EMM 2020

Permanent URI for this collectionhttps://ir.lib.pdn.ac.lk/handle/20.500.14444/5724

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Effect of habitat differences on morphology, anatomy and fecundity of lichens
(University of Peradeniya,Sri Lanka, 2020-10-23) Edirisinghe , E.S.M.; Athukorala, A.D.S.N.P.; Jayasundare, K.B.
The effect of habitat differences on morphology, anatomy and fecundity of the lichen species have been rarely studied. However, this would help understand the mechanisms by which some lichens thrive while some get eliminated from the habitat. The objectives of the study were 1) to identify the lichen species common to a site in the middle of the Kandy City (KC) and a site inside the University of Peradeniya (UP, 2) to compare their morphology, anatomy and fecundity of common species between sites. Lichen species were randomly sampled from tree barks and fallen branches and identified using standard keys. Morphological and anatomical characteristics of the lichen thallus, sexual and asexual reproductive structures such as number of apothecia, and ascospores were compared between 2 sites using hand lens, dissecting microscope and compound microscope. Among 39 species found in University premises and 15 species around the Kandy Lake, 5 species, Physcia sp, Parmotrema sp, Lecanora sp, Graphis sp, and Lepraria sp, were common to both sites. As expected, mean thallus area of 4 species, except Lepraria was significantly smaller in KC site than UP site. The change of colour in Thallus (green to grey) were significant in all species between KC and UP. Thickness of upper cortex (significant, P=0.041), medulla layer and lower cortex were higher in KC site than UP site in Parmotrema sp. while thickness of algal layer is smaller in KC site. A decrease in apothecial number was observed in Lecanora sp. at KC site compared to UP site. The current study showed that changes in certain morphological, anatomical and reproductive characteristics can be triggered by the changes in the environment and may attributed to recorded air pollution in KC site suggesting that such species can be used to monitor the quality of the environment.
Challenges influencing domestic water consumption in the Dompe GN division
(University of Peradeniya,Sri Lanka, 2020-10-23) Kaushalya, G.N.; Manawadu, L.; Wijeratne, V.P.I.S.
Water is essential to life. It serves as the base for social and economic development of any country in the world and domestic water is a fundamental requirement for human welfare and a better living standard. As a result of urbanization and population growth, more water is likely to be demanded for domestic proposes, and it has become the third largest water consumer from total water consumption after industry and agriculture. The aim of this study was to identify the major challenges associated with the water consumption in the urban and semi urban sector the in Dompe GN Division. Research data collection was mainly conducted through a questionnaire survey (N=100). The sample was selected based on main drinking water source (groundwater and tap water) using stratified random sampling method. In addition, focus group discussions were conducted to identify the major problems and challenges influencing domestic water consumption in the study area. The Problem Tree Analysis, ranking methods, inferential analyses and spatial point pattern analyses become the main data analysis method for identifying the major problems related to water consumption. All analyses were carried out using ArcGIS 10.1 and Excel 2013 software. The study of 392 domestic ground water wells reveal that the distribution density of groundwater wells was 0.4274. The daily average water consumption of the study area is 119.44 liters person per capita per day. In the wet season the majority of household (65%) use groundwater resources for their daily activities, but in the dry season most of them used the government water supply for their daily activities. In this situation the households face different problems such as lack of drinking water sources, poor water quality, spatial and temporal drinking water quantity etc. The + analyses of the questionnaire survey reveals that the majority of household (80%) face the problem of inadequate the water storage during the dry season. Finally, the result of the study would benefit the sustainable water resource development and to provide an adequate water supply to the study area.
Treatment of reverse osmosis (RO) reject water using modified adsorbent from drinking water treatment sludge
(University of Peradeniya,Sri Lanka, 2020-10-23) Kavindi, L.I.U.; Kularathne, A.; Jayasinghe, N.S.; Weragoda, S.K.; Prabaharan, M.; Thushyanthi, S.
Both, reject water of Reverse osmosis (RO) plants and alum sludge of drinking water treatments cause a challenging threat to the environment. Accordingly, in this studyalum sludge in drinking water treatment was used to modify an improved adsorbent material to absorb fluoride, chloride, bromide, nitrate, and sulphate ions in the RO reject water. In addition, one-month and two-month-old separate samples from each sludge lagoon in the Kandy-South water treatment plant were obtained in chronological order to investigate the impact of exposure time of sunlight in drying effects on the adsorption ability. Furthermore, the sludge samples were oven-dried and pyrolyzed for 300 °C, 400 °C, 500 °C, 700 °C, 800 °C, and 900 °C temperatures. Initially characterized RO reject water was allowed to come in contact with the modified adsorbent material for the ion removal experiment. Above mentioned ion concentrations were analyzed in the filtrate solution. The adsorption experiments were carried out by varying contact time (20-90 hours) and adsorbent dosage (0.1-5 g). Ion Chromatograph (Eco IC, and Metrohm) for analyzing ion concentrations in filtrates and the scanning electron microscope (SEM) for the characterization of the developed adsorbents before and after physical activity were used. The analyzed results showed that the fluoride removal could achieve up to 55% while 1% removal of Nitrate and Sulphate in one-month-old and two-month-old oven-dried adsorbent material. Accordingly, there was no effect on the time factor for oven-dried material. Finally, it could be concluded that the adsorption ability of oven-dried material for fluoride ions is prominent. Further, it can suggest that this is an easy and environment-friendly method to treat the RO reject water.
Optimum conditions for adsorption of aqueous manganese (II) by bamboo woodbBased activated carbon
(University of Peradeniya,Sri Lanka, 2020-10-23) Pathirathne, I.S.; Herath, D.C.; Jayasinghe, N.S.; Weerasekara, L.; Weargoda, S.K.; Udagedara, D.T.
The presence of excessive amounts of Manganese in water creates substantial issues both in health and industrial sectors. Activated carbon is being used extensively in the remediation of contaminated water, as an effective and economically viable solution. This study was conducted to examine the optimum conditions for the adsorption of Mn (II) onto activated carbon derived from Bamboo wood. Bamboo Wood Activated Carbon (BAC) was prepared by chemical activation by impregnation with potassium hydroxide (KOH) at 1:1 ratio followed by pyrolysis at 800 °C for 2 hours. The estimated cost of BAC production was 0.26 US$/kg. Batch adsorption studies were conducted to investigate the influence of contact time, pH, and adsorbent dose on the adsorption process while using Commercial Activated Carbon (CAC) as a reference. Both BAC and CAC have obtained the maximum removal efficiency (equilibrium) by 5 hours of contact time with 50.3% and 95.0%, respectively where the saturation of adsorption sites obtained. The optimum removal efficiency (RE) of Mn (II) was observed at pH 6 for BAC and CAC, which is 58.0% and 87.0%, respectively while RE of BAC was 57.0% and RE for CAC was 91.0% at pH 7. Although it showed highest REs (59.0% for BAC and 99.0% for CAC) at pH 9 but this was neglected since Mn (II) removal occurs due to precipitation at this condition. The highest RE showed at adsorbent dose of 5.0 g/L for BAC (89.0%) and 7.0 g/L for CAC (98.0%) for the study. Accordingly, it can be concluded that the aforementioned optimum conditions could be used for effective remediation of Mn (II) through adsorption onto BAC with lesser production cost than CAC (1 US$/kg). The results from the study can be applied for optimizing an isotherm model for the adsorption of Mn (II) onto BAC and can be extended for increasing the Mn (II) removal efficiency and adsorption capacity by using different activating agents and activating temperatures.
Comparative study on determination of water quality using physicochemical parameters and benthic macroinvertibrates of the Sarasavi oya, University of Peradeniya, Sri Lanka
(University of Peradeniya,Sri Lanka, 2020-10-23) Amandakoon, A.M.T.I.; Jayasundera, A.C.A.
Water pollution affects the water quality and the biodiversity of the aquatic community. The present study determines the water quality using benthic macro invertebrates and physicochemical parameters of the Sarasavi Oya, University of Peradeniya, Sri Lanka at three locations (X, Y and Z) of the 400 m stream stretch for a period of three months from March to May in 2019. Physicochemical parameters such as temperature, pH, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Biological Oxygen Demand (BOD5), Dissolved Oxygen (DO), nitrates and orthophosphates were measured with three replicates. Macroinvertebrate community were studied along a five meter line transect at the locations. Weighted Arithmetic Water Quality Index (WAWQI) for physicochemical parameters and relative abundance, Shannon-Wiener Index (SWI) and Simpson Index (SI) for biological indicators were calculated. The mean values of temperature, pH, EC, TDS, DO, BOD5, nitrates and orthophosphates in the Sarasavi oya were 24.1°C, 6.98, 0.08 mS cm-1 , 0.03 g L-1 , 5.30 mg L-1, 1.96 mg L-1, 0.43 mg L-1, and 0.04 mg L-1, respectively. However, these values do not exceed the maximum limits of water suitability for aquatic life introduced by Central Environment Authority (CEA). WAWQI (X=8.52, Y=17.42, and Z=23.97) indicate that A-grade water (excellent water quality) is available in the Sarasavi Oya. The macroinvertebrates recorded with the highest relative abundance in X, Y, and Z locations were water strider (Geris adelaidis), Water stick insect (Ranatarafiliformis) and Fresh water crab (Paratelphusa sp.), respectively which indicate the better water quality at X than in Y and Z. SWI (X=2.05, Y=1.84, and Z=1.93) and SI (X=0.14, Y=0.18, and Z=0.16) explains that the highest diversity in sampling locations. SWI has been found with a positive correlation with DO, whereas negative correlation with BOD5, EC, TDS, nitrates, phosphates and WAWQI. SI has been found with a negative correlation with DO and positive relationship with BOD5, EC, TDS, nitrates, phosphates and WAWQI. The results also reveal that there is a direct relationship between physicochemical parameters and the macroinvertebrate diversity and the water quality was suitable for healthy growth of macroinvertebrates in the stream.
Performance assessment of a wastewater treatment plant in a textile industry: a case study
(University of Peradeniya,Sri Lanka, 2020-10-23) Croos,S.B.; Bandara, I.M.N.D.; Jayakody, J.K.P.N.D.; Jayanetti, P.N.; Subashini ,W.A.I.; Sewwandi, B.G.N.
The wastewater discharged from the textile industries consists of various chemicals and dyes that can cause serious environmental issues. This study was carried out to assess the performance of a wastewater treatment plant operating in a textile industry in Colombo. The existing wastewater treatment plant in the industry is operated as an intermediate treatment process, which has two pathways as DAF method and Clarifier method including the units of equalization tank, cooling tank, DAF, clarifier tank, and filter press etc. The treatment process is carried out to meet the discharge requirements given by the BOI before sending it to the central wastewater treatment plant. The objectives of the study were to analyze the physico-chemical parameters of the wastewater at different locations of the treatment plant and to determine the removal efficiencies of physico-chemical parameters. Samples were collected at the points selected from different locations at the wastewater treatment plant for the measurements of color (red, yellow and blue), TDS, TSS, COD and heavy metals using standard methods. The temperature, pH, and electrical conductivity were measured onsite on a weekly basis. The removal efficiencies of COD, Fe, Cd and TSS were 68%, 71%, 57% and 75%, respectively. The results of the study show that the pH, temperature and COD of the effluent of the treatment plant meets the BOI discharge standards. However, the concentrations of TDS, TSS and color of the effluent of the wastewater treatment plant exceed the standard discharge limits to the central wastewater treatment plant. Therefore, the conclusion of the study was that the performance of the existing wastewater treatment plant is acceptable for pH, temperature, electrical conductivity and COD removal. Further, the treatment plant has to be improved specially at the point of adding FeSO4 and decolorant and at the effluent discharging point. This is mainly to achieve a better performance in removing TDS, TSS to meet the required BOI standards and especially for the color removal since it affects the treatment performance of the central wastewater treatment plant.
Environmental monitoring and risk assessment: a new view using diffusive passive sampling technique (DGT and DET)
(University of Peradeniya,Sri Lanka, 2020-10-23) Kankanamge,N.K.; Croot ,P.; Teasdale,P.; Welsh , D; JianyinHuang; Bennett,W.
Regulatory environmental monitoring is mainly based on the spot sampling of water, sediment, soil, and biota and conventional analysis. These well-established ex-situ conventional methods have limitations and the analysed samples may not accurately reflect the in-situ concentrations due to the artefacts resulting from spot sampling, sample oxidation and changes in temperature. Diffusive passive samplers (diffusive gradients in thin films (DGT) and diffusive equilibration in thin films (DET)) overcome these limitations. The research to date in this field has clearly demonstrated the power of applying DGT and DET samplers to investigate contaminant biogeochemistry in water, sediment, and soil systems. We have developed and applied several DGT and DET methods for the analysis of trace metals, sulfide, iron (II), and nutrients in water/sediment/soil. Here we present various examples of the monitoring application of DGT and DET methods to investigate contaminant biogeochemistry in water and sediments. These examples range from the investigation of metal (loid) concentrations in marine sediment pore waters, the measurement of elevated concentrations of iron (II) and sulfide in different habitats. Methods including the Chelex binding layer DGT for measuring trace metals and REEs in marine water, Chelex-Metsorb mixed binding layer DGT for measuring trace cations and oxyanions in sediment pore waters, and the colorimetric iron (II) and sulphide DET methods for the measurement of high-resolution pore water iron (II) and sulfide concentrations are discussed. This work consider current approaches for the assessment of bioavailability of metals in water and sediments, and how DGT stands as a step forward in suite of tools available. These studies demonstrate that the DGT technique has strong potential link chemical monitoring and ecotoxicology to predict contaminant risk.
Toxicity assessment of fungicide containing thiram 80% WP using Eisenia fetida and Allium cepa as indicator species
(University of Peradeniya,Sri Lanka, 2020-10-23) Dilrukshi,R.A.H.; Gunawardena,M.P.
Ecotoxicology is the science of contaminants in the biosphere and their effects on the components of the biosphere. Predicting the exposure and effect of contaminants is difficult for all relevant ecological entities. Agrochemicals are used extensively in fields to kill pests and weeds, which may exert toxic effects on other non-target species including earthworms and common onion. This research was conducted to evaluate the acute and chronic toxic effects of a commercial fungicide containing Thiram 80% WP, which is carbamate, on Eisenia fetida (earthworms) and Allium cepa (Common Onion). Earthworms are better indicators of the health of the soil because 60% - 80% of soil biomass represents earthworms. In this study earthworm species, Eisenia fetida was used because they can be bred within two weeks. Allium cepa is used in this study because they have a high absorbent level and high root growth rate. Eisenia fetida was exposed directly to aqueous solutions in five different concentrations (6 mg/L, 8 mg/L, 10 mg/L, 12 mg/L, and 14 mg/L) while distilled water was used as the control. Six Eisenia fetida were used in each sample and three replicates were performed. After 48-h exposure to Thiram 80% WP mortality of Eisenia fetida increased along the concentration gradient. Overall results of the acute toxicity test of Eisenia fetida, indicated an LC50 value of 12.636 mg/L and any behavioral changes could not be observed. Acute toxicity was evaluated to Allium cepa, by 72-h experiment of root growth with a range of fungicide concentrations (40 mg/L, 80 mg/L, 120 mg/L, 160 mg/L, and 200 mg/L) and tap water was used as the control. After 72-h exposure to Thiram 80% WP, root growth of Allium cepa was reduced along concentration gradient and overall results indicated an EC50 value of 22.183 mg/L. Recommended formulations of fungicide Thiram 80% WP of 640 g/hectare – 1600 g/hectare, and LC50 value for earthworms is 560 mg/kg of soil. According to the results fungicide Thiram 80% WP can be concluded as toxic, but further studies should be conducted to evaluate the acute and chronic effects
Removal of excess phosphate ions in water using 1-D Magnesium Oxide nanowires
(Universirty of Peradeniya,Sri Lanka, 2020-10-23) Indeewari,K.M.; Abeysooriya , K.H.D.N.; Rajapakse,R.M.G.
In the recent few decades, the rate of phosphorous cycling has been increased because of rapid development in agriculture and industries causing more wastewater generation. When untreated wastewater containing phosphate is discharge into water bodies such as lakes and, tanks it can cause eutrophication, which leads to harmful effects on the ecosystem and human health. Hence, phosphate removal is important in the control of eutrophication. Adsorption is one of the effective and economical methods for the removal of phosphates. This study focuses on a simple, low-cost and a novel approach towards the removal of excess phosphate ions from aqueous solution by adsorbing on to one dimensional (1D) Magnesium Oxide Nanowires (MONWs). The nanowires were synthesized via hydrothermal method using urea and magnesium acetate at 180 °C for 2 h. The synthesized MONWs were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, particle size analyzer and scanning electron microscopy. Additionally, the phosphate removal efficiency was studied using ion chromatography technique. The optimum removal percentage (99.5%) was obtained with 50 ml of 3 mg L-1 phosphate solution and 0.075 g of synthesized MONWs. Phosphate adsorption is found to be less sensitive to the pH variations. Moreover, adsorption data were fitted with Freundlich isotherm with an R2 value of 0.952. Adsorption kinetic data were fitted to the pseudo second-order model and yield an R2 value of 0.995 suggesting that the adsorption process is chemisorption. Furthermore, phosphate removal efficiency influenced by the presence of competitor ions. This study found that MONWs have a potential application for wastewater treatment.
Comparison of environmental technological practices on pollution abatement of hotels in Kandy, Sri Lanka
(University of Peradeniya,Sri Lanka, 2020-10-23) Karunarathna,G.T.A.M.D; Lakmali, W.M.U.
The environmental pollution caused by the hotel industry significantly impacts humans and nature. Environmental technology aims to protect the environment through offering ways to lower the pollution in a sustainable manner and provide new ways to avoid depletion of natural resources. This study aims to compare how hotels in Kandy district abate the environmental pollution with and without environmental technologies. Both primary and secondary data were used to fulfill the objectives of this study. Primary data were mainly collected through key informants discussions with chief engineers of hotels and questionnaire-based survey conducted on employees of hotels. Secondary data were collected from Municipal Council in Kandy, books and internet related to the hotel industry. The study found that the use of environmental technology reduces the risk of harm to the environment and society. Sewage Treatment Plant (STP), Solid Waste Treatment, Solar Energy Production and Biogas Production can be taken as the methods that hotel industry uses. They remove the contaminants through STP system before disposing waste water. The purified water is being used on hotel gardens. By using solar energy, they generate the energy needed for their hotels. Kitchen waste and sewage use to produce biogas for lighting purposes and generating heat. These systems have huge advantages such as attraction of tourists to revisit destinations, Eco-friendly certifications, increased stand of their hotels, cost reduction for waste disposal etc. However, hotels without environmental technological practices do not have the advantages mentioned above. The majority of hotels in Kandy use traditional methods to deliver waste to the urban council instead of using environmental technologies. This incur additional costs daily. This is mainly because of the lack of awareness about environmental technological practices, reluctance to get away from the traditionalism and there is no need to use such a methodology to protect environment. Therefore, the study recommended that technologies are a great value in preventing pollution
An assessment of current air pollution monitoring processes in Sri Lanka
(University of Peradeniya, Sri Lanka, 2020-10-23) Weerakoan,T.P.; Perera, M.T.C.
Amidst increased emphasis on limiting air pollution around the world, in Sri Lanka many discussions have taken place, but implementation of practical measures of air pollution monitoring is rare. Thus, the objective of this study is to study the current air pollution monitoring and control procedures in Sri Lanka. This may contribute to adverse weather conditions and diseases. Even the medical researchers have pointed out that health impacts of air pollution in Sri Lanka have been underestimated. In order to achieve this objective, this study was carried out primarily as a critical literature review. Through this study researchers will learn that there are only a handful of places where air quality is measured in the country. There are numerous air pollution monitoring processes that were implemented recently, but the air quality level in major industrial cities have increased and it is on rise in rural areas as well. Currently Sri Lankan air pollution monitoring process is carried out mainly by means of human resources which has not been effective so far. Even with the current human- centric monitoring processes where the incurred cost is very high the air pollution levels are on the rise. On top of that, apart from vehicular emission other sources of air pollution are less monitored or not monitored at all. It is imperative to measure air pollution by factories, air travel, power generation, vehicular emissions as well as biomass burning using technology-based monitoring systems, which would reduce the cost of operations for relevant authorities. Researchers also recommend that, focusing on un-monitored air pollution activities such as biomass burning and waste burning as well. There should be alert systems in place to notify the authorities when the air pollution levels are breached from such activities.
Construction complications and challenges in the process of installing landfill gas and leachate collection system to the Meethotamulla solid waste dump site closure
(University of Peradeniya,Sri Lanka, 2020-10-23) Chandrasena, W.K.N.; Premasiri, H.D.S.
The Meethotamulla Municipal Solid Waste (MSW) dumpsite was one of the largest open dumping sites operated in Sri Lanka. As estimated in 2017, about one million ton of waste stock was collected at the site with an area of 78,000 m2 up to the height of 45-50 m range. Because of the heavy load of waste dump on top of the thick peat layer, the waste dump collapsed in 2017 leading to the death of 32 people. As an immediate action taken by the Government of Sri Lanka, further dumping of MSW to the Meethotamulla dumpsite was terminated. Since the beginning of the dumpsite at Meethotamulla it has created a lot of environmental problems such as unmanaged gas emissions, odour problems and leachate contamination to surrounded water bodies. The Government of Sri Lanka decided to reclaim the site as an Urban Park. The Urban Development Authority (UDA) was assigned the responsibility of managing environmental and social hazards. The National Building Research Organization (NBRO) was designated as the consultant to the project. The reclamation and closure process considered all technical design works including slope stability, leachate management, landfill gas management, final cover material selection and the development of surrounding areas. The concepts used for the design and construction were based on results obtained by an experimental trial fill of 50x30m2 compacted waste up to 5 m height. Recorded CH4, CO, H2S, VOC concentrations at gas wells were 10-30%, 19 ppm, 42 ppm, 16 ppm, respectively. The major challenges encountered during the implementation of the design were, installation of gas wells and leachate collection blankets without removing or replacing of waste from the site. As a systematic approach followed in the construction stage, site specific trench system and cut and fill methods with benching were practiced to install the gas wells and leachate blankets. Site specific testing methods have been developed for testing waste compaction, landfill gas content, efficiency of gas wells and leachate collection system. These smart approaches were facilitated to resolve construction complications and to cover the construction targets.
Anaerobic digestion of municipal solid waste: a review of operational issues
(University of Peradeniya,Sri Lanka, 2020-10-23) Ellangasinghe,M.A.; Kalpage, C.S.; Danthurebandara,M.; Ellangasinghe, M.A.; Ariyarathna,S.M.W.T.P.K.
Anaerobic digestion of municipal solid waste (MSW) has two-fold advantages: a feasible solution for environmental pollution control and a source of low-cost energy. Nevertheless, it has not yet gained as much attention as aerobic digestion, mainly because of the high capital expenditure and difficulties in stabilizing the reactor operations. The aim of this study is to find out the operational issues especially behind solid waste anaerobic digestion. In comparison to liquid phase anaerobic digestion, solid waste anaerobic digestion requires a larger amount of inoculum and much longer retention time. Poor mixing of solid substrate in the bioreactor negatively impacts on mass and heat transfer, and thereby on reaction kinetics. The intermediate volatile fatty acid (VFA) accumulation is one of the major issues in solid waste digestion. The VFA accumulation occurs because of biochemical reactions of complex and heterogeneous molecules in the substrate. The substrate is a mixture of different molecules belonging to four main categories: carbohydrate, protein, lipids and cellulose. The VFA is formed at different rates as a result of the hydrolysis and acetogenesis of vastly different components in the substrate at different rates. The highly soluble substrate increases the VFA concentration rapidly, and as a result the pH is dropped suddenly to create an inhibitory environment for acetogenic and methanogenic reactions. Another serious problem with the substrate is the presence of organically bound nitrogen compounds. Inhibitory products such as ammonia, ammonium, nitrites and nitrate that enters the system during the metabolic activities of these compounds and make the process unstable. Particle size of the substrates too determines contact surface area of microbes and then the rate of reaction. Finally, it is concluded that though the municipal solid waste is a sound substrate for anaerobic digestion, there are several issues to be addressed further.
Detection of landuse and landcover change: a study of the Pottuvil DSD, Ampara
(University of Peradeniya,Sri Lanka, 2020-10-23) Hicmathullah,M.L.M.; Nanthakumaran, A.
Issues of landuse / landcover changes and the relationships of these changes have become much considered in recent years. Thus, the objectives of this research were to study the nature, extent, rate of changes and to analyze the spatiotemporal change patterns of landuse/landcover in the Pottuvil Divisional Secretariat Division (DSD) for sustainable management of land use. Multi-temporal Landsat TM1987, TM1996, ETM2003, TM2009 and OLI-TIRS2017 images were used for this study. Based on the extent of the study area to obtain the appropriate accuracy assessment 200 training samples were selected for the classification of the Landsat images using supervised maximum likelihood method in QGIS 3.10.1 and landuse maps were generated and change detection analysis was performed from 1987 to 2017. Agricultural land, forest cover, settlements, sandy land, scrubland and water bodies were identified for the landuse classification. Distinct changes have occurred in the landuse pattern. Results revealed that nearly 13.5% of agricultural land and 3.3% of settlements increased from 1987 and 13.4% of forest cover, 3.7% of water bodies and 0.3% of sandy land decreased from 1987 in the total area cover of the Pottuvil DSD. Conversions of land from forest cover (1775 ha) and scrubland (1786 ha) to agriculture represent the most significant land use change in the study area. The rate of change was as high as 3.36% for increasing settlements and agricultural lands were converted from other lands by 3.09% per year. The unutilized lands (13.93 ha) and abandoned settlements (3.38 ha) and abandoned agriculture lands (1.66 ha) were identified. Therefore, it is crucial that development plans be accompanied with a sustainable livelihood options for a better future of the country. Spatiotemporal landuse/landcover changes in GIS platform may be used to supplement the available tools for urban planning and sustainable environmental management in the region.
Determination of lignocellulose biodegradation efficiency of enriched microbial consortia from compost, cow dung and coir retting water
(University of Peradeniya,Sri Lanka, 2020-10-23) Bandara,S.M.D.C.; Rizvi, E.M.J.M.
Various drawbacks of fossil fuels have demanded the need for alternative sources of energy such as biofuels and second-generation bioethanol from lignocelluloses is favoured because of the food insecurity caused by first-generation bioethanol production. Even though lignocellulose is the most abundant, sustainable and cost- effective renewable biomass on earth, degradation of lignocelluloses to produce bioethanol is difficult because of its complex and robust structure. This study investigated the capability of microbial consortia enriched from compost, cow dung and coir retting water to degrade three lignocellulosic materials i.e., rice straw, corn straw and sawdust. Alkaline pretreated lignocellulosic substrates and a mixture of the three substrates in equal ratios were inoculated separately with the three microbial sources and a mixture of the three microbial sources, which were enriched twice (4 days each) using the same pretreated lignocellulosic substrate or the substrate mixture as the only source of carbon in basal culture medium (5 g of peptone powder and 3 g of yeast extract powder in 1 L of distilled water of pH 7). Four replicates each per treatment and a non-inoculated control was maintained in a completely randomized design, with no aeration at room temperature. The lignocellulose biodegradation ratio was tested by acetic acid-nitric acid reagent after 5 days of incubation. Statistical significance of the results were analyzed using one-way ANOVA (p <0.05). Subsequent mean comparisons of treatments were done by Turkey’s test using Minitab 19.2 version. All the substrates had a significantly higher degradation ranged from 21.43% - 66.70% compared to their control. Highest degradations of 66.70% and 58.12% were found in rice straw by enriched consortia from microbial mixture and compost, respectively. The values are comparable to 60% and 75% of rice straw degradation in two different studies which were incubated for 4 and 7 days respectively at 50 °C utilizing microbial consortia developed from compost by several enrichment cultures. The use of mixtures compared to the individual components alone both in the case of lignocellulosic substrates and microbial sources showed a positive effect on lignocellulose biodegradation. Further studies will reveal the bioethanol production efficiency of these lignocellulosic substrates and microbial sources.
Land-use land-cover change of the Unawatuna beach area in Galle: a special emphasis on the human impact
(University of Peradeniya,Sri Lanka, 2020-10-23) Kanchana,A.M.W.
Costal Eco systems are rich in natural resources and especially, tropical coastal zones in a developing country support economic development and social welfare of the country. As a result of that the coastal zone attracts people to utilize their resources. This unlimited human consumption of the resources makes a reason to rapid land-use land-cover change in the coastal area. The study area consisted of three Grama Niladari (GN) Divisions namely, Bonavista, Yaddehimulla, and Unawatuna Central located along the Unawatuna coast. The objective of the study was to identify the change of coastal land use land-cover of Unawatuna area during the period of 1956- 2018. Primary and secondary data were collected for the study. Primary data were collected via five focus group discussions, aerial photographs, google earth images and questioner survey selecting 10% of sample from each GN division. Secondary data were collected through research papers, reports and internet. The qualitative and quantitative methods were used to analyze the collected data. Tables, maps, figures and photographs were used to present information. In 2018, more build up areas, strong road network and less coastal vegetation cover can be observed comparing with 1956 and 1994. Coastal land-use land-cover of the area had become more complex with the human activities. It was found that land-use land-cover of the area was dominated by the expansion of tourism infrastructure. Overcrowding, development activities and urbanization were identified as the main drivers that influenced land- use land-cover changes. As a result of land-use land-cover changes, negative impacts such as habitat loss for associated species, coastal erosion, and decrease of coastal vegetation cover including the reduction of aesthetic value of the area was evident. Removal of illegal constructions and introducing reservation areas will be effective to minimize the negative impact
Productivity thresholds in a tank-based agriculture system: a case study
(University of Peradeniya,Sri Lanka, 2020-10-23) Sirimanna,S.; Prasada, D.V.P.
Tank cascades are human-made systems of water retention in water deficient agricultural systems. The logic of a cascade lies in maintaining an appropriate balance between the catchment area and the command area, and facilitating a continuous water flow in the downstream direction. This study investigates the current status, water use efficiency and production thresholds in 17 tanks of Mahakanumulla, a small village tank cascade system in the North Central province of Sri Lanka, using the cross- sectional survey methodology. In this cascade system, we estimate a total water holding capacity of 0.0026 km3 and a release volume of 0.0018 km3, supplied to a total command area of 494.56 hectares. Average yields of 2156 kg per acre and 252.6 kg per acre were calculated based on the survey responses for Maha and Yala seasons, respectively. The large difference in productivity across Maha and Yala is characteristic of solely rain-fed systems. The calculated average water productivity in the cascade is 124.55 kg per m3 of tank water. We calculate tank production thresholds varying from 40 kg per m3 to 268 kg per m3. There are productivity losses in the midstream arising from land use changes. Analysis reveals that while the quality of physical tank structures is not correlated with water productivity, the land uses in the command area are correlated with water productivity. This finding highlights the need for socio-economic interventions in addition to physical improvement in the tank structure for the sustainable functioning of cascade systems.
Exploring the impact of green operations practices on the organizational environment and financial performance in manufacturing sector organizations in the Anuradhapura district
(University of Peradeniya,Sri Lanka, 2020-10-23) Aravinda, M.A.K.N.; Rajapakshe,P.S.K.; Sandaruwan,R.G.P.; Upali,M.M.R.
Climate Change results in both pressure and drivers for Sri Lankan enterprises to improve their environmental performance. As a developing country, Sri Lanka has to balance economic and environmental performance. If the firms needed to get strong performance continuously, they re-establish their corporate strategy by introducing and implementing more integrated sustainable green operations practices. When reviewing literature regarding green operations practices, developed countries are prominent than developing countries. Hence in the Sri Lankan context, this concept must be identified for organizing the manufacturing sector. To achieve the aim of this study, an in-depth literature study and empirical research were undertaken. A self - 41 administered questionnaire was completed by 80 operational managers from 80 manufacturing firms in the Anuradhapura District using convenience sampling method. To investigate the relationship between the Green Operations Practices and Environmental and Financial Performance, 4 hypotheses were tested. A conceptual framework was developed by researchers for the current study based on the survey. According to the correlation analysis results revealed significant positive relationships between these variables. The ordinary linear regression analysis was used to examine the impacts of these variables and a regression model is formulated. Green Production significant positive impact on Organizational EF Performance (Beta = 0.737) and there is a significant influence because of significant value is less than 0.05 (0.05>0.000). Green policies and organizational EF performance have positive and significant influence. Because of the positive Beta, value (0.267) and significant value is (0.006). Green marketing has a positive impact on organizational performance. Because of Beta value is 0.065, but there is insignificant influence because of significant value (0.582) is greater than 0.05. This study will contribute to the all the society, decision makers and policy makers. The results also provide various implications for managers and present some suggestions for future researches.
Recycling of low-quality waste aggregate with plastic coating for Asphalt production
(University of Pradeniya,Sri Lanka, 2020-10-23) Manchanayake , M.A.M.O.; Niroshani, K.P.; Sumathipala, H.M.C.M.; Fernando , M.H.Y.K.; Dissanayake, P.B.R.; Kawamoto , K.; Rathnayake,R.M.L.D.
The plastic waste has become a major threat to the environment. Finding a proper disposal method for plastic waste is the need of hour. Plastic shows some bituminous characteristics, so it can be used as a coating material on an aggregate surface. Concurrently, considerable amount of aggregate in the construction industry is discarded as waste because of its low quality. Such unacceptable properties of aggregate can be improved by coating aggregate surface with polythene. In this research, the mostly available aggregate type in Sri Lanka, namely Hornblende Biotite Gneiss with low mechanical properties, which is out of requested international standards were initially coated with polythene by changing the polythene content percentage wisely, 0%, 5%, 10% and 15% according to the weight of aggregate using dry method to prepare Plastic Coated Aggregate(PCA). Laboratory experiments revealed that, mechanical properties such as Los Angeles Abrasion Value, Aggregate Impact Value and Aggregate Crushing Value of PCA’s were achieved requested international standard values at 10% polythene content. Hence aggregate surface is covered with a polythene film, bonding ability of bitumen with polythene is relatively unknown. Therefore, above mentioned PCA’s were secondly coated with bitumen by changing the bitumen content percentage wisely, 4%, 5% and 6% according to the weight of aggregate to investigate the bonding and strength characteristics. Three laboratory tests, namely Marshal Stability test, Bitumen Extraction test, Stripping Value test were conducted. 7.5KN of maximum stability value was observed in the sample with 15% polythene and 6% bitumen contents by showing 49% increasement of stability compared with other samples. Only 85% of bitumen could be extracted in 15% PCA’s, predicting higher bonding ability is resulting at higher polythene contents. No stripping of bitumen was observed in 10%, 15% PCAs’. Therefore, this study revealed that waste aggregate can be recycled by preparing PCA to produce asphalt.
Energy recovery from the gravity-fed Mawathagama Galagedara integrated water supply project
(University of Peradeniya,Sri Lanka, 2020-10-23) Rathnasekara,A.K.R.L.; Weerakoon,S.B.
The water sector is committed to contributing towards “affordable and clean energy” Sustainable Development Goal by reducing carbon foot print of the water supply projects. Accordingly, the excessive pressure generated in pipelines in gravity-fed water supply systems that is usually dissipated by break pressure tanks is given attention as source for recovering energy using micro hydropower plants (MHPP).This study presents a Case Study of economic feasibility of integration of a MHPP to recover dissipating hydro energy in the gravity-fed Mawathagama Galagedara Integrated Water Supply Project (MGIWSP) by the deployment at different stages of the project.Economic analysis of following three cases were carried out considering revenue and cost streams; the cost anticipated for the MHPP installations, operation and maintenance, and revenue by selling electric energy to the Ceylon Electricity Board. NPV, IRR, payback period, benefit cost ratio and debt service coverage ratio are used to investigate the economic feasibility of three cases. a. MHPP is integrated at the project design. Cost increase due to the pipe modification and MHPP is the capital cost. Here cross- saving is considered. b. MHPP is integrated at the project design. But the cost of the pipe installation and MHPP is the capital cost. Cross-saving not considered. c. Installation of MHPP as a later option after water supply project is done. Total modification cost included. In Case (a) NPV is Rs. 42 MN, IRR of 34%. Case (b) was not economically feasible and Case (c) was only marginally feasible. According, MHPP should have been added at the planning stage and it is not economically feasible to install a MHPP to MGIWSP now.

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