Environmental Management
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Item A Determination of air pollution in Colombo and Kurunegala, Sri Lanka, using energy dispersive X-ray fluorescence spectrometry on Heterodermia speciosa(Scientific and Technological Research Council of Turkey (TÜBİTAK), 2011) Gunathilaka, P.A.D.H.N.; Ranundeniya, R.M.N.S.; Najim, M.M.M.; Seneviratne, S.Sri Lanka is facing severe environmental problems such as air and water pollution due to rapid industrialisation and urbanisation. Because there have not been many studies on heavy metal pollution in Sri Lanka, the present study attempts to contribute to the literature a determination of metal pollution using indicators found in lichen specimens. Our study utilised energy dispersive X-ray l uorescence spectrometry to determine element concentrations resulting from air pollution in the lichen species Heterodermia speciosa Wulfen. h ese samples, collected from Colombo and Kurunegala, Sri Lanka, were analysed using the energy dispersive X-ray l uorescence (EDXRF) method in order to determine the concentrations of 13 dif erent elements. A radioisotope excited X-ray l uorescence analysis was applied to the elemental analysis of lichens using the method of multiple standard addition. Our qualitative analysis of spectral peaks showed that the samples contained potassium, calcium, titanium, iron, manganese, copper, zinc, lead, bromine, rubidium, strontium, yttrium, and gallium. Samples from the environment around Colombo, which is a highly congested urban area with much industrial development, were found to be more polluted when compared with Kurunegala, a city that is less congested and without industries. Concentrations of K, Ca, Ti, and Fe were always higher than other elemental concentrations in the lichens we analysed, a fact attributed to the proximity to the sea or exposed earth crustal sources. From the elements reported from the 2 cities, K, Ca, Ti, Fe, Mn, Zn, and Pb were reported at concentrations higher than background levels. Levels of Pb and Zn in samples from Colombo were higher than those from Kurunegala, relecting the increased vehicular trai c. h is study reveals that the common lichen species Heterodermia speciosa can be used as an indicator lichen to analyse the pollution level and other elements in the atmosphere.Item Abundance-Biomass Comparison approach to assess the environmental stressors in Diyawannawa wetland in monsoonal and non-monsoonal seasons(Sri Lanka J. Aquat. Sci, 2018) Wijeyaratne, W.M.D.N.; Bellanthudawa, B.K.A.Abundance-Biomass Comparison (ABC) approach is a graphical approach that compares the abundance and biomass of organisms in order to predict the environmental stress level of an ecosystem. The present study was conducted in selected sites located at non-rehabilitated and rehabilitated areas of the Diyawannawa wetland in Sri Lanka in the monsoonal and non-monsoonal seasons. The ABC was performed on the macrobenthic mollusk species collected from the study sites. Eight species of macrobenthic mollusks, namely, Bithynia tentaculata, Melanoides turbeculata, Melanoides turriculus, Thiara scabra, Lamellidens marginalis, Pila globosa, Gyraulus saigonensis and Lymnaea stagnalis were recorded during the study period. Based on Principal Component Analysis, B. tentaculata, and, P. globosa were identified as characteristic gastropod species that could be used to classify study sites in the rehabilitated and non-rehabilitated areas of this tropical wetland system. In the monsoonal season, overlapping cumulative percentage dominance of abundance and cumulative percentage dominance of biomass curves in sites A, B, and F indicated partially disturbed environmental conditions. The site C of the non-rehabilitated area, showed a typical undisturbed condition and the sites D and E of the rehabilitated area the cumulative percentage dominance of biomass curve was located above the abundance curve, indicating disturbed environmental conditions in these sites during monsoonal season. During the non-monsoonal season in all the sites except site F of the rehabilitated area, the cumulative percentage dominance of abundance curve was located above the biomass curve, indicating undisturbed environmental conditions in these sites. In the site F, the cumulative percentage dominance of abundance and the cumulative percentage dominance of biomass curves were crossing each other, indicating partially disturbed environmental conditions at this site. The values of the W statistic, which ranged from 0.004 to 0.374 in the non-monsoonal season and ranged from 0.1 to 0.2 in the monsoonal season, and pollution and water quality categorization by modified biotic index (MBI) were in agreement with the results of the ABC approach.Item Adapting Sri Lanka to Climate Change: Approaches to Water Modelling in the Upper Mahaweli Catchment Area(Climate Change Research at Universities. Springer, Cham, 2017) Gunawardena, M.P.; Najim, M.M.M.Water flow and water quality changes in surface water bodies due to climate change is a major problem worldwide, typically in river eco-systems. To address these issues, proper monitoring of river flow variations and water quality is necessary, but daily monitoring and data collection is greatly time consuming and costly. Therefore, a study was done with the objectives to calibrate and validate the HEC-HMS 3.5 and HEC-RAS 4.1.0 models to simulate flow variation and water quality variations respectively in Nillambe Oya, Sri Lanka. The development of such models are a significant requirement in the present scientific world to predict river flow and water quality variations as an adaptation for the climate change. The HEC-HMS 3.5 model was used to generate flow which is needed for HEC-RAS 4.1.0. Daily flow data for five years (from October 1991 to September 1996) were used to calibrate the HEC-HMS 3.5 model and another set of daily flow data for five years (from October 1994 to September 1999) were used to validate the model. HEC-RAS 4.1.0 model was calibrated using water quality data collected and analyzed in five days. The validity of the calibrated model was evaluated using water quality data collected in the other four days. The calibrated and validated HEC-HMS 3.5 model reliably predicted the flow in Nillambe Oya. The calibrated and validated HEC-RAS 4.1.0 model simulated Dissolved Oxygen (DO), Biological Oxygen Demand (BOD) and Nitrate Nitrogen (NO3-N) splendidly. Orthophosphates was also predicted reliably by the model, but the simulation of organic Phosphorus was not that sensible.Item Alaboratoryassessment of the survival and verticalmovement of twoepibenthicgastropodspecies, Hydrobia ulvae (Pennant) and Littorina littorea (Linnaeus), afterburial in sediment(Journal of Experimental Marine Biology and Ecology, 1998) Chandrasekera, L.W.H.U.; Frid, C.L.J.Physical disturbance may result in the burial of the epibenthic fauna in sediment. The patches thus created undergo a `recovery' which may include the buried fauna migrating through the sediment to regain their original position in the sediment. A series of laboratory experiments were carried out to investigate the effects of prolonged burial on twoepibenthicgastropodspecies, Hydrobia ulvae and Littorina littorea, under various sediment temperature regimes. Their ability to regain the sediment surface under simulated winter (i.e. 7.5�C) and summer (i.e. 20.3�C) temperature conditions was studied in relation to the depth and the duration of burial. The effects of sediment silt and water content was also examined in a separate experiment. The proportion of H. ulvae surviving burial in natural sediment to 5 cm depth decreased with increasing duration of burial and sediment temperature. Burial to 5 cm was fatal to L. littorea within 24 h at all the temperatures examined. In sediment mixtures which had, by dint of large interstitial spaces, a good supply of oxygen or which were very fluid (i.e. `high silt-high water' sediment) a large proportion of H. ulvae and L. littorea regained the surface within 1 day of burial. No individuals of either species regained the surface in sediment mixtures with high silt and low water contents, this included the unaltered natural sediment treatment. In all cases, the depth of burial significantly reduced the surface regaining ability of L. littorea while it had no effect on H. ulvae. The survival and the escape behaviour of buried H. ulvae and L. littorea is discussed in relation to their respiratory metabolism and the oxygen stress in the sediment. The potential contribution of the buried fauna to the recovery of soft-bottom patches is assessed.Item An analysis of the U.S wood products import sector: Prospects for Tropical wood products exporters(Journal of tropical forestry and Environment, 2012) Bandara, W.A.R.T.W.; Vlosky, R.P.Item An overview of policy and institutional distribution for drinking water supply in the Arsenic affected areas in Bangladesh(The Environ Monitor, 2008) Haque, M.A.; Najim, M.M.M.Item An Overview of the Wood Product Import sector in the U.S.(2009) Bandara, W.A.R.T.W.; Vlosky, R.P.Item Application of home remedial techniques to reduce hardness and Assessment of Variation of physical and chemical parameters of well water in Vadamaradchi(Wetlands Sri Lanka 2018, 2018) Suvendran, S.; Wijeyaratne, W.M.D.N.Vadamaradchi aquifer is considered to be the best ground water source in Jaffna peninsula. Therefore, some wells in Vadamaradchi are used as collector wells which supplies water to fulfil domestic water requirements of the residents in Jaffna peninsula. The present study was conducted with the objectives of assessing physical and chemical parameters of water in selected wells in Vadamaradchi and to identify suitable home remedial techniques to treat the increased hardness of water. Variation of physical and chemical parameters of water collected form 10 collector wells in Vadamardchi aquifer were analyzed and were compared with those parameters in bottled drinking water (Knuckles brand) and with SLSI drinking water quality standard. Along with that the replicate water samples collected were subjected to boiling at 1000C for 10 minutes, filtration through commercial mineral filter and Moringa oleifera leaf powder filter. Total hardness (254.4 mg/L) of the collector wells exceeded the SLSI drinking water standards. Filtration through Moringa oleifera leaf powder filter significantly increased TH and filtration through commercial mineral filter did not caused a significant reduction in TH. However, boiling water at 1000C for 10 minutes significantly reduced TH accounting for 16 % reduction.Item Application of the HEC-HMS model for runoff simulation in a tropical catchment(Environmental Modelling & Software, 2013) Halwatura, D.; Najim, M.M.M.Item Assessing the environmental stress in the Diyawannawa wetland using macro-benthic molluscan diversity based Abundance-Biomass Curves(Sri Lanka Association for the Advancement of Science Proceedings of the 73rd Annual Sessions, 2018) Bellanthudawa, B.K.A.; Wijeyaratne, W.M.D.N.The present study assessed the variation of macrobenthic molluscan abundance and biomass with spatial variation of water and shallow sediment quality parameters in the rehabilitated and nonrehabilitated regions of the Diyawannawa wetland. Six sampling sites, reflecting various land uses in the non-rehabilitated (Site A,B,C) and rehabilitated (Site D,E,F) areas of the Diyawannwa wetland, were selected. At each site, DO, nitrate concentration, total phosphate (TP) concentration, BOD5, COD, chlorophyll-a (Chl-a) concentration of water, sediment conductivity, sediment pH, sediment percentage organic matter (%OM), sand%, silt%, clay%, and abundance and biomass of macrobenthic molluscs were recorded. Sampling was done from April to October 2016. One way ANOVA followed by Tukey’s pairwise comparison was used to assess the spatial variation of water and sediment quality parameters. The correlation between macrobenthic mollusc abundance and water and sediment quality parameters were determined by Pearson’s correlation analysis. Abundance- Biomass Comparison (ABC) Curves of molluscs were plotted. The significantly high mean abundance of Bithynia tentaculata (35), Melanoides turbeculata (5), Lamellidens marginalis (3) and Pila globosa(2) were recorded in site F, of the rehabilitated area where there was a significant input of solid waste, runoff sediments and organic matter. A significant spatial variation of nitrate N, COD, BOD5, Chl-a, DO, % sand, % OM, sediment pH, and conductivity was recorded in rehabilitated sites. Significantly high mean nitrate, Chl - a, COD, and % OM were recorded in site F. Bithynia tentaculata and Pila globosa showed a significant positive correlation with shallow water Chl - a, nitrate content, TP, COD and BOD5;Bithynia tentaculata was the biomass dominant species in all sampling sites. The highest and lowest percentage of biomass of Bithynia tentaculata was recorded in Site F (78.13 %) and in Site B (41.40%) respectively. The ABC curves indicated Site A as a typical unstressed site while Site F as a heavily stressed site. All the other sampling sites were moderately stressed and the level of disturbance varied among the sites. Further based on water and sediment quality data, it can be concluded that most of polluted sites (Sites E and F) are in moderate to heavily stressed condition, while comparatively less polluted sites (Sites A to D) are in unstressed to moderate stressed condition.Item Assessing toxicity of inland surface waters impacted by industrial wastewater released from an export processing zone located near Kelani river basin using physic-chemical analysis and plant based bioassay(Sri Lanka Association for Fisheries and Aquatic Resources, 2016) Kuruppuarachchi, H.D.; Pathiratne, A.Item Assessing toxicity of two industrial zone effluents reaching Kelani River,Sri Lanka(Journal of national science foundation Sri Lanka, 2018) Hemachandral, C.K.; Pathiratne, A.Evaluation of the effcaey of waste treatment technologies of industnal waste is a major challenge for sustainable industrial development world-wide. Hence, new strategies are needed to assess interactive toxic effects of all substances present in the treated waste. This study assessed potential toxic hazards of treated effluents discharged from common wastewater treatment plants of two mclustrlal zones located in the Kelani River basin using Allium cepa (common onion) test system. The results showed that the final effluents of both industrial zones under undiluted and diluted (1 IS v/v) conditions mduced cytotoxrcity on all occasions, with evidence of significant (p < 0.05) mlto-depression In the root meristem and retardation of root growth in A. cepa. Genotoxlc hazard of the effuents was evident by frequent mcrease of nuclear and chromosomal abnormalltles, and occasional development of micronuclei in the root merlstem. Dilution of the effluents to 1 reduced the genotoxic effects generated in A. cepa roots by the final effuents_ The results revealed that waste treatment technologies m these two mdustnal zones need to be upgraded m order to ehmmate cytotoxlc and genotoxrc hazards associated with the treated effuents_ The results highlight the importance of incorporatmg practically feasible bioanalytical tools such as A. cepa root based test system on a regular basis for evaluating the efficacy of waste treatment technologies.Item Assessment of Climate Extremes Based on SPI in WL1a Agroecological Zone - A Case Study from Kuruwita, Sri Lanka(Sri Lanka Journal of Technology, 2020) Mendis, B.R.C.; Rasmiya Begum, S.L.; Najim, M.M.MDrought and flood are the simple most significant climatological hazards in Sri Lanka, which primarily affects agricul tural productivity. Proper understanding and investigation of climatic extremes like drought and floods, plays a key role in planning and management of household, municipal, agricultural and industrial activities even with varied water availability. Therefore, the present study aimed to asses onset, severity and occurrence of drought and wet episodes (months) in Kuruwita region, which belongs to the Low Country Wet Zone Agro-ecological region using the Standardized Precipitation Index (SPI) at various time scales. SPI analyzed at 12 months’ time interval revealed that out of 45 years of study period (1961-2005), there were only four (1976, 1980-1981 and 1996) and six (1985-1986, 1988-1989, 2003-2004) drought and wet hydrological years, respectively. Further, the hydrological years 1981 and 2004 were identified as more affected years by drought and wet events, respectively, with relatively higher occurrence of climate extremes depicted by SPI, than normal conditions. The South-West monsoon (SWM) was found to be more prone to extreme climatic conditions, leading the Yala cropping season to become more abnormal with occurrence of more drought and wet months in Kuruwita. Therefore, the study suggests that implementation of proper mitigative measures like installation of rainwater harvesting systems, reuse or recycling of rainwater, cultivation of stress tolerant crop varieties, adaption of different cropping systems would be beneficial to minimize such adverse effects and for sustainable development in Kuruwita areaItem Assessment of continuous wet day rainfall frequency distribution in the intermediate zone in Sri Lanka(University of Sri Jayawardhanapura, 2013) Jayasuriya, M.T.; Najim, M.M.M.Item Assessment of current water pollution status and accumulation of trace metals in Mugil cephalus from Negombo estuary(Journal of Threatened Taxa, 2021) Najim, M.M.M.; Kithsiri, H.M.P.Industrial and domestic solid waste dumping are the major pollution sources polluting the Negombo estuary. Polluted water and sediments in the estuary may cause heavy metals accu mulation in fish. Therefore, this study was aimed to assess physico - chemical parameters in water, heavy metals (Zn, Pb, Hg, Cd, Cu and Cr) in water and fish tissues, to compare the levels of metals in fish tissues with the available maximum recommended standards. The study was carried out from January to December 2016 and monthly sampling was done from the selected sampling sites. Physico - chemical parameters and metal levels were detected through standard methods. Water quality results revealed that temperature, salinity, pH, EC, TSS, BOD and nutrient levels were below the maximum permissible limits and COD levels were higher than the discharge of industrial wastewater quality standards of the CEA, Sri Lanka. According to the results, metal levels in water of the estuary were below the tolerance limits for the wastewater standards of the CEA except for Hg. In the Northern region of the estuary, higher Pb, Cu and Cr levels were reported from the fish species collected. As the “X-Press Pearl” shipwreck has posed a serious threat to the Negombo estuary, this study can be considered as a baseline for the future studies on water and sediment pollution and bioaccumulation of heavy metals in edible fish species from the estuary.Item Assessment of drinking water quality of domestic wells in Chunnakam and Vadamaradchi, Jaffna peninsula(Sri Lanka Association for the Advancement of Science Proceedings of the 73rd Annual Sessions, 2017) Suvendran, S.; Wijeyaratne, W.M.D.N.An assessment of the quality of drinking water was carried out by measuring 12 selected physicochemical parameters for selected domestic wells in Chunnakam and Vadamaradchi areas of Jaffna. Vadamaradchi is used as the reference site, as this area is considered to have the best fresh water in Jaffna peninsula. The measured physico-chemical parameters of water from selected domestic wells were compared with the standards established by World Health Organisation (WHO) and Sri Lanka Standards Institution (SLSI) for drinking water. Spatial and temporal variation of parameters among sites was analysed using Two-way ANOVA. The characteristic water quality parameters of the sampling sites were identified using Principal Component Analysis (PCA). Significantly high concentrations of nitrate and oil & grease were recorded in Chunnakam (p<0.05), whereas significantly high dissolved oxygen (DO) and pH were recorded in Vadamaradchi. Nitrate concentration of the wells ranged between 0.021 – 40.1 mg/L, while 30% of these wells exceeded WHO permitted nitrate standard level, 11mg/L. Oil & grease (OG) of the wells ranged from 0.011 to 0.373mg/L, while 70% of wells in Chunnakam exceeded the SLSI permitted standard limit for OG, 0.2mg/L. A significant temporal variation of DO, total solids and total hardness was recorded in Chunnakam, while pH, DO and total phosphorus showed significant (p<0.05) temporal variations in Vadamaradchi. The wells in Vadamaradchi were characterized by high DO, low nitrate, and low OG, while the wells in Chunnakam were characterized by high nitrate and OG. The values recorded in the current study can serve as baseline values for future water quality monitoring and management studies in Chunnakam and Vadamaradchi.Item Assessment of invasion of Najas marina, Linnaeus 1753 in Madu Ganga estuary, Sri Lanka using ASTER data of Terra satellite(Institute of Biology, Sri Lanka, 2015) Silva, T.M.S.D.G.; Dahanayaka, D.D.G.L.; Wijeyaratne, M.J.S.Item Assessment of rainfall frequency distribution in the intermediate zone of Sri Lanka(Sri Lanka Association for the Advancement of Science, 2013) Jayasuriya, M.T.; Najim, M.M.M.Item Assessment of the climate change variability in the intermediate zone of Sri Lanka through continuous wet day rainfall frequency distribution analysis(Symposium proceedings of the Water Professional?s Day, 2013) Jayasuriya, M.T.; Najim, M.M.M.Item Benthic macro-invertebrates as environmental flow indicators – a case study: Gurugoda oya, Sri Lanka(Sri Lanka Association for the Advancement of Science, 2014) Munasinghe, D.S.N.; Najim, M.M.M.