Micropollutants in drinking water from source to tap - Method development and application of a multiresidue screening method

• Published in: The Science of the total environment 2018-06, Vol.627, p.1404-1432
• Main Authors: Tröger, Rikard, Klöckner, Philipp, Ahrens, Lutz, Wiberg, Karin
• Format: Article
• Language: English
• Subjects: Drinking water; Mass spectrometry; Micropollutants; Multiresidue method; Vattenbehandling; Water Treatment
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2018.01.277

•A multiresidue method was developed to trace micropollutants in drinking water.•A field study from source to tap detected a range of organic micropollutants at each sampling point.•Conventional drinking water treatment was found inefficient for many micropollutants. [Display omitted] A multi-residue screening method for simultaneous measurement of a wide range of micropollutants in drinking water (DW) resources was developed. The method was applied in a field study in central Sweden on water from source to tap, including samples of surface water (upstream and downstream of a wastewater treatment plant, WWTP), intake water before and after a DW treatment plant (DWTP, pilot and full-scale), treated DW leaving the plant and tap water at end users. Low detection limits (low ng L−1 levels) were achieved by using large sample volumes (5 L) combined with ultra performance liquid chromatography high resolution mass spectrometry (UPLC-HRMS). In total, 134 different micropollutants were analyzed, including pesticides, pharmaceuticals and personal care products (PPCPs), drug-related compounds, food additives, and perfluoroalkyl substances (PFASs). Of these 134 micropollutants, 41 were detected in at least one sample, with individual concentrations ranging from sub ng L−1 levels to ~80 ng L−1. Two solid phase extraction (SPE) cartridges (Oasis HLB and Bond-Elut ENV) were shown to be complementary in the field study, with three compounds detected exclusively using HLB. The total concentration in treated drinking water (56–57 ng L−1) was at a similar level as upstream from the WWTP (79–90 ng L−1). The composition of micropollutants changed along the water path, to a higher fraction of food additives and PFASs. Median treatment efficiency in the full-scale DWTP was close to 0%, but with high variability for individual compounds. In contrast, median treatment efficiency in the pilot-scale DWTP was ~90% when using nanofiltration followed by a freshly installed granulated active carbon (GAC) filter.