Browsing by Author "Yatawara, M.D.M.D.W.M.M.K."

Now showing 1 - 17 of 17

Analysis of existing municipal solid waste management practices: A case study in Kelaniya Pradeshiya Sabha area
(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Senanayake, M.W.P.N.S.; Sewwandi, M.K.V.N.; Showmika, R.; Thilini, P.G.I.; Ubhayawardhana, W.S.M.T.; Yatawara, M.D.M.D.W.M.M.K.
A significant amount of solid waste has become a pressing issue with rising population, urbanization, economic activities and consumerism, especially in urban and sub-urban areas creating negative impacts on both environment and human health. Lack of infrastructure and financial resources, poor public participation in waste management process and less enthusiasm of government representatives have also been contributed to complicate the situation. Personal experience and literature revealed that existing SWM systems established in most local authorities are not properly functioned. Therefore, significant gaps are visible in solid waste management process in different local authorities. The present study was planned to explore municipal solid waste management system in Kelaniya Pradeshiya Sabha (KPS), as a key area in Gampaha district to identify best practices and gaps. Data were collected through interviews and questionnaire survey from three categories (officers in KPS, sanitary employees in KPS and general public in KPS area). Descriptive statistics were used to analyse data. Results revealed that waste reduction and capacity building were priority areas in KPS. Though the institutional capacity has been developed to certain extent in KPS, further attention is needed to overcome existing issues. Implementing new policies is further suggested to overcome some existing obstacles. However, the outcome of the study is a framework developed for best practices of solid waste management which can be used at local authorities for effective and efficient municipal solid waste management.
Assessment of the composition of the beach litter: a case study n two beaches in Sri Lanka
(Department of Zoology and Environmental Management, University of Kelaniya, 2015) Priyadarshani, S.P.I.; Pushpadayana, B.; Surakshi, W.A.G.N.; Weerasinghe, S.D.N.A.M.A.M.; Yatawara, M.D.M.D.W.M.M.K.
Blue revolution and environmental sustainability: are we in the correct path?
(Sri Lanka Association for Fisheries and Aquatic Resources, 2016) Yatawara, M.D.M.D.W.M.M.K.
Comparison of indoor and outdoor windrow composting methods of MSW in relation to final product quality
(The Institute of Biology, Sri Lanka, 2016) Karunapala, H.M.B.N.; Yatawara, M.D.M.D.W.M.M.K.
Comparison of the efficiency of the selected compost bins in composting of kitchen and mixed garden waste
(Department of Zoology and Environmental Management, University of Kelaniya, 2015) Thangavelu, A.; Udayangani, H.A.S.; Wijerathne, T.M.; Fazal, A.G.M.; Yatawara, M.D.M.D.W.M.M.K.
Diurnal variation in the feeding patterns and food preferences of Dwarf panchax (Aplocheilus parvus)
(Sri Lanka Association for Fisheries and Aquatic Resources, 2015) Fernando, G.K.A.W.; Jayakody, S.; Wijenayake, W.M.H.K.; Galappaththy, G.N.L.; Yatawara, M.D.M.D.W.M.M.K.; Harishchandra, R.D.J.; Wanninayake, W.M.T.B.; Deniyage, S.L.
The food and feeding studies of fish are useful to explore the possibilities of using them for various purposes such as aquaculture and biological control of problematic organisms. In the current study feeding patterns and diet composition of Aplocheilus parvus (E: Killi fish/Drawft panchax), a common surface feeding predator inhabiting freshwater systems were explored. A. parvus was collected from an abandoned brick pit in Pannala in 2012. Twelve fish were caught every two hours for 24 hours. Plankton net was used to obtain a representative sample of food items present in the system. Gut fullness, total and standard length of fish, total weight and gut weight were determined and using copepod as an arbitrary unit, total numbers of food items of individual fishes were estimated. The time at which active feeding occurred was established from total food particle amount and relative gut weight. Diet of A. parvus mainly consisted of adult or larval stages of insects and copepods. Also, gut had a higher fullness in day time compared to night. The peak gut fullness occurred during 1630 in males whilst females had the peak gut fullness at 1230. Copepods were detected mostly during late morning, whilst insect parts and coleopterans were present in all time periods. Main food items detected in the environment in descending order of abundance were copepods, filamentous algae and insects. This study demonstrated that A. parvus selectively preys on insects compared to other aquatic food sources during day time.
E-Waste management in selected institutions in Colombo and Gampaha Districts
(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Athukorala, S.M.W.; Handapangoda, H.M.A.K.; Yatawara, M.D.M.D.W.M.M.K.
Electrical and electronic waste (e-waste) is one of the most rapidly growing environmental problems in the world including Sri Lanka. This preliminary study was carried out to identify the attempts of e-waste management in selected institutions in Colombo and Gampaha districts. A questionnaire survey followed by interviews was carried out among randomly selected 20 institutions in Colombo and Gampaha districts. Descriptive statistical methods were used to analyze data. Results revealed that about 55% of respondents reuse their e-waste and 15% of respondents continue recycling the discarded e-waste. Most respondents (95%) has knowledge on e-waste and the effects of unsafe disposal. In addition, 60% of respondents were not aware of any projects or activities on e-waste management by government and local authorities. However, most of the types of electronic devices that are used by these institutions were more or less similar. Further, the survey revealed that the respondents showed willingness to contribute to e-waste management and willingness to pay or willingness to accept for a green product which will not harm the health of human and the environment. The study suggests to conduct proper awareness programmes to the employees in the institutions on handing over, disposal and management of e-waste. In addition, proper monitoring programmes of recycling or disposal is utmost important as e-waste contains a substantial amount of valuable recyclable materials and has potential to become a lucrative business in the country.
Effect of dietary fish meal replacement in the formulated food by heat processed soy bean meal on growth, survival and crude protein level of fingerlings of genetically improved farm tilapia (Gift)
(2005) Yatawara, M.D.M.D.W.M.M.K.
Effect of dietary fishmeal replacement in the formulated food by heat processed soybean meal in growth, survival and crude protein level of fingerlings of Genetically Improved Farm Tilapia (GIFT)
(Sri Lanka Association for Fisheries and Aquatic Resources, 2006) Yatawara, M.D.M.D.W.M.M.K.; Hettiarachchi, M.
Lesson 32: Generation of biogas from degradable organic wastes
(Research Services Centre, Faculty of Science, University of Kelaniya, 2015) Yatawara, M.D.M.D.W.M.M.K.
Potential Use of Selected Macrophytes Based Constructed Wetlands for the Treatment of Landfill Leachate
(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Perera, K.R.S.; Yatawara, M.D.M.D.W.M.M.K.
Phytoremediation using constructed wetlands (CWs) is widely practiced for the removal of contaminants in landfill leachate. The present study was planned to assess the potential of floating macrophytes (Eichhornia crassipes and Pistia stratiotes) and emergent macrophytes (Typha angustifolia and Chrysopogon zizanioides) in improving the quality of leachate discharged from a Sequencing Batch Reactor (SBR) system located at Dompe sanitary landfill, Gampaha, Sri Lanka. The batch type CWs were arranged to identify the suitable dilution of leachate (as 0%, 25%, 50% and 75%) for the optimum plant growths. Based on the preliminary investigations, the potential of improving leachate quality by (ia) E. crassipes (T501) (ib) T. angustifolia (T502) and C. zizanioides (T503) at 50% dilutions and (ii) T. angustifolia (T04) and C. zizanioides (T05) at 0% dilution were assessed in continuous flow CWs. Water quality parameters including temperature, pH, electrical conductivity, turbidity, BOD, COD, TSS, phosphate, ammonium nitrogen, nitrate, sulphate and color were tested once in five days for 40 days period. Results were subjected to One-way ANOVA followed by Tukey’s pair wise tests in Minitab 14. Two sample t-test at 95% CI was also applied as required. With respect to controls, percentage reductions of measured parameters increased in wetlands having either floating macrophyte, E. crassipes or selected emergent macrophytes. Nevertheless, among the emergent plants, C. zizanioides [(T503) and (T05)] showed the highest performance in improving leachate quality followed by T. angustifolia [(T502) and (T04)]at both dilutions. Although E. crassipes (T501) showed higher percentage reductions of the selected parameters at 50% dilutions, this is not recommended as leachate dilutions are impractical in CWs. P. stratiotes has proven unsuccessful in the present study. Therefore, among the plant species selected, C. zizanioides that performed at 0% dilution could be recommended as the best plant for the remediation of leachate draining from SBR system.
Public participation in solid waste management in Kolonnawa urban council in the western province in Sri Lanka
(Department of Zoology and Environmental Management, University of Kelaniya, 2015) Kodituwakku, K.A.R.K.; Yatawara, M.D.M.D.W.M.M.K.
Reduction of Color, COD, and BOD5 of Treated Leachate Using an Activated Coconut Charcoal – Fired Clay Brick System
(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Rajapaksha, N.M.; Yatawara, M.D.M.D.W.M.M.K.
Removal of color from waste water by activated carbon is a common practice and studies have also been done with fired clay bricks. Nevertheless, no studies have been carried out to evaluate the removal of color by a combination of activated carbon (CC) and fired clay bricks (BR). The present study was therefore, planned to evaluate the potential of the combination of CC (activated by ZnCl2) and BR for the removal of color, chemical oxygen demand (COD) and five day biochemical oxygen demand (BOD5) of the treated leachate discharged from sanitary landfill located at Dompe, Gampaha,Sri Lanka. CC was impregnated with 0%, 5%, 10%, 15% and 20% ZnCl2 and activated in an oven at 2000C afterwards. The activated CC – BR systems were prepared in PVC pipes with the ratio of 1:0 (T1), 0:1 (T2-T6), 1:1(T7-T11), 1:3(T12-T16) and 3:1(T17-T21) BR particles and CC respectively. Leachate was filtered through the prepared systems at flow rate of 1L/hour. Color, COD, BOD5 and pH of filtrate were measured. Percentage reductions of parameters were first subjected to arcsine transformation and then to One-Way ANOVA in MINITAB 14. Tukey’s pair wise comparisons were also carried out to identify significant differences of parameters among different percentages of activated carbon. Results revealed that 20% ZnCl2 impregnated CC and BR at 1:0 system showed the highest percentage of color (>90%) and COD (>85%) reductions. CC - BR at 1: 1(CC activated by 20% ZnCl2) (T-11) and CC - BR at 3: 1(CC activated by 20% ZnCl2) (T-16) showed the highest percentage of BOD5 (more than 95%) reduction. After 5-hour filtration, 20% and 15% ZnCl2 impregnated CC and BR at 1:0 system showed pH lower than 6. The lowest pH was observed from 20% ZnCl2 impregnated CC. The study concludes that CC impregnated with high amount of ZnCl2 has a great potential to remove the color of leachate. Thus, the present study recommends the combination of 20% ZnCl2 impregnated CC: BR at 3:1 ratio as the most suitable combination for the removal of color, COD and BOD5 of the biologically treated leachate.
Removal of Heavy Metals from Sewage Sludge by Floating Macrophytes; Eichhornia crassipes (Mart.) Solms., Pistia stratiotes L. and Salvinia molesta Mitch
(19th Conference on Postgraduate Research, International Postgraduate Research Conference 2018, Faculty of Graduate Studies,University of Kelaniya, Sri Lanka, 2018) Kodituwakku, K.A.R.K.; Yatawara, M.D.M.D.W.M.M.K.
The land disposal of sewage sludge generated from industrial waste water treatment plants is a major environmental concern as the sludge has been contaminated with heavy metals. Hence, immobilization of such metals prior to land disposal reduces the burden of posing environmental risks. The present study was therefore planned to assess the efficacy of Eichhornia crassipes, Salvinia molesta and Pistia stratiotes to control heavy metals in diluted sludge (1:5) from the Common Waste Water Treatment Plant (CWWTP) in Biyagama Export Processing Zone, Biyagama, Sri Lanka. Equal weights of the second generation of above three plant species were introduced to batch type constructed wetlands of 63 L capacity. The experimental set-up was kept for 28 days. The weekly harvested plant and sludge samples were pre-treated and digested using Mars 6 Microwave digester. The heavy metals Zn, Pb, Ni, Cd and Fe analyzed using Atomic Absorption Spectrophotometer (Analitikjena NOVA 400P). The methods used for sample preparation, digestion and quantificational analysis were established generating satisfactory analytical precision. Statistical analysis was performed using Minitab 14 software. The results revealed that root accumulated much higher concentrations (more than 50.0%) of Fe, Zn, Pb, Ni and Cd than shoots. The plant uptake of Fe, Zn, Pb, Ni and Cd increased with increased exposure time. Nevertheless, the removal capability of metals by these plants differed from each other. S. molesta showed significantly higher Zn (36.0% in Cycle-1 and 40.0% in Cycle-2), Fe (26.6% in Cycle-1 and 25.6% in Cycle-2) and Ni(26.9% in Cycle-1 and 33.7% in Cycle-2) removals from sludge than E. crassipes and P. stratiotes by 28 days exposure period for both cycles (p < 0.05; ANOVA after arc-sign transformation of data). In addition, E. crassipes showed significantly higher Pb (41.2% in Cycle-1 and 46.4% in Cycle-2) removal than P. stratiotes and S. molesta. Moreover, P. stratiotes showed significantly higher Cd (27.1% in Cycle-1 and 29.3% in Cycle-2) removal than other two species (p < 0.05; ANOVA after arc-sign transformation of data). The present study concludes that floating macrophytes E. crassipes, S. molesta and P. stratiotes significantly reduce the heavy metals Zn, Pb, Ni, Cd and Fe from sewage sludge
Soil Degradability of Food Wrapping Polythene Films Manufactured from PLA, PBAT and LDPE
(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Abeywickrama, M.S.J.; Yatawara, M.D.M.D.W.M.M.K.
Food wrapping polythene films manufactured from different virgin materials have become a major environmental concern at present as these films take much time for the complete degradation in the environment. This study assesses the soil degradability of films manufactured from poly-L-lactic acid (PLLA) (28%) + dimethyl ester (38%) + starch (26%) + auxiliaries (8%) (F001), poly-lactic acid (PLA) (F002), poly butylene adipate terephthalate (PBAT) (F003) and low-density polyethylene (LDPE) (F004) in natural soil. The tensile strength, elongation, moisture and water absorption of manufactured films were analyzed at the beginning of the experiment. Half of the manufactured films was immersed in food waste contaminated water and buried at 10 cm depth in soil. The other half was also buried without processing at the same depth in soil. The study was carried out for four months. Percentage degradability was calculated after 02- and 04-month intervals and by using weight losses as a representative parameter of the degradability. Results revealed the significantly highest tensile strength and elongation from manufactured F004. In addition, manufactured F004 showed the significantly lowest water absorption and moisture content (p < 0.05; ANOVA). Nevertheless, the highest percentage degradability (94%) in soil was observed from F003 followed by F002 contaminated with food waste. Moreover, the results showed a poor degradation (< 1%) of films manufactured from F004. The results further revealed that the films contaminated with foods degraded more than films those haven’t contaminated with foods. Therefore, the present study concludes that food wrapping polythene manufactured from PLA and PBAT showed a significant degradation potential within four months whereas films manufactured from LDPE did not show a remarkable degradation within the same time duration.
Use of effective microorganisms for rapid composting of mixed garden waste and kitchen waste in windrows at University of Kelaniya
(Department of Zoology and Environmental Management, University of Kelaniya, 2015) Yapa, Y.M.H.S.; Amasha, K.G.E.; Chandrasekara, M.M.; Suhaina, M.S.F.; Yatawara, M.D.M.D.W.M.M.K.
Use of Processed Tea Waste Powder and Fiber in Improving the Properties of Rice Husk Ash Filled Compressed Stabilized Earth Blocks
(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Madhushani, K.L.; Yatawara, M.D.M.D.W.M.M.K.
Rice husk ash (RHA) and processed tea waste (PTW) are major agricultural wastes. A recent study has shown that 7.5% of soil can be replaced with RHA in Compressed Stabilized Earth Blocks (CSEBs) due to its pozzolanic properties. Since PTW shows good pore-forming ability, the present study was planned to determine whether there is a potential to improve properties of previously upgraded CSEBs by replacing soil with PTW powder or fiber. The mixing percentage of soil, cement and RHA was 86.25: 6.25: 7.50 in the previously upgraded block. Five types of CSEBs of 300 mm x 150 mm x 100 mm (L x W x H)) were manufactured by replacing 0% (Control- BC), 3 %(B3), 5% (B5), 7% (B7) of soil by PTW powder and 3% (BF) of soil by PTW fiber. The suitability of properties of raw materials were tested prior to manufacture CSEBs. Mechanical properties of manufactured CSEBs were tested. Data were subjected to One-way ANOVA followed by Tukey’s pair wise comparison in MINITAB 14. The values were compared with SLS 1382: 2009 and British standards. The dry and bulk densities and weight reductions of PTW incorporated blocks (B3, B5, B7 and BF) showed significantly higher reductions (p <0.5) than that of Controls. B3 showed the highest compressive strength (3.8 Nmm-2) except Controls. In addition, B3 also showed the lowest surface erosion (pitting depth = 0 mm and pitting rate = 0 mm min-1) and the highest durability (Slake durability Index = 90). In addition, B3 showed the lowest loss on ignition (12.5%) and the percentage weight reduction (6%) except controls. According to SL standard 1382 part 1: 2009, only blocks BC and B3 were suitable for construction of walls (Grade 3). In addition, B3 was also suitable for external walls compared to control blocks. When compared with the British standards, only BC was suitable for load bearing walls for two storey houses. Considering all aspects, 3% of PTW powder incorporated CSEBs with 7.5% of RHA can be recommended for single story buildings and for external use in places where PTW is highly abundant.