Assessment of Water Quality and Bacteriological Indicators of Sewage Pollution in Bahr El-Baqar Drain, Eastern Nile Delta, Egypt

Abstract

This study assessed the seasonal and spatial variation of the water quality physicochemical parameters, major dissolved ions, and the bacteriological indicators of sewage pollution in Bahr El-Baqar drain, Eastern Nile Delta, Egypt, in the summer and winter seasons of 2018. Results showed that the drain water contained higher values of the physicochemical parameters: pH, Total dissolved salts (TDS), Electrical conductivity (EC), Dissolved oxygen (DO), Biological oxygen demand (BOD), and Chemical oxygen demand (COD), which are typical for domestic and industrial wastewater. The concentrations of dissolved salts (mg/L) in the drain water followed the decreasing order: Cl − (743.5) > NO 3 − (30.26) > NH 4 + (18.22) > PO 4 3-(2.63). Additionally, the bacteriological indicators; Total Viable Bacteria (TVC), and Total Coliform (TC) groups in the investigated drain water samples. Results of TVC, which counted by standard plate method (SPC) and the TC showed high seasonal levels of sewage pollution in the water of the Bahr El-Baqar drain, particularly in the summer samples. The TVC ranged from 3.8 × 10 4 (winter) to 6.4 × 10 5 CFU/ml (summer), which highly exceeds (≤ 1000 CFU/ml) the recommended limit set by Egyptian Law No. 48/1982 for protection of the River Nile and waterways from pollution. Similarly, the TC ranged from 1.3 × 10 6 (winter) to 9.3 ×10 7 CFU/ml (summer), which highly exceeds the World Health Organization (WHO) safe limit (≤1000 CFU/100 ml) for wastewater use in irrigation. This study provides the current pollution status of Bahr El-Baqar drain to find sustainable solutions for the national water vulnerability crisis.