Riverbank filtration for drinking water supply - a proven method, perfect to face today's challenges

Abstract

Hygiene standards and parasites have been a special focus of drinking water utilities for several years. In this context the development of new, high-tech water treatment methods is often taken into consideration. However, we have been applying riverbank filtration as an inexpensive, natural method in Düsseldorf for over 130 years. Indeed it had been introduced for “hygiene reasons” at the time and, according to our experience, riverbank filtration is well suited to meet these “new” hygiene challenges. We have intensively examined the infiltration of river water into the aquifer. We view this core process as the prerequisite for the sustained function of riverbank filtration. It is closely linked with the retention of turbid matters in the riverbed and the shearing forces on the subsurface. In addition, we have investigated the effectiveness of bank filtration as regards the elimination of microorganisms over recent years. According to these examinations, bacteria are reduced by an average of 3 log orders by bank filtration; individual breakthroughs correlate with high water events. According to our measurements Giardia and Cryptosporidium have been completely eliminated in riverbank passage. The retention of three examined types of viruses was also found to be almost completely accomplished.

Pre/post-closure assessment of groundwater pharmaceutical fate in a wastewater-facility-impacted stream reach

“…Pre-closure results illustrate the risk that the mobility of effluent-derived pharmaceutical contaminants poses to adjacent shallow groundwater ecosystems and to waterreuse applications that depend on efficient contaminant attenuation over short subsurface flow-paths , including bank filtration and artificial recharge (Diaz-Cruz and Barcelo, 2008;Eckert and Irmscher, 2006;Grunheid et al, 2005;Heberer et al, 2004;Irmscher and Teermann, 2002;Jekel and Grunheid, 2005;Maeng et al, 2010;Maeng et al, 2008;Tufenkji et al, 2002).…”

Effects of Urbanization on Groundwater

“…The quality of RBF process filtrate ultimately depends on the physical, chemical, and microbiological processes in the aquifer (Schijven et al, 2002;Hunt et al, 2002). As surface water passes through the river bed and/or bank and into the subsurface, various biotic and abiotic attenuation processes such as adsorption, precipitation/dissolution, ion exchange, oxidation / reduction, hydrolysis, biodegradation, physico-chemical filtration, straining, and mixing with groundwater change the physical, chemical, and microbiological quality of the water (Amrhein et al, 1992;Bourg et al, 2002;Irmscher and Teermann 2002;Hiscock and Grischek 2002) (Figure 7.3). These attenuation processes occur within two distinct zones: the biologically active colmation layer, where intensive degradation and adsorption processes occur within a short residence time, and along the main flowpath between the river and abstraction well where degradation rates and sorption capacities are lower and mixing processes greater (Hiscock and Grischek, 2002); physico-chemical filtration and straining of small particles and microorganisms also continue here.…”

Studying the effect of design parameters on riverbank filtration performance for drinking water supply in Egypt: a case study

“…RBF is considered as a green, sustainable and an economic technology. Removal of pollutants, turbidity, suspended solids, pathogens, biodegradable compounds, non-polar organic compounds, and heavy metals from surface water has been approved in the locations where RBF was implemented around the world (Irmscher & Teermann 2002;Weiss et al 2003;Massmann et al 2008;Dash et al 2010;Sandhu et al 2011;Gutiérrez et al 2017). The flow through the aquifer dilutes the concentration peaks, that may result from sudden spills in the river or during floods (Hiscock & Grischek 2002;Abdel Wahaab et al 2019).…”