Browsing by Author "Kumari, K.E.D.K.W."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Chemical Removal of Fluoride from Drinking Water Using Gypsum
    (Uva Wellassa University of Sri Lanka, 2012) Kumari, K.E.D.K.W.
    An excess amounts of fluoride in drinking water cause detrimental health effects such as dental and skeletal flurosis. According to the World Health Organization (WHO), the maximum acceptable concentration of fluoride in drinking water is 1.5 mg/L. According to Sri Lanka Standard desirable and permissible levels of fluoride are 0.6 mg/L and 1.5 mg/L respectively. In tropical countries like Sri Lanka, the lowering of the fluoride regulatory limits in drinking water is required due to high consumption of water by the people living in these regions. Therefore excess fluoride in drinking water must be removed to the permissible level. There are several techniques available to remove excess fluoride from drinking water based on adsorption, precipitation, ion exchange, membrane separation. Most of these methods are highly specialized and cost intensive in that they cannot be implemented successfully at community level. In this research fluoride removal ability was investigated using gypsum based on precipitate common ion effects. Gypsum was separated in to different particle sizes (mesh sizes: 500 j.im, 250 1.1m, 125 63 i.n). The definite (10 ppm) fluoride solutions were prepared and study the fluoride removal ability of the gypsum under different particle size, pH levels and variation of the dose. The residual fluoride concentration is decreased with the particle size of the gypsum and the maximum fluoride removal is obtained the gypsum particles which have diameter below 63 gm. The pH for maximum removal of fluoride was around 8. The residual fluoride concentration in solution decreased with the addition of gypsum. When gypsum content is in excess, the residual fluoride concentration has decreased showing an optimal value at 2.50 g gypsum. Gypsum can be used to mitigate fluoride in drinking water. The particle size effect on fluoride removal efficiency was accounted for to increase in specific surface area.
  • No Thumbnail Available
    Item
    Removal of Fluoride from Drinking Water using Gypsum
    (Uva Wellassa University of Sri Lanka, 2012) Kumari, K.E.D.K.W.; Attanayake, A.N.B.; Udagedara, D.T.
    Excess amount of fluoride in drinking water causes detrimental health impacts such as dental and skeletal flurosis. According to the World Health Organization (WHO), the maximum acceptable concentration of fluoride in drinking water is 1.5 mg/L (Darchen et al, 2010). According to Sri Lanka Standards desirable and permissible levels of fluoride is 0.6 mg/L and 1.5 mg/L respectively. In tropical countries like Sri Lanka, the lowering of the fluoride regulatory limits in drinking water is required due to high consumption of water by the people living in the regions with high natural fluoride concentrations. Therefore, excess fluoride in drinking water must be removed to the permissible level. There are several techniques available to remove excess fluoride from drinking water based on adsorption, precipitation, ion exchange and membrane separation. (Dou et al, 2012). However, most of these methods are highly specialized and cost intensive in that they cannot be implemented successfully at community level. In this research we propose to utilize gypsum, a ubiquitous mineral in nature, to mitigate excess fluoride from drinking water based on precipitating common ion effects