http://dr.lib.sjp.ac.lk/handle/123456789/1166 Mon, 29 Dec 2025 02:34:21 GMT 2025-12-29T02:34:21Z http://dr.lib.sjp.ac.lk/handle/123456789/3091 Release Of Methane and Carbon dioxide Gases from Municipal Solid Waste Landfills in the Colombo Metropolitan Region Kumari, S. M. S. R. Attached; Environmental and social problems caused from improper solid waste disposal are some of the biggest environmental threats Sri Lanka faces at present. Most of the waste generated in Sri Lanka ends up directly in open disposal sites on land. These disposal sites are overloaded and uncontrolled. Often the sites selected are marshy areas on lowland. These open dumps have posed serious environmental and social threats. Air pollution from landfill emissions, ground water pollution from leachates, health problems due to breeding of disease causing pests and social problems such as decreasing land values and aesthetic appeal of an area etc. are some of these problems. Currently about 60 temporary open dumpsites are in operation within the Colombo Metropolitan Region (CMR) alone. All of them can be said to be temporary because they are small in size, unplanned and unengineered. As in most other low and middle income countries Sri Lanka has a high percentage of organic content in their waste. Due to this high percentage of organic waste (80-90) high amounts of Carbon dioxide and Methane are released in to the atmosphere from anaerobic degradation under low oxygen conditions prevalent in uncontrolled landfills. Thus in addition to many other social and environmental problems, Green house gas contribution is another major concern arising from the current waste disposal practices in Sri Lanka. It has been estimated that through out the world about 8% of methane that is released in to the atmosphere comes from landfills. This study intends to estimate the amount of greenhouse gases that is Carbon dioxide and Methane that is released into the atmosphere annually from the landfills under study operating in the Colombo Metropolitan Region. Most of the landfills are open dumpsites. Colombo, Gampaha and Kaluthara districts are located in the CMR in which 45 local authorities are included. All the relevant data was collected from each local authority in CMR by using questionnaires, primary interviews, field observations and past data. Scholl Canyon gas generation model was used to estimate greenhouse gas emissions from the municipal solid waste degradation in the dumps in the CMR. As model inputs the amount of waste dumped annually, the age of the waste and the gas generation potential of the waste was used. Gas generation potential was calculated on the basis of the composition 'of waste. It was found that methane gas emission is 1507.681 x 10 3 m 3 and CO2 gas emission is 9474.516 x 103 m 3 in CMR in the year 2003. Wed, 05 Oct 2016 09:28:09 GMT http://dr.lib.sjp.ac.lk/handle/123456789/3091 2016-10-05T09:28:09Z http://dr.lib.sjp.ac.lk/handle/123456789/3088 PHYSICAL, CHEMICAL AND BIOLOGICAL PARAMETERS OF WATER QUALITY AT SOME SELECTED SAND MINING LOCATIONS OF THE LOWER REACHES OF KALUGANGA Ranasinghe, M.S. Attached; Out of 103 rivers in Sri Lanka the 3 rd largest major river is Kaluganga,which hasthe highest volume of discharge as a percent (%) of precipitation per year out of the Sri Lankan rivers. It originates 2243m above mean sea level (Sripada), is 118km in lengthand opens to the sea at Kalutara. The lower reaches of Kaluganga is a densely populated zone where the inhabitants are highly dependent on sand mining activities, which adversely affect the qualityof the water in the river. In this study to assess the extent of mining effects, six sites were selected. Out of those sites, water samples were collected from one site for monitoring purposes, the location of the Kethhena water intake. In the other five sites heavy sand mining activities are going on. To compare the variation of chemical, physical & biological parameters in water, samples were collected from each site and analyzed weekly for two months. The physical parameters measured include - temperature, turbidity, suspended solids and electrical conductivity. Chemical parameters assessed include pH, dissolved oxygen, BODs (biochemical oxygen demand), alkalinity, water hardness, [Cl] and COD (chemical oxygen demand). The data were analyzed by T-Test of Mean using GLM procedure of MINITAB for comparison with inland water quality standards in Sri Lanka. The data were analyzed by TWO WAY ANOVA using GLM procedure of MINITAB. Followed ONE WAY ANOVA with Tukey's pair wise comparison. Microscopic and macroscopic identification of biological parameters were carried out According to the results obtained, the value of pH, temperature and dissolved oxygen were in the desirable level. But some values like conductivity, suspended solids, turbidity, alkalinity, [Cn, [Fe], phosphates as P20S were higher than the desired range. BOD5 was low, which means low level of free organisms and organic matter in the river water because of habitat destruction by mining. [Cn along the river indicates that salt-water intrusion was directly effected by mining activities, lowering the riverbed. COD, DO, pH, Nitrogen, and water hardness were lower than the standards. Anabena spp., Nostoc spp., Microcystis spp., Closterium spp., Cosmarium spp., Occilatoria spp., Spirogyra spp., Spirulina Spps. were found as biological indicators in the water at mining sites but was low in abundance. At the site of water intake, few species were identified but abundance was higher than in other sites. These include, Occilatoria spp., Closterium spp., and,Cosmarium spp., Spirogira spps.. According to the above results it can be concluded that water quality at the selected sand mining locations of the lower reaches of Kaluganga are adversely affected and that sand mining activities may be a contributory factor. Wed, 05 Oct 2016 09:24:27 GMT http://dr.lib.sjp.ac.lk/handle/123456789/3088 2016-10-05T09:24:27Z http://dr.lib.sjp.ac.lk/handle/123456789/3078 EXTENDED COST BENEFIT ANALYSIS OF BIOGAS GENERATION USING MUNICIPAL SOLID WASTE KARUNARATHNA, K. G. S. P. Attached; Solid waste is a growing problem in Sri Lanka in the absence of proper management measures. Development and implementation of a National strategy for municipal management is essential in order to reduce environmental, social and the economic problem associated with the present disposal practices. Such strategies however, need to be subjected to proper economic analysis in order to arrive at informed decisions. The present study presents an extended cost benefit analysis of a biogas generation plant that uses munipal solid waste as the raw material. To dispose vegetable market garbage available in Wattala, Kandana and Ja-ela areas productively, the 640 Mt capacity biogas/ bio fertilizer project has been housed at Muthurajawela (along Hamilton canal, Elakanda), by the National Engineering Research & Development Center of Sri Lanka (NERDC), which uses Dry Batch Anaerobic Digester Technology. Among the other biological treatment options, anaerobic digestion is the most cost effective, due to the high-energy recovery linked to the process and its limited environmental impacts. Economic analysis has been carried out to identify costs and benefits associated with the above project. Several environmental valuation methods have been applied to value the identified costs and benefits. The main benefit of reduction of municipal solid waste has been estimated as Rs 1,093,444 per year. Contingent valuation method (CVM) was used to estimate this benefit using samples from Wattal-Matnla, Ja-ela, and Peliyagoda local authorities. Green house gas (methane) emission from solid waste was estimated through Scholl Canyon model and valued using avoided global damage cost approach. Benefits of biogas as an energy source, organic fertilizers and employment benefits were estimated by market based approach. The project is viable from economy and environment point of view with net present value of Rs. 249.43 million for 20-year period with 10% discount rate. This analysis provides a justification for undertaking solid waste management strategies in a technologically environmentally and economically viable manner. Wed, 05 Oct 2016 09:01:50 GMT http://dr.lib.sjp.ac.lk/handle/123456789/3078 2016-10-05T09:01:50Z http://dr.lib.sjp.ac.lk/handle/123456789/1435 The Problems and Prospects of Domestic Tourism Sector in Sri Lanka Shantha, M. Sunil Fri, 28 Feb 2014 09:10:21 GMT http://dr.lib.sjp.ac.lk/handle/123456789/1435 2014-02-28T09:10:21Z