Mineral Resources and Technology Degree Programme (MRT)

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Ground Water Contamination by Fertilizer – Case Study from Vauniya
(Uva Wellassa University of Sri Lanka, 2011) Vasan, S.
Well water is an important water source which provides drinking water supply especially to dry zone of Sri Lanka. Therefore considering in the quality of groundwater is essential to ensure the health of human and other living things. However the quality of groundwater varies place to place, mainly depending on its geological origin even though, it is become deteriorated by various anthropogenic activities. Nowadays in Sri Lanka this is especially due to the extensive use of agro chemicals. In this content, this study was carried out regarding the groundwater contamination by fertilizer. The study was focused on 10Km2 area encircled the paddy land associated with Vavuniya Tank. Topographic map of the study area was grasped deeply for the site visit to acquire hydrogeological features. Flow direction was roughly assumed by investigating hydrogeological features. In this area 67 well water samples were collected for the water quality analysis. In which the well water samples were tested for the pH, Electrical Conductivity (EC), Nitrate (NO3-), Phosphate (PO43) and Potassium (K±). Those quality parameters were plotted on the digitized map using ARCGIS 9.3 and graphical quality variation were critically commented. Besides this illustration the results were analyzed by MINITAB 14.0. It has been found that the lower elevation part of the study shows the significant variance with nitrate concentration, pH, and EC measurements though phosphate and potassium do not show more variations. The soil composition of the highly polluted area of the low land area is sandy clay that soil property may enhance the nitrate pollution of groundwater.
The Study of Natural Attenuation of Agricultural Chemicals by Clay
(Uva Wellassa University of Sri Lanka, 2012) Dissanayake, D.M.A.L.
Sri Lankan modern agriculture uses enormous quantities of organic and inorganic agricultural chemicals for their cultivations. Currently glyphosate is one of the most applied organic herbicide in Sri Lanka with increasing importance. The Studies on dynamic of these agrochemicals in soils are very complicated which helped to reduce the concentration of the chemical contaminants in the environment. This is known as natural attenuation. The adsorption, downward movement and the degradation are the most important attenuation process that used to achieve the objective of this research, the attenuation capacity of selected agricultural chemical by clay. Known concentration of 360 g L-1 glyphosate leachate was passed through laboratory clay mixed soil and washed quartz sand columns. The batch adsorption experiment was conducted by equilibrating soil samples with increasing concentrations of glyphosate concentration of the supernated solution. The column leachate and the batch experiment glyphosate analyzed were done by a UV-Spectrophotometer at 435 nm. Initial and the final measured soil Nitrogen content of column and the observed soil chemical and physical properties were used to get the conclusion on soil selected from Badulla. The leaching concentration of glyphosate from soil columns was decreased with increasing volume eluted and the leaching percentage of glyphosate was 60%. The glyphosate concentration remained in soil was 40%. Furthermore the adsorption experiment showed that the rate of glyphosate adsorption in Badulla soil sample was higher than 1 and the adsorption data was fitted well to Langmuir isotherm which assumes that a maximum adsorption occurs when all adsorption sites are occupied and indicating that the amount adsorbed increases linearly with increasing glyphosate concentrations. The nitrogen content (N content) of soil had been increased after glyphosate application to soil columns due to biodegradation of glyphosate. The results indicated that the Adsorption and biodegradation of glyphosate were important processes in determining the attenuation of glyphosate in soil. Badulla soil has a significant rate of natural attenuation capacity.
Removal of Hardness from Drinking Water Using Montmorillonite Clay Material
(Uva Wellassa University of Sri Lanka, 2012) Meegoda, D.N.N.
Hard water contains mainly calcium ions. It consumes soap before lather will form, deposits soap curd on bath tubs, and forms scale in boilers, water heaters, and pipes. This paper deals with the use of Montmorillonite clay in water softening application, which was done in both batch modes. Montmorillonite is a smectite clay based on bi-dimensional lamellar alumino-silicate structure leading to a naturally high surface area/volume ratio. The interlayer spacing, pore diameter and also particle size of Montmorillonite can be modified in the level of nano-scale. It is additionally expansive in liquid and cation exchangeable. The batch experimental results informed that the hardness removal by Montmorillonite is possible. Calcium was removed from hard water by ion-exchange mechanism with the natural exchangeable cations, such as sodium and potassium ions, located between the Montmorillonite layers. The present study focuses on Calcium(Ca) and Magnesium(Mg) removal by adsorption using particle size within the range of 25011m-125mm without pretreatment or activation.The optimum agitation time and optimum pH were 5.5 and 60 minutes respectively for Calcium ion and 5 and 60 minutes for Magnesium ion. The removal followed the Langmuir isotherm with R2 =0.957.
Magnetometer Characterization of Iron Ore Deposit in Buttala, Sri Lanka
(Uva Wellassa University of Sri Lanka, 2012) Hewathilake, H.P.T.S.
Sri Lanka is endowed with mineral resources though many mineral occurrences were not fully assessed and quantified identifying the true potential. Mostly the geological formations of the valuable mineral engage with complex structures such that a detailed exploration program is essential to assess the grade, recovery, characteristics and quantity of the ore(s). The occurrence of the magnetite in Palawatte area was first discovered by the GSMB during the geological field mapping of the Buttala sheet (1:50,000) in 1999. Based on some sporadic studies as regards this iron ore were reveal that, the deposit containing considerably higher amount of magnetite but the significant factor is in the reserve estimations, most of the previous studies considered the total interesting area (the ridge of the Horakagodakanda hill) as the deposit. Since the underneath geological settings of the deposit is unknown, such an evaluation can be misled the future investigations and development of the deposit. Magnetic method is a very successful approach for exploring of minerals deposits with magnetic signature. As the one of the material that poses magnetic properties naturally, ferrous containing rocks and minerals provide anomalous signatures than of the background magnetic field that enabling to screen the same. A Proton Precession Magnetometer was used for the data acquisition (model - GSM-19TW). Based on the geomorphological and terrain conditions field data acquisition was continued randomly with an integrating GPS antenna to the magnetometer. Acquired raw data files were processed integrate with the Gem Link (version 5.2) and Geosoft.Oasis.Montaj (version 6.4.2 HJ) software. The processed total field magnetic intensity map and the anomaly map show the intensity of the positive anomalies is higher than the negative anomalies and a systematical stretch of positive and negative anomalies. Furthermore the anomaly map conspicuously illustrates the dipole behavior of the magnetic source beneath the interested area and confirms the geological configuration of the source body is a dike which dipping along the south-east direction.
Investigation the Usability of Sludge as a Brick Material
(Uva Wellassa University of Sri Lanka, 2012) Indika, W.P.
In the world, the annual sludge (dewatered) production from the waste water treatment plants is very high but this sludge cannot use for any industry or any other purposes. So this sludge amount is accumulating in lagoons without any solution. Utilization of sludge as an addition to construction bricks Is a win—win strategy because it not only converts the wastes into useful materials but it also alleviates the disposal problems. Flocculants and some polymers are used when treat waste water. These chemicals are reducing the cohesiveness of sludge and act as binders. By using this properties sludge can be introduce for concrete bricks in limited amount. In the world very high demand for the concrete bricks but very limited raw material in the world for this industry. If can be introduce alternatives for this materials that is much saving for future construction works. In this study will be introduced, the suitable conditions of using dried Sludge in manufacturing of bricks under the standard levels with newly developed methods. This work has demonstrated the amount of sludge and rice husk ash that can be used in the cement brick with standard water absorption and compressive strength. The proportion of sludge and proportion of RHA are the two Key factors affecting the quality of brick. In all, the recommended proportion of sludge in brick Is 20%, and RHA proportion is 5%.
Improvement for Naula Water Treatment Plant and Distribution
(Uva Wellassa University of Sri Lanka, 2012) Athukorala, L.A.D.M.
Naula Reservoir has been selected as source of Naula Water Supply Scheme. During the dry season blackish color sludge is formed within water distribution system. And foul smelling occurs in the distribution system. In this research main purpose is the study this problem in Naula water Treatment Plant. Main Objective of this research is Propose the feasible and economical solution for appropriate to the Sri Lanka, problem involve Naula Water treatment Plant. Methodology mainly contains three parts. Sample collection, DO variation with depth, Analysis of the samples. Samples collection was done in the reservoir, treatment plant, and the distribution system. Algae identification sample was collected from the surface water of the reservoir. All the collected samples were undergoes with the chemical and physical parameter analysis. S2- content, NO3- content as N, NH3 content as N , PO43- content were measured as chemical parameters and pH, color, Turbidity, Conductivity were measured as physical parameters. Findings indicate that the Naula reservoir has thermal stratification. And the anaerobic condition in the hypolimnium of the reservoir. pH level of the anoxic hypolimnium is low and it creates acidic condition in the reservoir bottom. Sulfide content was also high in the hypolimnium of the reservoir. These two results are strong evidence for the Sulfur reducing bacteria (SRB) habitant. Sulfide content high in the bottom and it may form the hydrogen sulfide gas. It will form the foul smell (rotten egg smell). That will cause for the foul smelling in the distribution and Sulfides are precipitates in the pipe lines as black precipitates. For the problem in the Naula treatment plant feasible solution is the aeration. In Naula reservoir water is stagnated and does not mixing air well. Another option is floating intake. Other option is Granular Activated Carbon (GAC) column filtration for raw water. It will remove the organic matters and the microorganism in the raw water.
Water Quality Index Calculation and Management System
(Uva Wellassa University of Sri Lanka, 2012) Jayasinghe, H.M.B.N.
A decision support system is a way to model data and make quality decisions based upon it. It's widely used in the world for the various kind of process automation. Decision support systems that just collect data and organize it effectively are usually called passive models where they do not suggest a specific decision but only reveal information. An active decision support system actually processes data and explicitly shows solutions based upon that data. The water is found almost everywhere on Earth. Water resources like rivers, lakes, which provide water contain a lot of pollution, garbage unfit for consumption. Some diseases take time to present visible signs, but it does not mean they are inactive in your organism. To be clean, the water should undergo a number of treatments necessary to make it drinkable. So it is must to have purification technology for the waste water. So the waste water treatment plants act a major role in these issues. When considering the procedures taken after the water treatment process was always based on manual calculations and recordings. Water purification plants may interact with lots of manual processes. It means the process taking much time consuming. So the final evaluation and chemical, biological treatment process get delayed. So to prevent those types of draw backs there are some computerized programmable calculation and analytical techniques going to be introduced to the laboratory staff. To solve this problem automated system will be a solution in which guarantees the rational selection. The technological influence to the system is HTML, MySQL, php and some other web developing technologies. Current issues in the computerized water chemistry analysis are not much deep in progress. For an example the swimming pool water quality calculator. The validity of the system has been verified by test running and comparison with an existing plant data. Automated system will make the life easier in productively and qualitatively.
Investigation of Engineering Properties of Laterite Bricks
(Uva Wellassa University of Sri Lanka, 2012) Wickramasinghe, A.N.R.
There is a deficiency of row materials for housing in Sri Lanka because of population growth. So there is an unfulfilled demand for traditional row materials such as river sand and clay. Serious environmental problems are caused because of over excavation of above row materials. To prevent this situation we should focus towards low cost and environmental friendly alternative row materials which are existing in sufficient amount in Sri Lanka. Laterite soil and quarry dust are most abundant resources in western part of the Sri Lanka. Bricks can be manufactured using mainly laterite soil and cement. Because of the lack of the required particle size distribution the strength of the earth bricks can be reduced. To improve required particle size distribution quarry dust was mixed with laterite. The initial results indicated that adding 45% of quarry dust improves the compressive strength of laterite brick. Then laterite bricks were produced using laterite soil, quarry dust and cement mixtures with various percentages. The dry and wet compressive strength was measured from the produced bricks. Sieve analyze was done for laterite soil, quarry dust and the best material mixture to get the particle size distribution of above materials. Particle size distribution curve of the laterite was used in this study was poorly graded and addition of 45% quarry dust corrected this deficiency. The brick which is made from laterite and quarry dust mixture can be stabilized using low amount of cement. This brick is more suitable for wet conditions as well as dry conditions. Because of this brick 55% of quarry dust can be saved while achieving higher compressive strength than 100% quarry dust. The material mixture (45% of quarry dust with laterite) is more economical and environmental friendly for brick production for walling.
Study the Effects of Particle Size and Other Engineering Properties of Granular Soils on Compaction
(Uva Wellassa University of Sri Lanka, 2012) Anushka, M.D.
Granular soil is mostly used in construction field as a filling material. Compaction is the densification of soil material by the use of mechanical energy. Soil is compacted by removing air and water from its pore spaces. There exists a certain amount of moisture that a soil can have where the maximum unit weight is obtained. When the soil is compacted to this state, it is referred to as the maximum unit weight. Basically such moisture content, soil type, as well as force that applied to compact the soil is influenced on compaction of soil. In this experiment, peculiarly granular soil has been used because that is widely used in construction field. Particle size is the important parameter that varies during the experiment. Mainly, influence of gravel size particles on compaction has been determined. A common difficulty encountered when specifying compaction requirements is the natural variation in the gradation of the filling material as well as weakly compacted filling materials will cause to failures of construction. This research basically performed to determine the compaction of granular soil that mixed with various percentages. Therefore first ten samples of experiment were selected from one soil type. All these samples were tested under the Standard proctor compaction test. Standard proctor test was little bit modified requirement of the experiment. These ten samples were taken by applying cone and quartering sampling method. Those samples were sieved and separated into different particle sizes using American standard sieve set with sieve shaker. Then measured gravel size fraction of each sample was mixed thoroughly with fraction of particle size that less than 2mm (particle size below the gravel size) with various percentages by using sample splitter (10% of gravel size with 90% of fines, 20% of gravels with 80% of fines etc.) are tested for proctor compaction tests were carried out for mixed samples. Some of the data have deviated from others. But considerably gradual increasing of dry density with increasing percentage of gravel size particles could be observed. As well as sample which has highest dry density has 80% of gavel size particles. The sample which has lowest dry density has 10% of gravel size particles.
Determining the Source Rock of Gem Deposits Found in Halangoda Lake at Diyathalawa
(Uva Wellassa University of Sri Lanka, 2012) Wimalasuriya, K.M.D.C.M.
Sri Lanka has been famous all over the world for its vast potential and vast varieties of gemstones. 25% of the landmass of the country is gem bearing. The studies clearly indicate the vast gem potential of Sri Lanka yet to be unearthed. However, gem deposit exploration in Sri Lanka is still based on more traditional methods than modem technical methods. Application of modern scientific methods in gem exploration is therefore a national requirement for Sri Lanka. Halangoda lake was constructed in the premises of the Sri Lanka Military Academy (SLMA) at Diyatalawa and it consists of gem deposits. The lake was fed by two streams while narrow valleys and hillocks are presented around the lake. Well defined crystal shaped and sub angular gemstones are found from this deposit. The geological mapping procedure was carried out to determine the source rock of this peculiar gem deposits which can be great support to identify same kind of gem deposits in the area nearby. Base map was prepared using 1:10,000 topographic map and satellite images. The road traversing method was selected to perform geological mapping of the lake area. Global Positioning System (GPS) was used to mark precise location of outcrops. The strike and dip of the foliation planes were measured using the Brunton® compass. Their lithological units were named and other special geological features were recorded. The identified three lithological units are Garnet biotite sillimanite gneiss (Khondalite), Garnet hornblende biotite gneiss and Quartzofeldspathic gneiss. Some of Quartzite traces which are not in mappable scale were found. The general strike and dip of foliation of the north eastern part of the map were N 80° E and 30° NW respectively while the general strike and dip of foliation of the south western part of the map were N 40° W and 40° NE respectively. Khondalite is the gem bearing rock type found in this area. Geological, geomorphological and hydrological features also prove the possibility of transportation of gemstones from the khondalite rock in to the lake. Therefore khondalite is the source rock of gem deposits found in Halangoda lake at Diyathalawa.
Detection and Identification of Bacteriological Contamination and Some Heavymetals (Fe, Mn & Zn) Contamination of Groundwater in Gurunagar Area, Jaffna Peninsula
(Uva Wellassa University of Sri Lanka, 2012) Sriskantharaja, A.
Jaffna Peninsula is mainly depends on groundwater sources because other fresh water sources are not available. Groundwater contaminated with microbiological and heavy metals constituents can cause a variety of water related diseases. Groundwater intended for human consumption should be safe, palatable and aesthetically pleasing. Coliform group has been extensively used as an indicator of drinking water quality and historically led to the public health protection concept. The aim of the present study were carried out to determination and identification of bacterial species of groundwater and to determine the concentrations of heavy metals (Fe, Mn, Zn) in groundwater at gurunagar located in Jaffna compare the results with guidelines from WHO. Seventeen sampling points were collected from different places in Gurunagar area. Sixty one Water samples were collected from these sampling points. Most Probable Number (MPN) method has been currently used for assessment of the microbiological quality of drinking water. Bacterial identification was carried out using biochemical tests. Water samples were analyzed by Flame Atomic Absorption Spectroscopy for their heavy metals concentration. A total of bacterial species: Escherichia coli, Klebsiella spp, Salmonella, Shigella and Enterobacter were identified form groundwater samples. The bacteria belonging to the family enterobacteriaceae (coliforms) showed the maximum occurrences in water samples. The high total coliforms count 2400 MPN index/100 ml in groundwater samples. Different selective media like Eosine Methylene Blue (EMB) and MacConkey were used to isolate bacteria rather than one increased the chances of successful isolation/identification. The identified bacteria were reconfirmed through the use of biochemical (IMViC) tests made for this purpose. The average abundance order of trace element contents in groundwater samples are: Fe > Mn > Zn, respectively. The maximum determined concentrations of Fe, Mn and Zn are 0.0339, 0.0100 and 0.0017 mg/l.
Leaching of Aluminium and Its Incorporation into Rice During Cooking under Different Fluoride Concentrations in Water
(Uva Wellassa University of Sri Lanka, 2012) Amarasooriya, A.A.G.D.
Majority of the people in Sri Lanka use aluminumcooking utensils for cooking rice and other types of food. Aluminum is toxic to human if injected in excessive concentrations. Leaching of aluminum from cooking utensils has been reported by several investigations.Since fluoride in water has an affinity to make complex ions with aluminum. Fluoride in cooking water can enhance attraction ofaluminum in to the cooking medium and hence to the cooked food. Under the present study naturalaluminum level andleaching of aluminum and its incorporation in to rice during cooking under different fluoride stresseswere studied. Aluminum was determined using a UV Spectrophotometric method. The experiment was done in the laboratory where rice was cooked in a glass beaker with an aluminum plate in it under different fluoride concentrated water. Samples were then digested so that aluminum could be determined by spectrophotometrically. Natural aluminum level of the raw rice (Oryza sativa)was significantly large. It was observed a concentration of0.2038mg/g aluminumin rice. Rice cooked at the present of aluminum plate but without fluoride watershows an addition of 0.0065mg/galuminum to rice. An addition of 0.1367mg/galuminum was noted at a fluoride concentration of 6mg/1 in water which is comparative to highest fluoride levels of Sri Lankan ground water. Total aluminum was found to be high in the rice cooked under normal water as well as in the fluoride richwater. Aluminum in cooked rice increased with theincreasing fluoride concentration in the water. It was found that total aluminumlevel in cooked rice was 0.2135 mg/g when cooked in fluoride free water and it was 0.3438 mg/g at 6 mg/1 fluoride in water. The maximum allowed aluminum intake per normal personis 0.1428 mg/kg body weight per day. Based on the assumption that one person who eat 250 g rice per day, the aluminum intake according to present experiment is greater than 0.1428 mg/kg and hence risky. present study shows that Sri Lankan community in areas of fluoride rich ground water are vulnerable to inject of high aluminum at toxic levels through aluminum cooking utensils alone. The risk can be much higher when substandard aluminum pots that are easily dissolved in cooking medium.
Chemical Removal of Fluoride from Drinking Water Using Gypsum
(Uva Wellassa University of Sri Lanka, 2012) Kumari, K.E.D.K.W.
An excess amounts of fluoride in drinking water cause detrimental health effects such as dental and skeletal flurosis. According to the World Health Organization (WHO), the maximum acceptable concentration of fluoride in drinking water is 1.5 mg/L. According to Sri Lanka Standard desirable and permissible levels of fluoride are 0.6 mg/L and 1.5 mg/L respectively. In tropical countries like Sri Lanka, the lowering of the fluoride regulatory limits in drinking water is required due to high consumption of water by the people living in these regions. Therefore excess fluoride in drinking water must be removed to the permissible level. There are several techniques available to remove excess fluoride from drinking water based on adsorption, precipitation, ion exchange, membrane separation. Most of these methods are highly specialized and cost intensive in that they cannot be implemented successfully at community level. In this research fluoride removal ability was investigated using gypsum based on precipitate common ion effects. Gypsum was separated in to different particle sizes (mesh sizes: 500 j.im, 250 1.1m, 125 63 i.n). The definite (10 ppm) fluoride solutions were prepared and study the fluoride removal ability of the gypsum under different particle size, pH levels and variation of the dose. The residual fluoride concentration is decreased with the particle size of the gypsum and the maximum fluoride removal is obtained the gypsum particles which have diameter below 63 gm. The pH for maximum removal of fluoride was around 8. The residual fluoride concentration in solution decreased with the addition of gypsum. When gypsum content is in excess, the residual fluoride concentration has decreased showing an optimal value at 2.50 g gypsum. Gypsum can be used to mitigate fluoride in drinking water. The particle size effect on fluoride removal efficiency was accounted for to increase in specific surface area.
Assesment of Heavy Minerals in Stream sediments of Wellawaya Area
(Uva Wellassa University of Sri Lanka, 2012) Chathurangani, A.S.M.
The study of heavy minerals placer deposits of the stream sediments in Wellawaya in Uva province in Sri Lanka at boundary of Highland Vijayan complexes was carried out; the surface sediment samples from ten locations of different tributaries along the kirindi oya are collected. The main framework of this research is to study the identification of various type of heavy minerals in stream sediments in Wellawaya and analyze grain size distribution in stream profile. The heavy mineral analysis involved separation of sand grains into different sizes; density separation of heavy minerals using heavy liquid, and magnetic separations and identify types of each mineral using transmitted light microscope. Results show that the sediments with 0.125mm grain size dominate in all the samples. Studying stream profile is involved measuring weight of each sieve fractions and they analyze using graphs. Identified heavy minerals in sample locations are Ilmenite, Rutile, Garnet, Sillimanite, Zircone, Monozite, Hornblende, Magnetite, Biotite, Muscovite, and Limonite. Magnetic, Physical, and optical properties of minerals are used to identify types of heavy minerals. There are six stream layers and two of them are gravel layers while others are poorly sorted.
Arsenic Removal from Water Using Magnetite Coated Quartz Sand Column
(Uva Wellassa University of Sri Lanka, 2012) Gamlath, P.G.R.C.A.
Arsenic has become a major contaminant of concern due to the increase knowledge of its toxicological and carcinogenic effects. This fact has prompted the need to investigate suitable methods for lowering arsenic concentrations in drinking water by rapid, simple and low cost techniques so the process utilizing natural geo materials as adsorbents has been promising. The sorption of As (III) and As (V) onto iron oxides has been studied previously and proven success. In this research Sri Lankan Magnetite coated quartz sand are evaluated as arsenic sorbents due to their high surface area and minimal production of waste. Magnetite coated Quartz was prepared according to literature. Columns with different fillings and operating conditions were set up to evaluate the effect of their combinations on Arsenic removal. Effluent solutions were collected at 1 h interval for each trial and analyzed for residual Arsenic through Atomic Absorption Spectrophotometer. Experiments were conducted separately for Arsenic (iii) and (iv). Magnetite coated Quartz accomplished better Arsenic removal with an iron weight of 14.68 mg el. In this work arsenate was better adsorbed than arsenite. Moreover the experimental results visualized a significant difference in Arsenic removal over the investigated grain size ranges and removal efficiency of As (v) decreased above pH 6 and comparably As (iii) removal efficiency against pH variation demonstrated consistent pattern. The experimental results suggest that the adsorption generally depended on the surface area of the adsorbent and adsorption isotherm results were best fitted with Langmuir model. Further, the maximum adsorption capacity of As (iii) was greater than As (v). The decrease of arsenate removal efficiency in alkaline pH can be explained by the formation of colloids. As for the conclusion, this study demonstrated that Magnetite coated sand could be an effective media for Arsenic removal from water in a fixed bed reactor.
Applicability of Red Earth in Manganese Removal from Groundwater
(Uva Wellassa University of Sri Lanka, 2012) Uthishdiran, S.
Manganese is commonly present in groundwater worldwide. The presence of manganese in the drinking water supply is not harmful to human health, however it is undesirable. Bad taste, discoloration, staining, deposition in the distribution system leading to after growth, and incidences of high turbidity are some of the aesthetic and operational problems associated with manganese in water supplies. Different mechanisms (physical, chemical, and biological) may contribute to the removal of manganese in filters and the dominant mechanism depends on water quality and process conditions applied. Under the commonly applied treatment conditions in manganese removal plants, the oxidation-floc formation mechanism (floc filtration) is commonly believed to be dominant. Adsorption characteristics of manganese onto Natural Red Earth (NRE), have been studied in batch technique to ascertain the effect of pH, ionic strength, initial sorbent and sorbate concentrations, temperature and effect of other cation and anion. Solid suspension (10 g/L NRE) was sufficient to remove Manganese up to 1 Oppm. Manganese adsorption achieved its maximum adsorption of nearly100% at neutral to slightly acidic conditions. The rate of adsorption of manganese was very fast. Manganese adsorption onto NRE was better explained by Langmuir-Freundlich isotherm. These results suggested that the NRE could be effectively used as a low cost candidate for removal of Manganese from environmental water.
Ecological Purification System Modification of Slow Sand Filter
(Uva Wellassa University of Sri Lanka, 2012) Hewamadduma, A.D.
Unsafe drinking water is a major cause of water-related diseases that predominantly affect people living in developing countries. Today there are many technologies available to treat unsafe water; however, most of these are suited for use with low turbidity source water. The treatment of high turbidity water (>40 NTU) is a challenge that was investigated in this research. Slow sand filtration process is an established rural area water treatment, technology widely used in developing countries to treat low turbidity drinking water. This research investigates modifications to the ecological slow sand filter design to color and turbidity reduction in high turbidity water. During field tests conducted at Doluwa, in Kandy. A modified ecological slow sand filter with lmm grain size sand layer for added filtration and gave condition to grow filamentous algae on top of the sand bed and reduce supernatant water level till half of present water level; achieved the greatest color and turbidity removals, according to these condition. Because of larger grain size (1mm) sand used for filter media, then suspended material was not mostly deposited on top of the sand bed in ecological slow sand filter. The field tests, during April 2012, showed the Ecological slow sand filter was capable of reducing water turbidity by 85%, and color by 90% on average than unmodified slow sand filter. Average filtration rate, before algal mat was growth on top of the sand bed; 0.4014 m3hr-lm2.After algal mat was growth on the top of the sand bed; the average filtration rate was 0.4007m3hr-1m2. So optimize filtration rate was 4007m3hr- The filamentous algae was mainly affected to reduce color and turbidity in water. Modification of ecological slow sand filter in Doluwa, spirogyra was the dominant algae type growth on the top of the sand bed. During photosynthesis process, air bubbles were released by the algae from top of the sand bed. Therefore suspended material was attached with air bubbles and come to the supernatant water. Those suspended material was floated on the supernatant water. Scum was used to remove those suspended material from the ecological filter. So suspended material was not containing on the top of the sand bed.
Hazard Analysis, Risks Assessment and Prioritize of Transmission and Distribution of KSWTP to Develop a Water Safety Plan
(Uva Wellassa University of Sri Lanka, 2012) Pabasara, H.L.K.
Currently drinking water quality control has been based on the detection of pathogens and measuring the concentration of chemicals .After that compare with the national and international standards. But this methodology is very slow, Complex and high cost. As well as water supply systems end product testing hardly can be considered a sound method for representative of water quality states. Because a small fraction of the total volume of water used for chemical and physical analysis .So that do not know what happen to the other large fractions. That means there chemical and physical analysis .Moreover, the monitoring frequency does not guarantee representative results in time and space as well. A circumstantial description of the water supply system is essential for the latter risk assessment process. Because system is provide considerable information to identify the places where the system is vulnerable to hazardous events and related hazards. Data analysis was done by using graphs and tables. Risk assessment was done by using semi quantitative risk matrix from previously collected data. After that two maps were plotted from the residual chlorine variation along direct line and the tanks. In risk assessment the significant and less significant risk was differentiated According to the semi-quantitative risk approach lot of risks in transmission and distribution system of KSWTP are in high level and they are significant. Most risks are mainly affected to the human health and cause harmful effect to the human. Eventhough KSWTP providing high quality water to the consumer it can be changed during the transmission and distribution
Geological and Anthropogenic Influences on Distribution of Fluoride and Nitrate in Groundwater: Case Study in Eight Areas, Sri Lanka
(Uva Wellassa University of Sri Lanka, 2012) Sethuraman, K.
Consumption of water with excessive fluoride and nitrate in groundwater is becoming a crucial issue on human health in Sri Lanka. Dental fluorosis & Skeleton fluorosis are the major health impacts based on excessive amount of fluoride as well as hypothesis on causing chronic kidney disease (CKD), fluoride toxicity is found as a major liable cause. On the other hand the excessive usages of nitrate and unplanned disposal of wastages are increased nitrate levels significantly in many countries, including Sri Lanka. Particularly, nitrogenous compounds in groundwater for drinking have been considered as a possible risk factor for oesophageal cancer and blue baby syndrome. Having lack of understanding on the actual need of fertilizer, farmers usually tend to apply surplus amount increasing nitrogen pollution. Accordingly, this research was conducted to deepen the understanding on distribution of fluoride and nitrate in groundwater in the dry zone and geological and anthropogenic influences.. Hence, groundwater quality was analysed in eight areas which have been recognized mostly as agricultural districts in Sri Lanka; namely Anuradhapura, Puttalam, Mannar, Jaffna, Trincomalee, Nuwara Eliya, Batticaloa and Hambantota. Thirty (30) well water samples were collected from each district. The colorimetric method was used for the detection of nitrate and fluoride concentrations in the field. The field analysis results were further confirmed by analytical laboratory at Toyama Prefectural University, Japan, Among the eight areas, Kalpitiya area was found for the most polluted groundwater by NO3-, ranged from (0-366) mg/L as NO3-. In addition, NO3- concentration in Anuradhapura, Jaffna and Nuwara Eliya were reported as ranging from (0- 131), (0 - 50)and (0- 76) mg/L as NO3- respectively. On the other hand, F- was found highest in Anuradhapura as average 1.2 mg/L and also significant in Mannar (0.5 mg/L), Trincomalee (0.8 mg/L) and Hambantota (0.9 mg/L). The research clearly indicates the abundance of fluoride in groundwater especially in the dry zone. The major sources are fluoride bearing minerals in bedrock and soil zone. Due to the flushing by rainfall, low concentration of fluoride in groundwater is experienced in Nuwara Eliya. In addition to that, influence of agriculture, excessive nitrate levels in groundwater is apparent irrespective to climatic zones.
Study of Ground Water Quality in Badulla Municipality Area
(Uva Wellassa University of Sri Lanka, 2012) Ustrasiya, V.E.D.
Groundwater has an important source and the quality being measured by contamination of various parameters. Badulla municipal area has major water source from Badulla Oya, anyhow it was one of the important issues during the dry season, however in some cases people using groundwater for various purpose. The main purpose of this study was to determine current groundwater quality of Badulla municipality area by compare with SLS drinking water standard to determine whether it is portable or not and develop some hydro chemical distribution map of Badulla municipal area for further study. According to that 40 groundwater samples were collected randomly with GPS coordinates and analyzed for physiochemical parameters of EC, TDS, pH, Turbidity, Alkalinity, Total hardness, Chloride, Fluoride, Nitrate, Phosphate, Sulphate, Sodium, Potassium, Calcium, Magnesium, Iron, Manganese, Zinc. The relationship between resultant quality and SLS drinking water standards was compared and discussed. The analyzed quality results were interpreted using Visual MINTEQ to calculate the approximate ion species, precipitation of solid phases and the type of water was classified by plotting piper diagram using Rockware AQ.QA. Hydro chemical distribution maps were developed using ArcGIS. The results was showed almost all the parameters were not exceeded SLS drinking water standard except phosphate and nitrate This study was showed that Badulla municipality area had almost good groundwater quality anyhow the location of badulla central and southern part had some problem of nitrate and phosphate from the results of few wells which was near to municipal dumping and agricultural land. Chemical speciation showed some relationship with phosphate, fluoride and manganese. According to the range and mineral species of fluoride and manganese, it will be an issue of fluoride and manganese in future. The main water type was calcium and non-dominant.

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