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Developing a Drumstick (Moringa Oleifera) Incorporated Functional Drinking Yoghurt
(University of Peradeniya , Sri Lanka, 2014-07-04) Weerasinghe, L. T. K.; Madhujith, T.; Sarananda, K. H.
Moringa oleifera leaves have been reported to be a rich source of β-carotene, protein, vitamin C, calcium and potassium. In addition, it is reported that Moringa leaves possess bioactives that bring about a myriad of health benefits. Incorporating Moringa into yoghurt can increase the health benefits. Moringa oleifera leaf samples, sugar and gelatin were obtained from local market. Liquid milk was purchased from University of Peradeniya and the starter culture was obtained from Veterinary Research Institute (VRI), Gannoruwa. Moringa leaf powder (DMLP) was prepared by drying, grinding and sieving of Moringa leaves. The particle size of DMLP was less than 125 μm. Set yoghurt was prepared incorporating varying quantities of DMLP [0.5, 1, 2 and 4%, (w/w)] to the yoghurt mixture. Stirred yoghurt was prepared following the same procedure with the exception of adding extra sugar or water. The so prepared set and drinking yoghurt samples were evaluated for sensory attributes to select the best concentration of DMLP for drinking and stirred yoghurts. According to the paired preference test, drinking yoghurt containing 1% DMLP was the most preferred yoghurt formulation, thus set yoghurt was dropped from the rest of the study. It was observed that 1% DMLP was the most preferred formulation for drinking yoghurt. Furthermore, the selection of the best flavouring agent for set and drinking yoghurts was also carried out through the sensory analysis. Mango flavour was the most preferred flavouring agent for 1% DMLP added drinking yoghurt. Proximate analysis of the best set and drinking yoghurts was performed following standard AOAC methods. Proximate analysis revealed that drinking yoghurt containing 1% DMLP contained 74.28 ± 0.03% moisture, 25.72 ± 0.03% dry matter, 3.91 ± 0.655% ash (on dry weight basis) and 1066.91 mg/100g ± 28.39 calcium. The titratable acidity, TSS and pH of yoghurt were 0.82 ± 0.010%, 21.97 ± 0.06% and 4.60 ± 0.01, respectively. It is concluded that Moringa dry leaf powder, which carries many bioactive properties can be incorporated into drinking yoghurt without affecting the sensory attributes.
Effect of Substituting Calf Milk Replacer with Porcine Whole Blood on the Growth and Performance of Bull Calves
(University of Peradeniya , Sri Lanka, 2014-07-04) Wijetunge, W. M. G. I. S. L.; Himali, S. M. C.; Senavirathna, N. G.; Cyril, H. W.; Vidanarachchi, J. K.; Randheera, C. S.
Most of the calves in the commercial farms are fed with milk replacer during their liquid feeding period. As an alternative low cost protein ingredient, porcine whole blood was evaluated by substituting as a possible calf milk replacer. Twelve (12) male Holstein-Friesian calves (weight 40±5 kg and 21±10-day old) were used for the experiment. The study period was 42 days. After adaptation period of seven days, calves were assigned randomly for three groups. The control group of calves was fed with100% calf milk replacer, while the other two groups were fed with milk replacer substituted with 10% whole blood and 15% whole blood. The animals were fed with 4 L and 3 L of milk replacer/milk replacer containing whole blood per day in the first month and for the rest of the research period respectively. All other management practices were performed similarly for all the calves used in the experiment. Daily intakes, rectal emperature and fecal consistencies of each animal were recorded. Body weight, heart girth, body length, skinfold thickness were measured weekly. Daily intake of milk replacer/milk replacer substituted with blood was the same for all calves throughout the experiment period. Body weight gain/week, heart girth, body length, skinfold thickness were analyzed as repeated measures ANOVA using the Mixed Procedure of SAS. There was no significant difference (p>0.05) in the body weight gain (2.5±0.6kg/week), heart girth (85±5 cm), body length (68±5 cm) and skinfold thickness (1.090±0.2cm), concentrate intake (3±1.9 kg/week) among the treatments. The result of this experiment demonstrates that 10% and 15% of calf milk replacer can be successfully substituted by porcine whole blood. The findings suggest the possibility of using whole blood of pigs obtained as a slaughterhouse by-product to reduce the cost of feed in rearing calves.
Spatial variability of organic carbon desnity in cashew cultivated red latosol soils of Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11) Wickramasinghe, W.M.K.M.; Karunaratne, S.B.; Gajanayake, B.; Abeysinghe, D.C.
Soils contribute to regulate major biochemical cycles and in case of carbon (C) cycle it plays a vital role. In fact soil act as the largest terrestrial pool of C. Therefore, much attention is given to quantification of below ground C stocks or densities and uses this information for long term monitoring of C sequestration potential. In this study, an attempt was made to quantify the spatial variability and subsequently map (predict) the soil organic carbon (SOC) densities under cashew grown in Red Latosol soils. For this, a sub set of 22 ha was selected from the cashew seed garden in Elluwankulama, Puttalam district managed by Sri Lanka Cashew Corporation. A design- based sampling scheme namely stratified random sampling was adopted in this study. The stratification was carried out using compact geographic stratification (based on coordinates) with the aid of k-means clustering algorithm and the study area was divided into five strata. Total of 100 sampling locations were sampled where 20 sampling locations were allocated to each stratum. For all sampled locations, SOC density was calculated. In calculating of SOC density, a pedotransfer function (PTF) was used to predict the bulk density for sampling locations which did not measure bulk density in the field. Geostatistical approach was used to create higher resolution digital soil map of SOC density across the study site. Both PTF predicted bulk density values and geostatistical models were validated and statistically assessed using mean error (ME) and root mean square error (RMSE) indices. Summary statistics revealed that mean SOC %, bulk density and SOC density reported as 0.96 % (±0.21), 1.43 gcm-3 (±0.03) and 4.12 (±0.82), respectively. Results revealed that the bulk density values predicted by PTF reported ME of 0.0041 gcm-3 and RMSE of 0.0044 gcm-3 values for Red Latosols in the study site. The optimum spatial model for SOC density was identified as spherical model which reported lowest RMSE (0.769 ) and ME (0.00084 ) values. The nugget-to-sill ratio showed a moderate spatial dependence for SOC density (0.43). Furthermore, results revealed that spatial auto-correlation (range parameter) of SOC density goes up to 82 m. This indicates that in future sampling of Red Latosols in order to characterize the spatial variability of SOC density, sampling interval should be maintained within 82 m. Predicted SOC density over the study area reported a mean value of 4.14 (±0.34) while 3.95 and 4.34 for quantiles one and third, respectively. Results further revealed that majority of the land extent (13.4 ha) in the study site reported SOC density in between 4.0 to 4.5 . The information generated in this study could be useful in national carbon accounting programs, carbon credit programs and for site specific fertilizer application.
Geostatistical mapping of selected soil chemical properties in red latosols of Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Eranga, R.L.A.A.; Karunaratne, S.B.; Abeysinghe, D.C.; Gajanayake, B.
Soils are highly variable even at the field scale and detailed studies of spatial variability of soil properties across the landscape are important to manage soils in a sustainable manner. Geostatistics enables to quantify the spatial variability and subsequently prepare detailed digital soil maps. In this study, an attempt was made to quantify the spatial dependence and map the selected soil chemical properties (viz. pH, exchangeable potassium (K) and available phosphorus (P)) in Red Latosols of Sri Lanka. As the study site, a sub set of 22 ha was selected from the cashew seed garden in Elluwankulama, Puttalam District managed by Sri Lanka Cashew Corporation. A design-based sampling scheme namely stratified random sampling was adopted in order to collect soil samples. The stratification was carried out using compact geographic stratification using k-means clustering algorithm and study site was divided in to five strata. Total of 100 sampling locations were sampled where 20 sampling locations were allocated to each stratum. For each considered soil chemical property we deployed a geostatistical approach to create higher resolution digital soils maps and to quantify the spatial distribution of respective soil chemical properties across the study site. The geostatistical models were cross validated and calculated mean error (ME) and root mean square error (RMSE) in order to assess the model quality. Spatial model quality results obtained from the cross validation analysis revealed that, calculated ME values for soil pH (0.002) exchangeable K (0.403 ppm), and available P (0.004 ppm) were closer to zero which suggests unbiased estimation. In case of RMSE, all considered soil chemical properties reported lower values, which includes for soil pH (0.354), exchangeable K (13.581 ppm), and available P (1.673 ppm), respectively suggesting accurate estimation. In analysis of spatial dependence, nugget-to-sill ratio showed strongly structured spatial dependencies with negligible random variations for all considered soil chemical properties. Results further revealed that spatial correlation (range parameter) of pH, exchangeable K and available P reported as 31 m, 98 m and 54 m, respectively. This information is vital to carry out future soil sampling of Red Latosols in order to optimally characterize the spatial variability of considered soil chemical properties by maintaining sampling interval within the estimated range parameter. Furthermore, it was indicated that pH values in most areas of the study site varied from very strongly acidic (4.5) to strongly acidic (5). The exchangeable K and available P levels are mainly distributed within fairly low (58.5-78 ppm) to medium (78-97.5 ppm) and fairly low (7.5-15 ppm) categories, respectively. Maps produced in this study provide valuable information on spatial distribution of considered soil chemical properties including nutrient status within the study site that can be used as a guide to conduct site specific fertilizer applications, intercropping and other management practices, in an environmental friendly manner.
Interaction of ferrous ions and free chlorine on microbiological quality of drinking water
(University of Peradeniya, Sri Lanka, 2015-11-06) Munasinghe, T.S.; Abayasekara, C.L.; Chandrajith, R.; Jayawardana, A.
University of Peradeniya has a nearly 60 year’s old water distribution network that consists mainly iron pipelines, most of which are now corroded to a large extent, adding iron rust to water. The aim of this study was therefore to investigate the possible consumption of free chlorine that added in to water for disinfection by iron dissolved from pipes. If free chlorine is reduced due to iron, the available amount of free chlorine would not be sufficient for the disinfection of microorganisms in water. A laboratory simulated study was carried out to investigate the possible reaction between ferrous ion and free chlorine in water using a series of and free chlorine mixtures. The effect of the reaction on the inhibition of microorganisms were also determined by spiking Serratia spp. (a total coliform) and Escherichia coli (a fecal coliform) into known mixtures of and free chlorine. The and free chlorine contents were measured spectrophotometerically while viable microbial count was assessed using membrane filtration technique that followed a confirmation tests. Furthermore free chlorine and microbiological quality were determined periodically using 27 water samples that were collected from various points of the University network. The results of this study indicated a rapid reaction between and free chlorine. The rate of free chlorine reduction was directly proportional to the amount of in water. Although inhibition of Serratia spp. and E. coli was observed due to free chlorine in water, the effect reduced drastically with increasing in water. Serratia sp. decreased gradually with the ascending chlorine levels at levels of 0.2 and 1.0 mg/L. Total inhibition of Serratia sp. were observed at 2 and 3 mg/L of while E. coli was inhibited at levels of 1.0, 2.0 and 3.0 mg/L. The content in the water distribution network of University of Peradeniya were ranged from <0.01 mg/L to 0.64 mg/L (desired value is <0.3 mg/L), while the desired free chlorine level (0.2 mg/L) was observed only at two locations (Faculty of Veterinary Science and Meewathura treatment plant). Total coliforms were detected in samples collected from Upper Hanthana, Marcus Fernando Hall, University Temple, Science Faculty, Mars Hall and Medical Faculty, while fecal coliforms were detected only in a sample from Marcus Fernando Hall. The results of microbiological test showed that water distributed from the Kandy Municipal Council and Meewathura plants are suitable for drinking, but water distributed from the Upper Hanthana plant was not suitable for human consumption according to the World Health Organization (WHO) Standards (0/CFU per 100 ml for both total and fecal coliforms) and Sri Lankan Standards (3/CFU per 100 ml for total coliforms and 0/CFU per 100 ml for fecal coliforms). The possible reason behind the unsuitable microbiological quality of water may be related to the reaction between and free chlorine in water. It was also noted that, a high level of in water was inhibitory to microorganisms in water and remove bacteria by formation of clumps.
Investigating the influence of climatic parameters on river mahaweli water quality associated with leachate chemistry
(University of Peradeniya, Sri Lanka, 2015-11-06) Weerakoon, W.M.D.S.K.; Kalpage, C.S.; Manipura, A.; Ziyath, A.M.; Weragoda,S.K.
Increased solid waste generation due to rapid urbanization and industrialization is a major problem around the world. Landfilling or open dumping is the most common disposal method of municipal solid waste (MSW) in developing countries. However, majority of these landfills are not properly managed, resulting in contamination of nearby groundwater and surface water bodies by the landfill leachate run-off. In Kandy, the canyon method is commonly used for MSW disposal. In this method, a suitable canyon (depression) has been filled with dumped waste, without taking any measures to prevent or minimize hazards arising from dumped waste. According to the available literature, chemistry of the leachate generated from a landfill is seriously influenced by the climatic parameters. Therefore, the study was conducted to understand the relationship between the climatic parameters and the leachate chemistry and the association of these two factors with the river water quality to ensure the safety of drinking water consumers. Landfill leachate, river water and groundwater samples were collected weekly from the leachate drain of the Gohagoda landfill, four locations along Mahaweli River (two upstream and two downstream points from where leachate drain to the river) and from two wells within the landfill, respectively, for a period of two months. The samples were preserved, stored and analyzed according to the Standard Methods. Daily temperature and rainfall data were also collected from the Horticultural Crop Research and Development Institute, Gannoruwa, and the statistical analysis were performed with MINITAB version 17.0. The study found that the concentrations of components (pH, Biological Oxygen Demand, Chemical Oxygen Demand, Ammonia Nitrogen, Phosphate) in the Gohagoda landfill primary leachate were higher than the recommended standards of tolerance limits for discharge of effluent for inland surface waters by the Central Environmental Authority and most parameters were similar to the values reported in the past studies. According to the results, Total Organic Carbon (TOC) concentration showed significant differences (0.001) at 5 % probability level (P< 0.05) in upstream and downstream river water samples leading to conclude that leachate has a negative impact on the river water quality. Apart from TOC, the Pearson Correlation Analysis and the ANOVA on other parameters (pH, Electrical Conductivity, Dissolved Oxygen, Total Dissolved Solids, Phosphate, Nitrate-Nitrogen, Ammonia-Nitrogen, Total Nitrogen, Biological Oxygen Demand, Total Carbon, Total Organic Carbon, Inorganic Carbon, Cadmium) did not show any significant impact of Gohagoda leachate on Mahaweli River water. This is attributed to the dilution effect and few of the leachate parameters were affected from the temperature and rainfall. Therefore, further studies are necessary to investigate the influence of other climatic parameters such as wind pattern and solar radiation on leachate and river water quality.
Impacts of sea level rise and bed level accretion on residence time of Negombo lagoon, Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Pushpakumara, P.K.P.; Nandalal, K.D.W.; Weerakoon, S.B.
Water quality of an aquatic system is highly influenced by residence time (RT), which indicates how long a constituent is retained inside the system. This paper focuses on the effect of climate change induced future sea level rise (SLR) and associated bed level variations on RT of Negombo lagoon, Sri Lanka. The hydrodynamic behaviour of the lagoon was numerically simulated using Delft3D surface water modelling suite. The time required to drop the concentration of a constituent to of its original value was calculated as the RT of the lagoon. Anticipated maximum SLR of 79 cm at the end of the 21st century, predicted by the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, was considered as the future sea level of the lagoon. Three bed level accretion conditions, namely, no bed level accretion, accretion of the lagoon bed level by 50% of the SLR (partial bed level accretion condition) and accretion of the lagoon bed level similar to the SLR (full bed level accretion condition), in response to the anticipated SLR were considered. RT was calculated for each bed level variation under low (5.64 ) and high (41.93 ) streamflow conditions. Model predicted RTs of the lagoon at present are 22.4 days and 12.4 days under low and high streamflow conditions, respectively. Under the absence of bed level accretion, RT is increased up to 32.2 days (+43.7%) and 17.8 days (+43.5%) due to SLR in low and high streamflow periods, respectively. Under partial bed level accretion, RT is decreased up to 18.1 days (-19.2%) and 12 days (-3.2%) in low and high streamflow periods, respectively. RT is decreased up to 13.4 days (-40.2%) and 8.5 days (-31.5%), under full bed level accretion, in low and high streamflow periods, respectively. The results reveal that the climate change induced future SLR and the associated bed level accretion influence the RT of the lagoon altering the lagoon water quality.
Very low frequency electromagnetic (vlf em) method for vein graphite investigation in crystaline rock terrain : a case study in Rangala, Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Karunarathne, K.M.P.C.; Dharmagunawardhane, H.A.
Vein graphite formations in Sri Lanka show systematic orientation rather than random. They follow define brittle structures alone in mineralized regions, but pinching out behaviour of veins make them difficult to be detected by traditional drilling methods. At present, exploration for new graphite veins is important factor for continuation of graphite industry. Electromagnetic Surveys are some of the most common survey methods in globe for the conductive mineral exploration. A Very Low Frequency (VLF) electromagnetic survey was carried out using EM 16 handheld instrument for the field data collection. Rangala graphite mine area is situated in the Kegalle district within the crystalline terrain of Sri Lanka. Survey grid was designed perpendicular to the primary signal transmitting direction. Positive to negative inphase reading variation along survey lines was used as primary indication of subsurface conductor. Simple numerical filtering method was used to reduce random fluctuation of the anomalies. Interpretation of individual anomalies indicated that the conductive zones present at an average depth of 10m-15m. These anomalies have followed vein orientation of NW-SE as shown by previous investigators. Overlapping of anomalies with already identified veins and drill hole data verified relationship between anomalies and graphite veins. At least fourteen conductive bodies were identified during the study, indicative of graphite veins. According to the anomalies, lengths of the veins vary between 20m-150m with steep dipping. VLF anomalies indicated a very significant correlation with the already located graphite veins, thus conforming the other anomalies represent yet undiscovered graphite veins. The study further revealed that VLF method can be effectively and economically used in graphite exploration in Sri Lanka, instead of costly drilling based investigations.
Assessment of green space in the colombo city liaisons with gis and in-situ data
(University of Peradeniya, Sri Lanka, 2015-11-06) Madurapperuma, B.D.; Kuruppuarachchi, K.A.J.M.
Urban sprawl in Colombo City is increasing due to centralization of social and economic endeavors. Urban forests and green infrastructure make the city cleaner and healthier to raise the standard of environment quality and aesthetic beauty. This study examines the green urban space in Colombo City using geographic information system and green cover was compared with in-situ ground truthing data in selected locations. A supervised learning algorithm was adopted to classify ESRI base image to three major land-use/cover classes: green space, built-up and water using training samples within Colombo City. Landsat 8 satellite imagery that acquired on 14.04.2015 was used to calculate Normalized Difference Vegetation Index (NDVI). Then green space of the NDVI image was extracted using polygonal vector feature class of the classified image. The results showed that 29% of the area was green space, 67% was built-up and 4% was water. Coefficient of agreement (Khat) was calculated for the classified image resulting in 0.81 overall accuracy. The NDVI values showed the intensity of greenness of vegetation. The difference of NDVI values were compared using available base maps. Then NDVI results were utilized to assess the green space in the field systematically to gauge how species contributes for varying greenness. The results and the method adopted in this study eventually provide valuable insights for city planners and policy makers to establish new green urban space to uplift environmental quality of potential sites in Colombo City.
Communication and adoption of waste management practices of urban and semi-urban households in Trincomalee district
(University of Peradeniya, Sri Lanka, 2015-11-06) Ganegoda, P.; Wanigasundera, P.
Waste disposal has become a serious issue in Sri Lanka, making her one of the highest waste generating countries in Asia. Previous research findings state that the key to successful waste management system is the cooperation of citizens, which could only be gained through public awareness, which is lacking in Sri Lanka. Thus, the focus of this research was to find out the role communication has in creating awareness and promoting adoption of waste management practices. Moreover, the research specifically focused on finding out the communication channels by which people receive information of waste management and the message content of those channels affecting the level of awareness and adoption of waste management practices. The data gathered from three purposively selected Divisional Secretariat divisions based on the ethnicity, as the study area is a multi-ethnic area; 200 households were selected randomly from both urban and semi-urban GS divisions. Trincomalee Town and Gravets and Kinniya DS divisions, which are functioning under the urban councils, represent the majority of Tamil and Muslim populations, respectively, whereas Kanthale DS division functions under Pradeshiya Sabha represents majority of Sinhala population. Data were gathered using a questionnaire and analyzed using Statistical Package for Social Sciences. Results revealed that people received messages related to waste management by around 20 communication channels, which can be categorized into three: national mass communication channels, provincial formal communication channels, and informal communication channels. Among them, mostly used communication channel was the television. In addition, respondents used Public Health Inspectors, school education, Urban Council/Pradeshiya Sabha, and newspapers to receive information. However, a large amount of information respondents received was not directly related to waste management. The information received through school education, television, newspaper and non-governmental organizations showed a significant positive impact on awareness level, but, only school education had a significant positive impact on adoption level. In conclusion, the results emphasize that communication plays a major role in creating awareness of people regarding waste management. However, it alone cannot contribute to improve the adoption level, which requires the contribution of supporting services, such as the service of informal waste collectors and implementing rules and regulations.
Climate change adaptation practices in crop cultivation : case study in Anuradhapura district
(University of Peradeniya, Sri Lanka, 2015-11-06) Ranasingha, R.M.C.K.; Nanthakumaran, A.
Climate change, mainly the variation in rainfall in the recent past years, causes frequent floods and drought in many districts in the country. The variation in rainfall and frequent floods and droughts affect the crop cultivation, and thereby challenging the food security of the country. Further, it affects the livelihood of the farming community in the tank based agriculture systems which includes the major and the minor irrigation tanks. Many minor irrigation tanks receive water from rainfall, store and supply for agriculture during non-rainy season. Very often the water stored in the minor irrigation tanks is not sufficient to fulfill the water requirement for agricultural purpose, because of the limited tank storage. The objective of this study was to identify the adaptation measures practiced by the farmers to overcome the effects of climate change due to rainfall variation under minor irrigation tanks. Since Anuradhapura district lies in the dry zone of Sri Lanka and many small and marginal farmers involved in crop cultivation, it was selected for this study. Stratified random sampling was done to select 150 farm households from 15 minor irrigation tanks in Anuradhapura district. Primary data from the farm households using structured questionnaire and the rainfall data for the past 31 years from the year 1984 as secondary data from the Meteorology Department were collected for analysis. Percentage analysis and the graphical representation were carried out using MS Excel. During 1984 to 2014 the average annual rainfall was 1293 mm with a coefficient of variation of 22 percent. The rainfall was above normal in 13 years with a deficit in 13 years, and very scarce in five years. The survey revealed that the crop insurance, cultivation of short duration crops, cultivation of drought tolerant rice varieties, inter cropping, changing the planting and harvesting date and agro forestry were some of the adaptation strategies practiced by farmers in the study area. The percentage analysis revealed that 94% of the farmers had crop insurance, 90 % of the farmers cultivated short duration crops, 72% of the farmers switched to cultivation of drought tolerant varieties, 46% of the farmers practiced intercropping, 30% of the farmers changed the planting and harvesting date, and 28% of farmers practiced agro forestry strategy as adaptation measures for climate change. Though the farmers in the study area practiced these climate change adaptation strategies to some extent, dissemination of knowledge about appropriate adaptation strategies towards farming community is essential to protect the livelihood of the farm households, while ensuring the food security of the country. Thus, the farmers may be given proper support by supplying short duration and drought tolerant rice varieties and selected seedlings for agro forestry.
Assessment of nitrogen, phosphorous and potassium concentrations in different raw material vermiwash
(University of Peradeniya, 2015-11-06) Dilani, P.G.I.L.; Loganathan, P.
The study was carried out from November 2014 to April 2015 within the premises of Vavuniya Campus of University of Jaffna. The main objective of this study was to analyze nitrogen, phosphorus and potassium (NPK) concentrations of vermiwash (VW) prepared with different raw materials. Study was targeted on several other objectives such as to seek the handiness of recycling vegetable waste and mango leaves through VW preparation, to prepare VW from green plant species which cause trouble in the environment. Five plastic barrels were used to establish the vermi-bed. A tap was fixed at one horizontal limb of the container. Then, a base layer of small gravels was placed. Over that a layer of fine sand was placed. Then, a layer of top soil was added and it was covered with a layer of cow dung. Excess amount of water was sprayed and allowed to drain-off. After that the tap was closed. Four different types of raw materials, namely vegetable waste, mango (Mangifera indica) leaf litter, parthenium (Parthenium histeroporous) and water hyacinth (Eichhornia crassipes) were used for the preparation of VW. Control unit was maintained. In control, only top soil and cow dung bed were used without adding any extra feeding material. Locally available Earth worms (EWs) were collected from an open land field of Agriculture School in Vavuniya, where livestock wastewater discharges. Fifty surface and subsurface local EWs were introduced in to each vermi- bed. After 60 days of processing, 4.5 L of VW from each unit was collected after passing 5 L of water into each unit. Three samples from each Vermiwash preparation unit and control were collected for physiochemical analysis. Physiochemical characteristics of different raw material driven VW were analyzed using one-way ANOVA. Significant differences were observed between different raw material driven VW and control, including available nitrogen (P ≤ 0.0001), available phosphorous (P ≤ 0.0001), exchangeable potassium (P ≤ 0.0001). Highest concentrations of nutrients were recorded in Parthenium VW (highest ) and Vegetable waste VW (highest and highest K+). The pH of VW was slightly alkaline (7.6 – 8.4). Vermiwash with 1:5 dilution (V/V) was lying within a range of 7.1 - 7.4. Near neutral range of 5.5 - 8.5 is suitable for crop foliar spraying solutions. EC range of 0.5 –1.5 dS/m in soil indicates suitable condition for cropping. Electrical Conductivity (EC) of different types of VW with 1:5 (V/V) dilutions was confirmed range from 0.7 – 1.4 dS/m. This study confirmed feasibility of VW preparation with environmentally troublesome weeds (Parthenium and Water hyacinth). The vermiwash contains considerable concentrations of nutrients in it. Vermicomposting is increasingly becoming popular as an organic solid waste management strategy. The preparation of VW with selected raw material confirmed alternative solution for controlling vegetable waste and mango leaf litters because there is no garbage after prepared VW. The amounts of nutrients in VW will be sufficient to apply for leafy vegetables where low chemical fertilizer applications are prescribed. There is still a requisite of continuing study in this field ahead to, compare the effectiveness of VW application on crop growth with recommended chemical fertilizer application. That will find whether VW replace the chemical fertilizers fully or partially; and to confirm relationship between nutrients concentration in pure raw materials and after it is proceeded in to Vermiwash.
Effect of biochar on phosphorus availability and fixation in some rubber (hevea brasiliensis) growing soils of Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Nandasena, M.A.G.H.; Dharmakeerthi, R.S; Herath, H.M.S.K.
In most rubber [Hevea brasiliensis (A. Juss.) Muell. Arg.] growing soils, phosphorus (P) availability is very low and added P fertilizers become unavailable to the rubber plant due to strong fixation of it into Fe and Al oxide minerals prevalent in these soils. Some studies have observed that amending soils with biochar (BC), a co-product of thermochemical conversion of lignocellulosic materials into advanced biofuels, has increased the P uptake and cut down chemical P fertilizer usage in rubber nursery plants. Therefore, a laboratory incubation study was undertaken to determine the dynamics of soil P availability in three rubber growing soils amended with BC made from rubber wood (RWBC). Three soil types, i.e. Reddish Brown Latasolic (RBL) soil from Parambe, Reddish Brown Earth (RBE) soil from Thanamalwila, and Red Yellow Podsolic (RYP) soil from Payagala were amended with RWBC at 0, 2 and 5% by weight. The soil moisture content was maintained at 80% of water holding capacity and P availability was determined at 0, 1, and 4 weeks during the incubation period. P fixation of soils amended with RWBC was assessed using the Portch and Hunter (2002) method. Available P contents were very low (4.1 to 10.7 ppm) in the three soils and was in the order RYP < RBE < RBL. Application of RWBC increased the available P content by 3 to 7 folds and the increase was in the order of RBE < RBL < RYP. The available P content decreased with incubation time and the greatest decrease (52%) was in RBL while the lowest (42%) was in RBE soil at 4 weeks after incubation in 5% BC amended treatments. Among the three soil types studied the RYP soil had the lowest P fixation ability, while RBL was the highest P fixing soil. Application of BC decreased the P fixation in RBE and RBL soils but not in RYP soil. The greatest decrease was observed when RWBC was applied at 5%. Therefore, amending rubber growing soils with RWBC appears to have altered the dynamics of available P in a positive manner.
Decolourization of crystal violet synthetic dye from aqueous solution by woody biochar
(University of Peradeniya, Sri Lanka, 2015-11-06) Wathukarage, A.; Iqbal, M.C.M.; Priyantha, H.M.D.N.; Vithanage, M.
Colour removal from textile effluents prior to their disposal is an emerging concern due to its adverse effects on the environment and public health. Biochar can be used effectively as a biosorbent for removal of dye contaminants. This study investigated the adsorption of a basic dye, Crystal Violet (CV), from aqueous solutions on to biochar derived from Gliricidia sepium pyrolysed at 700 °C (GBC700). Pyrolysis was done under a heating rate of 7 °C min⁻ ¹. The adsorption process was investigated through batch experiments by varying pH, adsorbent dose, initial dye concentration, and contact time. The sorbent dosage, initial dye concentration and contact time were set as 0.5 - 6.0 g L⁻¹, 5 - 200 mg L⁻¹ and 5 min - 24 hr, respectively. The effect of pH was determined through edge experiments at pH 3 to 9. The equilibrium data was analyzed using the Langmuir, Freundlich and Hill isotherm models. Pseudo first order, Pseudo second order and Elovich kinetic models were used to investigate the kinetic data. Results indicated that the optimal adsorbent dose was obtained at 2 g L⁻¹ and the optimum contact time was 12 hr. The adsorbed amount was increased from 5.5 mg g⁻¹ at pH 3 to 8.0 mg g⁻¹ at pH 9 while the equilibrium was reached at pH 7. Since higher pH conditions lead to increasing the negative charge density of GBC700 and the electrostatic attraction to the dye cations can be enhanced. Crystal Violet removal efficiency was 99% at 20 mg L⁻¹. According to the Langmuir model, maximum adsorption capacity was observed at 30.4 mg g⁻¹ at 30 °C. The experimental data fitted well with the Freundlich isotherm model (r² = 0.9788) and Pseudo second order kinetic model (r² = 0.9703) which suggests the importance of multilayer adsorption to heterogeneous sites in biochars. The adsorption process is highly pH dependent. Crystal Violet molecule may interact with the GBC700 through the mechanism of 𝝅-𝝅 electron donor-acceptor interactions between the π-electron rich graphene surface of biochar and 𝝅-electron deficient CV dye molecule. The use of Gliricidia biochar pyrolysed at 700 °C could be a sustainable solution to remove CV in aqueous media while compromising the waste problem by using Gliricidia byproduct.
Forecasting international tourism income of Sri lanka : trend analysis
(University of Peradeniya, Sri Lanka, 2015-11-06) Konarasinghe, K.M.U.B.
Growth of the tourism industry in Sri Lanka shows the historical development mainly in two ways. That is the growth of tourist arrivals and income. Tourism impacts on the economy of Sri Lanka, which rely heavily on foreign exchange earnings. This has been a general interest of the government. Therefore, the government needs reliable forecasting to cope with uncertain situations and developing sound strategies to maintain the growth of tourism industry. This study was focused on identifying an appropriate trend model for forecasting international tourism income of Sri Lanka. Monthly income data from 2009 to 2013 were obtained from statistical reports of 2012 and 2013 of Sri Lanka Tourism Development Authority (SLTDA). The study concerns the period of post-war, which is after the year 2009. Model fitting was done by utilizing data from January 2009 to April 2012 and data from May 2012 to May 2013 were utilized for model verification. Four trend models were tested with log transformation including one linear and three nonlinear models. Residual plots and Anderson-Darling tests for residuals were used as the model validation criterion. Forecasting ability of the models was assessed by considering Mean Absolute Percentage Error (MAPE), Mean Square Error (MSE) and Mean Absolute Deviation (MAD). Box and whisker plot showed no outliers in the data set. Results revealed that Quadratic Trend Model has least MAPE’s in model fitting and verification: 0.90% and 1.12 %, respectively. MAD and MSE also confirmed the smallest deviation compared with other trend models. Residual plots and Anderson-Darling test confirmed the normality of residuals. Also, residuals Vs fits confirmed the independence of residuals. It was concluded that the Quadratic Trend Model with log transformation is suitable for forecasting international tourism income in Sri Lanka. Monthly income for the period from May 2012 to November 2013 were forecasted by the model and found them close to the actual income. It is recommended to try other time series techniques, namely, decomposition techniques, Auto Regressive Integrated Moving Average (ARIMA) models etc., to capture the seasonal behavior of the series.
Chemical and isotope characteristics of kidney stones (urinary calculi) from Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Weerasinghe, A.; Abeygunasekera, A.M.; Senaratne, A.; Weerasooriya, R.; Chandrajith, R.
Mineralogical, chemical and isotope characteristics of fifty (50) urinary calculi samples collected from removal surgeries were investigated. Fourier Transform Infrared Spectroscopy (FT- IR) technique was used to determine the mineralogical composition while elements Na, K, Ca, Mg, Zn and Fe in kidney stones were determined using Atomic Absorption Spectrophotometry. Stable isotope ratios of V and 18O were measured with isotope ratio mass spectrometer (IRMS). Stone samples were classified into four mineral groups based on FTIR characteristics in which whewellite (calcium oxalate) stones are dominant among apatite, uric acid (uricite) and struvite stones. Apatite stones are enriched with trace elements compared to other stone types in which phosphates act as an important metal-bearing phase. Uricite stones showed the lowest trace metal contents. The of urinary calculi ranged between -34 and -17 ‰ whereas value of kidney stones varies from -8.94 and -26.72‰. Most samples, particularly whewellite and apatite-uricite stones indicated more depleted values (-32 to -34‰). Since the isotopic composition of animal biominerals reflect those of ingested food and water, the more depleted in kidney stones are possibly due to heavy consumption of C3 dietary components. The isotope fractionation between inorganic reservoirs and biominerals of human body is important to understand the sources of elements in such biomaterials.
Preliminary study on use of activated coconut coir as adsorbent for removal of chloride and fluoride in water
(University of Peradeniya, Sri Lanka, 2015-11-06) Bandara, H.K.M.S.N.; Kottegoda, N.; Perera, A.D.L.C.
Chlorine is a powerful germicide used in killing many disease-causing microorganisms in drinking water and reducing them to almost non-detectable levels. However, it can react with organic matter in the water and form dangerous, carcinogenic trihalomethanes if present in excess. Fluoride has beneficial effects on teeth at low concentrations in drinking-water, but excessive exposure to fluoride in drinking-water, or in combination with exposure to fluoride from other sources, can give rise to a number of adverse effects. This is a preliminary study to investigate the ability of activated coconut coir (ACC) to remove Cl ⁻ and F⁻ anions in water. Coconut coir, a lignocellulosic polymer, was activated by treating with phosphoric acid followed by pyrolysis and used as an adsorbent for the removal of Cl⁻ and F⁻ anions from an aqueous solution. Activated product was characterized by Fourier Transform Infrared (FT-IR) Spectroscopy, Scanning Electron Microscope (SEM) and X-ray diffraction techniques and adsorption capacity was measured using methylene blue number. Chloride and fluoride ion removal ability of activated coconut coir was studied by using standard salt solutions of KCl and NaF, respectively. The concentration of Cl⁻ was determined using chloride ion selective electrode and that of F⁻using SPADNS (sodium-2-(parasulfophenylazo)-1,8-dihydroxy-3,6-napthalene) reagent. After activation, coconut coir gains more porosity and adsorption capacity. This can be attributed by the high Methylene Blue (MB) number of 331.30 mg g⁻¹obtained for ACC. The FT-IR data indicates appearance of new functional groups such as carboxylate and phosphate after activation process. The Powder X-Ray Diffraction pattern of synthesized ACC sample showed a peak at an angle of 2θ = 24° corresponding to the hexagonal graphitic carbon structure of (002) plane. The surface morphology and pore structures were analyzed using SEM; SEM images of activated product showed pores in the nanometer size scale. The Presence of nanometer size pores introduces higher adsorption capacity into the ACC. The maximum percent removal of Cl⁻ observed was 30% and that of F- was 40% in single filtration. The equilibrium adsorption studies of Cl ⁻ and F ⁻ anions show that experimental data fits well to linear forms of both Freundlich and Langmuir isotherms implying homogenous and monolayer coverage. The Langmuir constant for Cl ⁻ was 388.00 dm³ g⁻ ¹ and that for F ⁻ was 420.00 dm³ g⁻ ¹ The Freundlich constants for Cl⁻ and F⁻ were 0.022dm³ g⁻ ¹ and 0.012dm³ g⁻ ¹, respectively. The phosphoric acid activated coconut coir has the potential to be used as low-cost adsorbent for the removal of Cl⁻ and F⁻ anions from water.
P-T-t Evolution of calc-silicate rocks in the South-Western highland complex of Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Sameera, K.A.G.; Perera, L.R.K.
Recent studies on calc-silicate rocks from the Southwestern Highland Complex of Sri Lanka have renewed the interest on the reconstruction of the P-T-t and fluid evolution in this part of the island. Present study is another contribution to understand the P-T-t path and fluid conditions of the calc-silicate lithologies around Galle and Middeniya-Embilipitiya areas in the Southwest. Based on petrography and mineral assemblages, the studied calc-silicate lithologies can be subdivided into three main groups; Group I – wollastonite-bearing but grossularite-absent assemblages, Group II – grossularite-bearing but wollastonite-absent assemblages, Group III - both wollastonite and grossularite-absent assemblages. Formation of different assemblages is possibly a result of peak metamorphic P, T conditions, the chemistry of protoliths, graphite precipitation and response to fluctuation of level during prograde path. Critical reaction textures in Group I lithologies indicate breakdown of, (1) wollastonite calcite + quartz, (2) wollastonite + dolomite → calcite + diopside, (3) scapolite → calcite + quartz + plagioclase, (4) alkali feldspar + wollastonite → scapolite + quartz + K+, that are important in re-constructing the P-T-t evolution of the terrain. Diopside rims around quartz in Group II assemblage suggest the reaction, (5) dolomite + quartz → diopside + CO2. In addition, local occurrences of fluids involving reaction textures such as myrmekitic intergrowth of plagioclase + quartz between calcite + K-feldspar and replacement of diopside by hornblende have been observed in calc-silicate rocks from the study area. Peak metamorphic assemblage of the Group I suggests a stabilization temperature of about 800-8500C at 5 kbar, and 0.2 in the fluid phase. The retrograde reactions (1), (2) and (3) suggest isobaric cooling (IBC) following peak metamorphism during which internal fluid buffering prevailed. But the IBC reaction anorthite + wollastonite → grossularite + quartz, noted from elsewhere was not present in the studied samples perhaps due to lower lithostatic pressure in the study area. The reactions (4) and (5) suggest isothermal decompression (ITD) following the IBC path, and other fluid involving reactions noted in the study area suggest both hydration and influx during final stages of metamorphic evolution. The retrograde reaction textures in the studied calc-silicates and the inferred IBC and ITD P-T-t segments for the Southwestern Highland Complex correlate well with the results of previous P-T-t studies of calc-silicate, pelitic and mafic rocks in the Highland Complex. Further, presence of grossularite-absent assemblages, the reaction textures (1), (3) and (4), and the inferred P-T-t path for the study area strongly correlate well with mineral assemblages, reaction textures and P-T- t evolution in the Kerala Khondalite Belt within the Trivandrum Block of Southern India.
Spatial variability of soil properties in a calcic red latosol soil scape in the nothern area of Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Nerogini, S.; Vitharana, U.W.A.; Karunainathan, T.
The information on the spatial variability of soil properties is vital for the better management of soil and to increase the crop productivity. This study was conducted to explore the short-scale spatial variability of selected chemical and physical soil properties of a Calcic Red Latosol soil scape in the Alaveddi area in the Jaffna district. The study area consisted of 2.5 ha and samples were collected within the plough depth (0- 30 cm) by using stratified random sampling scheme. This was achieved by firstly defining a sampling (spacing 29 x 29 m) grid. Subsequently, a random sample was added within each grid cell. The variability of soil clay content, silt content, sand content, organic matter (OM), pH (soil to water ratio of 1:2.5) , electrical conductivity (EC) (soil to water ratio of 1:5) were investigated for all the samples (n=40) and available phosphorous, exchangeable potassium were investigated for selected samples (n=9) by means of classical and geo statistical analysis techniques. The coefficient of variation of properties ranged from 4% (pH) to 32% (clay content). The experimental variograms calculated for soil properties were best fitted with spherical model. According to the relative nugget effect (RNE -ratio of nugget to the sill) of variograms, the clay content, sand content, silt content, electrical conductivity and organic matter exhibited a highly spatially structured variability (RNE < 25 %), whereas a medium structured variability was observed for soil pH (RNE 25-75 %). The observed spatial dependencies of soil properties indicated that sampling space for future studies can be ranged from 20 m (pH) to 70 m (sand). The maps of texture, OM further illustrated a strong short-scale spatial variability indicating the potential of site-specific soil management in the study area.
Evaluation of the status in environmental flow maintainance at mangalathiriya anicut in Aththanagalu oya, Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Udayanga, N.W.B.A.L.; Najim, M.M.M.
Determination of the volumes of flows that should be maintained for the sustenance of the natural eco systems under pristine conditions (Environmental Flows [EF]), remains complicated and difficult, causing a challenging situation for the sustainable management of water resources in many countries. As a tropical developing country with agriculture based economy, Sri Lanka is in need of utilizing the available lentic and lotic water sources heavily to support its economy. Yet, the management of such water sources in an ecofriendly sustainable manner without significantly affecting, both the environment and the economy, requires the maintenance of environmental flows. Thus, the quantification and long-term maintenance of EF requirements of lotic waters has emerged as a crucial requirement in sustainable management of water resources. Therefore, the Range of Variability Approach (RVA) was devised to evaluate the sufficiency of the flows at the downstream of the Mangalathiriya anicut for the sustenance of downstream riverine ecosystems. The Hydrologic Engineering Centre - Hydrologic Modelling System (HEC-HMS) version 3.5 model was calibrated and validated for the Aththanagalu Oya catchment and the daily river flow values for the past twenty years (1994-2014) were generated at the pre weir of the Mangalathiriya anicut. The downstream flows were calculated by deducting the drinking water requirements of the anicut. The existing flow regime at the post-weir was subjected to a RVA analysis, while utilizing 32 different hydrological parameters. The RVA targets (set based on the flows of pre weir site) and rate of non-attainment (for the flow at the downstream of the weir of Mangalathiriya anicut) were calculated to evaluate the sufficiency of the downstream flow regime to cater the EF requirements of downstream ecosystems. The rate of non-attainment of the IHA group 1 and group 2 parameters range in between 33 - 100 % suggesting a moderate to severe level of ecological degradation of the downstream ecosystems. In the IHA group 3, inability of calculating the timing of lower limit of annual extreme water condition due to the prevalence of similar minimal flow levels for several days forced the annual minima to be left uncalculated. Yet the annual maxima reflect a rate of non- attainment of 43 %, while the rate of non-attainment of both IHA group 4 and 5, range in between 48 - 100% and 53 - 100 %, respectively suggesting an ecological degradation of moderate to severe degree. Furthermore, the mean rate of non-attainment of 57.15 % predicts an overall moderate degree of ecological degradation of downstream ecosystems due to the operation of the Mangalathiriya anicut of Aththanagalu Oya. Thus, the results of the current study emphasizes that an adequate level of EF regime is not maintained at the downstream of the Mangalathiriya anicut in Aththanagalu Oya in accordance with the RVA.

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