Browsing by Author "Bandara, NJGJ"

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item: Thesis-Abstract
A Tool for initial environmental assessment of road rehabilitation projects
Ambalavanar, J; Bandara, JMSJ; Bandara, NJGJ
The environmental assessment process involves the prediction of changes over time in various environmental aspects as a result of a proposed project. The prediction of the nature, extent, and magnitude of environmental changes likely to result from a proposed project is aided by various tools and techniques, the choice of which depends upon the impacts of concern, data availability or lack thereof, and the appropriate specificity of quantitative models. However, the choice of the appropriate method for conducting an environmental assessment can only be guided by certain criteria, but no single method will meet all the necessary criteria. The environmental assessment is mandatory in Sri Lanka since 1988 only for the projects listed under the category of "prescribed projects" in the National Environmental Act (NEA)The road rehabilitation projects do not fall in to the above category unless it falls within sensitive areas or resettlements of more than hundred families are involved or projects located wholly or partly outside the coastal zone with a road length exceeding 10kms. However, for funding purposes foreign agencies have made this mandatory even though they exempted from the environmental assessment according to the NEA. In practice this study might consume more time depending on the size of the project. As a result we might loose foreign aid allocations and prospective donors. Therefore a quick alternative method for environmental assessment is essential. This study develops a checklist for Initial Environmental Assessment (IEA)of road rehabilitation projects which consumes only a week or so to carry out the IEA. The checklist was generated based on the literature survey, discussions with subject experts, questionnaire surveys and field observations made on road rehabilitation projects. It identifies activities, corresponding environmental impacts and suitable mitigations for each component of the road rehabilitation project. This study is unique because the attempts were made to provide much information as possible on the techniques and methods available for handling different issues in the environmental assessment process and it is specially designed to suit the Sri Lankan conditions. Further, it gives possible mitigatory measures for each impact and also comprehensively covers all relevant impacts identified in presently use checklists in Sri Lanka there by cut down the amount of time required for preparation. The RDA and other road sector organizations could use this checklist in future for their IEA studies. It is hoped fervently that, this study would provide a significant step ahead in improving the process of IEA and hence they may absorb more foreign aid funds and attract prospective donors. Also this study recommends that, the use of checklist by a panel of experts, initiating a search for new cost effective mitigation measures, include the conditions stipulated on environmental clearance in to the project contract document, deploying a strong monitoring team, make available an environmental complain form at the project site, conduct site meetings regularly to discuss the issues ' problems, report the progress to relevant authorities and providing training for the officials.
item: Conference-Extended-Abstract
Improved and transparent methodology to compare alternatives in transport sector environmental impact assessments
(2006) Bandara, NJGJ; Bandara, JMSJ
The objective of an environment impact assessment (EIA) is to ensure that the development options under consideration are environmentally sound and sustainable and environmental consequences are recognized and taken in to account early in the project design. A number of EIA reports related to transport sector projects have been prepared during the last 15 years in Sri Lanka. A careful evaluation of these reports clearly indicate that majority of them have not fulfilled the objectives of an EIA even though they appear to satisfy the terms of reference (TOR) given by the project approving agency.
item: Thesis-Full-text
Phthalic acid esters in urban watercourses of Colombo and their treatment
(2019) Danushika, UAAG; Jayaweera, MW; Bandara, NJGJ; Manatunge, JMA
Urbanization of many cities with industrial, commercial, and residential areas in the world takes place at an unprecedented scale. Di-2 Ethylhexyl Phthalate (DEHP) is commonly used as a plasticizer in a number of industries which has become a precursor to cause DEHP contamination of watercourses through untreated or partially treated industrial wastewater effluents. Such contamination may result in bioaccumulation and bio-concentration in biota, so that it will adversely affect humans through the food chains. The presence of six PAEs (dimethyl phthalate (DMP), diethyl phthalate (DEP), di (n-butyl) phthalate (DBP), benzyl butyl phthalate (BBP), bis(2-ethylhexyl) phthalate (DEHP), and di(n-octyl) phthalate (DnOP)) in 22 shallow urban watercourses in Colombo and suburbs of Sri Lanka was investigated and the effect on fish community was analyzed. EPA 8061A method was used in analyzing PAE concentrations in samples and Gas Chromatography / Mass Spectrometer was used. Titanium dioxide (TiCb) and Modified Coal-derived Fly Ash (MCFA) were successfully synthesized and characterized using Fourier-Transform Infrared Spectroscopy, Environmental Scanning Electron Microscopy, and X-ray diffraction. Effectiveness and efficiency of TiC>2 and MCFA in the removal of DEHP from wastewaters was identified. According to the results obtained, the average concentrations of DEP, DBP, BBP, and DEHP in all watercourses varied between 2.5-265.0, 1.0-32.0, 61-108, and 12— 165 pg/L, respectively. DMP and DnOP values were below the limits of quantification (DMP-0.5 pg/L, DnOP-l.O pg/L) for all watercourses. DEHP was the most abundant PAE in many watercourses. The significant factors affecting the ubiquitous presence of PAEs in watercourses are the inherent properties of each PAEs, the presence of industrial and household products with great potential for the migration of PAEs in the sub-catchments, and the quality of receiving water. The contamination levels of PAEs in most of the watercourses are alarmingly high, as evidenced by higher concentrations of DEHP and DBP than those of Canadian permissible levels for the protection of aquatic life (16 and 19 pg/L). iii Isolated lakes which are not adjoining to urban industries, showed depleted adverse effects, most of the urban lakes were observed a significant potential for adverse effects on fish. Thus, the ecological risk of PAEs in urban watercourses in Sri Lankan environments should be considered. TiC>2 nanoparticles were used to remove DEHP through photocatalysis. The photocatalysis with TiC>2 for the destruction of DEHP was found to be a promising technique in removing DEHP from industrial wastewaters. The most economical dosage of TiC>2 would be one gram and it needs to be photocatalysed for a period greater than 44 minutes for complying with the permissible level stipulated for DEHP (16 pg/L) for the protection of aquatic life. The cost of the photocatalysis with Ti02 was around Rs.120 and the cost could be further reduced when the material (TiC>2) is reused for subsequent usage. Even TiC>2 was reused for five times, inherent properties for photocatalysis were not changed. An initial level of 171 pg/L of DEHP was successfully removed with 98% efficiency by three grams of MCFA dosage and consequently, regenerated with NaOH twice for the effective use. The maximum monolayer adsorption capacity of MCFA was 63.6 pg/g of DEHP. MCFA is a potential candidate for the effective removal of DEHP from industrial wastewaters as its raw materials are readily available.
item: Conference-Abstract
Tool for initial environmental assessment of road rehabilitation projects
(Department of Civil Engineering, University of Moratuwa., 2010) Ambalavanar, J; Bandara, NJGJ; Bandara, JMSJ; Pasindu, HR
The environmental assessment process involves the prediction of changes over time in various environmental aspects as a result of a proposed project. The prediction of the nature, extent, and magnitude of environmental changes likely to result from a proposed project is aided by various tools and techniques, the choice of which depends upon the impacts of concern, data availability or lack thereof, and the appropriate specificity of quantitative models. However, the choice of the appropriate method for conducting an environmental assessment can only be guided by certain criteria, but no single method will meet all the necessary criteria. The environmental assessment for development projects are mandatory requirement in Sri Lanka since 1993. The detailed assessments are required only for the projects fall under the category of prescribed projects of the National Environmental Act. The Road rehabilitation projects do not fall in to the above category unless it falls within sensitive areas or resettlements of more than hundred families are involved. However, for funding purposes foreign agencies have made this mandatory even though they exempted from the Environmental Assessment according to the NEA act. Therefore a quick alternative method for environmental assessment is essential for this purpose. For these reasons, the present study was conducted to develop a checklist for initial environmental assessment of road rehabilitation projects which only consumes a week or so to carry out the environmental assessment. The checklist was generated from the information collected from literature survey, questionnaire surveys and field observation of six actual road rehabilitation projects from planning, construction and operational phases. It identifies activities, corresponding environmental impacts, suitable mitigation and the monitoring requirement for each component of road rehabilitation projects. Notwithstanding the lesser time it takes, it will certainly help Sri Lanka to absorb more foreign donors and aids with effective assessments and also to attract prospective donors. The checklist is user friendly as activities and impacts are predetermined and linked to each other and it could be used in any road rehabilitation projects by the subject experts in order to be effective and accurate. Also the study discovered that to avoid opposition from the general public for the proposed development, the compensation should be paid at the planning stage and a strong monitoring system should be implemented during construction and operational phases. A search for new cost effective mitigation measures is recommended and the checklist has to be upgraded accordingly.
item: Conference-Abstract
Use of Ultra-Violet assisted Titanium Dioxide photocatalysis for the removal of di (2-ethylhexyl) phthalate from industrial wastewaters
Danushika, UAAG; Jayaweera, MW; Bandara, NJGJ; Manathunge, JMA; Gunawardena, WB
Urbanization of many cities with industrial, commercial, and residential areas in the world takes place at an unprecedented scale. Di (2-ethylhexyl) Phthalate (DEHP) is a commonly used plasticizer in number of industries and becomes a precursor to cause DEHP contamination of watercourses through untreated or partially treated industrial wastewater effluents. Such contamination by DEHP may result in bioaccumulation and bio-concentration in biota so that it will adversely affect humans through food chain. Titanium dioxide (TiO2) nanoparticles were experimented to remove DEHP through photocatalysis. The photocatalysis with TiO2 for the destruction of DEHP was found to be a promising technique in removing DEHP from industrial wastewaters. The most economical dosage of TiO2 would be one gram and it needs to be photocatalysed for a period of approximately 45 minutes for complying with the permissible level stipulated for DEHP (16 μg/L) for the protection of aquatic life. The cost of the photocatalysis with TiO2 was around Rs. 120 and the cost could be further reduced when the material (TiO2) is regenerated for subsequent usage. TiO2 was regenerated for three times with inherent properties for photocatalysis being not changed. This technique could be successfully applied to lessen the DEHP levels in the urban watercourses of Sri Lanka.