IRSPAS 2018
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Item Investigation of fluoride adsorption capacity of characterized graphene oxide based super sand(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Perera, R. T.; Pathirannehe, P. N. S.; Weerasooriya, R.; Kumarasinghe, A. R.; Liyanage, J. A.Sand is conventionally used in water treatment plants to control water turbidity. This research work was aimed for improving its performance using a chemical modification to remove other water contaminants as well. Thus improved substrate was designated as “Super Sand”. Super sand has proven to be a better adsorbent for the removal of fluoride from water. Fluoride is an essential constituent for human health and toxicity of the fluoride depends on the concentration of the fluoride in the drinking water source. The fluoride adsorption capacity of characterized super sand was determined. Graphene Oxide (GO) was synthesized using the modified Hummers method and then GO was coated with purified sand for the generation of super sand. Single GO coated super sand and multiple GO coated super sand were synthesized for the investigation of fluoride adsorption capacity. GO and super sand were characterized using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectrometry (EDXAS), Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD) analysis and surface titration. Surface titration curve depicted that surface charge of super sand vary with pH value of the medium. Between pH 4 to 7 it has a total positive charge and above pH 7 it has a total negative charge. In order to determine the fluoride adsorption process, isotherm studies were done for both single coated and multiple coated super sand. According to the isotherm studies, single coated super sand has the maximum fluoride adsorption capacity at 2 mg/L fluoride concentration and multiple coated one has maximum fluoride adsorption capacity at 3 mg/L fluoride concentration. Further optimization studies were also performed and finally it was proved that fluoride adsorption by the super sand follows the Langmuir isotherm model. Further, FTIR analysis of super sand and fluoride adsorbed super sand at different pH mediums depicted that adsorption process is a chemisorption process. However, FTIR peak patterns depend on the pH of the medium. Hence, it can be concluded that surface modified super sand is suitable for the fluoride removal from the fluoride contaminated drinking water.Item Chemical analysis of selected Ayurvedic drugs: Yashtikalkaya and Rajahpravartanivati(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Madhushanthi, K. P.; Liyanage, J. A.Ayurvedic medicines have been widely used in Sri Lanka for thousands of years. Although they are considered as beneficial and free of side effects, some toxicity is reported. Therefore, objective of this study was determination of constituents of these drugs to ensure the quality and safety of consumers. Most of the Ayurvedic drugs contain inorganic minerals. Palmanikkam, Sinakkaram, Kasis and Tankana are mineral compounds that are used as raw materials in drug preparations. They are enriched with metals including Cu, Al and Fe. Using above materials Yashtikalkaya and Rajahpravartanivati were prepared in the laboratory according to the Ayurvedic pharmacopeia. Commercially available drugs were also collected. All these samples were subjected to wet digestion and metal concentrations were determined using Atomic Absorption Spectrophotometry. Volatile compounds present in Yashtikalkaya were determined using GC-MS. Cu concentration in palmanikkam, a raw material for Yashtikalkaya was 238.400 ± 0.011 mg/g and after purification it was 238.360 ± 0.124 mg/g. In prepared Yashtikalkaya Cu concentration (1.354 ± 0.402 mg/g) was higher than in the commercially available samples (1.030 ± 0.165 mg/g). Fe concentration in Kasis, a raw material for Rajahpravartanivati was 70.040 ± 0.290 mg/g and after purification it was 81.310 ± 0.729 mg/g. In prepared Rajahpravartanivati Fe concentration (8.469 ± 0.059 mg/g) was higher than in the commercially available samples (3.748 ± 0.121 mg/g). Although Pb, Cr, and Zn containing raw materials were not used for the preparation of those drugs, they were in detectable levels but all values are within the safe level. Butyl acetate, ethylbenzene, p-xylene, 1-ethyl-3-methyl-benzene, eugenol, tetradecanoic acid, 3pentadecyl-Phenol, methyl palmitate,4-methoxy-6-(2-propenyl)-1,3-benzodioxole were detected as volatile compounds. The amount of water can strongly affect the rate of the degradation of a drug. In prepared Rajahpravartanivati moisture content (6.41±0.03%) was higher than in the commercially available samples (5.15 ± 0.02%) and in prepared Yashtikalkaya it was (39.26 ± 0.06%) higher than in commercially available samples (30.12 ± 0.12%). In prepared Rajahpravartanivati water soluble ash value (78.20 ± 0.02%) was higher than in the commercially available samples (74.99 ± 0.48%) and in prepared Yashtikalkaya it was (68.20 ± 0.02%) less than in commercially available samples (88.62 ± 0.16%). Hence the quality controlling aspects have to be implemented in the manufacturing process to avoid variations of those values in different brands of the same drug.