Junior Research Symposia
http://repository.kln.ac.lk/handle/123456789/10233
2024-03-29T00:17:10ZAnalysis of existing municipal solid waste management practices: A case study in Kelaniya Pradeshiya Sabha area
http://repository.kln.ac.lk/handle/123456789/16681
Analysis of existing municipal solid waste management practices: A case study in Kelaniya Pradeshiya Sabha area
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.
2017-01-01T00:00:00ZComparison of Soil properties in three selected sites within the premises of University of Kelaniya, Dalugama, Sri Lanka
http://repository.kln.ac.lk/handle/123456789/16680
Comparison of Soil properties in three selected sites within the premises of University of Kelaniya, Dalugama, Sri Lanka
Dissanayaka, D.M.C.P.; Dissanayaka, C.T.M.; Weerathunga, D.M.; Wijesekara, N.T.A.; Perera, G.L.D.N.; Abeykoon, H.L.S.N.; Ranasingha, B.M.C.J.; Kanagasabai, S.
The soil physical and chemical properties largely determine the plant growth and it is
a determinant of the composition of faunal communities. The objective of this study
was to compare the soil physical and chemical properties in three selected sites within
the premises of University of Kelaniya.
The study was conducted in three selected sites within the University of Kelaniya;
botanical garden, university ground and in a construction area. A total of three soil
samples were extracted from each site using soil corer to analyze the soil moisture
content, organic matter content, soil pH, soil surface temperature, bulk density,
particles density and porosity.
According to the results of present study the soil porosity is highest in botanical
garden (81.6%) with relatively undisturbed soil whereas the soil moisture content and
the organic matter content were highest in university ground (moisture content= 1.27;
organic matter content= 6.27%). The construction site that subjected to severe
disturbances due to heavy machinery usage, showed the highest bulk density (0.39
Mg/m3) and lowest porosity (78.7%) from all three sites.
This study reveals that the soil properties within the university premises shows a
considerable variation which can be explained with the degree of disturbance to the
area.
2017-01-01T00:00:00ZImpact of invasion of Cogon grass (Imperata cylindrica) on the physical and chemical properties of soil
http://repository.kln.ac.lk/handle/123456789/16679
Impact of invasion of Cogon grass (Imperata cylindrica) on the physical and chemical properties of soil
Bandara, M.S.P.M.; Dilshara, R.M.P.; Gunarathne, D.K.O.B.; Senevirathne, H.; Udayanthika, S.K.I.; Kumari, C.
Cogon grass (Imperata cylindrica) is an invasive species found in many parts of Sri Lanka. This species is among the top ten worst weeds in the world. Cogon grass is found on road sides, mining sites, abandoned plantations and many other areas with disturbed soil forming a dense field like monocultures. The objective of this study was to assess the impact of the invasion of Cogon grass on soil physical and chemical properties.
The present study was conducted in a selected site at Nelumdeniya, a village located at Eastern part of Sabaragamuwa Province. Three sites were identified within the study area, of which two sites are invaded by Cogon grass with a high to low level of cover. The remaining site without the weed (undisturbed site) was used to assess the condition of soil before invasion of the weed in above sites. From each site five soil samples were extracted using a soil corer to analyze soil particles density, soil bulk density, porosity, moisture content, organic matter content, conductivity and Nitrogen content (kdjeldahl method) in soil.
The moisture content of undisturbed site (0.78) was less than the two sites invaded by the Cogon grass (0.88 and 0.89). The organic matter content (OM) and the Nitrogen content of soil in undisturbed site (OM= 0.163%, N= 0.14%) was higher compared to the other two sites (OM= 0.083% and 0.107%; N= 0.13% and 0.11%). The bulk density and the porosity was higher in affected areas than the undisturbed site. The study reveals that the invasion of Cogon grass affects both the physical and chemical properties of soil.
2017-01-01T00:00:00ZEffect of ammonia inhibition on anaerobic conversion process of pig manure
http://repository.kln.ac.lk/handle/123456789/16678
Effect of ammonia inhibition on anaerobic conversion process of pig manure
Sandani, W.A.P.; Amarasekara, D.A.T.; Kodithuwakku, D.S.; Rathnasiria, P.G.
Anaerobic digestion process inhibits due to the presence of ammonia, sulfide, light metal ions (Na, K, Mg, Ca, and Al), heavy metals, and some organics (cholorophenols halogenated aliphatic, N-substituted aromatic, long chain fatty acid). Ammonia is the main inhibitory factor in pig manure as it contains nitrogen. Although it is an important buffer in the process and an essential nutrient for microorganisms, if not controlled, high concentrations causes to operational failures. It is also leading to a low methane yield.
Since ammonia has free cell membrane-permeability, it is the active component causing ammonia inhibition. As ammonia is hydrophobic, the molecule diffuses passively into the cell which causes proton imbalance and potassium deficiency. Free ammonia concentration depends on the total ammonia (NH3 + NH4+), pH and temperature. Total ammonia concentrations level of around 1700–1800 mg/l, completely inhibitory to the inoculum which has not adapted. Literature shows that, with adaptation, inhibitory total ammonia nitrogen levels could increase up to 5000 mg/l. By using a semi continues anaerobic digestion process with an anaerobic inoculum and pig manure, can achieve that adapted inoculum. Adapted inoculum can give more than 250ml of bio gas volume per 50ml of pig manure which has 7% w/w solid content.
Because of above phenomena methonogen bacteria can be completely inhibited while Acetogen bacteria still can produce acids in a toxic environment. Therefore, acids are formed leading to lower methane yield. Due to that reason, when pig manure is anaerobically digested with adapted inoculum, pH drops from 6.5 to 6.3 during first 3days.
There are several methods mentioned in literature to reduce the ammonia inhibition directly in the anaerobic processes such as adaptation of microorganisms, co-digestion, increasing the COD:TKN (Chemical Oxygen Demand: Total Kjeldahl Nitrogen), dilution of the reactor content and adding trace elements. In this research Co digestion strategy was used to minimize ammonia accumulation in pig manure anaerobic digestion process. Pig manure was digested with food waste in different ratios. Adapted inoculum was used for this process.
2017-01-01T00:00:00Z