bluuebunny/crossref_metadata_2025 huggingface dataset:
Degradation Potential of Biodegradable Plastics under Laboratory Conditions
Authors: Sandeepani G.D.V.A.  , Ranatunga R.R.M.K.P.
Published: February 2024

Conventional plastics are one of the greatest environmental issues due to their excessive usage and slow degradation. Biodegradable plastics have been introduced as a promising solution to the issue. However, the degradation potential and the best exposure conditions for biodegradable plastics are not well understood in the local context. Therefore, the present study was conducted to evaluate the degradation potential of some commercially available single-use plastics labeled as ―biodegradable‖. Two brands of lunch sheets (LS1 and LS2) made from Polylactic acid (PLA), Polybutylene adipate terephthalate (PBAT), and corn starch, and one waste bag made from Low- density polyethylene (LDPE) and Linear low-density polyethylene (LLDPE) were tested against cellulose filter paper (FP) as a positive control. Degradation was tested using mass loss analysis, biogas production, and FTIR spectrum analysis together with visual analysis. The test materials were subject to different exposures, i.e., placed under seawater, beach sand, freshwater, sand with overlying freshwater, and under direct sunlight for 210 days, and anaerobic exposure for 60 days. LS1 had the highest mass loss of 73.3% in freshwater and the lowest of 9.5% in sunlight exposure. LS2 recorded the highest mass loss of 59.3% in compost exposure and the lowest of 2.9% in sunlight exposure. Waste bags recorded 1.5% as the highest mass loss in the sand with overlying freshwater and the lowest 0.3% under direct sunlight which is the lowest among all four samples. FP has shown the highest and lowest mass loss in composting and direct sunlight exposures at 79.7% and 6.2%. The degradation of FP indicates that the conditions required for biodegradation were present in the exposure environments. Direct sunlight exposure does not show a significant impact on the degradation of any of the test materials. The waste bag does not show considerable degradation under any exposure. The carbon dioxide gas production was 8.76×10-4 mol, 18.49×10-4 mol, and 2.88×10-4 mol in LS1, LS2, and waste bag, respectively. LS1 and LS2 showed visual damages and also changes in the FTIR spectrum. However, waste bags did not show any changes visually or in FTIR spectra. Therefore, it can be concluded that LDPE and LLDPE products did not undergo a detectable degradation though PLA, PBAT, and corn starch products show clear signs of degradation. The study needs to be repeated in situ to better understand the degradation behavior in actual exposure situations. 

Keywords: Biodegradable plastics, Degradation, Plastic pollution
Degradation Potential of Some Biodegradable Polymers: Do they Degrade?
Authors: Wijetunge D.S.  , Ranatunga R.R.M.K.P.  , Manage P.M.
Published: February 2024

Biodegradable products were invented and commercially introduced to curb the catastrophic impacts of non-degradable plastics. These intend to act as a green solution since they are manufactured to degrade in the environment without accumulating as waste plastics. Three commercially available products labeled as ―biodegradable‖ i.e. salad plate (SPL), lunch sheet (LS), and garbage bag (GB), were tested for degradation potential in six different exposure media i.e. seawater (SW), beach-sand (BS), freshwater (FW), freshwater sediment (FWS), compost, and ultra- violate (UV) rays, with controlled and uncontrolled conditions simulating the natural environment. Cellulose filter paper (CFP) was the positive control. SW, FW, FWS, and BS were placed in four separate glass tanks while compost was prepared in a 100L plastic storage box. A UV chamber was fabricated to expose samples to UV radiation. SW tank was equipped with a wave pump, and FW tank was continuously aerated. All samples were cleaned, cut into manageable sizes, inserted in synthetic mesh pockets (except for those exposed to UV), labeled, and placed inside the media in triplicates. UV-exposed samples were directly placed in boiling tubes inside the chamber equipped with 15 W LED UV bulbs providing 280-320 nm irradiation. Initial weights were measured and the weight loss over five months was recorded. Physical parameters including temperature, pH, salinity, and conductivity were measured in each sampling. RAMAN spectroscopy and Scanning Electron Microscopy were performed initially to find out the test samples‘ chemical composition and surface structure. CFP and SPL contained cellulose, LS contained Poly Lactic Acid (PLA) and Poly Butylene Adipate Terephthalate (PBAT), and GB contained Poly Ethylene (PE) as major components. Degradation potential was calculated in terms of percentage weight loss with time, and visual remarks of degradation were recorded. The highest weight-loss percentages of CFP (100%), and SPL (100%) were observed in FWS (both in 122 days) and compost (in 92 days, and in 122 days respectively) media. LS showed faster degradation (20% weight loss in 92 days) in compost while GB showed slight fragmentation (2% weight loss in 57 days) under UV during the first five months of sampling. Comparatively minimum signs of degradation were observed in GB in all exposures. CFP, SPL, and LS samples were discoloured and fragmented into small pieces during the degrading process. All products showed lesser degradation potential in SW, FW, and UV exposures. The experiment will be continued further to understand the degradation process. 

Keywords: Degradation, Biodegradable products, Abiotic degradation, Plastic pollution
A Comparative Benefit-cost Analysis for the Potential Waste Management Options for the Western Province, Sri Lanka
Authors: De Silva K.W.C.V.  , Gunawardena U.A.D.P.
Published: February 2024

Sri Lanka generates 7,000 metric tons of solid waste per day while only 3,242 tons are being collected. Within the Western province 1783 metric tons are collected daily. Management of municipal solid waste is mainly a responsibility of local governmental entities. Only a few waste management options are often practiced while economic aspects of this problem are rarely taken into consideration. The present study was designed therefore with the objective of analysing current and potential waste management options for the western province and identifying the best option that maximises the net benefit to the country. Seven different options for municipal solid waste management were identified for the analysis (option 1–open dumping; 2-sanitary landfilling; 3- recycling paper, polythene, glass and other recyclable waste (15%) and open dumping the rest; 4- composting the biodegradable (62%) and open dumping the rest (38%); 5-composting the biodegradable (62%), recycling paper, polythene, glass and other recyclable waste (15%) and open dumping the remaining; 6–waste to energy handled by the government; 7–waste to energy collaborated with private organizations). Then costs and benefits, including environmental costs related to each option were identified and quantified using literature and information obtained from interviews held with coordinators of waste management projects under both government and private sectors. Economic cost-benefit analyses were conducted for the seven options for a period of 30 years assuming that a constant amount of municipal solid waste (100 MT) per day is treated by each method. All seven models were developed on the basis of current municipal solid waste composition. According to the net present value analysis, five options resulted in negative net present values, while options four and five showed positive net present values. In the next step, the value of compost was re-estimated considering the replacement benefit of imported nitrogen, phosphorus and potassium fertilizer which has yielded a much higher net present value than earlier. Furthermore, option five was identified as the economically most profitable option. The results of the study will provide guidance toward designing the most economically and environmentally viable waste management options for urban areas of Sri Lanka. 

Keywords: Municipal solid waste, Composting, Recycling, Cost-benefit analysis
Valuation of Ecosystem Services for Driving Community-assisted Forest Landscape Restoration in Endane Biodiversity Corridor, Sri Lanka
Authors: Madawala M.M.G.I.N.M.B.  , Rajasooriya P.G.C.L.  , Fernando A.P.S.  , Perera A.  , Gunatilleke I.A.U.N.  , Nanayakkara S.  , Geekiyanage N.
Published: February 2024

The ecosystem services: direct or indirect benefits of ecosystems to human well-being, need to be recognized in conservation and restoration decision-making. In the human-dominated southwest Sri Lanka, we have established a forest landscape restoration project (Endane Biodiversity Corridor) linking a peripheral forest reserve to Sinharaja Rainforest Complex. The ecosystem services provided by tea monocultures, abandoned tea lands, and lowland home gardens were estimated employing a range of methods for estimating respective ecosystem service values with data collected from household surveys, key stakeholder interviews, and survey of tree flora in 20 m × 20 m plots for estimating aboveground carbon stock. The benefit transfer approach was used to value the supporting and regulating services. The total value of ecosystem services provided by this forest corridor landscape was 6,465 USD ha/yr in 2021. This amount included: provisioning services of 1,950 USD ha/yr, supporting services of 645 USD ha/yr, regulating services of 3,807 USD ha/yr, and cultural services of 38.8 USD ha/yr. Overall, our forest corridor landscape of 59.3 ha provided 382,362 of USD of ecosystem services a year. In comparison to tea monoculture, species-rich home gardens generate a high amount of provisioning services. Our study site is prone to ecosystem degradation due to human activities like forest land encroachment, illegal gem mining, and over-harvesting of forest products. However, we recognize the opportunity of enhancing the biodiversity of monoculture tea gardens and home gardens of the corridor following the principles of agroforestry and enrichment planting. These results i.e., the ecosystem service values among different land uses, are imperative for financing and encouraging community participation for forest restoration activities.

Keywords: Forest resources assessment, Forest restoration, Common-based restoration
A Sustainable Form of Land Use under Borassus flabellifer: A Case Study in Jaffna District of Sri Lanka
Authors: Gnanavelrajah N.  , Sathasivam T.  , Jeyavanan K.  , Raveendran S.
Published: February 2024

Perennial plantations play a significant role in mitigating climate change and improve the plant diversity. This study was carried out to estimate the carbon sequestration potential of Plamyrah (Borassus flabellifer) land use in twelve different soil series in Jaffna district and to estimate the plant diversity of the same. Samples were collected from sampling quadrates of 10 mx10 m. A total of 75 quadrates were sampled. Numbers of quadrates in each soil series were selected based on the extent of Palmyrah plants and soil series. From each quadrate following data was collected: number of Palmyrah trees and other trees and their height and diameter at breast height. Soil samples were also collected within each quadrate at three depths, up to a depth of 30 cm. For the estimation of biomass carbon stock Palmyrah wood density was determined using 15 wood samples. Biomass carbon was estimated using the standard equations. Soil organic carbon percentage was determined by loss on ignition method. The total carbon stock was determined by the summation of carbon in palm biomass and soil carbon. Plant diversity was estimated in terms of number of species, Shannan Weiver index (SWI) and evenness. Soil organic carbon percentage of Palmyrah land use in different soil series ranged between 1.1-4.5%. Soil organic carbon stock in different soil series ranged 51-190 Mg/ha. There was no significance difference among soil organic carbon percentage of Palmyra land use in different soil series. Top most layer (0-10 cm) had significantly higher amount of soil organic carbon than sub surface layers (10-20 cm, 20-30 cm). Palm density of Plamyrah land uses in different soil series ranged 5-13/100 m2. Biomass carbon stock ranged between 2.83-6.80 Mg/100 m2. Biomass carbon stock in different soil series was significantly differed. Total carbon stock ranged 4.06-7.97 Mg/100 m2. A total of 22 plant species belonging to 13 families were identified in the Palmyrah land uses in the study area. Arecaceae family was vastly distributed in the palmyrah land use while Poaceae and Malvaceae were the poorly distributed ones. The mean value of Shannan Weiver Index (SWI) was 1.2 while evenness was 0.74. This study therefore concludes that the Plamyrah land use in the study area has great potential to sequester carbon in long term, while maintaining a reasonable tree species diversity.

Keywords: Soil carbon, Biomass carbon, Plant diversity, Carbon stock
Green Building Rating of High-Rise Buildings in Sri Lanka
Authors: Abeywickrama B.K.A.I.  , Witharana A.
Published: February 2024

As a result of urbanization, constructions of high-rise buildings become a major component of urban development. Constructing high-rise buildings contributes to social, economic and environmental development as well. There are many stages of construction including planning, designing, procurement and implementation. There is a wide range of sustainability practices which can be implemented in each stage of construction. In leading Sri Lanka to Sustainable Development, the green building rating system was introduced by National Green Building Council of Sri Lanka in 2002. This rating system has 100 total points and minimum of 40 points is required for green building certification. The rating system has different components. Among them sustainable sites category includes 25% of total points in green building rating system. This research study highlights the significance of sustainable sites category in order to award the green certification in green building rating system. For this research five major high-rise building construction sites in Colombo were selected and existing site selection practices of each site were investigated. Each site was visited and in-depth discussions were carried out with the planning engineer and other people in the construction site. The structured questionnaire was filled and scores were given accordingly where they have met the sustainable sites criteria. Two sites out of five could not earn single point as they did not fulfill the prerequisites of the site section category. The rest of the sites (three) earned 20, 19, and 18 respectively out of 25 points. In this study, lack of awareness in sustainable site selection practices has dropped the chances of being eligible for the green building certification. Since the minimum points required for green building certification is 40, buildings which are under planning or pre-construction stage have higher chances of obtaining silver, gold and platinum awards for green building certification. Therefore, sustainable sites category of the green building rating system contributes significantly to increase the score and therefore it is highly important in green certification & sustainable construction.

Keywords: Green concept, High-rise buildings, Sustainable development, Sustainable site selection
Urban Farms for Neighborhood Improvement and Social Well-being of Urban Areas in Kandy
Authors: Dilshani C  , Kulathunga S.  , Udawaththa C.
Published: February 2024

In the latter half of the 20th century, as urban populations increased in the majority of emerging nations, the reliability of urban food production and delivery networks decreased. Urban hunger increased concurrently with the urban population, speeding up by in response, urban farms spread over a growing worldwide. However, later other purposes were added to it and urban farms were nurtured. Globally, urban farms are changing as a result of political, economic, environmental, and technical advancements. With time, urban farming activities are becoming a reason to improve the value and quality of life in terms of economic, social, and other elements. In this research, it was investigated how urban farming affects the social well-being and neighborhood improvements of urban areas. Furthermore, it focuses on urban farms' relative attachment to the neighborhood and confidence, their impact on agriculture literacy and youth development, and the economic and food crises in the urban areas. It was sought to understand community perceptions of how urban farms can benefit cities through a qualitative study conducted in two urban farms in Kandy. Interviews with visitors, laborers, and professionals related to urban farming revealed the pathways by which community members view farms as improving neighborhoods and social well-being. According to this study, six characteristics are highlighted and evaluated: neighborhood attachment, neighborhood confidence, youth development, food access, agricultural literacy, and economic development. Benefits stemmed from a primary changes urban farms made to neighborhood improvement: the creation of public project involvement, the physical improvement of degraded space, the production of local food, and the creation of new businesses. These changes led to multiple perceived benefits, including increased social connectedness, a transformed physical landscape, an improved neighborhood reputation, and employment opportunities. But there were some points that should be developed. especially in cases of food access and youth development. Urban farms with strong social aims may appear to contribute little to economic development if measured using traditional indicators of success such as job creation or fiscal impacts, but they provide numerous other benefits for community development.

Keywords: Urban farms, Social connectedness, Physical improvement, Food access, Youth engagement, Economic development
Alternative Timber Applications for Sri Lankan House Construction during the Economic Crisis
Authors: Dabare E.T.D.  , Udawattha C.D.  , Udawattha C.D.
Published: February 2024

A crucial component of civilization, housing construction has evolved in a variety of ways based on new technology and materials. However, due to Sri Lanka's economic crisis, house building is now one of the most in-danger industries there. Subjectively, the cost of imported base building materials has grown due to the danger of inflation, and this increase is dependent on the US dollar exchange rate. The reason is that more than 50% of the building and raw materials are imported, and a rise in the US dollar value will raise the price of construction supplies. In order to find the best materials to reduce the cost of building a house based on imported materials, this study compares the life cycle quality of imported and local alternatives for imported materials made of timber. There are many various kinds of materials that have been utilized in house construction, but the focus of this study is on timber-based alternatives. The study is mainly focused on aluminum and glass as imported materials and timber as an alternative material. Based on life cycle cost analysis, these materials were compared using material costs and data gathered through interviews. Additionally, weighted analysis has been utilized to choose the optimum material based on consumer preferences, appearance and aesthetics, durability, and local availability of resources. Even though local materials are more affordable and score higher on other metrics, it was discovered that they may no longer be comparable to imported materials. People also rapidly switch back to imported materials when they are affordable after the economic crisis. It also found that local timber consumption increased during the economic crisis leading to deforestation.

Keywords: Alternative materials, Appearance, Durability of materials, Finishing materials, House construction, Life Cycle Cost Analysis, Timber
Potential of a Charcoal Evaporative Cooling Chamber for Extending the Shelf Life of Vegetables
Authors: Karunathilaka T.D.  , Rupasinghe C.P.  , Samaraweera M.D.S.
Published: February 2024

There are wide varieties of vegetables in Sri Lanka. The ambient temperature and relative humidity have an impact on rate of vegetables deteriorate. Evaporative cooling is a well-known, cost- effective way to reduce postharvest lost in order to lower the temperature and increase the relative humidity. This research was done to create a charcoal cooling chamber for increase the shelf life of vegetables combining polythene packaging and active packaging additives. The study was carried out in wet zone, Sri Lanka with a sizable chamber made of coconut shell charcoal. A rectangular box made of chicken wire with a 1 m3 capacity serves as the evaporative cooling chamber. It made of chicken wire mesh with a hardwood frame. The walls filled with 50 mm thick coconut shell charcoal and a water outflow 8.33 ml/min for wetting the walls. Vegetable samples without any treatment were placed in the charcoal chamber along with vegetables wrapped in sealed polyethylene (gauge 300) with and without active packing components. With a control sample held in ambient settings, the treatments were put to the test four times over the course of nine days. Both unloading and loading situations were used to evaluate the performance of chamber. Temperature drops of 4° C on average and 2.07° C on average, respectively, were seen in dry and wet climate conditions. 92.49% on average was the cooling efficiency. Sealed polyethylene bags without active packaging components were found to be the best treatment when taking into account physiological weight loss and sensory tests. When compared to the control group on days 3, 6 and 9 physiological weight loss was considerably (P<0.05) less in the sealed polyethylene bags without active packing components. When compared to the control sample total soluble solid content less in sealed polythene bag. The sensory evaluation for the treatments inside the chamber was more acceptable than for the control. Vegetables can store fresh for up to three days in evaporative cooling chamber without packaging. These chambers can install vegetable stalls on the side of the roads in Sri Lanka for temporary purposes.

Keywords: Charcoal, Evaporation, Shelf-life, Temperature, Vegetables
Thermal Evaluation of Vertical Greeneries for Building Façade with Different Orientations and Shading Percentages by Design-builder Simulation
Authors: Jayakody G.D.C.  , Jayasinghe G.Y.  , Halwatura R.U.  , Weerasinghe K.G.N.H.
Published: February 2024

Green facades are the innovative forms of vertical greenery systems which are good strategies for urban greenery to improve the micro-climatic conditions of the area. This research study examines the benefits of cooling load by the simulation of the typical building. Design-builder energy plus simulation tool is used to estimate the annual cooling energy of the typical building which consists of three stories with four façade orientations with varying shading percentages to determine the optimum vertical greenery solution while taking shading percentage and façade direction into account. Design-builder software was validated by measuring the 24-hour temperature of the existing indirect vertical garden. The validation study was carried by using a basic linear regression model analysis using Mini tab software. Under five shading percentages (0%, 25%, 50%, 75%, and 100%), the building was designed with four orientations (North, East, South and West). As a consequence, there were twenty possible situations, each with four regions and four orientations. Each scenario's yearly annual cooling load was estimated and compared to a reference condition for a building without plants using the software. For four major orientations with varying different shade percentages, an indirect green façade with Thunbergia laurifolia was integrated. Validation results exhibit R2 value was 0.976, indicating that the model can express 97.6% of the actual data changes. In terms of economics, the building façade with 25% and 50% greenery coverage with a south orientation and 75% greenery coverage with east orientation are the best vertical greenery solutions. The ideal façade is the one that is completely covered in greenery (100%) and faces east.

Keywords: Design-builder, Indirect green facade, Orientation, Simulation
Core-Shell Adsorbent Granules Fabricated from Sand/Graphene Oxide Nano-Composite for Adsorptive Removal of Pb (II)
Authors: Perera W.P.R.T.  , Perera P.L.R.A.  , Kumarasinghe A.R.  , Liyanage J.A.
Published: February 2024

Core-shell absorbent granules are produced by coating commercial sand gravels with graphite oxide (few-layer oxidized graphene sheets). Graphite oxide (GO) is synthesized chemically from vein graphite, a rare form of high purity natural graphite. Repeated coatings of graphite oxide on sand followed by low temperature (1200 C) thermal pyrolysis produce core-shell granules with a hierarchical structure in which sand gravels are covered by graphite oxide layers. The intention of this study is to assessment of feasibility of the mitigation of Pb (II) form the water by sand/graphene oxide nano-composite and study the dynamic behavior of the adsorption mechanism using the mathematical modeling. Individual materials and the resulting nanocomposite are characterized using a range of spectroscopic (FTIR, XRD, XPS) and microscopic (SEM/EDXA) techniques to elucidate the process of transforming individual materials into nanocomposite and to assess its suitability for removing Pb (II) from water. Stable sand/graphite oxide nanocomposites were obtained upon five times coating of GO on the sand surface and characterization shows that functionalized and a porous coating developed on the sand. The Pb (II) removal efficiency increases from high-acidic to neutral pH and decreases after basic (pH-8). The adsorption process takes 150 minutes to reach the equilibrium. After 150 minutes, the Pb (II) ion adsorption rate was constant. The maximum dosage of the nanocomposite needed to reach the equilibrium was 0.06g. Under the optimum conditions, 96.3% of Pb (II) removal efficiency was recorded from simulated Pb (II) containing water. According to the mathematical modeling, adsorption follows the Langmuir isotherm and fits well with the pseudo 2nd order kinetics model, indicating a homogeneous adsorption process via a monolayer process and Pb adsorbed onto the surface of the sand/GO nanocomposite by chemisorption. Sand/GO nanocomposite is an excellent candidate for removing Pb (II) from contaminated water.

Keywords: Adsorption, Graphene oxide, Sand, Water treatment
Characterization of Thermostable Cellulase Enzyme Isolated from a Hot Spring Bacterium: Bacillus sp.
Authors: Herath M.N.  , Sadeepa, H.D.D.  , Manage, P.M.  , Sirisena, K.A.
Published: February 2024

Cellulase is a complex of enzymes which consists of β-1,4-endoglucanase, cellobiohydrolase, and β-glucosidase. Cellulase contributes a significant share to the world enzyme market and is used in number of industries viz; paper and pulp, food and beverage, bioethanol, detergent and textile. The harsh industrial conditions such as high temperature, extreme pH levels and high substrate concentration etc. which is used in such industries adversely effect on structure and activity of enzymes. Therefore, huge amount of chemical catalysts which cause chemical wastes are used in industrial settings instead of enzymes. Since the chemical wastes adversely affect the ecosystem, isolation and characterization of thermostable cellulase enzyme-producing bacteria and exploring the industrial perspective of thermostable enzymes is a better approach towards green chemistry. The present study focused on characterization of cellulase enzyme produced by Bacillus sp., which shows optimum activity at 60 C under neutral conditions, isolated from Gomarankadavala hot spring in Sri Lanka. The effect of different Carbon sources: glucose and lactose, Nitrogen sources: peptone, tryptone, yeast extract and urea on enzyme production and different Carboxymethylcellulose (CMC) concentrations; 0.5%, 1.5% and 2%, on enzyme activity were measured using the DNS method. Under the optimum conditions, cellulase enzyme activity on different substrates: corn cob, rice bran and raw leaves were measured. The highest enzyme production was recorded in the culture medium which added tryptone as the nitrogen source and adding carbon sources to the culture medium showed an increase of cellulase enzyme production. The optimum CMC concentration for the enzyme activity was recorded as 1% and from all the optimized parameters, the substrate; raw leaves showed the highest enzyme activity of 11.305 U/ml. Further, a considerable amount of enzyme activity was recorded on corn cobs and rice bran as well. Thus, the thermostable cellulase enzyme produced by bacterium identified as Bacillus cereus isolated from Gomarankadavala hot spring could be successfully used in industrial settings such as kitchen/industrial waste management, bioethanol production, paper and pulp industry and textile industry which use high temperatures and cellulosic substrates as raw materials. 

Keywords: Thermostable enzymes, Cellulase, Industrial applications, Hot springs
Release of Potassium Ions from Feldspar by Organic Acids Present in Potassium-Solubilizing Bacteria
Authors: Thashmantha M.A.D.S.  , Ratnatilleke A.A.L.
Published: February 2024

Agricultural production and quality are determined by the nutrient levels in the soil. Permanent agricultural lands are usually nutrient deficient and it is compensated by fertilization. Recent studies have found that potassium-bearing chemical fertilizers caused some environmental issues and these fertilizers are expensive. Therefore, the development of a new method for supplying potassium to plants using ingredients found in Sri Lanka is important. In this respect, the bioconversion of feldspar using biotechnological processing to obtain potassium fertilizers is very promising. The overall objective of this study is to explore the release of potassium ions from feldspar (Microcline- KAlSi3O8) found in Sri Lanka by organic acids present in potassium-solubilizing bacteria to improve the efficiency of these minerals to use in more sustainable agricultural practices. In this research, the solubilization of feldspar with citric, oxalic, succinic, and tartaric acids (the main acids that are produced by potassium solubilizing bacteria) was studied, concerning the effect of acid type, the effect of each acid concentration, the effect of particle size of feldspar, the effect of incubation time, and the changes in pH over time. Ground feldspar (0.150–0.300 mm and 0.075– 0.150 mm) was separately shaken with 0.01, 0.02, 0.03, 0.04 and 0.05 M of each organic acid for different periods (1, 2.5 and 4 hours) and the released potassium ion concentration was measured using a flame photometer and pH change was measured using a pH meter. The extent of solubilization of feldspar was shown to be influenced by the type of organic acid used. In comparison to inorganic acids (H2SO4), some organic acids were more successful in solubilizing feldspar. Both oxalic and tartaric acids showed a higher capability of releasing potassium from the feldspar than other acids by up to 9 folds. The solubilization was insignificant for the same acid when the acid concentration was changed. The solubility of feldspar in all acids increased as the particle size decreased. The solubilization of feldspar was increased practically in almost all acids as time increased. pH was increased in almost all acids when the reaction time was increased. These findings show that both oxalic and tartaric acids are the most successful acids in solubilizing feldspar. Finding bacteria that secrete these acids as their major byproducts and conditions that secrete these acids would be beneficial for agriculture and feldspar can be used to supply potassium to agricultural lands. 

Keywords: Organic acids, Feldspar, Solubilization
Estimation of Water Yield and Soil Erosion in Samanalawewa Watershed in Sri Lanka using GIS-based InVEST Model
Authors: Premarathna W.D.U.  , Udayakumara E.P.N.  , Wanniarachchi D.N.S.
Published: February 2024

Ecosystem services (ES) are a group of tasks performed by the earth's ecosystems that are required to support life and offer benefits to humanity. Thus, this study explores two of the water-related ecosystem services, water yield, and soil retention that were distributed in the Samanalawewa Watershed (SW) and its eight sub-watersheds in Sri Lanka, over 20 years (2000-2020) with five- year time intervals. Soil and water conservation and water yield play an important role in ecosystem management. Hydrological balance is a crucial component of the hydrological ecosystem services. Assessing water yield and soil erosion are pivotal for watershed management. Thus, this study estimated and mapped the water yield and soil erosion, using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST 3.9.2) Annual Water Yield (AWY) and Sediment Delivery Ratio (SDR) model respectively. According to the obtained results, in 2000, 2005, 2010, 2015 and 2020, the estimated mean annual water yield was 2.62x105, 2.6x105, 3.5x105, 3.58x105 and 2.75x105 m3 ha-1year-1, respectively. Furthermore, the estimated mean annual soil erosion rates for the above- mentioned years were 53.2, 52.9, 69.7, 87.7 and 70.2 t ha-1 year-1. The estimated soil loss values of the SW are 10 to 18 times greater than the soil erosion tolerance (5 t ha-1 year-1) in Sri Lanka. The results show that the years 2015 and 2005 have the highest and the lowest water yield and total soil loss values, respectively. The upper part of the watershed has relatively moderate water yield and soil loss values than the lower part. These findings would be beneficial in developing watershed management strategies and in the implementation of suitable soil and water conservation techniques within the watershed. 

Keywords: Ecosystem services, InVEST, Samanalawewa watershed, Soil erosion, Water yield
A Study of Households’ Perception towards Solar Panel Installation Case Study: Villagers of Techno-park nearby Faculty of Technology, University of Sri Jayewardenepura
Authors: Pathirathna M.P.P.Y.  , Kuruppu R.E.  , Perera A.M.H.  , Soysa W.A.E.
Published: February 2024

In Sri Lanka, energy demand has been exponentially increasing with the outage of non-renewable energy sources. There is significant solar intensity in most of the areas in Sri Lanka. This study focused on the domestic solar power system since domestic solar panel usage (700 MW) is the country's highest contributor to solar energy usage. A photovoltaic (PV) system can supply electric energy to loads by directly converting solar energy through the photovoltaic effect with a flexible structure. This study aimed to analyze households' perceptions of solar panel installation. The study was conducted within a 5 km radius around the Faculty of Technology, the University of Sri Jayewardenepura, to analyze the awareness of solar-related technologies. A systematically developed questionnaire was used for the survey to collect the peoples' awareness based on environmental, social & economic beliefs. Thirty residential places (30) were interviewed. According to the results, a residential house's average monthly electricity consumption is 137.67 kWh. The mean monthly income in the area is sixty-eight thousand one hundred and sixty-six rupees and sixty-seven cents. Moreover, most people had solar energy knowledge (93.33%). Among them, 53.57% of the majority were willing to install Domestic Solar PV systems for residential places. From the consumers, 76.66% of the majority had an average level of awareness of the Environmental benefits of using renewable energy and 70.00% of the majority had an excellent awareness of government intervention in rooftop solar energy projects such as "Soorya Bala Sangramaya‖. From the defined awareness levels, further analysis was done on the lowest level of Awareness of Solar Energy to identify their characteristics. The majority of them were those who had lower energy consumption, were over the age of 60 and had a monthly income below twenty thousand rupees. According to the consumers, the best strategy for promoting Solar PV Systems was to lower the prices of existing Solar PV systems. Regulating the efficiency of the Solar PV system was identified by the existing Solar PV system owners. 

Keywords: Solar PV system, Techno-park, Photovoltaic panels
River Gem Mining, its Impacts and Mitigation: A Case from Kumbukkan Oya, Monaragala Divisional Secretariat Area
Authors: Premawansha O.G.K.R.  , Buddhika K.M.W.  , Priyankara T.L.A.  , Dissanayaka D.M.P.T.
Published: February 2024

Gem mining is one of the oldest industries and a major source of income in Sri Lanka. Both traditional and recent mechanical gem mining methods are currently being practiced. However excessive, uncontrolled and illegal gem mining activities have caused many adverse impacts. This study was carried out to analyze the environmental impacts of river gem mining and to propose suitable remedial and mitigatiory measures, with more emphasis on existing legal framework. Study was conducted along a 15 km stretch of Kumbukkan Oya in Monaragala Divisional Secretariat area, where both legal and illegal gem mining activities are taking place at a high intensity. Data were collected by spatial surveys, field surveys and interviews with mine-owners, government officials and general public. All observed mining sites were within the 60m area on both sides of riverbanks. More than 80.00% of the localities from 36 observed sites were unlicensed mines. Natural vegetation had been removed and banks were collapsed due to uncontrolled mining, destructing riverine and aquatic ecosystems. Deep pits were observed in riverbeds at 12 locations. Removed trees and debris were accumulated at the middle of the river, causing flow direction changes. Washing out of damaged banks and disturbances to the riverbed had increased river turbidity and siltation. High number of unlicensed mines, negligence of miners for license conditions, poor monitoring by relevant authorities, lack of cohesion in gem mining policies and laws and the lack of awareness have triggered these issues. Immediate cancellation of condition-violated mining licenses and initiation of legal actions against illegitimate mining activities are important in preventing unregulated mining activities. Systematic rehabilitation of damaged riverine vegetation and riverbanks shall be conducted. Issuance of mining licenses in compliance with the National Environmental (Prohibition of the use of equipment for exploration, mining and extraction of sand and gem) Regulations No.01 of 2006 in Gazette Extraordinary No.1454/4 dated 17.07.2006, demarcation of the ―Reservation Limit‖ of the river mentioned in the said Gazette Notification and obtaining Environmental Recommendations from Central Environmental Authority prior to issuing the license are important to avoid conflicts between the provisions of National Environmental Act and National Gem and Jewellary Authority Act. Issuance of licenses only subject to an acceptable rehabilitation plan submitted by the mine owners, continuous monitoring by relevant authorities and raising awareness among all the stakeholders shall be implemented. More comprehensive studies can be carried out to find the ability of implementing modern environmentally friendly mining technologies. 

Keywords: River gem mining, Impacts, Mitigation, Kumbukkan Oya
Faunal Diversity and Biodiversity Conservation within Homagama Mahinda Rajapaksha College, Sri Lanka
Authors: Abegunawardhana P.D.  , Aththanayake R.K.P.S.  , Galhenage D.T.T.M  , Dahanayaka K.S.S.S.  , Amarasinghe M.A.A.  , Nanediri D.G.S.  , Pathberiya I.N.
Published: February 2024

A faunal diversity survey was carried out to analyze the faunal diversity in Homagama Mahinda Rajapaksha College in Colombo District, Sri Lanka. The survey site is located in a suburban area that is surrounded by disturbed properties. The aim of the survey was to analyze the faunal diversity and recognize the special habitat types in the school premises for conservation purposes. It could recognize five major zones which have different types of microhabitats and rich in faunal diversity. The survey was done as a visual encounter survey, and smartphones, digital cameras and binoculars were used to collect data of the fauna species for documenting and identifying purposes. Also, pitfalls traps, light traps and beating were used as survey methods. The study was done for three days including three random sampling events during both day and night. Standard guides were used for identifying and photographs, notes on observations were sent to experts on each taxon for further confirmation. A total of 188 fauna species were recorded during the survey including 55 species of vertebrates including five classes (Aves, Amphibia, Mammalia, Reptilia, Actinopterygii) and 133 species of invertebrates including six classes (Insecta, Gastropoda, Diplopoda, Clitellata, Chilopoda, Arachnida). The study could document 30 bird, 14 reptile, 6 mammals, 4 amphibian and 1 ray-finned fish species as vertebrates and 95 insect, 5 mollusks, 3 millipede, 2 clitellate, 2 centipede, 26 arachnid species as invertebrate fauna species in the school premises. Based on the results of the survey, the fauna diversity of the studied site is stable and depends on the microhabitat types in the different zones. As a suburban area, the species richness of the site is in well conditions. To keep stable and increase the fauna diversity of the site, doing regular surveys and recording data, generating microhabitats, and conserving highly diverse habitat types are suggested. Unique species like Indian Hare (Lepus nigricollis), Indian Crested Porcupine (Hystrix indica) were observed and as the only venomous snake species, Merrem‘s hump-nosed viper (Hypnale hypnale) was recorded. The faunal diversity of the studied site helps to keep the unique surroundings there and keeping frequent records and data on the site will help to maintain the biodiversity with constructions in and around the school premises. 

Keywords: Faunal diversity, Suburban, Citizen Science, Conservation, Visual encounter
Relationship of Physico-chemical Properties of Water with Phytoplankton Abundance in Peraru Village Tank in Vavuniya District
Authors: Samarawickrama R.A.D.  , Nanthakumaran A.  , Sivakumar P.
Published: February 2024

The village tank cascade system, predominantly found in the Vavuniya district, satisfies the water demand for agriculture and domestic needs considerably. Among them, the Peraru village tank lies in a cascade line in the Vavuniya district. The water resource of Peraru village reservoir is treated by the National Water Supply and Drainage Board, Vavuniya, and distributed to the local public. As Peraru a drinking water fountain, the study of phytoplankton and water quality is important. The study's objective was to identify the phytoplankton and estimate the abundance of phytoplankton in the Peraru village tank along with the Physico-chemical characteristics of water. A phytoplankton sampling was done by using plankton net at the selected three locations of Peraru village reservoir weekly from March to April 2021. Totally, 24 samples were analyzed during the study period. Simultaneously, water samples were also collected at each site to determine dissolved oxygen, electrical conductivity, pH, turbidity, temperature, nitrate, and phosphate concentrations. Identification of phytoplankton was made based on standard guides, and the abundances of phytoplankton were estimated using Sedgewick- rafter counting cells. The results of Physico- chemical parameters were statistically tested using ANOVA and found correlations between the abundance of phytoplankton and Physico-chemical parameters. Phylum Bacillariophyta and genus Aulacoseira were the dominant phylum and genus in the Peraru village tank. Dissolved Oxygen (DO), Electrical Conductivity (EC), nitrate, and phosphate positively influenced the abundance of phytoplankton in the Peraru village tank, while turbidity negatively affected the same. 

Keywords: Phytoplankton abundance, Correlation, Physico-chemical parameters
Is the Forest Fire adjacent to St. Clair’s Waterfall Natural or Man-made?
Authors: Wijerathna L.P.S.D.N.  , Meegahakotuwa U.S.
Published: February 2024

Forest fires have been showing an increasing trend in Sri Lanka over the past few years. Previous studies proved that most of the forest fires in Sri Lanka were caused by human factors. The main objective of this study is to identify the causes of forest fires in close areas of St. Clair‘s fall, which is situated on the western slope of the Central Highlands and to investigate the impacts and measures to reduce forest fires. Primary data as well as secondary data were used for this study. Primary data was obtained through a questionnaire survey and focused group interviews from the study area of Hollyrood, Wattegoda, and Dewon GN Division. Twenty (20) households have been interviewed from the random sampling. Focused group interviews were held with the Nuwara Eliya Forest Conservation Department, Tea Estate companies and Thalawakele Police Station. Rainfall and temperature data were taken as secondary data for the period from 2010 to 2020 from the Department of Meteorology, Colombo. 83 respondents stated that forest fires occurs from January to April because of the high temperature and low rainfall recorded in these months. Patana grasslands are spared on the lower slopes of the left and right banks of waterfall area and plantation forest and Tea plantation have spread in the higher part of the slope. According to the Forest Department, the understory of Patana grassland and undergrowth for forest plantations are exposures to fire in this area. 96 respondents stated that forest fires are purposely started by the people to catch fish from the Kothmale Oya, build bonfire on the rock, and burn fish. Fires are generated through those flames. 63 stated that forest fires are done for ―jungle based feedings‖ for cattle herds by the people in the Thalawakele plantation settlement. They expect fresh grass to boom in the rainy seasons by setting fires in the dry season. 22 respondents stated that forest fires are purposely done for hunting purposes. Most of the fires occur on the left bank of the Kothmale Oya River. In order to prevent fires in this area, the fire breaks fire belt and such as corridors without and with floras are established as buffer zones on the right bank. This fire belt is maintain by Thalawakele Plantation Company. When a forest fire occurs, the Forest Department sends the SMS message to alert the community. Planting hana trees as a green belt can be recommended to reduce the occurrence of fires in this area. 

Keywords: Central Highlands, Random sampling, Bonfire, Hana trees