TITLE:
Assessment of Water Quality and Microbial Load of Dhaleshwari River Tangail, Bangladesh
AUTHORS:
Md. Khalid Hassan Real, Natasha Khanam, Md. Younus Mia, Marufa Nasreen
KEYWORDS:
Bacteria, Total Coliform, Escherichia coli, Vibrio cholerae
JOURNAL NAME:
Advances in Microbiology,
Vol.7 No.6,
June
26,
2017
ABSTRACT: The present study was undertaken to investigate some water quality parameters (pH, BOD, DO and water temperature), anion concentration (PO43- , SO42- 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 PO42- value 4.4 mg/l was found in May and lowest value of PO42- 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.