## Materials and Methods
### Characterization of Treated Diclofenac Solution and Extracts  
The standard deviation of the data was the basic statistical tool to give the amount of variation of the stated values. The confidence interval was estimated for the TU values (toxicity). UV-Vis spectroscopy was performed at a Tecan Infinite(r) 200 microplate reader (Tecan Trading AG, Mannedorf, Switzerland). Samples of 60 \(\upmu\)L were measured (triplicate) in a UV-STAR(r)Plate, 384 Well, F-Bottom, \(\upmu\)Clear(r), clear (Greiner Bio-One GmbH, Frickenhausen, Germany) well plate from 230-315 nm (5 nm slit width) and 316-400 nm (9 nm slit width) in 2 nm steps. Reversed-phase HPLC measurements were conducted at a Dionex UltiMate 3000 HPLC system equipped with pump, autosampler and a variable wavelength detector (Thermo Fisher Scientific, Waltham, MA USA) with a Kinetex 5 \(\upmu\)m Biphenyl 100 A Column 250 \(\times\) 4.6 mm (Phenomenex, Torrance, CA, USA). The analysis was performed with Dionex(tm) Chromleleon(tm), Version 6.80 SR14 (Thermo Fisher Scientific). The measurement was executed for 30 min with 60% acetonitrile and 40% of 0.5 mol-% trifluoroacetic acid at isocratic conditions. The detection wavelength was set at 278 nm. The total organic carbon (TOC) was quantified (triplicate) at a liquidTOC II (Elementar, Langenselbold, Germany) with high temperature oxidation between 850-900 \({}^{\circ}\)C and a wide range NDIR photometer. The concentration range was set to 20 ppm and calibration was performed prior to the tests. Samples were collected in glass vials at a volume of 25 mL and covered with tin foil. The samples were lyophilized prior to GC-MS measurements. The transformation products adsorbed on PVDF were extracted in a 10 mL ethanol and water solution (1:1). After 2 min of shaking, the PVDF adsorbent was removed. The extract as well as the irradiated diclofenac solutions were lyophilized. The dry residues after lyophilization were suspended in 1 mL of 10% ethanol solution. The analysis was carried out on a 6890N Network GC System (Agilent Technologies, Santa Clara, CA, USA) connected to an Agilent 5973 Network mass selective detector. The measurements were performed with the help of a Gerstel MultiPurposeSampler (Mulheim an der Ruhr, Germany). An incubation time of 20 min with a SPME fiber (65 \(\upmu\)m PDMS/DVB, Supelc, Bellefonte, PA, USA)  
Figure 1: Experimental setup for experiments with shielded PVDF. The adsorbent was placed in the petri-dish and is held in place by glass mounts. A cover that is half-coated with an opaque reflective foil was placed in a way that the adsorbent was either shielded or irradiated. at 303.15 K was chosen to reduce potential thermal decomposition. The analyst was separated on an Agilent HP-5 MS capillary column (60 m, 0.25 mm ID, 0.25 um df) with helium as carrier gas (1.4 mL min\({}^{-1}\) constant flow). The GC program started at 323.15 K and was increased to 523.15 K at a rate of 4 K min\({}^{-1}\). The final temperature was held for 20 min. Electron impact ionization was performed at 70 eV. A full scan mode over a mass range of m/z = 20-800 was performed. The toxicity tests on the marine luminescent bacteria _Vibrio fischeri_ were performed according to DIN EN ISO 11348-1: 2009-05 by the Umweltanalytische Labor of the Institut fur Siedlungswasserwirtschaft of RWTH Aachen with a LUMIStox using LUMIStherm System (Hach Lange GmbH, Dusseldorf, Germany). The test consisted of seven dilutions. The pH of the samples was corrected to 6.0 (\(SD\) = 0.2) before toxicity assessment tests using 0.1 M NaOH. According to the applied procedure, the self-produced (freshly grown) bacteria were reconstituted with reactivation solution, to provide a stock suspension of test organisms which was maintained at 15 \({}^{\circ}\)C and used to perform the test. The measurement of the bioluminescence was carried out at the start and after 30 min and the luminescence of the dilutions was compared with the negative control. A positive control was also included. Each dilution was tested in parallel.