Bacteria and Viruses in the Nile

Abstract

Microbial water quality along the River Nile varies with location and depends on flow rate, water use, population density, sanitation systems, domestic and industrial discharges, demands for navigation, and agricultural runoff. In Lake Victoria, bacterial indicators of sewage pollution and bacteria, morphologically and functionally close to Desulfovibrio, Desulfobacter and Desulfococcus have been detected. The growing population of Bahir Dar Town increasingly pollutes Tana Lake. The microbial load of the Blue and White Niles increases steeply at Khartoum, Sudan. Microbial conditions in Egypt often meet established water quality standards, but some areas are polluted by ca 34 industrial facilities, discharging to the Nile between Aswan and Cairo. Enteroviruses were isolated with a high frequency and positive results were high along 300 km in the south of Egypt. Deterioration is rapid in front of Cairo and in the delta (Damietta and Rosetta Branches), especially during low flow, due to municipal and industrial effluents and agricultural drainage. Here, the bulk of treated and untreated domestic wastewater is discharged to agricultural drains. Total coliform, (TC) bacteria reach 10(6) (most probable number, MPN 100 ml(-1)) in many delta drains, 200 times the Egyptian standard of 5 x 10(3) MPN 100 ml(-1). The Damietta Branch receives nutrients (primarily ammonia) and organics from the Delta Company for Fertilizer and Chemical Industries in Talkha, and agricultural drainage water in the vicinity of the Faraskour Dam. Raw sewage from villages also drains to the Damietta Branch. At ca 120 km downstream from the Delta Barrage, the Rosetta Branch receives polluted inflows from five drains (El-Rahawy, Sobol, El-Tahreer, Zaweit El-Bahr and Tala) and from industry at Kafr El-Zayat.