & M aspects as well as cost involvement, following places were visited: (i) Shivdaspura Village, Jaipur District (ii) Sil Ki ,Doongri Village of Chaksu Tehsil (iii) Kitalsar (Degana), Nagaur District (iv) Dungarpur District - Fluorosis control pilot project (UNICEF supported) (v) Beelwa, Jaipur District A report on the present day status of plants at places mentioned above is summarised. The report shows that in all these areas lack of know how, improper operations and maintenance, non availability of spare parts, isolated and unapproachable sites, erratic monitoring and surveillance, lack of on the spot analytical facilities and also of medical facilities and learned doctors, nutritionist, psychiatrists, social activists, myths and superstitions make the task more difficult. Fluorosis is the disease synonymous to scarcity, poverty, socially down trodden people and extremities of geological and geographical variability. The dissertation analyses the cause and effect of the crippling disease "fluorosis" and presents amicable, practicable, economically viable and sustainable long and short-term engineering and scientific solutions of the problem.