Performance Analysis of Some Low-Cost and Locally Available Adsorbents that Remove Excess Fluoride Ion from Raw Water to Develop a Filter for the Rural Population

Abstract

The fluoride content in drinking water is an existing concern for public health engineers and water scientists. An optimum concentration of fluoride in drinking water has beneficial effect including the prevention of dental caries and calcification of dental enamel for the children. However, on the contrary, excess fluoride content over permissible concentration galvanizes the risk of dental fluorosis, skeletal fluorosis, and crippling skeletal fluorosis. In this study, an effort has been made to have an insight into the fluorosis affected states of India and to recommend some cost-effective and efficient technology to eradicate fluorosis from India. The column study has been adopted for activated alumina, bone charcoal, and a batch study for cement granule. The present study has revealed the fluoride uptake capacity of 97.9% in the case of bone charcoal and 85.3% in the case of activated alumina which is more promising and efficient as compared to cement granules. But the manufacturing process of bone charcoal has certain environmental constraints and the cost is also much higher for the same. The maximum removal capacity has been obtained as 3.44 mg/g of activated alumina at a flow rate of about 5 l/h. The test results found for activated alumina have best fitted to the Langmuir adsorption isotherm model. Therefore, considering the economic constraints of the rural population and the ease of operation, the adsorption filter using activated alumina as the media might be recommended to remove fluoride from drinking water at the domestic level.