Bench-scale column evaluation of factors associated with changes in N-nitrosodimethylamine (NDMA) precursor concentrations during drinking water biofiltration

Copyright © 2019 Elsevier Ltd. All rights reserved..

Biofiltration has been observed to increase or decrease the concentrations of N-nitrosodimethylamine (NDMA) precursors in the effluents of full-scale drinking water facilities, but these changes have been inconsistent over time. Bench-scale tests comparing biofiltration columns side-by-side exposed to different conditions were employed to characterize factors associated with changes in NDMA precursor concentrations, as measured by application of chloramines under uniform formation conditions (UFC). Side-by-side comparisons of biofiltration media from different facilities fed with water from each of these facilities demonstrated that differences in source water quality were far more important than any original differences in the microbial communities on the biofiltration media for determining whether NDMA precursor concentrations increased, decreased or remained constant across biofilters. Additional tests involving spiking of specific constituents hypothesized to promote increases in NDMA precursor concentrations demonstrated that inorganic nitrogen species associated with nitrification, including ammonia, hydroxylamine and chloramines, and biotransformation of known precursors (i.e., municipal wastewater and the cationic polymer, polyDADMAC) to more potent forms were not important. Biotransformation of uncharacterized components of source waters determined whether NDMA precursor concentrations increased or decreased across biofilters. These uncharacterized source water component concentrations varied temporally and across locations. Where biotransformation of source water precursors increased NDMA precursor concentrations, ∼30-60% of the levels observed in column effluents fed with biofiltration influent water remained associated with the media and could be rinsed therefrom in either the dissolved or particulate form. Ozone pre-treatment significantly reduced NDMA precursor concentrations at one facility, suggesting that pre-oxidation could be an effective technique to mitigate the increase in NDMA precursor concentrations during biofiltration. Biofiltration decreased the concentrations of halogenated disinfection byproduct precursors.

Medienart:

E-Artikel

Erscheinungsjahr:

2019

Erschienen:

2019

Enthalten in:

Zur Gesamtaufnahme - volume:167

Enthalten in:

Water research - 167(2019) vom: 15. Dez., Seite 115103

Sprache:

Englisch

Beteiligte Personen:

Zhang, Zhong [VerfasserIn]
Ma, Ben [VerfasserIn]
Hozalski, Raymond M [VerfasserIn]
Russell, Caroline G [VerfasserIn]
Evans, Ashley N [VerfasserIn]
Led, Katrine O [VerfasserIn]
Van Dyke, Michele [VerfasserIn]
Peldszus, Sigrid [VerfasserIn]
Huck, Peter M [VerfasserIn]
Szczuka, Aleksandra [VerfasserIn]
Mitch, William A [VerfasserIn]

Links:

Volltext

Themen:

Biofiltration
Dimethylnitrosamine
Drinking Water
Halogenated disinfection byproducts
Journal Article
M43H21IO8R
N-Nitrosodimethylamine (NDMA)
Ozone
Softening
Waste Water
Water Pollutants, Chemical

Anmerkungen:

Date Completed 02.12.2019

Date Revised 07.12.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.watres.2019.115103

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM301883041