Browsing by Author "Udagedara, T."
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Item Assessment of Phytoremediation to Treat Selected Metals in Textile Wastewater(Uva Wellassa University of Sri Lanka, 2019-02) Premarathne, H.K.M.M.P.; Udagedara, T.; Young, S.M.Textile wastewater causes aquatic pollution and is toxic to both human and animals. The existing conventional treatment methods ultimately add heavy metals to the sludge making it unsuitable for future usage. Hence, there is an urge for an environmentally friendly, cost effective technological solution to treat textile wastewater to remove heavy metals prior to discharge to the environment. Thus, the present study describes the application of phytoremediation to remove metal pollutants from contaminated soil and water. This work aims to compile information on the removal efficiency of four different types of plants (Canna indica, Ipomoea aquatica, Monochoria vaginalis and Liminocharis flava) on five different types of metal pollutants (Mg, Cd, Cr, Cu and Mn) in textile wastewater. The plants were grown in soil media, where the initial concentrations of the metals were known, and a synthetically prepared textile wastewater was kept in contact with the plants for two weeks. The measurements were done after 1, 4, 7 and 10 days, where concentrations of metals were measured using Atomic Absorption Spectrophotometer. Results showed that Monochoria vaginalis and Liminocharis flava plants started to die after four days from the commencement of the study showing their incapability in phytoremediation, while Canna indica and Ipomoea aquatica showed growth characteristics. The overall removal efficiency of Mg, Cd, Cr, Cu and Mn by Canna indica were 90.32, 88.42, 85.33, 85.08 and 23.15%, respectively, whereas removal efficiency by Ipomoea aquatica were 89.88, 83.74, 82.49, 80.17 and 11.27%, respectively showing similar absorptions for both plants. The study concludes that the Canna indica is the best plant among the selected plant types for the removal of the chosen metal pollutants. Ipomoea aquatica was found to be the second highest effective plant which also signifies that, contaminated plant can cause health issues by consuming it as a food.Item Assessment of the Impact of Azolla pinnata at Demodara Water Treatment Plant Intake Reservoir(Uva Wellassa University of Sri Lanka, 2019-02) Jayasinghe, N.S.; Weerasekara, W.B.M.L.I.; Udagedara, T.; Weragoda, S.K.Demodara Water Treatment Plant intake reservoir is located in between Demodara and Badulla cities about 12 km upstream in Badulu Oya from Badulla. An invasive growth of floating macrophyte was observed from third week of January 2018. Water quality of treatment plant intake reservoir was studied by analyzing the reservoir water with the presence and the absence of the Azolla mat, to find whether there was any change in the water quality with the mat. Water quality close to the dam, lake at about 1 km upstream from the dam and upstream flowing water (about 500 m upstream from the lake) were analyzed in different depths (close to the dam 6.5 m and upstream lake 1 m depth). pH, turbidity, electrical conductivity, dissolve oxygen was analyzed on site and NO3-, Total PO₄ 3- , SO42-, Cl- and F- was measured using Ion Chromatograph and relative abundance of phytoplanktons were estimated using plankton nets (20 μm) and microscope with the presence of A. pinnata mat and following day of removal of A. pinnata mat. As a part of the study, two models were observed inserting 20 l of intake reservoir water and 22 g of Azolla for one model. pH, turbidity, conductivity was monitored for seven weeks. pH was decreased in the model with Azolla. Conductivity and turbidity did not show a significant change. pH decrement and Total PO₄3-, Phytoplankton increment was observed with the absence of the mat in Demodara reservoir. All the water quality parameters in treatment plant raw water were within the drinking water standards (SLS 614:2013), with the presence of Azolla mat. The Azolla didn’t appear after manual removal. Therefore, further studies and implementing a Water Safety Plan by proper catchment management is needed.Item Characterization of Electrical Properties of Sri Lankan Graphite(Uva Wellassa University of Sri Lanka, 2010) Geethika, A.K.K.; Wijayasinghe, H.W.M.A.C.; Attanayake, A.N.B.; Udagedara, T.Sri Lankan graphite is famous for its high quality which makes it suitable for various technological applications. However investigations on electrical properties of different varieties of Sri Lankan graphite have been very limited. The main objective of this project is to investigate different structural varieties of Sri Lankan vein graphite and characterize their electrical properties with particular attention on examining its applicability in rechargeable battery industry. Graphite is an extensively used carbonaceous material in industries. There are two main types of graphite, synthetic and natural. Various types of vein graphite samples were collected from Bogala and Kahatagaha/Kolongaha mines. The powdered graphite specimens were subjected to phase, purity, morphology, particle size and chemical analyses. Electrical conductivity of dense graphite pellets were measured by the d.c. four probe method in the temperature range between 25 °C to 100 °C. XRD phase analysis indicates the existences of appropriate phases of these graphite specimens. Further, the electrical characterization reveals the possessing of significant electrical conductivity hence indicating the high potentiality of Sri Lankan graphite for rechargeable battery applications. Key words: Electrical properties, Graphite, ConductivityItem Designing a Wastewater Treatment Plant for the Wastewater Discharge from Seafood Market(Uva Wellassa University of Sri Lanka, 2020) Suthassna, S.; Kottehewa, D.J.; Udagedara, T.Seafood is the main interest in the coastal areas; hence seafood markets are centralized towards the city and highly crowded place. A seafood market includes many varieties of fishes, crabs, clams, prawns, lobsters, cuttlefish, etc. from saltwater as well as from freshwater. In general, wastewater generation from the seafood market is not given much attention and thus, lack of awareness about the problematic factors associated with that. The wastewater from this mainly contains blood, shells, fines, fish heads, offal products, and detergents used for cleaning and washing. In this study, the wastewater generated from the seafood market in Trincomalee was investigated. The wastewater characterization was done for 5 months. The results of the wastewater characterization showed that the average value of pH, Total Suspended Solids (TSS), Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) were 7.62, 195.2 mg L-1 , 870.20 mg L-1 , and 88.20 mg L-1 , respectively which are exceeding the tolerance limit set by Central Environmental Authority of Sri Lanka. The oil and grease, nitrate, and phosphate are within the tolerance limit set by the Central Environmental Authority of Sri Lanka. The BOD: COD ratio was 0.1, which implies that the wastewater is less biodegradable, and biological treatment is not suitable in this case. The design of the wastewater treatment plant was proposed with chemical coagulation as a pre-treatment. Bar rack was placed as a preliminary treatment, then equalization tank was designed to control the flow variation, next the coagulation tank was followed by a clariflocculator. Finally, the design of the wetland with aerated Hyacinth system with recycle was proposed. Additionally, COD removal efficiency was checked with bio sorbents prepared using Water Hyacinth and Rice husk. Keywords: Sea food market wastewater, Wastewater characterization, Designing wastewater treatment plantItem Investigation of the Effectiveness of Salt Barrage in Jaffna Peninsula (5th Phase)(Uva Wellassa University of Sri Lanka, 2018) Sinthuparkavi, S.; Udagedara, T.; Gamachchige, T.To improve the quality and quantity of water resources in Jaffna peninsula, a barrage has been constructed converting the Upparu lagoon into a fresh water lake. Upparu lagoon with its increased fresh water volume is expected to recharge the underground storage and act as an additional surface storage desalinating the lands fringing the lagoon making them suitable for cultivation. Several previous studies have investigated the effectiveness of the barrage focusing on the water quality of different parts of the land bordering the lagoon. This research focuses on the area from the fringe of the lagoon into the land extending for 2 km perpendicular including Nallur, Kopay and Chavakachcheri D.S Divisions to evaluate the effectiveness of the barrage by delineating salt water intrusion patterns. Sixty-one wells were selected in a profile perpendicular to the fringe of the Upparu and Jaffna lagoons to measure in situ electrical conductivity (EC) and salinity in both wet and dry seasons. Out of 61 wells, thirty groundwater samples were selected for analysis of sodium and chloride. The EC of groundwater varies between 571 𝜇S cm-1 and 20,370 𝜇S cm-1 in wet season and between 991 𝜇S cm-1 and 20,620 𝜇S cm-1 in dry season. Salinity varies between 0.2% and 12.15% in wet season and between 0.45% and 11.3% in dry season. Chloride concentrations vary between 46.15 mg L-I and 5,183 mg L-1 in wet season and between 170.4 mg L-1 and 5,467 mg L-1 in dry season. Sodium concentrations vary between 22.8 mg L-1 and 6,259.4 mg L-1 in wet season and between 8.7 mg L-1 and 4,470 mg L-1 in dry season. Groundwater quality along the fringe of the Upparu lagoon far from the barrage is of good quality compared to the groundwater close to the barrage in both seasons. Even though the effectiveness of the barrage is less during both seasons due to insufficient run-off and seepage, analysis of past five year continuous data set reveals that the salinity of the groundwater in the fringe of the lagoon has reduced to moderate levels. If the barrage works properly as at the initial stages of its construction, the groundwater in the fringe of the lagoon will become fresh water in near future. However, further continuation of this research would deliver a much better result.