Heavy metals and trace elements analysis in groundwater around Mahaoya hot water springs

Groundwater in and around Mahaoya thermal springs found in the Precambrian highgrade metamorphic terrain of Sri Lanka were investigated to assess their geochemical properties with compared to normal regional groundwater of particular area and to produce a data set to develop a model of identification of thermal springs or mixing of thermal and non-thermal ground water. The main objective is this study is to compare the geochemical parameters of thermal springs with nearby cold ground water and interprets the geochemical relationships among them.Samples of low temperature (<35 °C) groundwater from nearby springs, piezometers and open wells were also collected for comparison. All samples were analyzed for their major and trace element compositions using Atomic Absorption Spectrophotometer and standard methods.These waters showed low concentrations of selected trace elements and were comparable to that of geothermal groundwater. Major cation and anion concentrations of thermal springs are similar to nearby cold springs. Close matches of geochemical data from geothermal and dug wells waters confirm the hypothesis of a common source

Screening of Cd, Cr and Zn Tolerant Bacteria in the Rhizosphere of Amaranthus viridis

Environmental pollution is one of the most conspicuous problems in the world. The heavy metal pollution causes adverse impacts on lives of human, animal, microorganisms and the environment. Thus, these heavy metals must eliminate from contaminated soil. This study aimed on removal of Cd, Cr and Zn from the contaminated soil by bacteriological methods. The rhizosphere of Amaranathus viridis plant grown in the unsanitary landfill of Badulla city was used to isolate the bacterial species by using Nutrient Agar medium. The Cd, Cr and Zn separately incorporated into NA plates with the concentrations of 25, 50 and 100 ppm, respectively and plates were inoculated by isolated cultures. The growth of cultures against the respective metals was examined. The assay was conducted in triplicates by following completely randomized design. The bacterial strains that resist the particular heavy metals were selected and further studied for heavy metal tolerance by analysing the changes of heavy metal concentration in culture plates by Atomic Absorbance Spectrophotometry (AAS). According to the results, 11 bacterial species (B1-B11) showed the growth in heavy metal incorporated plates. The majority of species had grown well in plates containing 25 ppm of heavy metals. AAS analysis showed the reduction of heavy metal concentration in inoculated culture plates. The highly declined Cd concentration was observed in plates with B4 and B5 in comparison to other bacterial cultures and the control, though the differences were not significant (p&gt;0.05). Cultures B3 and B6 showed the highest decline of Cr concentration in culture medium. Overall results showed that allbacterial strains couldreduce the concentrations of incorporated Cd, Cr and Zn in the media. Therefore, based on the bio remediation capacity, growing of A. viridis can be recommended as a remedial measure for heavy metal contaminated sites. The heavy metal tolerance bacterial species of the present study are yet to be identified.Keywords: Amaranathus viridis, Rhizosphere, Bacteria, Heavy metal

Groundwater Contamination in Jaffna Red Beds Mainly Focused on Nitrate and Trace Elements

The Jaffna peninsula is dependent on groundwater for all its water requirements andpredominantly for agricultural activities. Studies on effect of fertilisation and groundwaterpollution in such an area are of prime importance. Especially, nitrate rich drinking water ispotentially harmful to human health, particularly to infants. It is recommended that pregnantwomen and lactating mothers should limit nitrate consumption. According to the Jaffnahospital sources, people living in red bed area mostly affected by water bone diseases.Therefore, this study mainly focused on behaviours of nitrate and associated trace elements(Li, Cs, Cu, Sr, Zn, Mn, Fe, K, Mg and Na) in the wells around the red bed in order toinvestigate source and mobility.Physical parameters of water also can be determined the quality of water. The pH wasanalysed by using pH meter. The results were along the study area in WHO and SLS limit.Electric Conductivity is considered as an important water quality parameter in assessingdrinking and surface water. According to the SLS Standards, most of the sources had it abovethe permissible level. The source for the Salinity may be sea water intrusion in thisagricultural land area. Therefore, the water not suitable for the drinking purpose.Seventy randomly collected groundwater samples were analysed using atomic absorptionspectrometer (AAS, Varian 240). Results indicated that most of the wells were highlycontaminated with nitrate in red bed area than in the other regions. It was noted that, overdosage of fertiliser and agrochemicals cause for higher nitrate contamination. It is furtherobserved that the red bed in the area is unconsolidated and mainly formed by iron courtedsands with lower level of organic matter. This further concluded that nature of the red bedprovides favourable conditions for leaching nitrate to groundwater rather than retaining in thesoil. The trace elements such as K, Mg, Ca, Na, Sr, Li and Cu exceeded the permissible levelfor drinking water for all the wells. This may be due to sea water mixing with groundwaterthrough the groundwater flow or by wind spray. Especially, element Ca and Sr may haveaccumulated by weathering of shell fragments in the calcareous deposits in the area.Conversely element Cu may have leached from agrochemicals. However, Zn, Fe, and Bawere in lower concentrations. In general, there were significant correlations between theelements which clearly concluded that the sources for the contaminations are diverse andanthropogenic.Keywords: Fertilisation, Nitrate, Red bed, Groundwate