Supporting Information

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1 Supporting Information Cobalt-mediated Activation of Peroxymonosulfate and Sulfate Radical Attack on Phenolic Compounds. Implications of Chloride Ions George P. Anipsitakis, Dionysios D. Dionysiou, and Michael A. Gonzalez Number of pages: 17 List of Figures Figure S1. Evolution of 2,4,6-trichlorophenol following transformation of 2,4-DCP with Co 2 /Oxone. Effect of KHSO 5 dose as KHSO 5 :2,4-DCP mol ratio. Figure S2. 4-Nitrophenol transformation with Co 2 /Oxone. Effect of quenching agent as mol ratio of quenching species versus KHSO 5. Figure S3. The GC chromatograph of a standard showing the peaks corresponding to 2- chlorophenol, phenol, 2,4-dichlorophenol, 2,6-dichlorophenol and 4-chlorophenol. Figure S4. The GC-MS spectrum of phenol corresponding to the 7.71 min peak on S3. Figure S5. The GC chromatograph of a sample corresponding to the transformation of phenol with the Co 2 /Oxone system at reaction time of 20 min showing the peaks corresponding to 2- chlorophenol, phenol, 2,4-dichlorophenol and 4-chlorophenol. Compare with S3. Other conditions as in Figure 1 of the manuscript. Figure S6. The GC-MS spectrum of phenol corresponding to the 7.74 min peak on S4. Compare with S4. Figure S7. The GC chromatograph of a sample corresponding to the transformation of 2,4- dichlorophenol with the CoSO 4 /Oxone system at reaction time of 240 min showing the peak corresponding to pentachloroacetone. Conditions: [2,4-DCP] 0 = 500 mg/l, mol ratios KHSO 5 :2,4-DCP= 30:1 and KHSO 5 :Co= 100:1, sample quenched with MeOH. Figure S8. The GC-MS spectrum of pentachloroacetone corresponding to the 8.76 min peak on S7. Figure S9. The GC chromatograph of a sample corresponding to the transformation of 2,4- dichlorophenol with the Co 2 /Oxone system at reaction time of 5 min showing the peaks S-1

2 corresponding to 2,4-dichlorophenol and 2,4,6-trichlorophenol. Conditions: [2,4-DCP] 0 = 500 mg/l, mol ratios KHSO 5 :2,4-DCP= 60:1 and KHSO 5 :Co= 100:1, sample quenched with MeOH. Figure S10. The GC-MS spectrum of 2,4,6-trichlorophenol corresponding to the min peak on S9. Figure S11. The GC chromatograph of a sample corresponding to the transformation of 2,4- dichlorophenol with the Co 2 /Oxone system at reaction time of 10 min showing the peaks corresponding to 2,4-dichlorophenol, 2,4,6-trichlorophenol and 2-nitro-4,6-dichlorophenol. Conditions: [2,4-DCP] 0 = 1000 mg/l, mol ratios KHSO 5 :2,4-DCP= 30:1 and KHSO 5 :Co= 100:1, sample quenched with NaNO 2. Figure S12. The GC-MS spectrum of 2-nitro-4,6-dichlorophenol corresponding to the min peak on S11. Figure S13. The GC chromatograph of a sample corresponding to the transformation of 2,4- dichlorophenol with the Co 2 /Oxone system at reaction time of 6 days showing the peaks corresponding to 1,1,3,3-teatrachloroacetone, pentachloroacetone, 2,4-dichlorophenol and 2,4,6- trichlorophenol. Conditions: [2,4-DCP] 0 = 1000 mg/l, mol ratios KHSO 5 :2,4-DCP= 5:1 and KHSO 5 :Co= 100:1, ph 0 = 7.0 with 0.01M NaHCO 3 and KHSO 4. Figure S14. The GC-MS spectrum of 1,1,3,3-teatrachloroacetone corresponding to the 8.49 min peak on S12. List of Tables Table S1. Intermediates formed from the SRA on the quenching agent (substrate: 2,4-DCP, unless otherwise indicated) Table S2. GC conditions employed for the analysis of phenol and daughter products S-2

3 120x x x :1 10:1 4:1 Area 60x x x Time (min) Figure S1. Evolution of 2,4,6-trichlorophenol following transformation of 2,4-DCP with Co 2 /Oxone. Effect of KHSO 5 dose as KHSO 5 :2,4-DCP mol ratio. Conditions as in Figure 6 of the manuscript. For comparison, the corresponding peak areas of 2,4-DCP shown in Figure 6 were generally one order of magnitude higher than that of 2,4,6-TCP shown here. Scheme S1: SRA on 4-CP OH +SO 4 - -SO 4 2- OH + Co 3+ Co 2+ -H + O OH Co 3+ Co 2+ OH + + O -H + O OH O +SO 4 - -SO 4 2- OH O + Co 3+ Co 2+ -H + O O S-3

4 Effect of Quenching Agent. Methanol quenched the reaction of 4-nitrophenol with sulfate radicals almost as well as nitrite and thiosulfate; however at extremely high concentrations, due most probably to solvent effect, methanol showed to slightly facilitate the decomposition of 4- nitrophenol with Co/Oxone NP Ci/Co NaNO 2 104:1 Na 2 S 2 O 3 104:1 MeOH 104:1 MeOH 1367:1 Ag(I) 104: Time (min) Figure S2. 4-Nitrophenol transformation with Co 2 /Oxone. Effect of quenching agent as mol ratio of quenching species versus KHSO 5. [4-NP] 0 = 20 mg/l (0.144 mm) KHSO 5 :4-NP = 5:1, [Co] = 0.05 mg/l, ph 0 adjusted to 7.0 with 2 mm H 2 PO 4 - and 1 mn NaOH. The interaction of the reaction system with the various quenching agents utilized, led to the detection of the compounds listed in Table S1. Particularly in the cases when the quenching agent was an organic compound (i.e., methanol) several compounds detected were the result of a complex interaction among sulfate radicals, the quenching agent and the organic material coming from the transformation of the substrate. S-4

5 Table S1. Intermediates formed from the SRA on the quenching agent (substrate: 2,4-DCP, unless otherwise indicated) Quenching agent used Compound detected Sodium nitrite 2-Nitro-4,6-dichlorophenol Methanol Trichloroacetaldehyde 2,3-Dichloro-2-methyl-butane Dichloro-acetic acid methyl ester Trichloro-acetic acid methyl ester Ethanol 1,1-Diethoxyethane Methylene chloride Trichloroacetaldehyde 2,3-Dichloro-2-methyl-butane Sodium thiosulfate (phenol experiments) Octa-sulfur, S 8 The scavenging effect of sulfate radicals with the various quenching agents utilized is shown in reactions S1-S9 (34): - - SO 4 + NO 2 SO NO 2 (S1) HSO NO - 2 HSO NO V (S2) HSO NO 2 + OH - SO NO 3 + H 2 O 1.74 V (S3) HSO H + + 2S 2 O 2-3 HSO S 4 O 6 + H 2 O 1.73 V (S4) HSO H + + 2S 2 O 2-3 SO S 4 O 6 + H 2 O 1.67 V (S5) 2- S 2 O 3 + 2H + S + SO 2 + H 2 O (S6) - SO 4 + Ag + SO Ag 2+ (S7) - SO 4 + CH 3 OH HSO CH 2 OH (S8) - SO 4 + CH 3 CH 2 OH HSO CH 3 CHOH (S9) These reactions, the interaction of chloride ions with sulfate radicals and the sulfate radical attack on the substrate account for the formation of the compounds reported in Table S1. Chromatographs and Mass Spectra Table S2. GC conditions employed for the analysis of phenol and daughter products Gas Chromatograph Hewlett Packard 6890 Detector Mass Selection Column Glass capillary column SUPELCO Equity 5, Diameter 0.25 mm, Length 30 m Carrier and flow rate Helium at 1.5 ml/min Inlet temperature 250 o C Detector temperature 250 o C Temperature program 50 o C for 5 min to 220 o C at 20 o C/min 5 min final time S-5

6 2-CP 4-CP Phenol 2,6-DCP 2,4-DCP Figure S3. The GC chromatograph of a standard showing the peaks corresponding to 2-chlorophenol, phenol, 2,4-dichlorophenol, 2,6- dichlorophenol and 4-chlorophenol. S-6

7 Figure S4. The GC-MS spectrum of phenol corresponding to the 7.71 min peak on S3. S-7

8 2-CP 4-CP Phenol 2,4-DCP Figure S5. The GC chromatograph of a sample corresponding to the transformation of phenol with the Co2/Oxone system at reaction time of 20 min showing the peaks corresponding to 2-chlorophenol, phenol, 2,4-dichlorophenol and 4-chlorophenol. Compare with S3. Other conditions as in Figure 1 of the manuscript. S-8

9 Figure S6. The GC-MS spectrum of phenol corresponding to the 7.74 min peak on S5. Compare with S4. S-9

10 PCA Figure S7. The GC chromatograph of a sample corresponding to the transformation of 2,4-dichlorophenol with the CoSO4/Oxone system at reaction time of 240 min showing the peak corresponding to pentachloroacetone. Conditions: [2,4-DCP]0= 500 mg/l, mol ratios KHSO5:2,4-DCP= 30:1 and KHSO5:Co= 100:1, sample quenched with MeOH. S-10

11 Figure S8. The GC-MS spectrum of pentachloroacetone corresponding to the 8.76 min peak on S7. S-11

12 2,4-DCP 2,4,6-TCP Figure S9. The GC chromatograph of a sample corresponding to the transformation of 2,4-dichlorophenol with the Co2/Oxone system at reaction time of 5 min showing the peaks corresponding to 2,4-dichlorophenol and 2,4,6-trichlorophenol. Conditions: [2,4- DCP]0= 500 mg/l, mol ratios KHSO5:2,4-DCP= 60:1 and KHSO5:Co= 100:1, sample quenched with MeOH. S-12

13 Figure S10. The GC-MS spectrum of 2,4,6-trichlorophenol corresponding to the min peak on S9. S-13

14 2,4-DCP 2,4,6-TCP 2-N-4,6-DCP Figure S11. The GC chromatograph of a sample corresponding to the transformation of 2,4-dichlorophenol with the Co2/Oxone system at reaction time of 10 min showing the peaks corresponding to 2,4-dichlorophenol, 2,4,6-trichlorophenol and 2-nitro-4,6- dichlorophenol. Conditions: [2,4-DCP]0= 1000 mg/l, mol ratios KHSO5:2,4-DCP= 30:1 and KHSO5:Co= 100:1, sample quenched with NaNO2. S-14

15 Figure S12. The GC-MS spectrum of 2-nitro-4,6-dichlorophenol corresponding to the min peak on S11. S-15

16 TCA 2,4,6-TCP PCA 2,4-DCP Figure S13. The GC chromatograph of a sample corresponding to the transformation of 2,4-dichlorophenol with the Co2/Oxone system at reaction time of 6 days showing the peaks corresponding to 1,1,3,3-teatrachloroacetone, pentachloroacetone, 2,4- dichlorophenol and 2,4,6-trichlorophenol. Conditions: [2,4-DCP]0= 1000 mg/l, mol ratios KHSO5:2,4-DCP= 5:1 and KHSO5:Co= 100:1, ph0= 7.0 with 0.01M NaHCO3 and KHSO4. S-16

17 Figure S14. The GC-MS spectrum of 1,1,3,3-teatrachloroacetone corresponding to the 8.49 min peak on S13. S-17