Effective removal of bromate in nitrate-reducing anoxic zones during managed aquifer recharge for drinking water treatment: Laboratory-scale simulations

Feifei Wang; Doris van Halem; Lei Ding; Ying Bai; Karin Lekkerkerker-Teunissen; Jan Peter van der Hoek

doi:10.1016/j.watres.2017.11.052

Effective removal of bromate in nitrate-reducing anoxic zones during managed aquifer recharge for drinking water treatment: Laboratory-scale simulations

Water Res. 2018 Mar 1:130:88-97. doi: 10.1016/j.watres.2017.11.052. Epub 2017 Nov 27.

Authors

Feifei Wang¹, Doris van Halem², Lei Ding³, Ying Bai⁴, Karin Lekkerkerker-Teunissen⁵, Jan Peter van der Hoek⁶

Affiliations

¹ Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, PO Box 5048, 2600 GA Delft, The Netherlands. Electronic address: wff1986@163.com.
² Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, PO Box 5048, 2600 GA Delft, The Netherlands.
³ School of Civil Engineering and Architecture, Anhui University of Technology, 243000 Maanshan, China; Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, PO Box 5048, 2600 GA Delft, The Netherlands.
⁴ School of Earth Sciences and Engineering, Nanjing University, 210023 Nanjing, China; Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, PO Box 5048, 2600 GA Delft, The Netherlands.
⁵ Dunea, PO 756, 2700 AT Zoetermeer, The Netherlands.
⁶ Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, PO Box 5048, 2600 GA Delft, The Netherlands; Strategic Centre, Waternet, Korte Ouderkerkerdijk 7, 1096 AC Amsterdam, The Netherlands.

PMID: 29202345
DOI: 10.1016/j.watres.2017.11.052

Abstract

The removal of bromate (BrO₃^-) as a by-product of ozonation in subsequent managed aquifer recharge (MAR) systems, specifically in anoxic nitrate (NO₃^-)-reducing zones, has so far gained little attention. In this study, batch reactors and columns were used to explore the influence of NO₃^- and increased assimilable organic carbon (AOC) due to ozonation pre-treatment on BrO₃^- removal in MAR systems. 8 m column experiments were carried out for 10 months to investigate BrO₃^- behavior in anoxic NO₃^--reducing zones of MAR systems. Anoxic batch experiments showed that an increase of AOC promoted microbial activity and corresponding BrO₃^- removal. A drastic increase of BrO₃^- biodegradation was observed in the sudden absence of NO₃^- in both batch reactors and columns, indicating that BrO₃^- and NO₃^- competed for biodegradation by denitrifying bacteria and NO₃^- was preferred as an electron acceptor under the simultaneous presence of NO₃^- and BrO₃^-. However, within 75 days' absence of NO₃^- in the anoxic column, BrO₃^- removal gradually decreased, indicating that the presence of NO₃^- is a precondition for denitrifying bacteria to reduce BrO₃^- in NO₃^--reducing anoxic zones. In the 8 m anoxic column set-up (retention time 6 days), the BrO₃^- removal achieved levels as low as 1.3 μg/L, starting at 60 μg/L (98% removal). Taken together, BrO₃^- removal is likely to occur in vicinity of NO₃^--reducing anoxic zones, so MAR systems following ozonation are potentially effective to remove BrO₃^-.

Keywords: Bromate; Denitrifying bacteria; Managed aquifer recharge; Nitrate; Ozonation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biodegradation, Environmental
Bromates / analysis*
Bromates / chemistry
Drinking Water / chemistry*
Groundwater / chemistry*
Nitrates / analysis*
Nitrates / chemistry
Ozone / chemistry
Water Pollutants, Chemical / analysis*
Water Pollutants, Chemical / chemistry
Water Purification / methods

Substances

Bromates
Drinking Water
Nitrates
Water Pollutants, Chemical
Ozone