Abstract:
Jaffna Peninsula is mainly depends on groundwater sources because other fresh water sources are not available. Groundwater contaminated with microbiological and heavy metals constituents can cause a variety of water related diseases. Groundwater intended for human consumption should be safe, palatable and aesthetically pleasing. Coliform group has been extensively used as an indicator of drinking water quality and historically led to the public health protection concept. The aim of the present study were carried out to determination and identification of bacterial species of groundwater and to determine the concentrations of heavy metals (Fe, Mn, Zn) in groundwater at gurunagar located in Jaffna compare the results with guidelines from WHO.
Seventeen sampling points were collected from different places in Gurunagar area. Sixty one Water samples were collected from these sampling points. Most Probable Number (MPN) method has been currently used for assessment of the microbiological quality of drinking water. Bacterial identification was carried out using biochemical tests. Water samples were analyzed by Flame Atomic Absorption Spectroscopy for their heavy metals concentration.
A total of bacterial species: Escherichia coli, Klebsiella spp, Salmonella, Shigella and Enterobacter were identified form groundwater samples. The bacteria belonging to the family enterobacteriaceae (coliforms) showed the maximum occurrences in water samples. The high total coliforms count 2400 MPN index/100 ml in groundwater samples. Different selective media like Eosine Methylene Blue (EMB) and MacConkey were used to isolate bacteria rather than one increased the chances of successful isolation/identification. The identified bacteria were reconfirmed through the use of biochemical (IMViC) tests made for this purpose. The average abundance order of trace element contents in groundwater samples are: Fe > Mn > Zn, respectively. The maximum determined concentrations of Fe, Mn and Zn are 0.0339, 0.0100 and 0.0017 mg/l.
