# Approaching Breakthrough: Resource-Efficient Micropolitan Removal with MBR-GAC Configuration
## 2 Materials and Methods
### Sampling and Analysis  
The long-term evaluation has included 14 weekly samples collected over more than three years of operation. Automatic samplers continuously gathered flow-proportional composite samples from the untreated wastewater, the MBR effluent, and the final effluent after each GAC filter line. Weekly samples were also collected in the effluent from the full-scale WWTP for comparison. The OMPs investigated include a wide range of pharmaceuticals commonly identified in Swedish wastewater, along with the eleven different PFASs (PFAS11), as listed in Table 1. Due to economic considerations, PFAS analyses were not conducted for every sampling event. Figure 1: Schematic description of the plot configuration including cascade MBR-process and the two 2-stage GAC filter lines. In addition, pharmaceuticals and industrial chemicals listed in the proposed sewage directive for quaternary treatment, but not previously analyzed, were included in the last two sampling campaigns (see Table 14). Standard analytical methods, as described below, were applied at IVL's laboratory. Pharmaceuticals were extracted from water samples (200-300 mL) with solid phase extraction (SPE) using 200 mg 6 cc Oasis Hydrophilic-Lipophilic-Balanced (HLB) column from Waters. Then, 50 mg ethylenediaminetetraacetic acid (EDTA) was added to the sample together with 100 ng isotopically labeled internal standards prior to extraction. Filter-aid (4 g) was added to the column and the cartridge was washed with 6 mL methanol (MeOH) and conditioned with 6 mL milli-Q water (MQ). The sample was applied slowly (2 drops/sec). The column was washed with 2 mL MQ after sample application and analytes were eluted with 5 mL MeOH, followed by 5 mL acetone. The extract was evaporated to dryness under nitrogen stream and heat (40 \({}^{\circ}\)C) and re-dissolved in 1 mL MeOH: MQ (1:1) with 0.1% EDTA followed by sonication for 5 min and centrifugation at 14,000 rpm for 5 min. The supernatant was transferred to a vial. Analysis was performed with high performance liquid chromatography (HPLC) coupled to a triple quadrupole mass spectrometer (MS/MS) equipped with an electrospray ionization source (ESI) from Shimadzu (Oregon, USA). The analysis was performed in multiple ion monitoring mode (MRM) using both positive and negative ionization. The chromatographic separation was performed on a biphenyl Core-shell column (3.0 \(\times\) 100 mm, 2.6 \(\upmu\)m, 100 A) from Phenomenex (California, USA) with a gradient elution program and 0.4 mL/min flow rate. The mobile phases consisted of MQ with 2 mM acetic acid and MeOH. Analyte concentrations were quantified using a linear 7-point calibration with R2 \(>\) 0.990. Limit of detection and quantification (LOD and LOQ) were estimated from the noise quantified in the procedural blank samples (3x S/N and 10x S/N, respectively). Recoveries of each pharmaceutical compound were estimated from a spiked procedural blank containing 100 ng/mL of each analyte which was extracted and analyzed together with the samples. PFASs were extracted from water samples (200-300 mL) with SPE using a 150 mg Evolute WAX column with depth filter from Biotage (Uppsala, Sweden). Then, 10 ng isotopically labeled internal standard was added to the sample prior to extraction. The cartridge was washed with 4 mL 0.1% ammonium: MeOH (\(v/v\)) solution and 4 mL MeOH and then conditioned with 5 mL MQ. The sample was applied slowly (2 drops/sec). The column was washed with 4 mL 25 mM ammonium acetate buffer (pH 4) after sample application and analytes were eluted with 4 mL MeOH, followed by 4 mL 0.1% ammonium:MeOH (\(v/v\)) solution. The extract was evaporated to 1 mL under nitrogen stream and heat (40 \({}^{\circ}\)C). The extract was transferred to a vial and 50 ng volumetric standard (3,5-bis(trifluoromethyl)phenyl acetic acid) was added. Analysis was performed with HPLC-MS/MS equipped with an ESI from Shimadzu (Oregon, USA). The analysis was performed in MRM using negative ionization.