http://dr.lib.sjp.ac.lk/handle/123456789/8078 2026-01-07T06:15:41Z 2026-01-07T06:15:41Z Kumara, A.M.I.U. Jayathilake, W.G.A.N. Drechsel, P. Fernando, S. http://dr.lib.sjp.ac.lk/handle/123456789/8242 2019-01-28T05:21:16Z 2018-11-01T00:00:00Z

Supermarket Food Waste and Current Waste Reduction, Resource Recovery and Reuse Practices-Case Study from Colombo Metropolitan Area, Sri Lanka Kumara, A.M.I.U.; Jayathilake, W.G.A.N.; Drechsel, P.; Fernando, S. Estimated as nearly a third of global food production, food waste (FW) is a global challenge of pressing concern. Food losses occur throughout the food supply chain as food is grown and travels from the farmer to the consumer, with the largest losses incurred during transportation and retailing. Towards the end of the chain, the potential economic benefit of reducing waste per food unit is increases since money and resources are invested at every stage of the value chain. A study was conducted to analyse the quantities of FW generation in supermarkets, and existing waste reduction (WR) and resource recovery and reuse (RRR) options, opportunities and challenges. The supermarket-chains selected for the study were Cargills, Keells, Arpico and Laugfs. The commercial capital of the country, Colombo Metropolitan area was selected as the study area. Due to life style and high income by the residents, this area has the highest supermarket density in the country. One executive officer from the respective chain headquarters, and five outlet managers were interviewed from each supermarket-chain (n=20). The analysis focused on vegetables, fruits, fish, meat, groceries, bakery items and packed perishables. Selected outlets (n=5 per chain) were anonymously visited to observe existing practices, and to verify received information. All four supermarket-chains employ various WR/RRR strategies to reduce food waste such as using damage minimizing mechanisms during the transportation and on the shelves by the means of using crates and maintaining chilled environment, avoiding overstock by studying previous sales records, offering discounts for selected food categories to minimize wastage and other strategies linked to quality control (like expiration rate). The composition of the average monthly waste output from a supermarket outlet was dominated by organic wastes from vegetables (46%) and fruits (40%). Fish wastes (6%) and meat wastes (6%) were also noticeable in contribution. The average economic loss for supermarkets due to FW was estimated as nearly 216,000 LKR/month/outlet across the four chains (SD: 114002). Outlets that were practicing comparatively robust WR/RRR strategies such as discounting prices, preparing value added products by means of juices, salads or boiled vegetable packs from the fruits and vegetables were able to minimize associated economic losses. Supermarkets should be encouraged to experiment and support more WR/RRR options such as reuse leftovers as animal feed, energy recovery etc. and motivate customers to buy and consume optically imperfect foods, promoting related regulatory frameworks and seeking other incentives.

2018-11-01T00:00:00Z Wickramasinghe, W.A.W.I.C. Lasitha, D.S. Samarasekara, A.M.P.B. Amarasinghe, D.A.S. Karunanayake, L. http://dr.lib.sjp.ac.lk/handle/123456789/8241 2019-01-28T05:29:27Z 2018-11-01T00:00:00Z

Synthesis of Nanocellulose from Rice Straw Wickramasinghe, W.A.W.I.C.; Lasitha, D.S.; Samarasekara, A.M.P.B.; Amarasinghe, D.A.S.; Karunanayake, L. Polymers are composed of very high molecular masses formed by the combination of large number of simple molecules. They are a highly diverse class of materials which are available in all fields of engineering today. Polymers can be classified into two different types namely naturally occurring polymers and synthetic or man-made type polymers. Naturally occurring biopolymers were known materials before synthetic polymers appeared in the society. Synthetic polymers have a negative impact on ecosystems due to non degradable nature after the specific purpose. Bio-based polymers have become feasible alternatives to conventional petroleum-based polymers in sustainable development. Nanomaterials are considered as a critical tool for various sectors such as textiles, energy, environment, electronics, photonics, food, agriculture, biomedicine and health care. Nano scale materials provide superior properties due to their high surface area compared to their respective bulk structure. Rice is the most important crop occupying approximately 35 percent of the total cultivated area in Sri Lanka. Approximately 1.8 million farm families are occupied in paddy cultivation in the country. Rice straw is the major waste component that appears product of rice harvest. It is not currently used to convert into value added product. The cellulose is the most abundant renewable bio-polymer resource available on earth today. The rice straw of BG 352 was collected after harvesting in 2018 from Polgahawela paddy cultivation area in Sri Lanka for this research. Cellulose was extracted from agricultural waste using dewaxing, delignification and hemicellulose and silica removal treatments. Extracted cellulose was characterized by Fourier transform infrared spectroscopic technique (FTIR). SEM images revealed that isolated cellulose was mostly in the form of fibers with diameters ranging from 2-8 μm. The cellulose can be extracted from rice straw with high purity level. The yield of extracted cellulose is around 21%. Nano crystalline cellulose is a light solid substance can be obtained from plant matter which comprises nano sized cellulose material. This type of nanocellulose can be used in pharmaceutical, food and medical industries. Nanocellulose can be used as a food packaging material that prevents the spoiling of food contents and entry of oxygen in the food contents. Nano crystalline cellulose was synthezed from cellulose by following the acid hydrolysis, quenching, centrifugation, dialysis sonication and freeze drying processes in this research. Synthesized nano crystalline cellulose materials were identified as 5-70 nm diameter using SEM images. Therefore, locally available rice straw can be used as a source to synthesize nano crystalline cellulose.

2018-11-01T00:00:00Z Piyathilaka, A. Ranaweera, S. Sewwandika, N. http://dr.lib.sjp.ac.lk/handle/123456789/8240 2019-01-28T05:30:09Z 2018-11-01T00:00:00Z

Preparation and Characterisation of Waste Tire Pyrolytic Char Piyathilaka, A.; Ranaweera, S.; Sewwandika, N. Accumulation of waste tires is a serious environmental issue around the world. As a developing country, Sri Lanka also generates several hundred tons of waste tires every year. At the moment, there is no clear solution to dispose waste tires; however, pyrolysis is of interest to obtain tire pyrolytic oil which has a beneficial value as a fuel for broilers in local industries. After the pyrolysis, a black color-solid waste is formed as a byproduct which has no any economic value. In the pyrolysis process, waste tires are used as a feedstock and heated up to 400-450° C in a closed reactor in absence of oxygen. During pyrolysis, waste tires are broken down in to smaller molecules such as pyrolysis oil (45-55%), pyrolysis gas (8-10%), carbon black (30-35%) and steel (10-15%).The current study was focused on preparing and purifying pyrolytic char to investigate the possible end uses for the char produced. The collected char was processed by chemical and physical treatment methods separately. As the first step, physical separation methods were employed in a successive way; magnetic separation followed by particle separation by sieving. The magnetic separation allowed the char to become free from magnetic particles whereas sieving allowed separating impurities from char. In the second method, char was treated with an acid and a base which successfully leached metallic and other impurities from char. CHNS analysis was completed using Perkin Elmer 2400 serious. CHNS analysis results confirmed that purified carbon black sample contain 78.31% of C, 1.36% of H, 0.55% of N and 2.57% of S. Metal oxides analysis was completed using Horiba scientific XGT 5200 Xray analytical microscope. This confirmed that purified carbon black consist trace amount of Silica, Sulphur and Zinc. Particle size distribution was conducted using Malvern instruments master sizer 3000 particle size analyser. Particle distributed through 20 to 800 micrometer. Oil absorption capacity 96% 100 gcm-3 and Iodine absorption capacity 77 gkg-1. Therefore, we believe that these novel findings may shed the light on the possible use of tire pyrolytic char in many industrial applications in near future.

2018-11-01T00:00:00Z Piyathilaka, A. Ranaweera, S. Sewwandika, N. http://dr.lib.sjp.ac.lk/handle/123456789/8239 2019-01-28T05:31:35Z 2018-11-01T00:00:00Z

Pyrolysis as a Sustainable Waste Management Solution to Dispose Discarded Waste Tires Piyathilaka, A.; Ranaweera, S.; Sewwandika, N. Due to the rapid growth of vehicle usage in Sri Lanka, the waste tire generation is increasing exponentially and has become a serious environmental and social issue. Landfilling and burning of tires in open environment are not sustainable waste management solutions for the disposal of waste tires. The burning of tires produce air pollutants such as carbon monoxide (CO), sulphur oxides (SOx), nitrogen oxides (NOx), poly-aromatic hydrocarbons (PAH) and other toxic congers. These pollutants affect the human health causing skin rashes, eye irritation, respiratory problems and even cancers. As a sustainable waste management solution, pyrolysis can be recognized to dispose waste tires. Pyrolysis is a process of thermochemical decomposition of organic as well as inorganic material at elevated temperature in the absence of oxygen. The mechanism of pyrolysis process involves the molecular breakdown of larger molecules into smaller molecules. In the pyrolysis process, waste tires are used as a feedstock and heated up to 400-450° C in a closed reactor in absence of oxygen. During pyrolysis, waste tires are broken down in to smaller molecules such as pyrolysis oil (45-55%), pyrolysis gas (8-10%), carbon black (30-35%) and steel (10-15%). Pyrolytic gas can be used as a fuel source for domestic cooking purposes pyrolytic oil is suitable as an alternative fuel for various industrial applications due to its high net calorific value. Liquid fraction consists of xylene, toluene, styrene, and limonene. Pyrolytic char can be converted into carbon black by chemical and physical treatments Purified Carbon black can be used as a heating material or as a pigment in tire and plastic industry. Gaseous fraction mainly consists of a mixture of short chain hydrocarbons, and carbon monoxides/hydrogen mixture which is known as “syn gas”. Syngas is widely used a starting materials to produce gasoline. Syngas fraction consists of 11.21% of carbon dioxide, 26.82% of hydrogen 24.5% of methane 12.12% of ethane. CHNS analysis was completed using Perkin Elmer 2400 serious. CHNS analyses results confirmed that purified carbon black sample contain 78.31% of C, 1.36% of H, 0.55% of N and 2.57% of S. Metal oxides analysis was completed using Horiba scientific XGT 5200 X-ray analytical microscope. This confirmed that purified carbon black consist trace amount of Silica, Sulphur and Zinc. Particle size distribution was conducted using Malvern instruments master sizer 3000 particle size analyser. Particle size varies between 20 to 800 micrometers.

2018-11-01T00:00:00Z