Browsing by Author "Premaratne, W.A.P.J."

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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.
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.
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.
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.
Development and characterization of a slow release fertilizer system using ammonium nitrate incorporated Gliricidia bark particles.
(International Research Symposium on Pure and Applied Sciences, 2017 Faculty of Science, University of Kelaniya, Sri Lanka., 2017) Premaratne, W.A.P.J.; Thisera, P.A.U.D.
Best management practices for fertilizers in the application of plant nutrients should always aim to avoid a surplus of plant available nutrients in the soil. This will promote the efficient use of nutrients and minimize unfavorable effects on the environment. These conditions could be achieved by using slow release fertilizer systems. Experiments were conducted to determine the nitrogen (N), phosphorous (P) and potassium (K) contents in leaf, mid rib, root, bark and stem of gliricidia (Gliricidia sepium) plant and to develop a new slow release fertilizer system using ammonium nitrate (NH4NO3) incorporated gliricidia bark particles. Gliricidia plants were obtained from Rathmalagara estate, Madampe in Coconut Research Institute (CRI), Sri Lanka. New slow release fertilizer system was prepared from gliricidia bark particles (< 5 mm) after treating with a saturated solution of ammonium nitrate (NH4NO3). The morphology and physicochemical parameters of treated gliricidia bark particles were investigated. The release patterns of nitrogen from ammonium nitrate incorporated gliricidia bark particles (10 g) in a soil matrix (200 g) were investigated using columns with deionized water (pH 6.7). Parallel studies were carried out to evaluate the leaching patters of commercially available three nitrogen fertilizers sold in Sri Lanka in the soil matrix using the columns. Control reactions were carried out with ammonium nitrate in a soil matrix alone. Each experiment was carried in triplicate. Experimental results indicated that the level of nitrogen content in different parts of the gliricidia plants varied from 4599 mg kg-1 to 24381 mg kg-1. It was found that phosphorous content in gliricidia plant varied from 1367 mg kg-1 to 3143 mg kg-1. Potassium in different parts of the gliricidia plants varied from 140 mg kg-1 to 2600 mg kg-1. Therefore, gliricidia plant can potentially be used as a fertilizer source of nitrogen, phosphorous and potassium. After treating gliricidia bark particles with saturated ammonium nitrate, the total nitrogen content in gliricidia bark particles increased by more than six times with a maximum value of 67830 mg kg-1 after 6 hours. The initial nitrogen content in the bark was 10080 mg kg-1. According to the experimental results, within 24 hours more than 80% of the nitrogen was eluted from ammonium nitrate and commercially available fertilizers in the soil matrix given. However, only 24% of nitrogen was eluted from NH4NO3 incorporated gliricidia bark particles within 24 hours. After 15 days eluted nitrogen amount was recorded as only 43% from treated gliricidia bark particles. Therefore, it could be inferred that nitrogen was released from NH4NO3 impregnated gliricidia wood chips in a slow-release pattern. According to research data, it could be concluded that gliricidia bark particles have a great potential as a fertilizer carrier for the development of a nitrogen rich new slow release biomass fertilizer system.
Development of a new biofertilizer system using Gliricidia plants grown in Sri Lanka
(Faculty of Graduate Studies, University of Kelaniya, 2015) Premaratne, W.A.P.J.; Amarakoon, T.N.
Use of biomass fertilizers appears to be the most appropriate way of adding nutrients into the soil which is environmental friendly and suitable for local conditions. Among the biomass fertilizer sources, Gliricidia has been identified as the most suitable nitrogen fixing legume. Some experiments that have been carried out showed that the Gliricidia with high N content and low lignin level is more suitable as N source. An investigation carried out to determine the nitrogen (N), phosphorous (P), and potassium (K) contents of different parts of gliricidia plant and to develop a slow-release nitrogen biomass fertilizer systems using gliricidia plant. Four types of gliricidia plants (Provenance Trail Series of Gliricidiasepium 17/84 Oxford Forestry Institute (OFI), Gliricidiasepium 25/84 OFI, Gliricidiasepium 25/84 OFI and Gliricidiasepium (Local species)) were obtained from Rathmalagara estate, Madampe in Coconut Research Institute (CRI) in Sri Lanka. According to the experimental results the level of nitrogen in different parts of the gliricidia plants varied from 27860 mg kg-1to 5222 mg kg-1. It was found that phosphorous and potassium content in gliricidia plant varied from 892.2 mg kg-1 to 1258.2 mg kg-1 and from 208.6 mg kg-1 to 8678.5 mg kg-1 respectively. Biofertilizers were prepared from gliricidia bark chips after treated with a saturated solution of urea (CH4N2O). The morphology and physiochemical parameters of treated gliricidia bark chips were investigated. Experimental result indicated that after gliricidia bark chips were treated with urea, total nitrogen content in the bark increased by more than 200% giving the value as 36700 mg kg-1.The initial nitrogen content in the bark was 17878 mg kg-1. This study also evaluated the release pattern of nitrogen from impregnated gliricidia wood chips in a soil matrix and found that nitrogen was released in a slow-release pattern. The above findings confirm and gave promising results to further develop urea incorporated gliricidia bark particles as a slow-release new biomass fertilizer system.
Development of a New Biofertilizer System Using Gliricidia Plants Grown in Sri Lanka
(Faculty of Graduate Studies, University of Kelaniya, 2015) Premaratne, W.A.P.J.; Amarakoon, T.N.
Use of biomass fertilizers appears to be the most appropriate way of adding nutrients into the soil which is environmental friendly and suitable for local conditions. Among the biomass fertilizer sources, Gliricidia has been identified as the most suitable nitrogen fixing legume. Some experiments that have been carried out showed that the Gliricidia with high N content and low lignin level is more suitable as N source. An investigation has been carried out to determine the nitrogen (N), phosphorous (P), and potassium (K) contents of different parts of gliricidia plant and to develop a slow-release nitrogen biomass fertilizer systems using gliricidia plant. Four types of gliricidia plants (Provenance Trail Series of Gliricidia sepium 17/84 Oxford Forestry Institute (OFI), Gliricidia sepium 25/84 OFI, Gliricidia sepium 25/84 OFI and Gliricidia sepium (Local species)) were obtained from Rathmalagara estate, Madampe in Coconut Research Institute (CRI). According to the experimental results the level of nitrogen in different parts of the gliricidia plants varied from 0.43 % to 2.36 %.It was found that phosphorous and potassium content in gliricidia plant varied from 892.2 mg kg-1 to 1258.2 mg kg-1 and from 208.6 mg kg-1 to 8678.5 mg kg-1 respectively. Biofertilizers were prepared from gliricidia bark chips after treated with a saturated solution of urea (CH4N2O). The morphology and physiochemical parameters of treated gliricidia bark chips was investigated. Eexperimental result indicated that after gliricidia bark chips were treated with urea, total nitrogen content in the bark has increased by more than 200%. The initial nitrogen content in the bark was 17878 mg kg-1. This study also evaluated the release pattern of nitrogen from impregnated gliricidia woodchips in a soil matrix and found that nitrogen was released in a slow-release pattern. The above findings confirm and gave promising results to further develop urea incorporated gliricidia bark particles as a slow-release new biomass fertilizer system.
Engineered Nanomaterials from Mineral Resources: Application in Industry and Environment
(Sri Lanka Association for the Advancement of Science, 2016) Premaratne, W.A.P.J.
An evaluation of lead levels in paints sold in the Sri Lankan market
(Sri Lanka Association for the Advancement of Science, 2008) Premaratne, W.A.P.J.; Silva, N.J.
An investigation has been carried out to ascertain and evaluate lead levels in different solvent based and water based household paints sold in the Sri Lankan market. Unlike in developed countries, in developing countries like Sri Lanka, relatively little or no attention has been devoted to the potential for lead exposure which is considered to be a major health hazard. Lead has been used in paints, gasoline, water pipes and many other products. At present lead based paint is one of the most significant sources of lead exposure. There are two common basic types of lead pigments known as white lead (Pb(OH)2.2PbCO3) and red lead (Pb 3O4), which have been widely used in the paint and coating industry. Lead dust can form when lead based paint is scraped, sanded, or heated. But later people realised that exposure to lead dust released from lead based paints caused lead poisoning in children as well as in adults. Lead is a highly toxic, heavy metal. Its adverse effects on health include hyperactivity, low intelligence quotient (IQ) scores, hearing loss, behavioral disorders, kidney toxicity and anaemia In this study five brands of white coloured enamel paints and seven brands of white coloured emulsion paints sold in the Sri Lankan market as household coatings were investigated over a time period of six months in 2007. Experimental results indicated that the levels of lead in the enamel paints ranged from 5.7±1.7 mg kg-1 to 2452.3±109.1 mg kg-1 and it was from 4.1±0.3 mg kg-1 to 688.2±16.3 mg kg-1 in emulsion paint sample analysed. Out of the five enamel paint and seven emulsion paint brands analysed two enamel paint brands and one emulsion paint brand showed the presence of considerably high amounts of lead and thus those products cannot be recommended for applications, since they have a potential risk of causing health hazards pertaining to lead poisoning especially in children. Therefore, experimental results revealed that high levels of lead pigments and lead additives are still used by some paint and coating manufacturers in Sri Lanka with increased risk of exposure to people, for whom domestic sources of lead exposure is more important than exposure through leaded petrol.
An evaluation of Nitrogen (N), Phosphorous (P), Potassium (K) levels in Gliricidia plants grown in Sri Lanka to be used as biofertilizers
(Sri Lanka Association for the Advancement of Science, 2009) Premaratne, W.A.P.J.; Fernando, K.D.G.
Extraction of copper from copper bearing sulfide ores (chalcopyrite) by oxidative chemical leaching
(Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Premaratne, W.A.P.J.; Dharmarathna, A.C.S.
The extraction of copper from primary copper sulfide ores is much complicated and expensive. However, the successful metal extraction from natural mineral resources is very important, both environmentally and economically. The main objectives of this research work are to examine possible ways to increase the copper extraction from chalcopyrite (CuFeS2) using oxidative chemical leaching processes and to investigate oxidative leaching kinetics of chalcopyrite in sulfuric (H2SO4) acid medium. Chalcopyrite mineral sample was obtained from Geological Survey and Mines Bureau (GSMB) in Sri Lanka. Initial investigations characterized the chalcopyrite ore mineralogically and chemically. X-ray diffraction analysis of chalcopyrite ore reveled that only chalcopyrite (CuFeS2), azurite (Cu3(CO3)2(OH)2), pyrite (FeS2) and pyrrhotite (FeS) minerals were present. The copper content of the chalcopyrite ore sample was found to be 16.6% by weight according to the chemical analysis. The extraction of copper from chalcopyrite using hydrogen peroxide (H2O2), ferric sulphate (Fe2(SO4)3), potassium permanganate (KMnO4) and potassium dichromate (K2Cr2O7) oxidizing agents in acid solutions was studied using the 63-90 μm particle size fraction of chalcopyrite. The effect of temperature ranging from 30 ºC to 70 ºC, the effect of concentration of sulfuric acid ranging from 0.25 mol dm-3 to 5.0 mol dm-3 and the effect of pulp density ranging from 2% to 6% on the rate of dissolution of copper from chalcopyrite ore were also studied. The extraction rates are significantly influenced by the temperature and the concentration of the acid solutions. According to the oxidative chemical leaching results, the maximum extraction of copper was achieved with KMnO4 and then with K2Cr2O7, followed by H2O2 and Fe2(SO4)3. In this study maximum extraction of 70.2 % of copper was achieved at 0.1 mol dm-3 KMnO4 in 1.0 mol dm-3 H2SO4 acid. It was found that oxidizing agents improved the leaching kinetics of chalcopyrite in sulfuric acid medium saving both time and energy effectively and efficiently. A kinetic study showed that the dissolution of copper from chalcopyrite ore was controlled by chemical reaction process on the surface of particles. Based on the results obtained in this investigation, the apparent activation energy for the dissolution of copper using the Arrhenius expression was found to be 31.8 kJ mol-1.
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.
Hydrochemical analysis and evaluation of groundwater quality in Rathupaswala area in Sri Lanka
(Faculty of Graduate Studies, University of Kelaniya, 2015) Premaratne, W.A.P.J.; Tissera, W.S.L.
Water quality analysis is one of the most important aspects in groundwater studies. The physiochemical parameters of groundwater and soil play a significant role in classifying and assessing water quality. The groundwater quality is a function of natural processes as well as anthropogenic activities. The objective of the present work is to ascertain the major ion chemistry of groundwater and soil in Rathupaswala area in Sri Lanka. Water and soil samples were collected from 12 drinking water wells between 7º 02' 25" to 7º 04' 06" North latitude and 80º 00' 043" to 80º 2' 08" East longitude in Rathupaswala area. Each drinking water well was subjected to four times analysis within four months for pH, specific conductance, COD, hardness, and metal ions including Al, Fe, 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 appeared colorless, clear and odorless. The observed pH values of all the water samples were ranged from 4.8 to 6.5. Aluminium content in the water samples was not in the detectable limits and the maximum iron content observed was 0.14 mg L-1. Total magnesium and calcium contents were ranged from 4.9 to 29.3 as CaCO3 mgL-1. The majority water type in the study area was found to be Nabicarbonate water type. Groundwater soil samples were analyzed for pH, specific conductance, cation exchange capacity organic matters, mineral phases, and metal irons including Al, Fe, Ca, Mg and Na. Groundwater samples in studied area do not exceed the WHO standards for drinking water parameters except pH value. The recommended pH value was also achieved by boiling process of the ground water. Experimental data revealed that the pH range of groundwater and soil does not greatly influence on the Al, Fe, Ca, Mg and Na content in drinking water in this area.
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 water
Investigation of Lead Concentration in Road Dust Samples in Kiribathgoda Area, Sri Lanka
(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Silva, K.D.M.; Premaratne, W.A.P.J.
Heavy metal contamination has become one of the major problems in metropolitan cities all around the globe. Kiribathgoda area in Sri Lanka is one such hot spot. Anthropogenic activities have resulted in the increment of heavy metal levels in the earth’s crust. Analysis of outdoor dust is a useful technique to determine the heavy metal content in an urban area and thereby predict the extent of air pollution. This could open opportunities to relate the threat for human health by such toxic heavy metals in an unhealthy environment. This investigation was carried out by selecting a section from the main road of Kandy-Colombo in Kelaniya area. Ten sampling sites were selected and samples were collected as triplicates for three consecutive months. Their pH level and organic matter content were tested. Also, concentration level of the heavy metal Pb was determined using atomic absorption spectroscopy. The preliminary factors that favor the persistence of heavy metals in the environment were investigated and analyzed. It was observed that slightly acidic (pH 5.89±0.41) dust favor Pb deposition. The Pb content was found to be fluctuating around 22.01-84.52 mg kg-1. A good positive correlation (Correlation Coefficient 0.878) was observed in between Pb- Organic matter. It was evident that Pb exists in the environment for a very long time but their escape from nature is very slow. Hence it is necessary to study and understand the health risks associated with heavy metal toxicity on future studies developing from the findings of this research that will benefit the mankind.
An investigation of the adsorption of dye (Bromothymol Blue) by Sri Lankan montmorillonite clay
(Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Premaratne, W.A.P.J.; Perera, V.M.
Textile industries use dyes and pigments to color their products and thus produce wastewater containing organics with a strong color. However most of the synthetic dyes used in textile industry usually composed of aromatic structure, which makes them carcinogenic and mutagenic and non-biodegradable when discharged into waste streams. The removal of such colored agents from aqueous effluents is of significant environmental, technical and commercial importance. Clay has been accepted as one of the appropriate low cost adsorbents for removal of dyes from wastewater. Among the clay types montmorillonite has received considerable recognition because of its high adsorption capacity due to their lamellar structure which provides higher specific surface area and possibility to adsorb ions and other polar organic molecules on particle external site and in interlayer positions. In this study the adsorption of basic dye: Bromothymol blue (BTB) from aqueous solution by Sri Lankan montmorillonite was investigated. Montmorillonite clay used in this investigation was obtained from Murunkan clay deposit in Sri Lanka. Montmorillonite clay was examined for its performance as an adsorbent for the BTB removal. The effect of key operational parameters, such as contact time, initial dye concentration, adsorbent dosage, stirring rate and temperature were experimentally studied. Adsorption of BTB onto montmorillonite samples was studied by batch adsorption technique at 30±1 ºC using UV-Visible spectrophotometric method. For the BTB initial concentration of 70 ppm with the use of only 20 g/L of montmorillonite clay, the dye removal efficiency was found to be 63%. The equilibrium data was analyzed using Langmuir and Freundlich adsorption isotherms. Langmuir isotherm provided a better fit to the data. Characterization of clay before and after the adsorption was carried out by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) methods. XRD, FTIR and SEM data revealed that the dye did not penetrate in to the interlayer space of clay fully, but rather adsorbed on external surface by forming hydrogen bonding with the dye molecules creating a void free film on the clay surface. Experimental results confirmed that the Sri Lankan montmorillonite clay is an efficient adsorbent for basic dye removal. Therefore, Sri Lankan montmorillonite can be used as a promising low cost alternative adsorbent for removing basic dyes from dye wastewater.
Lesson 02: Determination of water percentage in a soil sample by gravimetric analysis
(Research Services Centre, Faculty of Science, University of Kelaniya, 2015) Premaratne, W.A.P.J.
Lesson 03: Determination of different fractions of soil by hydrometer test and textural triangle
(Research Services Centre, Faculty of Science, University of Kelaniya, 2015) Premaratne, W.A.P.J.
Lesson 04: Determination of soil density and its compaction or porosity
(Research Services Centre, Faculty of Science, University of Kelaniya, 2015) Premaratne, W.A.P.J.
Lesson 05: Determination of water percentage of a soil sample at field capacity
(Research Services Centre, Faculty of Science, University of Kelaniya, 2015) Premaratne, W.A.P.J.