Environmental Management
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Item Cyto-genotoxicity and quality of sediments in Dandugan Oya, Sri Lanka(Proceedings Of Tile 38th Annual, Sessions Of The Institute Of Biology, 2018) Wadasinghe, L.G.Y.J.G.; Wijeyaratne, W.M.D.N.Sediments are very important in maintaining aquatic ecosystem health. Dandugan Oya is a stream located in the Western province of Sri Lanka. Dandugan oya receives industrial waste from multiple sources. It also serves as a raw water source for public water supply in some suburban areas in the Gampaha District. This study was conducted with the objective of assessing sediment quality and cyto-genotoxic effects of sediments in Dandugan oya. Shallow sediments (5 replicates) were collected from six sites CA: Urban site; B and D: Industrial sites; C: water intake for public water supply; E: Agricultural site; F: Reference site) at two month intervals from May to November 2017 and sediment quality was analysed using standard analytical methods. Cyto-genotoxicity of the sediment elutriates were assessed using Allium cepa bioassay. Spatial variation of sediment quality and toxicity indices were analysed by ANOVA followed by Tukey's pairwise comparison using MINITAB 14 software. Significant spatial variations of sediment quality parameters and nuclear abnormalities were observed. Site B recorded significantly lower sand (37%) and significantly higher silt contents (44%) while site D showed a significantly higher clay content (40.6%). Significantly lower sediment pH (4.71) and sediment conductivity (25.29 VLS/cm) were recorded from reference site and highest total organic matter (2.32 %) content was recorded at urban site. Mean nuclear abnormalities ranged from 130/00 to 440/00 with significantly higher abnormalities in sites B (42%)) and D (440/00). Occurrence of nuclear buds and condensed nuclei in the interphase cells of the Allium cepa root tips exposed to sediment elutriates from industrial sites (150/00 and 180/00) were significantly higher (7 to 9 fold) compared to reference site. Further, Site B showed the highest condensed nuclei formation (610/00). However, occurrence of binuclei showed no significant spatial variations, The Mitotic index of the Allium cepa root tip cells ranged from 2.9% to 7.4% with significantly higher values in sites A and B, The results of the present study indicated the occurrence of potential cyto-genotoxic contaminants in the sediments of Dandugan Oya. Therefore, further investigations on the identification of the active forms of these contaminants are recommended in order to maintain the health of the ecosystem.Item Identification of Macrophyte Indicator Species to Evaluate the Water Quality in Wetland(Proceedings of the 22nd International Forestry and Environment Symposium 2017, 2017) Bellanthudawa, B.K.A.; Wijeyaratne, W.M.D.N.Present study conducted to assess the SP?ti?! yeri?tion of mecrophvte distribution 2nd water quality parameters of a rehabilitated and non-rehabilitated areas of the Diyawannawa wetland with the aim of identifying suitable macrophyte indicator species for water quality monitonng. Sites A, B and C were located in non-rehabilitated area and the sites D, E and F were located in rehabilitated areas in Diyawannawa wetland. The sampling was conducted from April to October 2016. At each site, water pH, temperature, conductivity, sa!inity, total dissolved solids (TDS), dissolved oxygen concentration (DO), biological oxygen demand (BOD5), chemical oxygen demand (COD), depth, visibility, total nitrate (TN), chlorophyli a (Chl a) and total phosphorus (TP) concentration were measured and the percentage cover of macrophytes were recorded. The correlation of percentage cover of macrophyte species to the water quality parameters were assessed using Pemson's correlation analysis. Principal component Analysis (PCA) based on the percentage cover of macrophyte species was performed to identify the characteristic species at each site. M[NITAB 14 software was used for statistical analysis ofdata. The percentage cover of Hydril/a verticil/ata, Pistia straiiotes and Cypreus iria did not show significant spatial variations among rehabilitated and non-rehabilitated areas. Significantly high percentage cover of Nymphaea ampla (64%) and Annona glabra (l I %) were recorded in site A in non-rehabilitated area. Eichhornia crassipes (22%) showed significantly high percentage cover in site B in non- rehabilitated area and site E in rehabilitated area. Cryptocoryne wendtii recorded significantly high percentage cover In sites A (10%) and E (7%), The highest mean percentage cover of Salvinia ;nolesta (30%) were recorded in site E. The spatial variation of physico chemical parameters Indicated significantly high DO in sites E (10.61 mg/l) and F (10.28 mg/l). Significantly high Chl a concentrations were recorded from sites B, E and F. In addition, site F recorded significantly high BOD5 (6.56 mg/l), TN (0.04 mg/l) and COD (454.8 mg/l). There was no significant spatial variation of TP among sampling sites. S. molesta and E. crassipes showed positive correlations with Chl a and TP and N. rubra showed a positive correlation with TN. H. verticillata and P. stratiotes did not show significant correlations with water quality parameters. According to PCA, considering PC scores I to 3, site A in the non-rehabilitated area was characterized by N. ampla and C. wendtii, site B by E. crassipes and P. stratiotes and site C by A. glabra. In rehabilitated area, site D was characterized by C. iria and Ceratophyllum demersum, site E by S. molesta and site F by N, rubra. The PCA based on water quality parameters grouped the sites E and F together and were characterized by high TN and Chl a concentrations. The results of the present study indicated that there is significant spatial variation of percentage macrophyte cover in relation to water quality parameters. Further, this study identified S. molesia and Eichhornia crassipes and N. rubr.a as suitable indicator of Chl a and TP and TN in wetland health monitoring studies.Item Biological remedies towards safe water...(Proceedings of the Twenty Fourth Scientific Sessions of the Sri Lanka Association for Fisheries and Aquatic Resources, 2018) Wijeyaratne, W.M.D.N.Water is considered as the most essential component in the human livelihood. Rapidly increasing world population, mainly in the developing countries in parts of Asia, North Africa and the Middle East, and sub-Saharan Africa have placed an inordinate demand on safe drinking and potable water. This ever increasing water demand have exceeded the avaiiabie suppiy oi safe fresh water in many regions oi the world. Some major river basins in Asia, North Africa and Middle East are facing severe water scarcity, and over extraction of ground water resources has become a growing problem in many parts of the world. The water scarcity problems are further intensified by increased water pollution due to point and non-point source inputs from urban, industrial and agricultural sectors. Water pollution has imposed severe health issues on human populations and ecological health impairments in aquatic ecosystems. Ensuring universal access to affordable and safe drinking water by 2030 is a target in one of the sustainable development goals. Therefore, the national and international efforts are being initiated to improve water purification infrastructure, provide proper •sanitation facilities, and encourage hygiene in rural, urban and sub urban communities. In addition, the importance of protection and restoration of water- related ecosystems such as forests, mountains, wetlands and riversäs identified in- order to mitigate water scarcity. However, the costs of treating polluted water and restoring water bodies has become a major concern in many countries. The cost of water treatment and aquatic ecosystem restoration requires investment of large amounts of funds and labor, which is unbearable by most of the developing and technology lagging countries. Therefore, natural and synthetic remediation methods have been studied to improve the quality of the contaminated water in many parts of the world, Compared to the chemical purification methods, use of natural materials is increasingly popular among many research groups as these methods provide more cost-effective, environmentally friendly alternatives of water purification. Biological water purification methodologies can be in treatment of domestic drinking water as well as for treating waste water before releasing thém to the environment. Many traditional water purification methodologies that have in practice for decades have been improved and modified by recent research findings to cater for wider community in need of purified water. Further, Many research have been to identify effective plant and microbial aggregations that can serve as universal communities in constructed wetlands in terms of remediation of heavy metal, suspended solids and nutrient pollution. treatment increasing'} researched 2nd as they can destroy and remove multiple contaminants simultaneously and have minimum sludge production and bacterial regrowth. Biological treatment can be used to remove natural organic matter, cclour, chloroform, perchlorate, nitrate, nitrite, bromate, iron, manganese, chromate, arsenate, and a variety of other contaminants cf polluted y.'2ter . cy.id2ticn prier to filtraticn cr settling, as wetl as the need for chemical reduction methods, and produces innocuous end-products, thus reducing the risk Of a contaminating the natural aquatic systems. Therefore, to achieve the sustainable development goal of ensuring availability and sustainable management of water and sanitation for all by 2030, the importance of the role of living organisms in water purification needs to be given a top priority as life and water is the driving force towards a sustainable future.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 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 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 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 Use of Rapid Bio-assessment Protocol (RBP) to assess the suitability of benthic macro invertebrates as bio indicators of water quality monitoring I the Ja Ela canal(Sri Lanka Association for Fisheries and Aquatic Resources, 2016) Wijeyaratne, W.M.D.N.; Kalaotuwawe, K.M.B.P.P.