Browsing by Author "Subramanium, S.S."

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Determination of heavy metals in soil in chronic kidney disease of unknown etiology affected areas of Karanbankulama (A preliminary study
(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Rajaguru, R. A. M. T. S.; Subramanium, S.S.; De Silva, R. C. L.
The increased prevalence of Chronic Kidney Disease of unknown etiology (CKDu) among specific occupational groups confined to specific geographical regions of Sri Lanka has dragged the attention of scientific community in recent years. The objective of the study was to determine the concentrations of heavy metals Cu, Cr, Zn, Pb and Cd and characteristics like moisture content, organic matter content, pH and conductivity in soil samples obtained in the areas which are affected CKDu. The study was conducted in the Karanbankulama area in North Central Province, Sri Lanka. Soil samples were collected from reservoirs and paddy fields. Prior to the heavy metal analysis an acid or acid combination such as HCl: HNO3, HNO3: H2O2 and HNO3 was examined to digest the soil samples aid with microwave digestion. A higher metal concentration was obtained for aqua regia for each metal mentioned above when a selected soil sample was treated with the above acid combinations. Flame Atomic Absorption Spectrometer was used for the analysis of the samples. The resulted concentrations were 10-37, 20-86, 3-30 and 25-50 mg kg-1 for Cu, Pb, Cr and Zn respectively. However, Cd was not in detectable limits by FAAS. The results showed that the concentrations of Cr, Zn, Pb were in the permissible levels set by WHO (World Health Organization) while the concentration of Cu was recorded slightly above the permissible levels in paddy field soil of some sites. The soil characterization studies showed that the pH of the soil in tanks and paddy fields was in between 5-7. Moreover, the soil conductivity measurements showed a considerable variation even between the samples of the same site. This may be due to the variations in the accumulation of fertilizer in the paddy field. Furthermore, the concentration of the electrolytes was less than that of the paddy fields. The organic matter percentage of the soils in tanks in two sites were relatively higher than other sites. The moisture percentage in the tank soil samples was in the range 1-4% while it was 1-3% in the soil samples in the paddy fields
Examination of naturally occurring clay in Pannala for removal of Cr(III), Pb(II), Cd(II), Ca(II) and Mg(II) from aqueous solution
(Sri Lanka Association for the Advancement of Science, 2013) Priyadarshani, D.K.A.; Subramanium, S.S.
Examination of the naturally occurring clay in Pannala area for the removal of nitrates and polycyclic aromatic hydrocarbons from drinking water
(Sri Lanka Association for the Advancement of Science, 2013) Ariyagnana, A.D.R.M.; Subramanium, S.S.
Occurrence of organic pollutants: pahs in water bodies around kelanitissa and kerawalapitiya power plants in Sri Lanka
(Journal of Science 2019, Department of Chemistry, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Chandrasiri, H.M.H.B.; Doole, F.T.; Subramanium, S.S.
Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds with more than one benzene ring formed due to natural processes such as forest fires and anthropogenic activities. These ubiquitous contaminants have gathered an interest due to their toxicity and carcinogenic activity. Exposure to PAHs has also been linked with cancer, cardiovascular disease and poor fetal development. PAHs are considered as persistent organic pollutants because of their stable chemical structure and inherent resistance to decomposition. In this study, the water bodies near two diesel fueled power plants in Sri Lanka i.e., Kerawalapitiya and Kelanitissa were selected to determine the presence of PAHs in surface water and its sediment. In the preliminary sampling rounds, the presence of PAHs were identified. With increased sample size, three sampling rounds were carried out. In addition to water and sediment from Hamilton canal and Sebastian canal, water samples from wells near both power plants were analyzed. PAHs in water samples were extracted to dichloromethane and analyzed by HPLC with UV-DAD (254 nm) and HPLC- FLD (excitation at 250 nm, emission at 410 nm). Sediment samples were pretreated before the analysis and then, PAHs were extracted to methanol by ultrasonication. The presence of low, medium and high molecular weight PAHs in water and sediment samples obtained from both sites were detected. Total concentration of PAHs in surface water samples obtained from Sebastian canal during rainy season (April 2015), dry season (July 2015) and rainy season (June 2016) were 0.11-1.71 μg/L, 2.36-14.68 μg/L and 6.88 μg/L - 10.05 μg/L, respectively. Furthermore, PAH content in water samples obtained from Hamilton canal during rainy season (April 2015), dry season (July 2015) and rainy season (April 2016) were 0.16-2.74 μg/L, 11.06- 54.89 μg/L and 5.35 - 7.79 μg/L, respectively. Well water samples obtained from Kelanitissa (W1) and Kerawalapitiya (W3) showed the presence of high amounts of BaP (0.025 μg/L) and BkF (0.339 μg/L) respectively which are higher than the guideline values for BaP (0.01 μg/L) and BkF (0.1 μg/L) according to European Unions’ drinking water standards. The total PAH amount in surface water in both sites were higher in dry season than that of in rainy season. This may due to accumulation of PAHs over the time in water bodies around diesel fueled power stations during dry seasons due to lack of water flow. By investigating more dry and rainy seasons, an accumulation trend can be identified to address the seasonal variation of PAHS in water bodies.
Polycyclic aromatic hydrocarbons in water bodies and sediment around kerawalapitiya and kelanitissa power plants of sri lanka - preliminary study
(Faculty of Graduate Studies, University of Kelaniya, 2015) Doole, F.T.; Jayalath, K.G.; Subramanium, S.S.
Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds composed of two or more aromatic benzene rings. PAHs are produced due to incomplete combustion of fossil fuels; such as coal, oil and due to pyrolytic processes; such as forest fires and volcanic activities. There are hundreds of PAHs in the environment, among them; sixteen PAHs have been classified as priority pollutants by the United States Environmental Protection Agency. Due to the harmful effect of PAHs towards living beings, studies have been conducted around water bodies in different parts of the world. This study aims to determine the type and concentration of PAHs in water bodies and sediment near two power plants of Sri Lanka. Kerawalapitiya Power Station (KW) and AES Kelanitissa Power Station (KL) are diesel fuel fired combined cycle power stations, which might have an influence on accumulation of PAHs in water and sediment around these power stations. During the dry season of the year surface water samples were collected from Hamilton Cannel (KW) and Sebasthian Cannel (KL), extracted using dichloromethane and analyzed using HPLC. PAHs from sediment samples were extracted using ultra sonicator and analyzed using HPLC. As the reference site, water and sediment samples were collected from a freshwater spring in Bandarawela. The study shows the presence of low molecular weight PAHs in water samples and most of the high molecular weight PAHs in sediments. Naphthalene, acenapthene and fluorene are the major PAHs present in the water and naphthalene, acenapthene, fluoranthene, pyrene and chrysene are the major PAHs present in the sediments. The total PAH concentration in surface water ranges from 0.38 – 1.89 μg/L in KL site whereas, it ranges from 0.40 – 2.21 μg/L in KW site. The preliminary study indicates the occurrence of PAHs in significant amounts around the two power plants, which is needed to be investigated further.
Pre-concentration and determination of trace amounts of heavy metals in beverages marketed in Sri Lanka using naturally occurring clay
(Sri Lanka Association for the Advancement of Science, 2014) Weeraratne, K.S.; Jayathilaka, J.M.P.I.; Subramanium, S.S.; de Silva, R.C.L.