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Research article - Peer-reviewed, 2020

A case study of organic micropollutants in a major Swedish water source - Removal efficiency in seven drinking water treatment plants and influence of operational age of granulated active carbon filters

Troger, Rikard; Kohler, Stephan J.; Franke, Vera; Bergstedt, Olof; Wiberg, Karin

Abstract

A wide range of organic micropollutants (n = 163) representing several compound categories (pharmaceuticals, pesticides, per- and polyfluorinated alkyl substances, flame retardants, phthalates, food additives, drugs and benzos) were analysed in water samples from the Gota Alv river (Sweden's second largest source water). The sampling also included raw water and finished drinking water from seven drinking water treatment plants and in addition a more detailed sampling at one of the treatment plants after six granulated active carbon filters of varying operational ages. In total, 27 organic micropollutants were detected, with individual concentrations ranging from sub ng L-1 levels to 54 ng L-1. The impact of human activities along the flow path was reflected by increased concentrations downstream the river, with total concentrations ranging from 65 ng L-1 at the start of the river to 120 ng L-1 at the last sampling point. The removal efficiency was significantly (p = 0.014; one-sided t-test) higher in treatment plants that employed granulated active carbon filters (n = 4; average 60%) or artificial infiltration (n = 1; 65%) compared with those that used a more conventional treatment strategy (n = 2; 38%). The removal was also strongly affected by the operational age of the carbon filters. A filter with an operational age of 12 months with recent addition of-10% new material showed an average removal efficiency of 92%, while a 25-month old filler had an average of 76%, and an even lower 34% was observed for a 71-month old filter. The breakthrough in the carbon filters occurred in the order of dissolved organic carbon, per- and polyfluorinated alkyl substances and then other organic micropollutants. The addition of fresh granulated active carbon seemed to iimprove the removal of hydrophobic organic compounds, particularly dissolved organic carbon and per- and polyfluorinated alkyl substances. (C) 2019 The Authors. Published by Elsevier B.V.

Keywords

Drinking water; Mass spectrometry; Micropollutants; Water treatment; Granular activated carbon; PEAS

Published in

Science of the Total Environment
2020, volume: 706, article number: 135680
Publisher: ELSEVIER

Authors' information

Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment
Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment
Norrvatten
Franke, Vera
Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment
Bergstedt, Olof
City Gothenburg
Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment

Sustainable Development Goals

SDG6 Clean water
SDG3 Good health and wellbeing

UKÄ Subject classification

Water Treatment

Publication Identifiers

DOI: https://doi.org/10.1016/j.scitotenv.2019.135680

URI (permanent link to this page)

https://res.slu.se/id/publ/104009