## 2 Materials and Methods
### Analytical Methodologies
#### 2.4.2 Phenolic Compounds Analysis  
Before analysis target compounds (NP, OP or PCP) were extracted from sediments with methanol in an ultrasonic bath (Transsonic-460/H, with a working frequency 40 kHz (1000 W)) for 15 min. After the extraction, the solution was centrifuged (5 min at 2500 rpm), transferred to a new vial and a new extraction of the sediment was done. After centrifuging the extracts were combined and stored at \(-20\)\({}^{\circ}\)C in the dark until analysis. Each sample was prepared in triplicate.  
Analysis of the target compounds in the influent and effluent of CWs and in sediment extracts was carried out by headspace-solid phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC-MS). The salting-out technique, addition of sodium chloride to a solution, was used following a methodology previously optimized [28]. For NP and OP analysis, HS-SPME was carried out in a 20 mL headspace vial closed with Teflon-lined septa (Supelco). For water analysis, 3 g of NaCl were added to 10 mL of the sample. For sediment, 3 g of NaCl and 200 mL of sediment extract were added to 9.8 mL of deionized water. For PCP, HS-SPME was carried out in 20 mL headspace vial closed with Teflon-lined septa (Supelco) containing 1 g of NaCl, 0.5 mL of a solution of Na2 CO3 (20% _w/v/v_; daily prepared), 0.1 mL acetic anhydride and 9.4 mL of water sample (forwater analysis) or 200 \(\upmu\)L of sediment extract plus 9.2 mL of deionized water (for sediment analysis). The mixture was pre-equilibrated at 70 \({}^{\circ}\)C for 10 min and shaken at 500 rotation per minute (rpm), being afterwards subject to HS-SPME (60 min at 70 \({}^{\circ}\)C and 250 rpm) in an automatic sampler CTC Analytic, CombiPal model (San Diego, CA, USA), using a 60 \(\upmu\)m polyethylene glycol (PEG) fiber (Supelco) for NP and OP analysis and a 65 \(\upmu\)m polydimethylsiloxane /divinylbenzene (PDMS/DVB) fiber (Supelco) for PCP analysis. GC-MS analysis was carried out with a capillary column CP-Sil 5 CB low bleed/MS (60 m length, 0.25 mm internal diameter and 0.25 \(\upmu\)m stationary phase film thickness) in a Varian 3900 GC coupled to a Varian MS using previously optimized conditions [28]. The carrier gas was helium (99.9995%). The ions monitored were 107, 108, 115 and 220 for NP, 41, 57, 97, 105, 135 and 206 for OP and 265.9, 266.8, 268.4 and 270.0 for PCP.  
Compounds' quantifications were obtained through calibration curves made with standard solutions of the compounds prepared in deionized water. During phenolic compounds analysis, blanks, standard solutions and doped samples were routinely analyzed, with recoveries ranging between 80 and 120%. For NP and OP, concentrations ranged from 1 to 60 \(\upmu\)g\(\cdot\)L\({}^{-1}\) and for PCP from 0.01 to 1.5 \(\upmu\)g\(\cdot\)L\({}^{-1}\). Limits of detection for water analysis were 0.25 \(\upmu\)g\(\cdot\)L\({}^{-1}\) for OP, 0.33 \(\upmu\)g\(\cdot\)L\({}^{-1}\) for NP and 4 \(\times\) 10\({}^{-5}\)\(\upmu\)g\(\cdot\)L\({}^{-1}\) for PCP. For sediments, limits of detection (LODs) were 0.12 \(\upmu\)g\(\cdot\)g\({}^{-1}\) for NP and OP and 0.030 \(\upmu\)g\(\cdot\)g\({}^{-1}\) for PCP.