Chemistry
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Item Monitoring of Rainwater Quality in Kandy and Peradeniya, Sri Lanka(2023) Wijewantha, H.L.S.S.; Dharaka, B.D.P.; Priyantha, N.; Deeyamulla, M.P.The composition of atmospheric deposition is a measure of air quality, an important aspect of the health of the ecosystem. Consequently, continuous monitoring of atmospheric deposition is crucial to obtain remedial measures to avoid undesirable aspects that would affect living things. In this context, the objective of this study was to determine the rainwater quality at selected locations in Kandy and Peradeniya area of Sri Lanka, namely, Kandy city, Polgolla and University of Peradeniya (UOP), and to identify possible correlations between quality parameters through statistical means. Forty (40) rainwater samples from the UOP site and seven (07) samples each from the Kandy city and Polgolla sites were collected from the 18th May 2020 to 28th April 2021. The volume weighted average (VWA) pH values of UOP, Kandy and Polgolla sites were determined to be 7.44, 7.19 and 7.19, respectively, and moreover, acid rain (pH < 5.6) occurrences were not detected during the sampling period. The VWA values of rainfall, conductivity, salinity, TDS and hardness at the UOP site were 40.12 mm, 51.93 µS cm− 1, 0.0300 ppt, 26.59 mg L− 1 and 13.55 mg L− 1, respectively. The corresponding values of the Kandy city site were 16.52 mm, 64.04 µS cm− 1, 0.0361 ppt, 30.80 mg L− 1 and 19.49 mg L− 1, respectively; and those of the Polgolla site were 33.10 mm, 53.90 µS cm− 1, 0.0310 ppt, 25.76 mg L− 1 and 19.31 mg L− 1, respectively. The VWA values of conductivity, salinity, TDS were the highest at the Kandy city site. Further, the VWA values of hardness at Kandy and Polgolla were approximately equal, probably due to spring of Ca2+ and Mg2+ particulates from the dolomite quarry located in Digana area. The most prominent anion was identified as Cl− in bulk deposition at all three sites, while NO3− showed the lowest concentration of all sites. Moreover, very strong significant positive correlations were identified between conductivity-TDS, conductivity-salinity, conductivity-hardness, TDS-hardness, TDS-salinity, salinity-hardness, SO42− - Cl−, and NO3− - Cl− according to relevant Pearson correlation coefficients. It is thus concluded that the pollutants come from the same sources, either natural or anthropogenic.Item Chemical composition of rainwater at three sites in Kandy/Peradeniya, Sri Lanka, and its effect on air pollution(2023) Madhushani, L.S.; Dharmapriya, T.N.; Dharaka, B.D.P.; Deeyamulla, M.P.; Priyantha, N.The composition of atmospheric precipitation, an important criterion considered to account for air pollution, is usually determined with respect to wet precipitation and dry precipitation, or as bulk deposition in combined form. Although rainwater quality should be continuously monitored in order to understand the extent of air pollution, such investigation lacks attention in Sri Lanka. This study was thus aimed to determine the composition of bulk deposition collected weekly for a period of eleven months from February to December 2019, in three sampling locations; namely the University of Peradeniya (UOP), Kandy City Central (KCC) and Polgolla. Parameters quantitatively determined, rainfall, pH, conductivity, salinity, total dissolved solids (TDS), hardness, anions: Cl−, NO3−, SO42−, F−, PO43− and trace metals: Zn, Fe, Al, Mn, Cu, Pb, Cr, using standard analytical methods indicated that the KCC site showed the overall highest degree of air pollution followed by UOP and Polgolla sites. Nevertheless, no acid rain occurrences were observed during the sampling period in any of the three sites according to pH measurements. Anions of bulk deposition showed the sequence Cl−> SO42− > NO3−in all three sites with Cl−and SO42- being dominant anions. Furthermore, trace metals of bulk deposition showed the sequence, Zn > Fe > Al > Mn > Cu > Pb, in all three sites. Bulk precipitation data analyzed using Pearson correlation showed high positive significant correlations between conductivity and salinity, conductivity and TDS, and salinity and TDS, among all water quality parameters. Among trace metals, the highest positive significant correlation was found to be between Fe and Mn at the UOP Site. The highest positive significant correlation was between Al and Zn at the KCC site. No correlation between trace metals was found at the Polgolla Site.Item Phyto-extraction of Chromium from Polluted Terrestrial Environments by Talinum triangulare (Ceylon Spinach) and the effect of External Chelators on the Chromium Extraction Potential(Research Journal of Chemistry and Environment, 2020) Jayalath, K.G.; De Silva, R.C.L.; Deeyamulla, M.P.The study was carried out to investigate the potential of Talinum triangulare (Ceylon Spinach) to remediate Cr contaminated soil under greenhouse conditions. In primary studies, T. triangulare showed significant resistance to Cr toxicity, however the amount of metal extracted was not sufficient enough to consider it as a potential phyto-extractor. Further pot experiments were conducted to find out the effect on Cr accumulation using EDTA as chelant under 2.0, 4.0, 6.0, 8.0 and 10.0 mmol kg-1 chelator concentrations. EDTA had virtually a significant effect on uptake of the metals by the plant and elevated Cr concentrations in plant organs as compared with the control. Optimum phytoextraction was observed when 2.0 mmol kg−1 EDTA was added with relatively high biomass production of plant species. EDTA modifies the uptake and the translocation of Cr by plants but the results concerning the uptake and the accumulation depend on the available Cr concentration in soil.Item Chemical characteristics of wet precipitation at Peradeniya in Sri Lanka(Environ Monit Assess, 2020) Liyandeniya, A.B.; Deeyamulla, M.P.; Abeysundara, S.P.The purpose of this research was to study chemical characteristics of precipitation in Peradeniya (Latitude 6.973701, Longitude 79.915256), Kandy District in Sri Lanka. This study was conducted during 2012 to 2014, and wet precipitation was analyzed for pH, conductivity, Na+, NH4+, K+, Mg2+, Ca2+, F−, Cl−, NO3−, SO42−, Pb, Cu, Mn, Al, Zn, and Fe for a total of 125 samples. Less than 2% events of acidic precipitation were recorded, and the VWA of the major ionic species present in precipitation samples were in the order of Ca2+ > Na+ > Cl− > NH4+ > SO42− > K+ > NO3− > Mg2+. Neutralization of acidity of precipitation is much more related to CaCO3 than NH3, and the presence of high content of Ca2+ strongly supports this fact. When considering marine contribution, SO42−/Na+, Ca2+/Na+, Mg2+/Na+, and K+/Na+ ratios are higher than the reference value suggesting that contribution of sources other than marine. Concentration of Zn is the highest while that of Mn is the lowest. Principal component analysis identified probable sources for major ionic and elemental sources as both natural and anthropogenic sources such as vehicular emission due to heavy traffic, waste incineration, bio mass burning, brass industry, and construction.Item Heavy metal contamination in road dust from Colombo-Katunayake Expressway, E03(Sri Lanka Association for the Advancement of Science, 2015) Priyadarshana, L.W.V.; Deeyamulla, M.P.; Priyantha, NamalItem Atmospheric deposition of Polycyclic Aromatic Hydrocarbons (PAHs) around two metropolitan areas in the western province of Sri Lanka, using moss (Hyophila involuta) as a biomonitor(Sri Lanka Association for the Advancement of Science, 2015) Jayalath, K.G.; Deeyamulla, M.P.; de Silva, R.C.L.Item Biomonitoring of atmospheric heavy metal deposition using moss (Hyophila involuta): Efficiency of different moss bag techniques(Sri Lanka Association for the Advancement of Science, 2013) Dharmasiri, P.H.A.N.; Deeyamulla, M.P.Item The role of washing of moss samples in analysis of heavy metal concentrations in moss biomonitoring studies(Sri Lanka Association for the Advancement of Science, 2013) Jayalath, K.G.; Deeyamulla, M.P.; de Silva, R.C.L.Item Identification of wild plants to phytoextract chromium from polluted terrestrial environments(Sri Lanka Association for the Advancement of Science, 2013) Liyanage, A.L.L.A.; Jayalath, K.G.; de Silva, R.C.L.; Deeyamulla, M.P.Item Comparizon of atmospheric deposition of heavy metals in Kandy and Puttalam areas in Sri Lanka using moss (Hyophila involuta) as a bioindicator: short term study(Sri Lanka Association for the Advancement of Science, 2013) Jayalath, K.G.; Deeyamulla, M.P.; de Silva, R.C.L.