Browsing by Author "Udagedra, D.T."
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Item Heavy metals and trace element distribution in Eppawala Apatite deposit(Uva Wellassa University of Sri Lanka, 2015) Wickramsinghe, P.C.B.; Udagedra, D.T.; Jayawardana, D.T.In Sri Lanka, the dominant source of drinking water used to supply major urban and rural communities is from wells, tanks, rivers, springs. Although there are no systematic and comprehensive water quality assessment programs in the country, there are increasing indications of water contamination problems in some parts of the country. Causes for water contamination are natural or anthropogenic. Among natural contamination, water-rock interaction is critical but remains hidden for most eyes. No sufficient study has been conducted on heavy metal contamination of drinking water of the Eppawala apatite area in Sri Lanka. The main objective of this paper is to determine the influence of some of the physicochemical parameters and heavy metals and trace elements in drinking water and its distribution of different parts of the Eppawala. Methodology The groundwater was studied around the Eppawala Apatite Deposit (EPD) using tube well and dug wells as the access. Sample size (60) was determined by distribution of the population around the EPD. Samples were collected in wet season and dry season. The electrical conductivity was measured in situ with Orion 3 Star EC meter. The collected water samples were analyzed for seventeen (17) parameters including major cations, anions, heavy metals and trace elements. Cations, heavy metals and trace elements concentration with the Varian SpectrAA AAS facility , Cl and HCO3 were measured using standard methods. The major cations such as Ca, Cu, Fe, K, Mg, Mn, Na, Zn, Cs, Sr, Li, Rb, and major anions such as SO4 2Cl , F and HCO3 were analyzed using the ORIGIN 8 and Surfer software. Results and discussion In terms of electrical conductivity, it ranged from 19.2ms/cm-1.02ms/cm in wet season and , F and Cl are the highly abounded elements in the selected area well water in wet season. That’s value are above the Sri Lankan drinking water strandedItem Removal of Arsenic (V) in Water using Humic Acid-Modified Meetiyagoda Kaolinite(Uva Wellassa University of Sri Lanka, 2013) Jayahansani, K.H.D.; Udagedra, D.T.; Weerasooriya, R.Kaolinite is one of the major clay types which can be used to remove ions from the water by using its adsorption capacity (Krishna and Gupta, 2006). Though several clay types are found in Sri Lanka, significant use of them for value addition purposes is not practiced.By considering that fact and the unique ability of kaolinite to remove ions from water is targeted throughout this research.Meetiyagoda kaolinite is used as clay type, because it is currently used only as a raw material for ceramic industry and none of the researches have been conducted to investigate its ability to remove ions from water. Therefore the ultimate goal of this study is to fill that gap and develop a value added product from Meetiyagodakaolonite. This research focuses on removing arsenic (V) from water while modifying kaolinite surface using Humic Acid in order to enhance its adsorption capacity and measuring the removal amount of arsenic (V) by changing amount of clay, concentration of arsenic (V) and pH. Methodology The purified Meetiyagoda kaolinite sample was taken from Meetiyagoda clay refinery and it was dried, ground and sieved to obtain 75µmparticle size.This particle size was preferred because, when particle size gets smallest it increases the surface area of kaolinite which results in more adsorption of arsenic on to kaolinite surface. Humic acid was prepared by mixing dried homo-ionized clay was prepared using kaolinite and 1M CaCl2.Previously prepared humic acid was readjusted to homo-ionized clay was added to pH neutral humic acid and the humic acid-clay suspension was incubated in mechanical shaker, then the suspension was centrifuged. Finally the humic acid coated clay sample was dried and used. The effect of arsenic removal by humic acid modified Meetiyagoda kaolinite was analysed while changing amount of humic acid modified clay, initial arsenic concentration and pH of the solution using Varian 700ES ICP-OES Atomic Absorption Spcetrophotometer.