Browsing by Author "Takahiro, K"

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item: Conference-Full-text
Characteristics of municipal solid wastes from selected plots located at up-slope and down-slope of the dumping site: a case study in Udapalatha/Gampola
(2013-11-13) Wijewardane, NK; Takahiro, K; Mowjood, MIM; Ken, K; Kurukulasuriya, LC
Open dumpsite has become the most widely used and common practices in most of the developing countries in waste management due to their lack of will, technology, capital and virtuous attitudes. This has elevated the risk to the ecosystem and humans derived by the improper dumping of waste in bare lands, sloping lands (valleys, river banks), wet lands etc. Characterization of waste is an important primary stage in studying dumpsites in sloping lands to identify its effects and potential remedial actions, and to develop new technologies to reduce their adverse effects on the environment and society. In this research, waste characteristics of some selected plots located at up and down slope of a dumpsite were studied to identify the possible difference and their relationships with the slope. The results revealed that waste characteristics such as ash content, combustible content, ignition loss and aggregated soil content vary in the plots located at up and down slope, suggesting that the rolling and sliding of larger particles in high sloping dumpsites has a profound effect in varying waste characteristics. This was further confirmed by the particle size distribution of both plots.
item: Conference-Full-text
Characterization of landfill leach ate from municipal solid wastes landfills in Sri Lanka
(2013-11-13) Sewwandi, BGN; Takahiro, K; Kawamoto, K; Hamamoto, S; Asamoto, S; Sato, H
Open dumping of municipal solid waste (MSW) is the most common way of handling solid waste in Sri Lanka due to high cost involved with advanced technologies for landfilling, lack of technical capacity, lack of know-how to manage landfill sites, and so on. Landfill leachate generated from the MSW landfill sites must be treated before dispose into the environment as it creates many social and environmental problems. Characterization of landfill leachate is important to identify the most critical pollutants present in the leachate and thereby to introduce suitable and applicable treatment technologies such as in-situ permeable reactive barrier technologies for contaminant remediation. Therefore, the objective of this research is to characterize landfill leachate collected from several MSW landfills in Sri Lanka. The leachate samples were collected from 12 landfill sites located in Matale, Hambantota, Kataragama, Bandaragama, Kolonnawa, Gampola, Gohagoda, Wennappuwa, Rathnapura, Negombo, Galle, and Matara. For the collected samples, general water quality parameters (pH, EC, DO, ORP, and SS), organic pollutants (BOD5, COD, TOC, IC, TN, TP), typical anions and cations (Cl-, SO42-, NH4+, K+, Mg2+, Ca2+, etc), and heavy metals (Cr, Mn, Fe, Se, Pb, etc) were measured. The results showed that most of the pollutants (F-, Cl-, PO43-, NH4+, Fe, Se, Pb, BOD5, and COD) exceeded the maximum tolerance limits in Sri Lankan Standards. It was found that the BOD5/COD ratio ranged from 0.01 to 0.6 for the most samples and the highest value of 0.6 was observed in the Kolonnawa sample. Measured EC values for all samples were high and varied ranging from 4.5 to 38.3 mS/cm, indicating the biological treatment system alone would not be effective in reducing the pollutants especially for heavy metals. The results of this study will be used in developing site specific remediation technologies in landfill leachate treatment.
item: Conference-Full-text
A statistical approach for landfill classification in Sri Lanka based on waste characteristics
(2013-11-13) Wijewardane, NK; Takahiro, K; Ken, K; Mowjood, MIM; Herath, GBB
Several parameters have been used to characterize wastes in dumping sites. It is not possible to measure all the parameters and also those parameters are not equally important for management options which are decided on priority basis. In fact some parameters are closely related to other parameters. Therefore, parameters have to be clustered for classifying the wastes in dumping sites. A study was conducted to develop a statistical procedure using available tools to cluster landfills based on landfill waste characteristics. Five waste samples were collected from three landfills in the central province of Sri Lanka to compare the waste characteristics followed by the use of data to elaborate the clustering procedure. Correlation diagrams, principle component and cluster analysis have been applied for eight parameters; Moisture content, Ash content, Unit Volume mass, Lower heating value, Particle density < 2mm, Plasticity index, pH and Electrical Conductivity. Statistical analysis was able to extract two main principle components as primary, and secondary which accounted for 92.1 % of the total variability establishing two main classes which can be further improved to be more representative and precise with the increased number of samples subjected to the analysis.