Author(s)

Md. Khalid Hassan Real¹, Natasha Khanam¹, Md. Younus Mia^1*, Marufa Nasreen²

¹Department of Environmental Science and Resource Management, Mawlana Bhashani Science and Technology University, Tangail, Bangladesh.
²Department of Biotechnology and Genetic Engineering, Mawlana Bhashani Science and Technology University, Tangail, Bangladesh.

The present study was undertaken to investigate some water quality parameters (pH, BOD, DO and water temperature), anion concentration (PO₄^3- , SO₄^2- and NO₃^- ) and the availability of some selected microorganisms consisted of total coliform, fecal coliform (Escherichia coli) and Vibrio cholerae in the Dhaleshwari river during the period from April to June 2015. The water samples were collected from three different stations of the river namely Belta (St-1), Kendua (St-2) and Charabari (St-3) under the Porabari union at Tangail Sadar Upazilla. Water temperature varied from 29.5 ^oC in June to 31.7 ^oC in May with a highest mean 31.17 ± 0.47 in May. The pH of water was slightly alkaline in nature and ranged between 7.25 in June and 8.45 in April. Mean concentrations of BOD 0.87 ± 0.19, 1.12 ± 0.6 and 0.97 ± 0.67 were recorded in April, May and June respectively. Highest PO₄^2- value 4.4 mg/l was found in May and lowest value of PO₄^2- 1.74 mg/l was found in June. Mean sulfate values at different months of Dhaleshwaririver were 6.61 ± 1.78 mg/l, 7.61 ± 2.16 mg/l and 3.68 ± 0.23 mg/l respectively. Nitrate concentration in water samples varied from 0.51 mg/l in June to 3.66 mg/l in April. Total coliforms bacteria were found high in all water samples and values ranged from 11.05 × 10⁸ - 19 × 10²³ cfu/ml. The highest load of total coliforms bacteria was recorded at St-2 in May and the lowest was at St-1 in April. The highest concentration of (Escherichia coli counted in water sample was 6 × 10¹³ cfu/ml at St-2 during June, while lowest concentration was 5 × 10⁵ cfu/ml at St-1 during May. The highest concentration of Vibrio cholerae was 9.66 × 10¹⁴ cfu/ml at St-1 during June, while lowest concentration was 4.2 × 10⁸ cfu/ml at St-3 during April. The high number of total coliform, Escherichia coli and Vibrio cholerae indicated significant level of microbial pollution in Dhaleshwari river. The presence of pathogenic organisms may pose not only health hazards to the users of the river water but also poses risks for the aquatic organisms especially fish of the water bodies. So the occurrence of high bacterial load concluded that the water of Dhaleshwari river is polluted and unhygienic for drinking and even unsuitable for domestic purposes without proper treatment.

Bacteria, Total Coliform, Escherichia coli, Vibrio cholerae

Real, M. , Khanam, N. , Mia, M. and Nasreen, M. (2017) Assessment of Water Quality and Microbial Load of Dhaleshwari River Tangail, Bangladesh. Advances in Microbiology, 7, 523-533. doi: 10.4236/aim.2017.76041.