Junior Research Symposia
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Item Analysis of existing municipal solid waste management practices: A case study in Kelaniya Pradeshiya Sabha area(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Senanayake, M.W.P.N.S.; Sewwandi, M.K.V.N.; Showmika, R.; Thilini, P.G.I.; Ubhayawardhana, W.S.M.T.; Yatawara, M.D.M.D.W.M.M.K.A significant amount of solid waste has become a pressing issue with rising population, urbanization, economic activities and consumerism, especially in urban and sub-urban areas creating negative impacts on both environment and human health. Lack of infrastructure and financial resources, poor public participation in waste management process and less enthusiasm of government representatives have also been contributed to complicate the situation. Personal experience and literature revealed that existing SWM systems established in most local authorities are not properly functioned. Therefore, significant gaps are visible in solid waste management process in different local authorities. The present study was planned to explore municipal solid waste management system in Kelaniya Pradeshiya Sabha (KPS), as a key area in Gampaha district to identify best practices and gaps. Data were collected through interviews and questionnaire survey from three categories (officers in KPS, sanitary employees in KPS and general public in KPS area). Descriptive statistics were used to analyse data. Results revealed that waste reduction and capacity building were priority areas in KPS. Though the institutional capacity has been developed to certain extent in KPS, further attention is needed to overcome existing issues. Implementing new policies is further suggested to overcome some existing obstacles. However, the outcome of the study is a framework developed for best practices of solid waste management which can be used at local authorities for effective and efficient municipal solid waste management.Item Comparison of Soil properties in three selected sites within the premises of University of Kelaniya, Dalugama, Sri Lanka(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Dissanayaka, D.M.C.P.; Dissanayaka, C.T.M.; Weerathunga, D.M.; Wijesekara, N.T.A.; Perera, G.L.D.N.; Abeykoon, H.L.S.N.; Ranasingha, B.M.C.J.; Kanagasabai, S.The soil physical and chemical properties largely determine the plant growth and it is a determinant of the composition of faunal communities. The objective of this study was to compare the soil physical and chemical properties in three selected sites within the premises of University of Kelaniya. The study was conducted in three selected sites within the University of Kelaniya; botanical garden, university ground and in a construction area. A total of three soil samples were extracted from each site using soil corer to analyze the soil moisture content, organic matter content, soil pH, soil surface temperature, bulk density, particles density and porosity. According to the results of present study the soil porosity is highest in botanical garden (81.6%) with relatively undisturbed soil whereas the soil moisture content and the organic matter content were highest in university ground (moisture content= 1.27; organic matter content= 6.27%). The construction site that subjected to severe disturbances due to heavy machinery usage, showed the highest bulk density (0.39 Mg/m3) and lowest porosity (78.7%) from all three sites. This study reveals that the soil properties within the university premises shows a considerable variation which can be explained with the degree of disturbance to the area.Item Impact of invasion of Cogon grass (Imperata cylindrica) on the physical and chemical properties of soil(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Bandara, M.S.P.M.; Dilshara, R.M.P.; Gunarathne, D.K.O.B.; Senevirathne, H.; Udayanthika, S.K.I.; Kumari, C.Cogon grass (Imperata cylindrica) is an invasive species found in many parts of Sri Lanka. This species is among the top ten worst weeds in the world. Cogon grass is found on road sides, mining sites, abandoned plantations and many other areas with disturbed soil forming a dense field like monocultures. The objective of this study was to assess the impact of the invasion of Cogon grass on soil physical and chemical properties. The present study was conducted in a selected site at Nelumdeniya, a village located at Eastern part of Sabaragamuwa Province. Three sites were identified within the study area, of which two sites are invaded by Cogon grass with a high to low level of cover. The remaining site without the weed (undisturbed site) was used to assess the condition of soil before invasion of the weed in above sites. From each site five soil samples were extracted using a soil corer to analyze soil particles density, soil bulk density, porosity, moisture content, organic matter content, conductivity and Nitrogen content (kdjeldahl method) in soil. The moisture content of undisturbed site (0.78) was less than the two sites invaded by the Cogon grass (0.88 and 0.89). The organic matter content (OM) and the Nitrogen content of soil in undisturbed site (OM= 0.163%, N= 0.14%) was higher compared to the other two sites (OM= 0.083% and 0.107%; N= 0.13% and 0.11%). The bulk density and the porosity was higher in affected areas than the undisturbed site. The study reveals that the invasion of Cogon grass affects both the physical and chemical properties of soil.Item Effect of ammonia inhibition on anaerobic conversion process of pig manure(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Sandani, W.A.P.; Amarasekara, D.A.T.; Kodithuwakku, D.S.; Rathnasiria, P.G.Anaerobic digestion process inhibits due to the presence of ammonia, sulfide, light metal ions (Na, K, Mg, Ca, and Al), heavy metals, and some organics (cholorophenols halogenated aliphatic, N-substituted aromatic, long chain fatty acid). Ammonia is the main inhibitory factor in pig manure as it contains nitrogen. Although it is an important buffer in the process and an essential nutrient for microorganisms, if not controlled, high concentrations causes to operational failures. It is also leading to a low methane yield. Since ammonia has free cell membrane-permeability, it is the active component causing ammonia inhibition. As ammonia is hydrophobic, the molecule diffuses passively into the cell which causes proton imbalance and potassium deficiency. Free ammonia concentration depends on the total ammonia (NH3 + NH4+), pH and temperature. Total ammonia concentrations level of around 1700–1800 mg/l, completely inhibitory to the inoculum which has not adapted. Literature shows that, with adaptation, inhibitory total ammonia nitrogen levels could increase up to 5000 mg/l. By using a semi continues anaerobic digestion process with an anaerobic inoculum and pig manure, can achieve that adapted inoculum. Adapted inoculum can give more than 250ml of bio gas volume per 50ml of pig manure which has 7% w/w solid content. Because of above phenomena methonogen bacteria can be completely inhibited while Acetogen bacteria still can produce acids in a toxic environment. Therefore, acids are formed leading to lower methane yield. Due to that reason, when pig manure is anaerobically digested with adapted inoculum, pH drops from 6.5 to 6.3 during first 3days. There are several methods mentioned in literature to reduce the ammonia inhibition directly in the anaerobic processes such as adaptation of microorganisms, co-digestion, increasing the COD:TKN (Chemical Oxygen Demand: Total Kjeldahl Nitrogen), dilution of the reactor content and adding trace elements. In this research Co digestion strategy was used to minimize ammonia accumulation in pig manure anaerobic digestion process. Pig manure was digested with food waste in different ratios. Adapted inoculum was used for this process.Item E-Waste management in selected institutions in Colombo and Gampaha Districts(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Athukorala, S.M.W.; Handapangoda, H.M.A.K.; Yatawara, M.D.M.D.W.M.M.K.Electrical and electronic waste (e-waste) is one of the most rapidly growing environmental problems in the world including Sri Lanka. This preliminary study was carried out to identify the attempts of e-waste management in selected institutions in Colombo and Gampaha districts. A questionnaire survey followed by interviews was carried out among randomly selected 20 institutions in Colombo and Gampaha districts. Descriptive statistical methods were used to analyze data. Results revealed that about 55% of respondents reuse their e-waste and 15% of respondents continue recycling the discarded e-waste. Most respondents (95%) has knowledge on e-waste and the effects of unsafe disposal. In addition, 60% of respondents were not aware of any projects or activities on e-waste management by government and local authorities. However, most of the types of electronic devices that are used by these institutions were more or less similar. Further, the survey revealed that the respondents showed willingness to contribute to e-waste management and willingness to pay or willingness to accept for a green product which will not harm the health of human and the environment. The study suggests to conduct proper awareness programmes to the employees in the institutions on handing over, disposal and management of e-waste. In addition, proper monitoring programmes of recycling or disposal is utmost important as e-waste contains a substantial amount of valuable recyclable materials and has potential to become a lucrative business in the country.Item Moisture reduction in Municipal Solid Waste (MSW) by parabolic solar dish method(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Heshani, A.L.S.; Abeysinghe, A.M.M.S.M.; Handapangoda, H.M.A.K.The moisture content of MSW in tropical countries is higher when compared with temperate countries due to the climate (hot and humid weather with abundant rainfalls), compositions and types of waste generated. The moisture adversely affects the waste to energy conversion process as the process consumes more energy to evaporate moisture from MSW. Therefore, waste to energy concept receives less attention in MSW treatments, especially in tropical region. However, reduction of moisture of MSW would be beneficial to convert waste into thermal energy effectively and efficiently. Use of solar energy is a widely-practiced strategy to reduce moisture content in many materials. In this concept, the present paper suggests a method to reduce moisture in MSW by utilizing solar energy. Objective of this study is Develop a Model for Moisture Reduction of MSW by using solar energy. The parabolic solar-energy concentration method is applied to convert solar energy into thermal energy. The method is used as a principle of solid waste moisture reduction instrument. Three major components can be identified in the instrument, namely shredder, parabolic dish and compacter. Purpose of shredder is to reduce the size of waste that enables the entry to parabolic center pipes. As well, it increases the surface region of waste to evaporate water vapor without difficulty. The parabolic dish consists with parabolic dish, solar radiation center with hot air fans and waste flow pipes. Concentrated solar energy is centralized by using parabolic dish. Then solar energy is converted into thermal energy when focus onto the counter and exhausted, hot air fan generate Dry Air flow with higher temperature, because of the properties of air flow, it reduces humidity and thereby decrease of moisture content is accelerated. Temperature of dry air flow in center level is higher than boiling point of water (T >100oC), and this high temperature conditions generated from concentrated direct solar energy to center level and heating element converts solar energy into heat through the process of Joule heating, flow passing through this heating element resulting in heating of the air. Contact time of air flow with waste stream depend on moisture reduction of waste. Also, the continuous solid waste stream is transferred through the pipes and speed of flow depends on the decrease rate of moisture content at a center level. Solar electrical energy is used to operate this instrument. This scheme is fully automated and electronic detectors are applied to measure temperature, moisture content. After reducing the moisture content in solid waste, it can be compressed and used to produce pellets. This resultant pellets can be used as fuel. Besides, it can be applied as ecofriendly bricks by mixing with strong solidified materials. In addition, no greenhouse gas emission is expected during the operation. Optimal instrument size depend on the Size of parabolic dish that displays quantity of solar energy concentrated to center point. As most of the industries have to spend a considerable amount of money on reducing the moisture content in the final disposal; especially in the Sri Lankan case, the waste generated is sent to a monopoly holder for further treatment. If industries can use this method as a preprocessing method to reduce moisture content in semi-solid or solid waste, it would reduce a significant cost. The proposed system is controlled according to a computerized system within specified limits. However, further development is needed to overcome bottlenecks and gaps in the system.Item Developing a rapid composting machinery system using Berkeley method(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Handapangoda, H.M.A.K.Municipal solid waste generation and management in most cities especially in developing countries have emerged as one of the stubborn environmental problems at present. This scenario could be attributed to low level of technology as it is not sophisticated and not sufficient to deal with the excessive quantity of waste generation. Recognizing those noteworthy amounts of organic waste fraction of MSW in developing nations like Sri Lanka, there ought to make necessary feasible fitting systems to convert this huge amount into a resource. Composting, one of the environmentally feasible methods that convert organic waste into useful materials brings several drawbacks. This paper suggests a system with computerized automated machineries with the aim of increasing the rate of composting in a comparatively short time period. Berkeley method composting is taken as the principle for this system. The system consists with a shredder, a pill rotator (mixer), an air flow controller, and moisture and temperature controllers. The system is a closed system that implements favorable conditions for the composting process. Air flow, moisture level and temperature can also be controlled in the system. Purpose of shredder is to reduce the size of waste that further facilitate fast composting. Humidity and temperature sensors are used to keep compost pill in optimal level of conditions. Pill rotator (mixer) is rotated periodically in a given time period to facilitate proper mixing to pill. In addition, shredder size, pill rotating time, air supply and moisture and temperature can be changed on waste composition. Advancement of this method is to convert organic materials into usable form in short time period with less space and labor requirement. Energy requirement for the operation process can be generated by solar power is another added advantage of the method. However, further development is needed to overcome bottlenecks and gaps of the system.Item Case study on usage of polythene bags in super markets of Colombo metropolitan and finding an alternative(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Athukorala, U.K.; Gamagedara, D.; Gayangani, E.M.; Chrishanthan, J.E.; Bandara, W.A.R.T.W.Polyethylene bags since their emergence in the 1940s, is an incredibly useful, highly convenient, strong and inexpensive, to both customers and businesses as a reliable way to deliver goods from the store to home. According to statistic, 20 billion polythene bags are being used per day in Sri Lanka. This creates massive amount of non-biodegradable waste which poses a huge threat to human, animal and the environmental health. This study was conducted with the primary objective of evaluating the current usage of polythene in super markets of Colombo District and to find alternatives to minimize the usage of polythene bags in super markets. Primary data were gathered by a questionnaire survey carried out among the four major super market chains as in Cargills Food City, Keells Super, Arpico Super Centre, Laugfs Supermarket to understand the usage of the polythene bags. Secondary data were gathered from observations, discussions, books, electronic media and other sources. Some paper bag alternatives were made; Cement Paper bag with oil paper coating, Cement Paper bag with corn husk as the bottom, Cement Paper bag with oil paper layering and Cement Paper bag with banana tree bark at the bottom to test the mechanical properties and feasibility of the option. The results from the Market survey signifies that averagely around 8 million of polythene bags are issued per month by all the outlets in Colombo district by each super market category. Therefore, study findings revealed that out of the four types of alternatives tested Cement Paper bag with banana tree bark at the bottom would be the best option as it showed the greatest mechanical properties. When look in to the cost associated with the production, all the four types of bags would have to bear the coat of 6.75 to 7.00 LKR. Therefore, Cement paper bag with banana tree bark at the bottom would be the ideal replacement for polythene bags use to pack different types of dry vegetables and food.Item Sustainable usage of solar energy through solar panel systems and implementation of an energy saving method in University of Kelaniya(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Weerasooriya, P.N.; Devinda, D.D.D.D.; Vinujah, M.Sun’s energy is one of the renewable energy sources that falls on earth surface and solar energy can be used as an alternative to electricity produced by burning fossil fuel. This case study was carried out to analyze the amount of energy that can saved through solar panel systems and to evaluate the perceptions of people about energy saving by solar panel system. Attempts were also made to assess the possibility of reducing cost of electricity in the University of Kelaniya through solar panel systems. This study was conducted in Gampaha district and information was collected by interviewing people through a structured questionnaire. The households with solar panel installations were chosen from the client list of a company providing net-metering solar panel systems and accordingly ten household premises where solar energy is used were included in the sample. Forty other households that are not having solar systems were also selected randomly. The data were analyzed using Microsoft Excel. Besides comparison of cost of electricity bill before and after using solar panel in 10 households with net-metering solar systems, degree of awareness of people about the option of solar panel system was determined in relation to education level and economic status. Awareness of household heads with energy saving methods and the percentage saving of electricity bill through installation of net-metering solar system were analyzed. Results indicated that 77% of household heads interviewed were aware of saving energy by solar panel systems and the remaining 23% was not aware. In the households where net-metering solar systems installed, 31.4% - 98.2% of electricity consumption cost was saved. Using gathered data, the potential saving of electricity consumption cost in selected buildings of University of Kelaniya was calculated, and was found that 97.35% of cost of electricity consumption could be saved by installing a net-metering solar energy system. Among general public, moving towards the option of energy saving by solar panel systems would be dependent on educational levels and economic status of household members.Item Assessment of water eutrophication in selected locations of the Diyawanna Oya using visual assessment method(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Samarawicrama, L.D.R.; Sanjeevani, K.S.; Sammani, D.G.P.; Rathnayake, A.K.V.H.; Wijeyaratne, W.M.D.N.Diyawanna Oya is one of the precious assets in the Colombo metropolitan of Sri Lanka. Some parts of Diyawanna oya is currently under the threat of eutrophication due to rapid development and urbanization of the area. There is a large number of low income houses and several large scale apartment complexes in close proximity to Diyawanna oya. Quality of water and habitat in most of the areas is mainly influenced by public effluent discharges to the canal system, which has a significant environmental effects on the wetland. The objectives of the case study were to use the visual assessment method to compare the levels of eutrophication and to identify the perspectives of the local community on the eutrophication. Three sites were selected for the study and, sites 1 and 2 were rehabilitated sites while site 3 was a non-rehabilitated site. Replicate water samples were collected from each site to cover wet and dry seasons. In visual assessment, presence of Pheriphytons , Phytoplankton, Free floating aquatic plants, Rooted submerged plants, color and odor of water was ranked according to standard visual assessment criteria. Face to face interviews using a questionnaire were carried out by interviewing 40 individuals in the local community. Considerable amount of Pheriphytons, Phytoplankton, Free floating aquatic plants, Rooted submerged plants were observed in sites 1 and 2 while site 3 indicated an elevated level of phytoplankton. The community survey revealed the lack of knowledge of the respondents on eutrophication is the major cause for eutrophication associated problems. The results of the community survey revealed that, majority of the respondent population (74.6%) that lives close proximity to Diyawanna oya does not use the water that can be obtained from that water body for any commercial activity as a result of heavy water pollution, lack of cleanliness and hygiene , but few people (25.6%) uses water that can be obtained mainly for washing vehicles and for fishing activities During the survey it was noted that the residents of the area have frequently suffered from various skin diseases (especially during the rainy season) and vector borne diseases such as Dengue and Filariasis. Majority (59%) of the respondents were not aware of the animal kills associated with eutrophication and related problems. While (41%) expressed observation of fish and bird kills from time to time. The results of this case study shows that Diyawanna oya is heavily polluted with sewage, domestic organic waste and cleaning materials. The pollution is worsened due to over population, urbanization, decrepit infrastructure, inadequate cleaning programs and malfunctioning in the existing programs and also due to breaches in local government management system. The results of this study highlights the immediate control measures to overcome the environmental impacts of eutrophication in Diyawanna oya.