Physicochemical and Bacteriological Analysis of Bagmati River in Kathmandu Valley

Abstract

Background: The Bagmati River, flowing through the heart of Kathmandu valley, has undergone considerable degradation in water quality that possesses a threat to the river ecosystem and public health. The study had been envisioned to assess certain physico-chemical parameters i.e. pH, temperature, Total Dissolved Solids (TDS), chloride, Dissolved Oxygen (DO) and Biochemical Oxygen Demand (BOD), bacteriological analysis i.e. Total Plate Count (TPC), Total Coliform Count (TCC), isolation and identification of Salmonella spp., Vibrio cholerae and their Antibiotic Susceptibility Test (AST). Methods: Six sites (B1-B6) were allocated along the Bagmati River from Baghdwar to Chobhar. Four samples were collected from each site and analyzed by standard procedures. Result: Maximum average of pH, temperature, TDS, Chloride, DO, BOD was recorded to be 7.6, 29°C, 386ppm, 201mg/l, 9.68mg/l, 229.25mg/l respectively. Maximum and minimum average of TPC was 5.39 106cfu/ml and 7.09 103cfu/ml while that of TCC was 1.91 106cfu/ml and 5.38 102cfu/ml respectively. 45.83% (N= 11) samples exhibited growth of Salmonella spp. of which 12.5% (n=3) isolates were found to be S. Typhi, 8.33% (n=2) to be S. Paratyphi and rest 25% (n=6) to be other S. enterica serovar. All Salmonella spp. isolates were sensitive to Ofloxacin. 41.67% (N=10) samples showed growth for Vibrio cholerae. All isolates were sensitive to Chloramphenicol and resistant to Erythromycin. Conclusion: The study reflected the current physico-chemical and bacteriological status of Bagmati River and emphasizes the need to reduce pollution so as to prevent the transmission of bacterial pathogens.