Browsing by Author "Kodituwakku, K.A.R.K."

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Evaluation of the Spatial and Temporal Trends in Household Solid Waste Disposal in Sri Lanka Using Geo-Informatics and Statistical Tools
(Department of Zoology, University of Kelaniya, Kelaniya, Sri Lanka, 2014-06) Udayanga, N.W.B.A.L.; Kodituwakku, K.A.R.K.
Generation of solid waste in large quantities and their improper disposal associated with the accelerated economic and technological advancement and population growth have raised growing concerns throughout the world including Sri Lanka. The complication of the composition and the quantitative increase of household waste have become a major issue in Sri Lanka. Localized trends in solid waste disposal play a critical role in drafting of policies and management plans for effective management of solid waste. Thus, a statistics and geoinformatics based analysis of the recent trends in household solid waste disposal was carried out to identify the characteristic disposal methods of household solid waste of each district, and to evaluate both spatial and temporal trends in household solid waste disposal patterns in Sri Lanka in order to facilitate the effective management of solid waste. Commonly practiced household solid waste disposal methods and percentage contribution of each method in each district in 2006-2007, 2009-2010 and 2012-2013 were obtained from the Department of Census and Statistics, Sri Lanka. The data were then subjected to Principal Component Analysis (PCA) to identify the major characteristic household solid waste disposal methods and the temporal variation of the household solid waste disposal methods in each district, by using PRIMER V 5.2.9. software package. Characteristic disposal method(s) of household solid waste in each district during the study period were recognized based on the scores of the Principal Components and districts that exhibit similarities in the disposal methods were grouped into clusters. Spatial maps of above recognized clusters that exhibit similar characteristic disposal methods were prepared using Arc GIS 9.2 and the spatial and temporal variation of such clusters were analyzed to identify the recent trends in household solid waste disposal. Generation of solid waste in large quantities and their improper disposal associated with the accelerated economic and technological advancement and population growth have raised growing concerns throughout the world including Sri Lanka. The complication of the composition and the quantitative increase of household waste have become a major issue in Sri Lanka. Localized trends in solid waste disposal play a critical role in drafting of policies and management plans for effective management of solid waste. Thus, a statistics and geoinformatics based analysis of the recent trends in household solid waste disposal was carried out to identify the characteristic disposal methods of household solid waste of each district, and to evaluate both spatial and temporal trends in household solid waste disposal patterns in Sri Lanka in order to facilitate the effective management of solid waste. Commonly practiced household solid waste disposal methods and percentage contribution of each method in each district in 2006-2007, 2009-2010 and 2012-2013 were obtained from the Department of Census and Statistics, Sri Lanka. The data were then subjected to Principal Component Analysis (PCA) to identify the major characteristic household solid waste disposal methods and the temporal variation of the household solid waste disposal methods in each district, by using PRIMER V 5.2.9. software package. Characteristic disposal method(s) of household solid waste in each district during the study period were recognized based on the scores of the Principal Components and districts that exhibit similarities in the disposal methods were grouped into clusters. Spatial maps of above recognized clusters that exhibit similar characteristic disposal methods were prepared using Arc GIS 9.2 and the spatial and temporal variation of such clusters were analyzed to identify the recent trends in household solid waste disposal.
Impact of one month old sludge as top inoculum layer of biogas floe rate in dry batch type digesters
(Sri Lanka Association for the Advancement of Science, 2015) Kodituwakku, K.A.R.K.; Yatawara, M.
Management of coastal resources: Lessons learnt from two coastal communities occupying the west coast of Sri Lanka
(Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Kodituwakku, K.A.R.K.; Wazir, S.R.; Aththanayake, A.M.H.L.; Silva, T.M.S.D.G.; Malshani, E.M.S.; Partheepan, K.; Thevendran, K.; Udayanga, N.W.B.A.L.; Sumanapala, A.P.; Jayanga, B.H.N.; Chandrasekara, W.U.
The livelihood of the coastal communities is mostly dependent upon the natural coastal resources. Questionnaire based field surveys were carried out focusing on the communities in two coastal towns on the west coast of Sri Lanka, Negombo and Chilaw, with an objective of evaluating and assessing the governance and the sustainable utilization and management of coastal resources there. The survey was carried out in December 2013, and consisted of face-to-face interviews and gathering information from households along the beach border that were selected through systematic sampling approach and from randomly selected stake holders on the beach, to satisfy the questionnaire. The chief executive officers of local government authorities viz. regional office of the Coast Conservation and Coastal Resources Management Department, Municipal Councils, Police Stations, and where necessary the incumbent of the Catholic Church in the area, were also interviewed to evaluate their role over the governance and management of the coastal resources. The analysis of survey data revealed that the major resource based income generation activities in Negombo beach was tourism (68%) while in Chilaw it was fisheries (75%). The major environmental issues in Negombo beach were pollution (35%), littering the beach by local tourists (27%) and illegal building constructions (20%), while those in Chilaw were pollution (43%), illegal house constructions (25%) and coastal erosion (26%). Therefore, the Negombo beach was cleaner (76%) than the Chilaw beach (27%). Since the major income generation activity in Negombo beach was tourism, the local government authorities paid special attention in maintaining law and order, carrying out beach cleaning programmes, daily removal of litter and waste, carrying out community awareness programmes on the importance of beach on tourism and usage of soft and hard engineering techniques to prevent coastal erosion. In addition, every tourist hotel was found to clean the beach façades under their purview, and beach vendors also supported these programmes. In fisheries dominated Chilaw, the inputs by the local government authorities were minimum except the Urban Council collecting household waste on weekly basis from the roadside bins. However, the village has a very strong community based management strategy led by the Catholic Church. The church plays a pivotal role in harmonizing the village, educating villagers on the proper disposal of garbage, preventing sand mining and use of harmful fishing practices, and coordinating the local government authorities to maintain proper sanitation as well as law, order and peace in the area. In contrast, the tourism dominated coastal zone in Negombo is managed by a strong co-management strategy that involves the contribution of the local government authorities and major stakeholders on the beach such as tourist hotels and the local community on the governess and sustainable management of the coastal zone.
Public participation in solid waste management in Kolonnawa urban council in the western province in Sri Lanka
(Department of Zoology and Environmental Management, University of Kelaniya, 2015) Kodituwakku, K.A.R.K.; Yatawara, M.D.M.D.W.M.M.K.
Removal of Heavy Metals from Sewage Sludge by Floating Macrophytes; Eichhornia crassipes (Mart.) Solms., Pistia stratiotes L. and Salvinia molesta Mitch
(19th Conference on Postgraduate Research, International Postgraduate Research Conference 2018, Faculty of Graduate Studies,University of Kelaniya, Sri Lanka, 2018) Kodituwakku, K.A.R.K.; Yatawara, M.D.M.D.W.M.M.K.
The land disposal of sewage sludge generated from industrial waste water treatment plants is a major environmental concern as the sludge has been contaminated with heavy metals. Hence, immobilization of such metals prior to land disposal reduces the burden of posing environmental risks. The present study was therefore planned to assess the efficacy of Eichhornia crassipes, Salvinia molesta and Pistia stratiotes to control heavy metals in diluted sludge (1:5) from the Common Waste Water Treatment Plant (CWWTP) in Biyagama Export Processing Zone, Biyagama, Sri Lanka. Equal weights of the second generation of above three plant species were introduced to batch type constructed wetlands of 63 L capacity. The experimental set-up was kept for 28 days. The weekly harvested plant and sludge samples were pre-treated and digested using Mars 6 Microwave digester. The heavy metals Zn, Pb, Ni, Cd and Fe analyzed using Atomic Absorption Spectrophotometer (Analitikjena NOVA 400P). The methods used for sample preparation, digestion and quantificational analysis were established generating satisfactory analytical precision. Statistical analysis was performed using Minitab 14 software. The results revealed that root accumulated much higher concentrations (more than 50.0%) of Fe, Zn, Pb, Ni and Cd than shoots. The plant uptake of Fe, Zn, Pb, Ni and Cd increased with increased exposure time. Nevertheless, the removal capability of metals by these plants differed from each other. S. molesta showed significantly higher Zn (36.0% in Cycle-1 and 40.0% in Cycle-2), Fe (26.6% in Cycle-1 and 25.6% in Cycle-2) and Ni(26.9% in Cycle-1 and 33.7% in Cycle-2) removals from sludge than E. crassipes and P. stratiotes by 28 days exposure period for both cycles (p < 0.05; ANOVA after arc-sign transformation of data). In addition, E. crassipes showed significantly higher Pb (41.2% in Cycle-1 and 46.4% in Cycle-2) removal than P. stratiotes and S. molesta. Moreover, P. stratiotes showed significantly higher Cd (27.1% in Cycle-1 and 29.3% in Cycle-2) removal than other two species (p < 0.05; ANOVA after arc-sign transformation of data). The present study concludes that floating macrophytes E. crassipes, S. molesta and P. stratiotes significantly reduce the heavy metals Zn, Pb, Ni, Cd and Fe from sewage sludge