Sources and behavior of ammonium during riverbank filtration

Ammonium is an undesirable substance in the abstracted water of riverbank filtration (RBF) schemes, due mainly to the complications it causes during post-treatment. Based on the investigation of case studies from 40 sites around the world, an overview of the sources and behavior of ammonium during RBF is given. Typical concentrations of ammonium in the bank filtrate (BF) are between 0.1 and 1.7 mg/l. The most common source of ammonium in BF is the mineralization of organic nitrogen occurring in the riverbed, while the most common sink of ammonium is nitrification in the riverbed. Ammonium surface water concentrations do not directly translate to abstracted concentrations. Transformations in the riverbed play a critical role in determining ammonium concentrations, whereby riverbeds with high amounts of organic material will have more electron donor competitors for oxygen, thus limiting ammonium attenuation via nitrification. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Ammonium is an undesirable substance in riverbank filtration schemes due to complications in post-treatment. Based on case studies from 40 sites worldwide, sources and behavior of ammonium during RBF were investigated. Typical concentrations of ammonium in bank filtrate range from 0.1 to 1.7 mg/l, with organic nitrogen mineralization in the riverbed being the main source and nitrification in the riverbed being the main sink. Transformations in the riverbed play a critical role in determining ammonium concentrations.