http://drw.jfn.ac.lk/handle/123456789/17 Tue, 12 May 2026 16:17:10 GMT 2026-05-12T16:17:10Z http://drw.jfn.ac.lk/handle/123456789/195 Removal of heavy metals from water using engineered hydrochar: Kinetics and mechanistic approach Nadarajah, K.; Bandala, E.R.; Zhang, Z.; Mundree, S.; Goonetilleke, A. The isotherm, kinetics, and thermodynamics parameters, and mechanisms involved in the adsorption of Pb2+ and Cu2+ ions from an aqueous solution using engineered hydrochar were investigated. The hydrochar was produced through catalytic hydrothermal carbonization of rice straw at 200 °C with (engineered hydrochar) and without (hydrochar) FeCl3 (1.2 %) as iron catalyst which has been reported to have the ability to enhance surface properties. Batch experiments were conducted to examine the effect of sorbent dosage, pH, and initial metal ion concentration on the adsorptive performance.The results obtained revealed that the addition of iron catalyst increased the surface functional groups, and exhibit better adsorptive performance compared to non-treated hydrochar. The adsorptive performance of engineered hydrochar was higher for Pb2+ compared to Cu2+, which can be explained by surface complexation, cationic- π interaction, and mass diffusion process with the initial removal performance limited by mass transfer process. The Langmuir isotherm model gave the best fit for the adsorption of both metals compared to the other models tested. The adsorption kinetics followed the Lagergren’s pseudo-second order model. Thermodynamic parameters revealed that Pb2+ and Cu2+ adsorption by engineered hydrochar is a spontaneous and endothermic process. Moreover, this study created new knowledge by providing an in-depth understanding of the effect of iron catalyst on the functional properties of engineered hydrochar and its adsorption mechanisms. Research on the use of catalysts in engineered hydrochar for pollutant removal is very limited. In addition, the study outcomes would contribute to the production of highly efficient magnetic hydrochars. Fri, 01 Jan 2021 00:00:00 GMT http://drw.jfn.ac.lk/handle/123456789/195 2021-01-01T00:00:00Z http://drw.jfn.ac.lk/handle/123456789/70 Mapping of groundwater potential zones in Killinochi area, Sri Lanka, using GIS and remote sensing techniques Kumar, P.; Herath, S.; Avtar, R.; Takeuchi, K. Groundwater is a vital natural capital for the consistent and economic provision of potable water supply for both rural and urban environments. There is now a strong consensus that climate change poses a fundamental challenge to the well-being of all countries, with potential of being the harshest on countries already suffering from water scarcity. Dry zone of Killinochi basin in Northern Sri Lanka, which was devastated by civil war for last 25 years, is again being revitalized by human settlement and urbanization in last couple of years. However, the decreasing trend in the rainfall regime of the dry zones and the increase in population size (temporary inflow) and, hence, the demand for water for irrigation and other livelihood requirements, calls for a sustainable exploitation of the groundwater resources in the region. The development of a reasonable model for groundwater potential is need for the present time. This work strives to generate groundwater potential zonation map using integrated use of remote sensing and geographic information system (GIS) for Killinochi area, Northern Sri Lanka. Five different themes of information, such as geomorphology, geology, soil type (extracted from existing topo sheet); slope [generated from shuttle radar topography mission (SRTM) digital elevation model (DEM)]; and land use/land cover (extracted from digital processing of AVNIR satellite data) were integrated with weighted overlay in GIS to generate groundwater potential zonation map of the area. The final map of the area was demarcated by four different zones of groundwater prospects, viz., good (5.32 % of the area), moderate (61.90 % of the area) poor (26.61 % of the area), and very poor (6.17 % of area). The hydrogeomorphological units, such as alluvial plain, low slope area, and land occupied by forest, are prospective zones for groundwater occurrence in the study area. Fri, 01 Jan 2016 00:00:00 GMT http://drw.jfn.ac.lk/handle/123456789/70 2016-01-01T00:00:00Z http://drw.jfn.ac.lk/handle/123456789/41 Application of Geospatial techniques for groundwater quality and availability assessment: A case study in Jaffna Peninsula, Sri Lanka Gunaalan, K.; Ranagalage, M.; Gunarathna, M.H.J.P.; Kumari, M.K.N.; Vithanage, M.; Srivaratharasan, T.; Saravanan, S.; Warnasuriya, T.W.S. Groundwater is one of the most important natural resources in the northern coastal belt of Sri Lanka, as there are no major water supply schemes or perennial rivers. Overexploitation, seawater intrusion and persistent pollution of this vital resource are threatening human health as well as ecosystems in the Jaffna Peninsula. Therefore, the main intent of the present paper is to apply geospatial techniques to assess the spatial variation of groundwater quality and availability for the sustainable management of groundwater in the coastal areas. The electrical conductivity (EC) and depth to water (DTW) of 41 wells were measured during the period from March to June 2014, which represents the dry period of the study area. Surface interpolation, gradient analysis, a local indicators of spatial autocorrelations (LISA) and statistical analysis were used to assess the quality and availability of groundwater. The results revealed that the drinking and irrigation water quality in the study area were poor and further deteriorated with the progression of the dry season. Good quality and availability of groundwater were observed in the western zone compared to other zones of the study area. A negative correlation was identified between depth to water and electrical conductivity in the western zone. Hence, relatively deep wells in the western zone of the study area can be used to utilize the groundwater for drinking, domestic and agricultural purposes. The outcomes of this study can be used to formulate policy decisions for sustainable management of groundwater resources in Jaffna Peninsula. Mon, 01 Jan 2018 00:00:00 GMT http://drw.jfn.ac.lk/handle/123456789/41 2018-01-01T00:00:00Z