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Item Activation of wood biochar and red brick using natural coconut vinegar(Faculty of Science, University of Kelaniya, Sri Lanka, 2020) Malka, U.K.M.; De Silva, R.C.L.; De Silva, D.S.M.; Chandrajith, R.Number of studies have been carried out to determine the efficiency of strong oxidizers in activating natural raw materials used in low cost water purification processes. However, rural communities find it difficult to acquire most of such chemicals. Therefore, this study was aimed to determine the ability of natural coconut vinegar, which is a common domestic acidic solution, in activating abundantly available potential water purifying materials to reduce calcium (Ca2+) ions from water, further reducing the water hardness. In this study mature barks of Glyricidia (Glyricidia sepium), Gadumba (Trema orientalis) and Ipil Ipil (Leucaena leucocephala) were collected and air dried. These were carbonized (400-450 °C) in a closed vessel (2 hours) to produce biochar. Both biochar and brick particles in the range of 2.0-5.6 mm were selected for the analysis. For the activation these samples were soaked in natural coconut vinegar (biochar/brick: vinegar, 1:2 V/V) for 24 hours and completely dried in an oven (120 °C) for 3 hours. Laboratory scale glass columns (2 cm in diameter) were used to calculate Ca2+ adsorption and retaining capacities. Filtrates were analyzed for Ca2+ using flame photometer. Ca2+ adsorption and retaining capacities of each material were calculated per unit bulk volume of the material. Each test was duplicated, and the average was recorded. Untreated red brick and biochar of Glyricidia, Gadumba, Ipil Ipil showed Ca2+ adsorption capacities of 0.44, 0.30, 0.31, 0.27 mg cm3 and retaining capacities of 0.19, 0.01, 0.02, 0.02 mg cm-3 respectively. Activated red brick and biochar of Glyricidia, Gadumba and Ipil Ipil showed Ca2+ adsorption capacities of 0.76, 0.58, 0.68 and 0.63 mg cm-3 and retaining capacities of 0.25, 0.20, 0.23 and 0.15 mg cm-3 respectively. Increase in Ca2+ adsorption and retaining capacities were observed in all the materials tested after activation with vinegar. Further studies are continued to use the vinegar activated natural materials in a low-cost domestic drinking water purification process.Item Use of natural curcumin extracted from turmeric in determination of boron in steel.(International Research Symposium on Pure and Applied Sciences, 2017 Faculty of Science, University of Kelaniya, Sri Lanka., 2017) Walpita, W. K. D. L. K.; De Silva, R.C.L.Boron containing alloy steels are used in constructional, automotive and many other applications. The presence of even trace amounts of boron affects greatly on the properties of steel such as hardness and machinability. As the traces of boron affect the properties of steel, it is important to determine it accurately and precisely in the manufacture of these alloys. Due to the drawbacks of common advanced techniques such as Atomic Absorption Spectroscopy (AAS), Inductively Coupled Plasma-Atomic emission Spectroscopy (ICP-AES), the universally accepted method for determination of boron in steel is the spectrophotometric method using curcumin as an auxiliary agent. Although curcumin is the most sensitive spectrophotometric reagent for the above analysis, synthetic curcumin is relatively expensive and it tends to degrade rapidly once it is exposed to air. Furthermore, this method is time consuming. One of the main objectives of this study was to investigate the possibility of using natural curcumin extracted from turmeric in the analysis instead of using synthetic curcumin. Curcuminoids were extracted from turmeric (Curcuma longa) using soxhlet extraction and they were separated using column chromatography. Extracted crude, separated curcumin fraction and synthetic curcumin were analyzed using FTIR. FTIR spectra of synthetic curcumin and natural curcumin were similar to each other and the spectrum of extracted crude indicate the presence of more carbohydrate impurities. Finally the possibility of using natural curcumin in the analysis of boron in steel was determined using the method given by American Society for Testing and Materials (ASTM). A boron-steel alloy sample found to be containing 0.26±0.01 percent of boron with synthetic curcumin gave 0.25±0.00 percent of boron with natural curcumin, indicating no significant difference in the determination. Cost analysis showed that it is more cost effective to use natural curcumin over synthetic curcumin. Findings of this study implies that natural curcumin extracted from turmeric can be used as efficiently and accurately as synthetic curcumin in the analysis and it is more cost effective in large scale industrial determination of boron in steel.