Browsing by Author "Najim, M. M. M."

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Analysis of spatial and temporal variabilities in soil properties under an oil palm cultivated land in Dodangoda, Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2024) Ariyarathna, T. D. S.; Najim, M. M. M.
The impacts of oil palm plantations on soil properties were not exclusively studied in Sri Lanka. Therefore, the oil palm cultivation at Culloden estate in Dodangoda in Kaluthara district was selected as a suitable study area to evaluate the variability of selected soil physical and chemical properties. The main objectives of this study were to evaluate the impacts of oil palm cultivation on selected physical and chemical properties of soil and to analyze whether there is a significant difference between soil properties in the oil palm site and a reference site. The selected plantation was divided into 3 zones to study the variability in soil parameters within the oil palm land. Three representative sampling points from each zone were selected. A composite sample was prepared mixing the soil from each sampling point in a particular zone. Three reference samples were taken from an abandoned grassland, located 600 m distance from the oil palm land. Monthly sampling was done for six months. Oil palm cultivation had silty clay soil, and the reference land had silty clay loam soil. Soil pH, electrical conductivity, bulk density, organic matter content, nitrogen and phosphorus levels of the study site indicated a significant difference compared to the reference site (p<0.05, Generalized Linear model, followed by the Tukey’s pairwise comparison as a post-hoc analysis at 95% level of confidence). The highest mean pH level was observed from the reference site as 5.58, while the lowest pH value was reported from the oil palm cultivation as 5.46. Soil pH was statistically significantly lower in the study site than in the reference site. Electrical conductivity was statistically significantly lower in the study site than the reference site. Also, organic matter content was statistically significantly higher in the reference site than the study site. Regarding the soil nitrogen content (%), the reference site reported the highest mean value as 0.28%, which was statistically significantly higher than that of the study site. Phosphorus content was statistically significantly lower in the reference site than the study site. Also, soil bulk density was statistically significantly higher in the study site than in the reference site. Even within the study site, the soil physicochemical parameters varied significantly, however, a general trend of an increase or decrease can be seen depending on the type of physicochemical characteristics considered. Organic matter content in the oil palm site increased in August due to harvesting practices and fertilization practices. A significant increase in soil nitrogen content was identified in September, due to the addition of nitrogen-containing fertilizer. Higher Soil bulk density in oil palm land indicated a significant impact on the soil compaction in oil palm cultivations. In conclusion, the soil properties in the oil palm cultivation land were significantly different from those at the reference site. To minimize negative impacts and promote long-term sustainability, the implementation of sustainable agricultural practices is recommended.
Effects of paddy cultivation on the water and sediment quality of drainage canals of an anicut scheme, Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Pathirana, S. P. Y. B.; Najim, M. M. M.
Paddy cultivation is a major and widespread agricultural practice in Sri Lanka. During the paddy cultivation, the water and sediment quality of nearby waterbodies can significantly change due to irrigation of paddy fields and agronomical practices. This research was conducted in a section of Morenna Anicut Scheme, Gampaha, Sri Lanka to assess the changes of water quality, sediment quality and flow aspects of the drainage canals with reference to a selected major irrigation canal during different agronomical practices of Maha cultivation season. Water and sediment samples were collected from four sampling sites from September (2022) to February (2023) selected based on a judgmental sampling method. Different physico-chemical parameters of water samples (temperature, pH, DO, salinity, EC, TDS, TSS, transparency, NO3 - and PO4 3- concentrations), sediment samples (particle sizes and heavy metal concentrations) and flow aspects (water depth and flow velocity) were analyzed employing standard procedures. Significant spatial and temporal variations of water and sediment quality parameters were observed (p<0.05, ANOVA) during the study period. The highest mean pH (6.61 ± 0.50), salinity (0.046 ± 0.004 ‰), EC (95.21 ± 6.95μS/cm), TDS (41.67 ± 3.74 mg/L), TSS (484.0 ± 220.0 mg/L), water depth (73.61 ± 4.38 cm), flow velocity (1.96 ± 1.81 m/s), PO4 3- concentration (1.865 ± 0.750 mg/L), Cd2+ concentration (0.626 ± 0.293 ppm), total Cr concentration (5.62 ± 3.46 ppm), Zn2+ concentration (0.130 ± 0.130 ppm) and Ni2+ concentration (0.203 ± 0.203 ppm) were recorded at sampling site 04 (end point of the major drainage canal). In spatial Principal Component Analysis, sampling site 04 was characterized by temperature, pH, salinity, EC, TDS, TSS, transparency, water depth, flow velocity, NO3 - and PO4 3- concentrations and heavy metal concentrations (Cd2+, total Cr, Ni2+ and Zn2+). In Cluster Analysis, sampling site 04 was significantly different from all the other sites based on the water and sediment quality parameters and flow aspects. Therefore, among all sampling sites, site 04 was heavily degraded. In temporal Principal Component Analysis, February (After harvesting paddy) was characterized by temperature, pH, salinity, EC, TDS and TSS and October – 2 (Just after sowing and first major fertilization) and December (After the second major fertilization) were characterized by NO3 - and PO4 3- concentrations and heavy metal concentrations (Cd2+, total Cr, Ni2+ and Zn2+). Therefore, except in September (prior to land preparation), the water and sediment quality were heavily degraded in all other sampling occasions. This study reveals that physico-chemical water and sediment quality parameters and flow aspects of drainage canals in the selected paddy-cultivation area are affected by irrigation and agronomical practices in the paddy fields. Water and sediment quality of the selected major drainage canal and minor drainage canal were degraded when compared to the selected major irrigation canal of the Morenna anicut scheme.
Groundwater Pollution Impact on Food Security
(Sustainability, 2023) Irfeey, A. M. M.; Najim, M. M. M.; Alotaibi, B. A.; Traore, A.
Global food security challenges have been burdened by a rapidly expanding population and its attendant food demands. Safer and higher-quality agriculture is one of the most essential solutions for addressing the growing problem. In agriculture that is safer, the quality of irrigation from a safer water source will boost food security. Groundwater is one of the most widely utilized water sources for agriculture. Safeguarding groundwater against contamination and preserving water resources is a rising global concern. Herein, previous literature studies were analyzed to determine the groundwater potential for food production of the various continents around the globe, as well as the various types of groundwater contamination, the sources of groundwater contamination, and the best methods for combating groundwater contamination in order to guarantee safe irrigation for agriculture and thus achieve food security. Consequently, the natural and anthropogenic activities that degrade the quality of the groundwater and transform it into contaminated water from harmful organisms, residues of organic and inorganic soluble and non-soluble salts of the groundwater from chemical, leachate from landfills, sewage systems, and biological contamination, are the major issues in safer agriculture, causing a number of problems in the growth of agricultural crops and leading to a negative impact on food production as well as on the health of the population. Proper identification of different sources of contamination and proper methods to prevent contamination from reaching groundwater, as well as governmental and institutional frameworks to combat contamination and treatment methods to treat contaminated groundwater, will contribute to the future achievement of food security by ensuring a safer irrigation method and agriculture.
Impact of Wastewater Treatment Plant on the Quality of Water in the Canals Passing Through Kurunegala City
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Samaraweera, S. A. P. T.; Najim, M. M. M.
Water scarcity is a growing concern worldwide, leading to the adoption of innovative treatment solutions. Urban stormwater drains collect runoff and wastewater released from many urban entities. Canals passing through Kurunegala city have been a traditional means of irrigation but also serve as stormwater drains collecting polluted water causing public health problems. Communities have complained about commercial establishments, residents, institutions, and hospitals releasing untreated wastewater into these canals. In response, the Greater Kurunegala Sewage Treatment Plant (GKSTP) was commissioned to address the issue in 2018. The GKSTP is not covering the whole city and is not operated up to its maximum capacity (73% of the capacity is operated). This study aimed to investigate the impact of wastewater treatment by the GKSTP on water quality in canals passing through Kurunegala City. Water samples were collected from seven sampling sites along the canals during the dry (DS) and wet (WS) seasons. Physical, and chemical parameters were measured to determine the water quality from each sampling point. The study employed General Linear Model (GLM) to assess the spatial and temporal variations in physicochemical parameters of water. Cluster analysis identified patterns, and Analysis of Similarities evaluated the significance. Distance-based Redundancy Analysis analyzed overall parameter influence on seven locations. The effectiveness of the GKSTP in improving water quality was evaluated using the Water Quality Index (WQI). Physicochemical parameters of water along Kurunegala city canals exhibited notable spatial and temporal variation (pWQI>69) in the canals. The GKSTP has a positive impact on the water quality of the canals, with significant reductions observed on key indicators of organic pollution and sedimentation, such as BOD5 and TSS. Improvements have been noted in nitrate levels, indicating a reduction in acidity and nutrient pollution. These findings suggest that the GKSTP is partially effective in removing pollutants from the canals. Unconnected areas need to be connected to the GKSTP to improve the effectiveness of the treatment plant.
Impacts of a partially connected wastewater treatment plant on the water quality of stormwater drains used as an irrigation source
(2024) Samaraweera, S. A. P. T.; Najim, M. M. M.; Alotaibi, Bader Alhafi; Traore, Abou
Urban stormwater drains in Kurunegala City collect runoff and untreated wastewater, leading to public health problems. The Greater Kurunegala Sewage Treatment Plant (GKSTP) was commissioned in 2018 and currently operates at 73% of its capacity to combat public health issues. This study assessed the water quality of canals, comparing it with standards and pre- GKSTP conditions. Water samples were collected from seven sites during dry and wet seasons, and physicochemical parameters were measured. The data underwent spatial and temporal analysis using the general linear model (GLM). Additionally, cluster analysis and distance-based redundancy analysis were employed. The water quality index (WQI) was employed to evaluate the effectiveness of the treatment plant. The study revealed significant spatial and temporal variations in physicochemical parameters along the canals (p < 0.05, GLM), with higher pollution levels during wet months. The WQI improved from 35 (2005) to 49 at present, indicating enhanced water quality (p < 0.05, ANOVA), although it remains unsatisfactory. This study provides novel insights into the limitations of conventional wastewater treatment practices, demonstrating that merely treating wastewater and discharging it back into canals is insufficient. Research underscores the importance of rethinking treated wastewater reuse in achieving multiple sustainable development goals (SDGs). This approach offers a pragmatic path forward for enhancing water security and environmental] sustainability globally.
Investigating the effluent quality of a sewage treatment plant in the Kelaniya area: A temporal analysis
(Faculty of Science, University of Kelaniya Sri Lanka, 2024) Jayasekara, J. M. P. M.; Najim, M. M. M.
Sewage treatment focuses on effectively removing contaminants from sewage to produce an effluent that is safe for discharge into the environment or reuse. Monitoring the effluent quality of a wastewater treatment plant is crucial for maintaining the treated effluent quality. There are growing concerns about the potential environmental impacts of the selected sewage wastewater treatment plant (SWWTP). However, there is a lack of comprehensive research to assess the actual impact of SWWTP on the local environment. Hence, the current study investigated the quality of the effluent of the selected SWWTP. This study was conducted by analysing variations of effluent quality parameters over 6 months (August 2023 to January 2024). Water samples were collected monthly and analysed for key water quality indicators using APHA methods. Temperature, pH, Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), Total Dissolved Solids (TDS), conductivity, salinity, and flow velocity were measured as key water quality indicators. The values of each parameter were compared with the tolerance limits for the discharge of wastewater or effluent into Inland Surface Waters presented by the National Environmental (Protection and Quality) Regulations. The temporal variations of the studied parameters of water samples were statistically analysed using a One-way ANOVA. Results suggest that COD values exceeded the standard values in August (654±16.8 mg/L), October (336.5±35.4 mg/L), November (273±16.8 mg/L), and January (95.2±11 mg/L). TSS values exceeded the standard values in August (87±14.2 mg/L) and October (60±1.74 mg/L) and Dissolved oxygen did not reach the standard values in October (4.47±0.09 mg/L) and November (4.46±0.03 mg/L). Nitrate concentration exceeded the standard values in August (16±1.14 mg/L) and January (13.54±1.04 mg/L). All the other parameters lay within the range of standard values. The cluster analysis of water quality parameters was used to identify the similarities between the sampling sites, and it revealed that effluent released into the environment in August has very different water quality values than other sampling months. All the parameters except pH exhibit significant temporal fluctuations. Low DO level suggested limitations in the aeration process or overload of the organic matter. Low DO levels can affect microbial activities and chemical reactions. Ultimately this can lead to elevated levels of COD and BOD. In addition, sand filtration and carbon filtration are not sufficient to remove soluble organic matter in the water. Therefore, it can be concluded that this treatment plant has some environmental implications due to high COD, TSS, DO, and nitrate levels. Further analysis of each step of the wastewater treatment plant is needed to thoroughly understand the causes of variations in the water quality parameters.