1,1,2,2-tetrachloroethene (≥99.5%), 1,1,2-trichloroethene (99.5%), trans-1,2-dichloroethene (trans-1,2-DCE; ≥98%), 1,1-dichloroethene (1,1-DCE; ≥99%), cis-1,2-dichloroethene (cis-1,2-DCE; ≥97%), 1,2-dichloroethane (1,2-DCA; ≥99%) and vinyl chloride (VC; 100 μg/mL in methanol) were purchased from Sigma-Aldrich (St. Louis, MO, United States). All other chemicals used to prepare analytical standards or feed solutions were analytical reagent grade.
Two milliliters of liquid samples obtained from the cathode chambers were immediately transferred to sealed 10 mL bottles filled with the high purity N2 gas (≥99.99%). The bottles were placed in a 25°C shaker for 30 min to reach the equilibrium. Concentrations of volatile organic compounds including PCE, TCE, trans-1,2-DCE, 1,1-DCE, cis-1,2-DCE, 1,2-DCA, and VC in the headspace (8 mL) were determined using a gas chromatograph (Agilent 7890A, Palo Alto, CA, United States) equipped with a 63Ni electron capture detector and DB-1301 column (30 m × 250 μm × 0.25 μm, Agilent). Ethene and methane were determined using a gas chromatograph (Agilent 7890A, Palo Alto, CA, United States) equipped with flame ionization detector (FID) and HP-5 column (30 m × 250 μm × 0.25 μm, Agilent). Headspace concentrations were converted to aqueous-phase using tabulated Henry’s law constants (Chen et al., 2018 (link)).
Two milliliters of liquid samples obtained from the cathode chambers were immediately transferred to sealed 10 mL bottles filled with the high purity N2 gas (≥99.99%). The bottles were placed in a 25°C shaker for 30 min to reach the equilibrium. Concentrations of volatile organic compounds including PCE, TCE, trans-1,2-DCE, 1,1-DCE, cis-1,2-DCE, 1,2-DCA, and VC in the headspace (8 mL) were determined using a gas chromatograph (Agilent 7890A, Palo Alto, CA, United States) equipped with a 63Ni electron capture detector and DB-1301 column (30 m × 250 μm × 0.25 μm, Agilent). Ethene and methane were determined using a gas chromatograph (Agilent 7890A, Palo Alto, CA, United States) equipped with flame ionization detector (FID) and HP-5 column (30 m × 250 μm × 0.25 μm, Agilent). Headspace concentrations were converted to aqueous-phase using tabulated Henry’s law constants (Chen et al., 2018 (link)).