Browsing by Author "Hettiarachchi, M"

Now showing 1 - 6 of 6

item: Conference-Extended-Abstract
Design of in-vessel continuous composting process for handling sugar industrial waste
(2006) Ariyaratne, H; Ishiyama, EM; De Alwis, A; Hettiarachchi, M; Gunasekera, MY
During the past decades Sri Lanka has not satisfactorily processed agricultural products which were a major burden to the national economy. Realizing the importance of value addition, the relevant processing of agricultural products have magnified significantly, resulting in a parallel generation of processed agricultural wastes. The major focus of this paper is the introduction of a high rate in-vessel composting process for handling one of the process wastes in the sugar industry.
item: Article-Full-text
The eco-social transformation of urban wetlands: A case study of Colombo, Sri Lanka
(Elsevier, 2014) Hettiarachchi, M; Morrison, TH; Wickramsinghe, D; De Alwis, A; McAlpine, CA
Recent studies in both the environmental sciences and geography highlight unforeseen ecological transformations occurring in eco-social landscapes. These transformations often result in ‘novel’ or ‘hybrid’ ecosystems that differ from the original ecosystems both in ecological character and social setting. However, little is known about the causes, consequences, and dynamics of such transformations in complex urban environments and the consequences for highly sensitive ecosystem types such as wetlands. This paper investigates the environmental history and recent ecological transformations in the urban wetlands of Colombo, Sri Lanka. Our methodology includes a combination of techniques from environmental history, wetland science and urban ecology. We investigate the ecological changes in the wetlands from colonial times to the present and establish relationships among wetland ecology (the hydro-soilvegetation nexus), landscape change, community, and governance factors. We conclude that from 1980 onwards, the Colombo urban wetlands have undergone an overall transformation in both wetland type (composition and structure) and the social setting. Hydrological modification, watershed urbanization and the changes in ecosystem use were identified as the main causes of wetland transformation with the causes and consequences of the transformation having complex feedback loops. We synthesize these relationships into a post hoc conceptual model that will be of broader utility as a general framework to understand eco-social interactions in the governance of urban ecosystems.
item: Conference-Abstract
Environmentally responsible selection and management of construction materials in disaster reconstruction
Fonseka, C; Hettiarachchi, M; Van Breda, A; Elwood, JP
Disaster reconstruction has become an important component in built environment planning in recent decades as the frequency, scale and intensity of both natural and manmade disasters are increasing globally. Despite the significant improvements in the disaster management sector, disaster recovery and reconstruction, especially in the developing world, faces challenges regarding efficiency and widespread social, economic and environmental impacts. The construction industry is typically engaged in a range of critical activities after a disaster, from provision of immediate temporary shelter to permanent reconstruction of public and private infrastructure. Therefore, sourcing, use and disposal of construction material is an important aspect of disaster reconstruction planning. On the one hand, massive resource shortfalls arise as a result of the new demand created by reconstruction needs, upsetting the markets and usual procurement practices of construction material. On the other, exponential increase of material extraction, transport and disposal can cause significant environmental and social impacts. This paper presents a framework in the form of a matrix which assists the ground-level decision-makers to select construction material in post-disaster reconstruction projects. This framework was developed considering material selection factors such as their relative importance in environmental sustainability, better practices in design, storage, use and disposal. The paper discusses this approach against three major cases of disaster reconstruction in the past decade: Post-Tsunami Reconstruction in Sri Lanka, Post-earthquake reconstruction in Haiti, and Typhoon Haiyan reconstruction in the Philippines.. The paper identifies the challenges that the construction industry faces in unexpected events and highlights better practices to enable efficient and sustainable recovery and a resilient built-environment.
item: Conference-Full-text
Natural and enhanced contaminated waters
(2005) Hettiarachchi, M; Karunarathne, S; Dissanayake, K
Chromium is a highly soluble transition metal of vital industrial importance. It occurs in both trivalent and hexavalent forms. Due to many well identified adverse impacts of chromium to human health and natural ecosystems, treatment of chromium contaminated waters and remediation of contaminated aquatic systems has become a major concern of environmental engineers. The currently practiced conventional mechano-chemical treatment systems for remediation of chromium contaminated waters have high operational costs, therefore alternative natural attenuation systems are becoming the focus of modern research. This paper presents an analytical review on application of natural attenuation methods in removal of chromium in Sri Lanka. Some results presented on phyto-remediation and sorption of chromium by gravels are original research findings of the authors. Some possibilities sited in-literature are also reviewed.
item: Conference-Full-text
Sword ferns for phytoremediation of chromium contaminated waters
(Department of Earth Resources Engineering, 2006-10) Hettiarachchi, M; Karunarathne, S; Dissanayake, K; Karunaratne, S
Chromium is a highly soluble transition metal of vital industrial importance. It occurs in both trivalent and hexavalent forms. Due to many well identified adverse impacts of chromium to human health and natural ecosystems, treatment of chromium contaminated waters has become a major concern and challenge for environmental engineers. The currently practiced conventional mechano-chemical treatment systems for remediation of chromium contaminated waters have high operational costs, especially when the concentrations are low. Therefore alternative natural attenuation systems are becoming the focus of modem research. This paper presents a research to asses the applicability of Common Sword Ferns in phytoremediation of water contaminated with low or medium concentration of bot trivalent and hexavalent chromium. Saword ferns (N. Exaltata) showed very high removal rates (about 99%) in a Hydroponic medium upto 50 ppmcontamination of T-Cr. The mass balance shows that most of the Cr taken up by the plant is retained in the roots (about 75 % or 3500 mg/kg). Little is translocated to above-ground tissues (4% or 120 mg/kg). Therefore the mechanism of removal is mainly Rizofiltration. The mechanism of uptake may be Biosorption or Active uptake by root cells. N. Exaltata hardly shows any symptoms ofPhyto-toxic affects upto 50 ppm of Cr +3, and 15 ppm ofCr+6• But in a Soil water system mass balances show that most of water soluble Cr+3 is sorbed to soil (about 90%). N. exaltata is poor in de-mineralizing, mobilizing and uptake of soil bound Cr +3. Sand has a remarkable capacity to immobilize Cr+3 in water.
item: Conference-Abstract
WireMe – IoT development platform for everyone
(2017) Pathirana, D; Sonnadara, S; Hettiarachchi, M; Siriwardana, H; Silva, C
In this paper we present the work in progress of WireMe IoT development platform, a simple way to deploy IoT systems in an intuitive approach. WireMe platforms’ simplified software and hardware modules enables users to deploy personalized web interface and program their hardware modules to achieve their home automation tasks without having deep technical knowledge in either of the above domains, with the help of visual programming. Apart from that, advanced users may extend this approach with the framework provided so that they can build their hardware and software modules to support our WireMe IoT platform as well. With this platform, kids can learn to build programming logics and learn about programming with code generation as well as people can build their typical IoT automation systems to monitor and control their IoT modules.