Analysis of physicochemical parameters and microbial status in Gulshan lake water

Abstract

Microbiological evaluation and physicochemical parameters of lake comprises detection of indicator bacteria of water pollution and pathogenic bacteria present in the surface layers of water. Polluted water has a significant impact on human health. Therefore examination of lake water for the presence of bacteria indicatory of sanitary state and of pathogenic bacteria as well as physicochemical parametes may supply information on water quality of the lake. In the present study, water samples were collected from three different sites of Gulshan lake of Dhaka city based on human activities from February 2014 to May 2014(summer to early rainy season). Different physicochemical parameters (pH, DO, temperature, TDS, conductivity) were measured and were inoculated into five different selective agar media, MacConkey, Mannitol salt agar (MSA), thiosulphate-citrate-bile salt-sucrose (TCBS), cetrimide agar and m-FC Agar to detect the presence of pathogenic bacteria. The overall bacterial count was high particularly on site3. Cultural and biochemical examinations revealed the presence of Escherichia coli, Enterobacter, Staphylococcus aureus, Pseudomonas and Vibrio species (V. cholerae, V. parahaemolyticus, V. mimicus and V alginolyticus) in the water samples. The results indicate that Gulshan lake water serves as a reservoir of various pathogenic bacteria and that people using the water might get diseases. This study emphasizes the need for elaborated microbiological examinations of water from Gulshan and other freshwater lakes