Riverbank filtration as an alternative treatment technology: AbuTieg case study, Egypt

Abstract

For drinking water production, surface waters bodies are exposed to pollution as a result of discharging untreated liquid wastes into them from industrial, agricultural and domestic activities. Riverbank filtration (RBF) offers a cost-effective technique for producing drinking water by removing many suspended solids, pathogens, and micro-pollutants. The test site is the wellfield for water supply into AbuTieg residents (Assiut governorate, 370 km south to Cairo). It consists of seven municipal wells penetrating the Quaternary aquifer which is mainly fed by the bank filtrate. The results demonstrate the effectiveness of RBF for removing the pathogens and suspended solids. However, ammonium, dissolved iron and manganese are found in the bank filtrate at higher concentrations than those in the Nile water, but still within the allowable limits except for ammonia concentration in winter, the increased of ammonia concentration might be explained by less infiltration of oxygenated Nile water to the aquifer where the Nile received less precipitation in winter time (low-flow period) as well as the impact of sewerage system surrounding the wellfield. Results of the microbiological analysis showed that removal of total and fecal coliform (E. coli) bacteria (cfu/100 ml) is about 3.0 logs and total algal about 3.5 logs. Finally, all the examined abstracted water samples have concentrations below allowable limits for drinking water in Egypt. © Springer Science+Business Media B.V. 2011.