Supporting Information s15

SUPPORTING INFORMATION

CATALYTIC DECHLORINATION OF DICLOFENAC

BY BIOGENIC PALLADIUM IN

A MICROBIAL ELECTROLYSIS CELL

Bart DE GUSSEMEa, Maarten SOETAERTa, Tom HENNEBELa, Lynn

b a a, VANHAECKE , Nico BOON , Willy VERSTRAETE *

aLaboratory of Microbial Ecology and Technology (LabMET), Faculty of Bioscience

Engineering, Ghent University, Coupure Links 653, B-9000 Gent, Belgium. bLaboratory of Chemical Analysis, Faculty of Veterinary Medicine, Ghent University,

Salisburylaan 133, B-9820 Merelbeke, Belgium.

*Corresponding author: Willy Verstraete, Laboratory of Microbial Ecology and

Technology (LabMET), Ghent University, Coupure Links 653, B-9000 Gent,

Belgium. Tel.: +32 9 264 59 76; Fax: +32 9 264 62 48; E-mail address:

[email protected]; Webpage: http://www.LabMET.UGent.be.

S1 S1. Details of U-HPLC-MS/MS analyses S1.1.Analyses of diclofenac and APA in synthetic medium

For the detection of diclofenac and APA at lower concentrations in synthetic medium, ultra-high performance liquid chromatography coupled to tandem mass spectrometry

(U-HPLC-MS/MS) was used. Chromatography was carried out on a Thermo

Scientific (CA, USA) Accela U-HPLC system comprising of a quaternary pump and autosampler, equipped with a Nucleodur C18 Pyramid column (100 mm x 2 mm,

1.8 µm, Macherey-Nagel, PA, USA). The column temperature was set at 35 °C.

Analytes were eluted at a flow rate of 0.3 mL min-1 using a gradient starting from

98% A (0.08% formic acid in ultra pure water) and 2% B (0.08% formic acid in acetonitrile) for 0.8 min, increasing to 65% B in 0.5 min, keeping at 65% B for 0.7 min, increasing to 100% B in 1 min and keeping at 100% B for another 2 min, before returning to the initial conditions during 1.9 min. The injection volume was 10 μL.

Precursor ion, S-lens RF amplitude, and collision energy (CE) in Q2 were optimized individually per compound (Table S1). Quantification and confirmation data were acquired in the selected reaction monitoring (SRM) mode, the transitions followed are displayed in Table S1. Instrument control and data processing were carried out by means of Xcalibur Software (Thermo Electron, CA, USA). The limit of quantification

(LOQ) was determined at 10 μg L−1 as the lowest point of the calibration curve.

Table S1. Collected SRM transitions and compound specific MS parameters.

2 Analyte Precursor Product S-lens Collision energy ion ion (RF amplitude)

(m/z) (m/z) (V) (eV)

Diclofenac 295.9 179.1 91 55

295.9 214.0 91 34

295.9 215.0 91 19

295.9 250.0 91 12

APA 228.0 167.1 84 32

228.0 180.1 84 35

228.0 182.1 84 17

S1.2.Analyses of diclofenac and APA hospital WWTP effluent

The samples of the hospital WWTP effluents were filtered and stored as described above. For the detection of diclofenac in this matrix, U-HPLC-MS/MS was performed as described above. However, other SRM transitions and other specific

MS parameters were used (Table S2). The LOQ was determined at 50 ng L−1 as the lowest point of the calibration curve.

Table S2. Collected SRM transitions and compound specific MS parameters for the detection in the samples of the hospital WWTP effluent.

S3 Analyte Precursor Product S-lens Collision energy ion ions (RF amplitude)

(m/z) (m/z) (V) (eV)

Diclofenac 296.0 214.1 78 34

296.0 250.1 78 13

S2. Biodegradability of APA S2.1. Experimental details of incubation experiments In order to assess the biodegradability of the complete dechlorinated compound APA, batch experiments were performed in a minimal medium prepared as previously described (2), supplemented with 6.5 μM or 1 mg L-1 APA (Sigma-Aldrich,

Belgium). An industrial produced nitrifying sludge, Ammonium Binding Inoculum

Liquid (ABIL), was added in 150 mL of the medium to a final concentration of 0.75 g

L-1 VSS. To examine the role of sorption, the test was repeated with the same amount of biomass after heatinactivation (121 °C, 30 min). A biomass-free control was included as well. Samples were taken at regular intervals for analysis of APA, NH4+-

N, NO2--N, and NO3--N.

S2.2.Chemical analyses The VSS content was measured according to standard methods (1). For the determination of NH4+-N, NO2--N, and NO3--N, 10 mL samples were taken, filtered over a 0.22 μm filter (Millipore) and kept at 4 ∞C for further analysis. NH4+-N was determined colorimetrically according to Greenberg et al. (1). NO2--N and NO3--N were determined using a Methrom 761 Compact Ion Chromatograph (Methrom,

Switserland). APA was measured as described above.

4 S2.3. Results and discussion While no removal was noticed in a biomass-free experiment after 7 days, ABIL was able to remove 94.6 ± 0.3 % of the present amount of APA. The biomass converted all ammonium (= 53 mg NH4+-N L-1) into nitrate after 5 days of incubation (data not shown). Sorption of APA to the biomass was not observed in a similar test with heat- inactivated biomass, thus suggesting that an active bacterial metabolism is responsible for the biodegradation of APA. As it is easily further degraded, we can assume that there is no further risk towards the ecotoxicity or mutagenicity of APA.

Figure SI1. APA removal as a function of time during 7 days incubation of ABIL biomass (0.75 g VSS L−1) in minimal medium supplemented with 1 mg APA L−1. To examine sorption of APA to the biomass, heat-inactivated biomass was incubated in a control experiment (0.75 g VSS L−1). Results from a biomass-free control in the minimal medium are also shown.

S5 References

(1) Greenberg, A. E.; Clesceri, L. S.; Eaton, A. D. Standard methods for theexamination of waste and wastewater; American Public Health Society: Washington DC, 1992; (2) De Gusseme, B.; Pycke, B.; Hennebel, T.; Marcoen, A.; Vlaeminck, S. E.; Noppe, H.; Boon, N.; Verstraete, W. Biological removal of 17 alpha- ethinylestradiol by a nitrifier enrichment culture in a membrane bioreactor. Water Res. 2009, 43 (9), 2493-2503.