Browsing by Author "Jayakody, JRUC"

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item: Article-Abstract
Effect of evaporation on sugar content of coconut water in desiccated coconut industry
(2016-05-24) Jayakody, JRUC; Amarasinghe, ADUS; Gunawardena, SHP
Coconut (Cocos nucifera L) water is the main constituent in the waste water of desiccated coconut industry. The high COD values of coconut water, 40000 mg/ Z, is the main reason for having significantly high COD levels, 17000-20000 mg/Z, in the effluent which has to be treated to meet the discharge water standards. Coconut water is found to be rich in sugar and nutrition but limited in industrial application due to its low concentration. The volume and sugar concentration of coconuts used in desiccated coconut industry in Sri Lanka was examined and the effect of evaporation on the total sugar content was evaluated. The average volume was found to be 124 mZ/coconut. A significant difference in average sugar concentration was observed for north western region, 32.567g/Z and southern region, 19.455 g/Z. Coconut water was concentrated by evaporating at 3 different pressures; vacuum of 47.4 k Pa, atmospheric pressure of 101.3 kPa and high pressure of 198.6 kPa. Coconut water was sterilized completely during evaporation at atmospheric pressure and high pressure. The degradation of sugar was increased with the increase of both pressure and concentration levels. pH level was decreased and the insoluble solid weight was increased with the increase in concentration level.
item: Conference-Abstract
Study on strength and durability of cellular cementfly ash blocks
Baskaran, K; Jayakody, JRUC; Sandaruwan, MAR
Fly ash which is a waste product collected during coal combustion has become an issue to the environment and human due to lack of proper disposal methods. The major barrier of fly ash not being used as a land filling material is its heavy metal composition. The usage of fly ash in concrete may also vary with the composition of unburned carbon in fly ash. If used in optimum proportions fly ash can give many benefits like cold weather resistance, high strength gains, a good admixture, a non-shrink material, great workability, reduced crack problems, reduced heat of hydration and CO2 emissions. Fly ash can be used in many applications as an additive in building materials such as bricks, blocks, concrete, road and embankment covers. Since fly ash is a by-product it possesses a very low embodied energy which in turn reduces the embodied energy of the product made out of fly ash to a considerably low value. Therefore, the introduction of fly ash into cement sand blocks as a raw material is a better sustainable practice. This research attempt focuses on finding a feasible and an effective solution for the coal fly ash problem in fluidized bed boiler and to check the suitability of coal fly ash cement blocks in building construction. An appropriate mix proportion for fly ash cement blocks is found through trial and error process and various different mix proportions can be tested to obtain a productive and sustainable result in future as well. Tests done for the determination of material properties proved that the raw materials used including fly ash are healthy and robust to be handled and incorporated into a day to day used product. Tests proved that the substitution of fly ash has created very less amount of change to the strength and durability. Also the experiments done on the heavy metal leachate confirms this product is eco-friendly and human friendly. Tests done on durability, strength and thermal properties have confirmed that fly ash can be used as an effective substitute for sand in cement sand blocks.
item: Conference-Full-text
Study on use of bottom ash in manufacturing cement blocks
(IEEE, 2021-07) Sritharan, D; Baskaran, K; Jayakody, JRUC; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
Bottom ash is a common by-product of thermal power plants or boilers. From an ecological and engineering point of view, the use of coal bottom ash in cement mixtures is a beneficial application. This study mainly aims to check the possibility of using bottom ash as a replacement to the fine aggregate in manufacturing 300mm×100mm×150mm solid cement blocks locally. Bottom ash from the coal-fired boiler in Sri Lanka was used to replace manufactured sand at different percentages by volume of sand. Mechanical and durability properties of cement blocks were determined at the ages of 14, 28, and 56 days. Finally, developed statistical models to predict compressive strength, water absorption, and density of cement blocks. The results showed that the density and compressive strength of cement blocks decreased, and water absorption increased with an increasing replacement level of bottom ash. From the analysis, it can be concluded that up to 45 per cent of fine aggregate in the cement blocks can be replaced with sieved coal bottom ash to produce cement blocks, which satisfy the requirements of current SLS standards.
item: Conference-Abstract
Study on using bottom ash in manufacturing conventional cement blocks
(Department of Civil Engineering, University of Moratuwa, 2021-11) Sritharan, D; Baskaran, K; Jayakody, JRUC; Hettiarachchi, P
Bottom ash is a common by-product of thermal power plants or boilers. Due to the depletion of natural sources of fine aggregates, there is a need to encourage the use of alternative materials. In this study, coal bottom ash is used as replacement for fine aggregates. From an environmental and economical point of view, the use of coal bottom ash in cement mixtures is a beneficial application. The significance of the present study is maximizing the utilization of coal bottom ash by using it in the manufacturing process of conventional 300mm x 100mm x 150mm solid cement blocks and then checking its suitability to the construction industry against Sri Lankan standards. Finally, statistical models were developed between compressive strength, water absorption, density, and other input variables. The raw materials utilized in this experimental study were ordinary Portland cement, manufactured sand, bottom ash, and water. Bottom ash from Brandix Textile (Pvt) Ltd., Wayamba Industrial Zone, Makandura, Gonawilla, Sri Lanka was used to replace manufactured sand at different percentages by volume of sand. 1:6 cement: fine aggregate mix proportion was proposed for this experiment with the 0.5 consistent water/cement ratio. In this study, conventional vibrocompaction was used to mould the cement blocks. The blocks were cured by spraying water twice a day till the day of testing. Finally, the mechanical and durability properties of cement blocks were determined at the ages of 14th, 28th, and 56th days. The results showed that the density and compressive strength of cement blocks decreased, and water absorption increased with an increasing replacement level of bottom ash. From the analysis, it can be concluded that up to 45% of fine aggregate in the cement blocks can be replaced with sieved coal bottom ash in small and medium scale conventional cement block manufacturing using the mix proportions attempted in the present study.
item: Thesis-Abstract
Study the factors influencing the production of ethanol from waste coconut water
(2016-06-09) Jayakody, JRUC; Amarasinghe, ADUS; Gunawardena, SHP
Coconut (Cocos nucifera L) water is found in abundance in Desiccated Coconut (DC) factories and it is the main constituent in the wastewater from DC industry. DC effluent does not meet the water discharge standards and has to be treated prior to the discharge. Coconut water contains sugars and nutrition but limited in industrial application due to its low concentration. The aim of this work is to explore the possibilities of value addition to waste coconut water from DC industry and cutting down the load on wastewater treatment plants. Two main coconut cultivating regions (north-west and south) were selected for sample collection. Coconut water volume per coconut was examined and statistical values of coconut consumption from DC factories were used to calculate coconut water discharged daily and annually from DC industry. Average coconut water volume per coconut found to be 124 ml. Total sugar concentration was used to calculate the total amount of sugar available in coconut water from the DC industry. The total sugar concentration in coconut water is low (North western region 32.6g/l, Southern region 19.5g/l), which will result low efficiency if used as the sugar source in fermentation. Hence, it was decided to improve the sugar concentration of coconut water obtained from the DC industry using evaporation. Evaporation was carried out at three pressure levels (47.4kPa, 101.3kPa and 198.6kPa) into four concentration levels. The effect of evaporation on the total sugar content was evaluated. Main drawback of evaporative concentration of coconut water was the thermal degradation of sugar ranging from 0.12% to 18%. During evaporation acidity and insoluble solids of the coconut water increased. The concentrated coconut water was fermented into ethanol with a good efficiency. Volume reduction level of 5 was sufficient to achieve sugar consumption efficiencies about 89% and evaporation could be carried out at atmospheric pressure. The fermentation efficiency had marginally dropped with the increase of the volume reduction level and the increase in temperature and pressure used for evaporation process. A significant drop in the fermentation efficiency was observed with high sugar concentrations and in the presence of inhibitors such as HMF and furfural which may be formed at high temperature evaporation to achieve high volume reduction levels. The annual coconut water wasted in DC industries was estimated to be about 36.3 million. However, the estimated producible pure ethanol amount from an average DC factory was estimated to be 50-60kg per day. Hence concentration followed by fermentation may not be an economical option for DC factories if pure ethanol is produced as the final product. However, there is a high potential for producing alcoholic beverage using waste coconut water from DC industry.