International Postgraduate Research Conference (IPRC)
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Item Green Synthesis and Characterization of Zirconia Nanoparticles Using Averrhoa bilimbi(International Postgraduate Research Conference 2019, Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2019) Jeyasakthy, S.; Premaratne, W.A.P.J.Nanostructured materials have numerous breakthrough applications in the field of engineering, medicine and science due to their exceptional physical and chemical properties. These nanoparticles are interesting not only for their wide variety of physical and chemical properties, but also for their antibacterial activity. Zirconia (ZrO2) nanoparticle is a ceramic material, which has attracted widespread scientific and industrial attention due to its interesting and useful properties such as higher strength, higher fracture, toughness, nonmagnetic, low thermal conductivity, wear resistance and corrosion resistance in acids and alkali. Synthesizing of nanoparticles from natural resources such as plant extracts or fruit juices have drawn significant attention due to many issues encounter from conventional methods of making nanoparticles. The present investigation is a biogenic green synthesis of zirconia nanoparticles (ZrNPs) using the fruit juice of Averrhoa bilimbi as nontoxic and ecofriendly reducing material. This work focused on a facile, ecofriendly and sustainable method to synthesize zirconia nanoparticles by bilimbi juice extraction. Bilimbi juice is known to have a high content of oxalic, citric and ascorbic acids. The synthesized ZrNPs were characterized using mass spectrometry (MS), X-Ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) and used to evaluate their antibacterial activity. MS results confirmed the presence of oxalic acid, ascorbic acid and citric acid in the Averrhoa bilimbi juice. The XRD pattern was used to characterize the structure of ZrO2 nano particles which showed that nanoparticles are tetrahedral. The size range of synthesized ZrO2 nano particles was found to be 10 to 50 nm from the SEM images and the energy dispersive X-ray spectroscopy (EDEX) confirmed the presence of elements, zirconium and oxygen in the nanoparticles. According to the antibacterial evaluation, the nanoparticle did not show any bactericidal or bacteriostatic activities. Therefore, the synthesized nanoparticles are more suitable for the dermatological preparation as an additive.Item An Investigation of Ground Water Quality in Ja-Ela Area in Sri Lanka(International Postgraduate Research Conference 2019, Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2019) Thamel, W.M.P.; Premaratne, W.A.P.J.Ground water plays major role in human life. It is the most important source of water supply for drinking, agricultural and industrial purposes. Groundwater quality has become crucial for water resources issues due to rapid increase of population, rapid industrialization, heavy use of fertilizers and pesticides in agriculture. Hydrochemical parameters of groundwater play a significant role in classifying and evaluating water quality. An investigation was carried out to analyze the ground water quality in Ja-Ela area in Sri Lanka for 10 drinking water well samples between 7º 07' 99" to 7º 09' 13" North latitude and 79º 89' 30" to 79º 90' 61" East longitude for a period of six months from December 2018 to May 2019. The physicochemical parameters studied were pH, conductivity, COD, hardness, and metals including Fe, Mn, Cd and Zn. The observed physicochemical parameters of ground water were compared with World Health Organization (WHO) standards. According to the observations, some ground water samples from Ja-Ela area were appeared brownish color with odor. The observed pH values of all fresh water samples ranged within the acceptable pH range (6.5-8.5) of WHO for drinking water, while pH values after boiling of those well water samples ranged from 8.5 to 9.0. According to the experimental results highest conductivity observed for fresh well water samples is 308.8 μS cm-1 which is lower than recommended value (750-3500 μS cm-1). All the well water samples in studied area have high COD values and high total magnesium and calcium content above the recommended values of WHO. Total magnesium and calcium contents were ranged from 184 to 329 as CaCO3 mg L-1. The cadmium content of the well water samples was not in the detection limits (< 0.003 mg L-1). The maximum iron content observed was 5.07 mg L-1. The maximum manganese content and zinc content were 0.06 mg L-1 and 0.14 mg L-1 which are lower than the recommended values of WHO standards. Experimental data revealed that groundwater in the studied area is not in the limit of COD, total magnesium and calcium content and iron content of WHO guidelines for drinking waterItem Analysis of Water and Sediment in Attanagalu Oya in Sri Lanka: Pollution Levels and Effects(In: Proceedings of the International Postgraduate Research Conference 2017 (IPRC – 2017), Faculty of Graduate Studies, University of Kelaniya, Sri Lanka., 2017) Premaratne, W.A.P.J.; Perera, H.S.M.The Attanagalu Oya plays a major role in national water supply since it contains four major national water supply and drainage board intakes. This study intends to investigate the water quality variation and pollution levelin Attanagalu Oya in Gampaha municipal council area.Sampling was conducted for a period of six months from November 2016 to April 2017 at nine locations situated between 7° 05' 33.8" to 7° 05' 53.1’’N latitude and 79° 58' 15.6"to 79° 59' 32.5"E longitude along the main river. Both water and sediment samples in the river were collected and tested for physical and chemical parameters. Electrical conductivity (EC), pH, titratable acidity, total hardness, chemical oxygen demand (COD), and metal ions content (Fe, Pb, Cd, Ni, Mn, Cu) were analyzed in water samples. EC, pH, organic matter content and soil texture were analyzed in sediment samples. Experimental results were ascertained to find out the quality and pollution level of water and sediment by comparing with the standards levels given by the Central Environmental Authority (CEA) in Sri Lanka and World Health Organization (WHO) guidelines. According to the experimental results, average pH values of water in the river was from 7.1 to 7.6 and did not exceed the proposed ambient water quality standards for fish and aquatic life. EC values ranged from 81.9 to 91.7 μS/cm and conductivity shows a drastic increment due to dry season. Titratable acidity, total hardness and metal ions content in water samples were not in the limits of CEA and WHO standards for drinking water parameters. COD values of water samples exceeded the maximum CEA standards during the sampling period. Sediment analysis indicated that physical and chemical parameters are not in the limits of CEA standards. Therefore, this study shows that the river is polluted and the effects being significant in the urban areas.Item Assessments of Drinking Water Quality and Water Treatment Process in Kalatuwawa Reservoir in Sri Lanka.(In: Proceedings of the International Postgraduate Research Conference 2017 (IPRC – 2017), Faculty of Graduate Studies, University of Kelaniya, Sri Lanka., 2017) Premaratne, W.A.P.J.; Senarathne, K.S.D.Kalatuwawa is one of the major water treatment plants which supplies water to Colombo city and it‘s sub-urban. Raw and treated water samples were collected from the Kalatuwawa water treatment plant located at 6 85‘ latitude and 80 18‘ longitude. Both raw and treated water samples were analyzed ninety times within six months (15 days per months) from July to December 2016 for pH, turbidity, conductivity, color, hardness, alkalinity, aluminum, iron, manganese and ammonia. According to the experimental results, pH was in the range of 6.58.5 in the treated water. The conductivity values ranged from 20.5 to 34.5 μS cm- 1 in raw water and it was from 48.5 to 74.5 μS cm- 1 for treated water. The hardness value range was from 5.5 to 6.5 ppm (as CaCO3) for raw water and from 15.5 to 25.5 ppm (as CaCO3) for treated water. Raw water and treated water alkalinities were 7.0-8.5 ppm (as CaCO3) and 13.0-19.5 ppm (as CaCO3) respectively. Aluminum concentration in raw water was 0.02-0.05 ppm and it was 0.1-0.2 ppm in treated water. Ammonia concentration in raw water in Kalatuwawa varied from 0.02 to 0.09 ppm and the maximum value in treated water was 0.01 ppm. Iron concentration in raw water was 0.5-2.0 ppm and it was 0.05-0. 07 ppm in treated water. Average color of the raw water was detected as 39-83 Pt/Co units and after treatment process average color indicated as zero value Pt/Co units. Average turbidity value was from 0.2 to 2.5 NTU for treated water. Experimental data revealed that treated water from Kalatuwawa reservoir is in the limits of World Health Organization (WHO) standards for drinking water parameters indicating efficient, effective and productive water treatment process.Item Assessment of Physicochemical Parameters of Water in Cooling Towers and Boilers: Testing and Comparisons.(In: Proceedings of the International Postgraduate Research Conference 2017 (IPRC – 2017), Faculty of Graduate Studies, University of Kelaniya, Sri Lanka., 2017) Premaratne, W.A.P.J.; Maithreepala, K.L.U.Scaling and corrosion effects of cooling towers and boilers can be identified by analyzing their water quality parameters. Cooling tower mainly has a refrigeration system, providing cooling in a wide range of applications such as such as chemical processing, power plants, steel mills and some manufacturing processes. Boiler is a vessel which has an enclosed system. In boiler, water is circulated and heated, either as steam or hot water to generate power or heat. This study investigated six cooling towers and six boilers selected from various industries such as food, beverages, dairy, manufacturing industry and hotels. Each water sample was analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), alkalinity, total hardness and chloride. According to the experimental results, in cooling towers pH value fluctuated from 7.6 to 8.7. The EC value ranged from 98.8 to 1215.5 µS cm1. The TDS varied in the range of 50.5 to 793.5 mg L-1. Alkalinity was detected from 18.3 to 343.6 mg L-1 as CaCO3. The value of total hardness and amount of chloride varied from 12.3 to 429.5 and 14.7 to 22.8 mg L-1 respectively. In boiler waters, the pH value varied from 8.7 to 11.2. The EC value was from 551.5 to 3997.8 µS cm-1. The TDS value was determined from 283.5 to 2748.5 mg L-1. The alkalinity varied in the range of 90.8 to 404.5 mg L-1. The value of total hardness and chloride varied in the range of 23.3 to 214.5 mg L-1 as CaCO3 and 9.6 to 23.5 mg L-1 respectively. The observed physicochemical parameters from water samples were statistically analyzed with one-way ANOVA. According to the experimental results, it was found that in most cooling towers and boilers physicochemical parameters of waters are not in the range of recommended standards values and have heavy corrosion and scaling effect. These effects can be minimized by correct chemical adjustment for the water quality parameters.Item Physicochemical Analysis of Ground Water Quality and Soil in Ja-Ela Area in Sri Lanka.(In: Proceedings of the International Postgraduate Research Conference 2017 (IPRC – 2017), Faculty of Graduate Studies, University of Kelaniya, Sri Lanka., 2017) Premaratne, W.A.P.J.; Anuruddha, I.G.G.U.Water pollution has become a common problem with the reduction of the availability of drinking fresh water resources. Hydrochemical parameters of groundwater and soil play a significant role in classifying and assessing the water quality. The objective of the present study is to ascertain the major ion chemistry of groundwater and soil in the Ja-Ela, Indiwita area in Sri Lanka. Water and soil samples were collected from 12 drinking water wells between 7 04‘ 29‖ to 7 04‘ 39‖ latitude and 79 53‘ 01‖ to 80 53‘ 04‖ longitude in the JaEla area. Each drinking water well was analysed six times within six months for pH, specific conductance, COD, hardness, and metals (using AAS method) including Al, Fe, Mn, Ca, Mg and Na. The observed physicochemical parameters of ground water were compared with World Health Organization Standards (WHO). According to the experimental results, all the ground water samples were appeared brownish colour with an odour. The observed pH values of all the water samples were ranged from 7.0 to 8.3. Aluminium content in the water samples was not in the detectable limits (<0.05 mg L-1) and the maximum iron content observed was 5.3 mg L-1. The maximum manganese content observed was 0.3 mg L- 1. Total magnesium and calcium contents were ranged from 42 to 581 as CaCO3 mg L-1. The majority water type in the study area was found to be Na-bicarbonate water type. Groundwater soil samples were analysed for pH, specific conductance, cation exchange capacity organic matters, mineral phases, and metals including Al, Fe, Mn, Ca, Mg and Na. Manganese content in soil was from 1.7 to 70.5 mg kg-1. Experimental data revealed that groundwater in studied area was not in the limits of WHO standards for drinking water parameters except the pH value and conductivity.Item Assessment of Water Quality Status and Pollution Levels in Maduru Oya Reservoir in Sri Lanka(Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2016) Kasthuriarachchi, T.D.W.; Wickramaarachchi, W.D.N.; Premaratne, W.A.P.J.MaduruOya reservoir was constructed in 1983 under the Accelerated Mahaweli Program. The dam is located in North Central province and the reservoir extends to Eastern province and Uva provinces (between 7º 32' 42" to 7º 39' 57" North latitude and 81º 11' 35" to 81º 12' 21" East longitude). It is reported that high amount of nutrients and other chemical residues accumulate in water of the reservoir due to heavy use of agrochemicals in the catchment area. Fifteen locations were selected for sub-surface water sampling and analysis from February to July in 2016. Temperature, pH, Dissolved Oxygen (DO), Electrical Conductivity (EC) and Turbidity were measured in-situ. Ammonical nitrogen, nitrate nitrogen, nitrite nitrogen, dissolved phosphate, and other chemical parameters such as alkalinity and hardness were also assessed. Water temperature of the reservoir varied from 29.7 ͦ C to 36 ͦ C while pH value was from 6.8 to 9.5. DO value was from 3.3 ppm to 9.4 ppm. EC varied from 94 μS cm-1 to 200 μS cm-1 and turbidity of water fluctuated from 0.96 NTU to 49.4 NTU. Ammonical nitrogen varied from 0.001 ppm to 0.652 ppm. Nitrite Nitrogen was from 0.001 ppm to 0.905 ppm and Nitrate Nitrogen was detected from 0.001 ppm to 1.131 ppm. The highest phosphate concentration was detected as 0.468 ppm near the dam site of the reservoir in July. Total hardness was from 21ppm to 68 ppm and alkalinity varied from 15 ppm to 190 ppm. The highest pH was recorded in June near the dam site of the reservoir and exceed the WHO standards for drinking water. The maximum nitrate and nitrite concentrations were recorded in June at the middle of reservoir and maximum ammoniacal nitrogen was also recorded in June and it was at the dam site. High accumulation of nutrients can lead to eutrophication in the reservoir and it causes the spreading of toxin producing algal species such as Microcystis affecting the ecosystem health and human livelihood.Item Spatial and Temporal Variation of Selected Physicochemical Parameters in Chilaw Lagoon in Sri Lanka(Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2016) Maddumage, M.D.S.R.; Azmy, S.A.M.; Premaratne, W.A.P.J.Chilaw Lagoon is an intermittently closed, shallow coastal lagoon located in the North Western province of Sri Lanka. Excessive shrimp farm development has resulted in pollution of the lagoon since the farms extract water from the lagoon and discharge the effluent to the same lagoon. This study investigated the seasonal and spatial variations of selected water quality parameters at fifteen different locations situated between 7° 29' 17'' to 7° 36' 25'' N latitude and 79° 47' 19'' to 79° 49' 02'' E longitude in the Chilaw lagoon for a period of six months (from March to August in 2016). Each water sample was analyzed at the sampling sites for pH, Electrical Conductivity (EC), Salinity, Dissolved Oxygen (DO), Turbidity, Air Temperature and Water Temperature as physical and chemical parameters. Nitrite Nitrogen, Nitrate Nitrogen, Ammoniacal Nitrogen and Dissolved Phosphate were also analyzed. According to the experimental results, pH values of water in the lagoon fluctuated from 6.7 to 9.3 and exceeded the proposed ambient water quality standards for fish and aquatic life. The lagoon DO levels varied from 1.25 to 6. 79 mg/L and the lower limit does not comply with the tolerance limit for fish and aquatic life. EC values ranged from 2.8 to 55.1 mS/cm and the corresponding Salinity variation was 2 to 35 ppt (parts per thousand). The surface water temperature and the turbidity of the water in the lagoon varied in the range of 27.4 to 33.9 ͦ C and 0.96 to 50.3 NTU respectively. Ammoniacal Nitrogen was detected from 0.01 to 0.25 mg/L. The maximum Nitrite Nitrogen value was 0.04 mg/L and it was 0.32 mg/L for Nitrate Nitrogen. The maximum level of Orthophosphate was observed as 0.29 mg/L. Therefore, pH, EC, DO, Salinity, Turbidity and nutrients showed a significant spatio-temporal variation that affects the aquatic life in the lagoon critically.Item Montmorillonite/TiO2 Advanced Hybrid Material Using Sri Lankan Clay: Preparation and Characterization(Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2016) Premaratne, W.A.P.J.Montmorillonite (MMT) is a naturally occurring crystalline silicate clay mineral. Nano titanium dioxide (nano-TiO2), particularly in the anatase form, is a photocatalyst under ultraviolet (UV) light. Nano-TiO2 is thus added to paints, ceramics, tiles, or other products for its sterilizing, deodorizing and anti-fouling properties and is used as a hydrolysis catalyst. The objective of this research is to enhance the photocatalytic activity of TiO2 by forming a hybrid material with MMT. Therefore, montmorillonite/TiO2 advanced hybrid materials was prepared using montmorillonite clay from Murunkan deposit in Sri Lanka. The cation exchange capacity (CEC) of Murunkan clay was found as 65 meq/100 g. Raw materials, intermediate products, and the MMT/TiO2 hybrid material were analyzed using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). XRD and EDX data analysis revealed the presence of TiO2 in the hybrid material as anatase form. According to XRD and SEM data analysis average particle size of the nano TiO2 was found to be 60 nm. SEM images showed that the microstructure of the clay has not been destroyed during the formation of the MMT/TiO2 hybrid material. UV-Visible spectroscopy was used to measure the effectiveness of the photocatalytic activity of the hybrid material versus nano TiO2 for the degradation of methyl orange. In this experiment methyl orange was used as a model organic pollutant. Experimental results showed that after 4 hours MMT/TiO2 hybrid material degraded 92% of methyl orange while nano TiO2 has only degraded 67% under diffused light. The synthesized MMT/TiO2 advanced hybrid material exhibited much higher efficiency in degrading methyl orange compared to the same weight of nano TiO2 alone.Item Nanosilica from Sri Lankan Vein Quartz: Synthesis, Surface Modification and Characterization(Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2016) Premaratne, W.A.P.J.; Priyadarshana, W.M.G.I.Vein quartz is one of the most abundant minerals in Sri Lanka and it is mainly mined for porcelain and materials industries. Vein quartz is an economically viable earth resource for the production of nanosilica through chemical methods as a value added product. Nanosilica is one of the widely used nanomaterials in adhesives, sealants, paints & coatings, cement-based building materials and rubber composites as a reinforcing, thickening and flattening agent. In this research work, pure nanosilica was synthesized by a chemical precipitation method from Sri Lankan vein quartz. Finley ground quartz was refluxed with 3 M NaOH and then 0.5 M H2SO4 was added drop wise to adjust the pH of the solution to be around 8.0 to precipitate nanosilica. X-ray diffraction (XRD) data indicated that the natural Sri Lankan vein quartz is highly crystalline and pure. Energy dispersive X-ray spectroscopy (EDX) data confirmed that vein quartz comprises pure silicon oxide with less impurities. Scanning electron micrographs (SEM) data showed that synthesized nanosilica particles from vein quartz were in the agglomerate form with average particle size of 50 nm. XRD data showed a strong broad peak around 22.14o (2) indicating synthesized nanosilica was in amorphous form. Fourier transform infrared spectroscopy (FTIR) data indicated the structural change from crystalline silica (in vein quartz) to amorphous silica by the absence of a sharp peak at 695 cm-1 in the FTIR spectrum of nanosilica synthesized. Silica nanoparticles were subjected to surface modification by oleic acid (C18H34O2). Thermo gravimetric analysis (TGA) graph indicated the thermal decomposition of oleic acid in functionalized nanosilica with a significant weight loss between 350 ºC to 400 ºC. FTIR data showed that modified nanosilica with oleic acid indicated a carbonyl stretching peak of an ester bond at 1711 cm-1, which confirmed the ester bonding between silinol group and the carboxylic group of the oleic acid.