TY - JOUR
T1 - Slow-release persulfate candle-assisted electrochemical oxidation of 2-methylnaphthalene
T2 - Effects of chloride, sulfate, and bicarbonate
AU - Septian, Ardie
AU - Shin, Won Sik
N1 - Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/12/5
Y1 - 2020/12/5
N2 - Slow-release persulfate candle (PSC)-assisted electrochemical oxidation (ECO) of 2-methylnaphthalene (2-MNA) in an undivided cell using graphite-sheet electrodes was investigated using Fe(II) as an activator. The effects of anions (Cl−, SO42−, and HCO3−) were investigated. In the PSC/ECO/Fe(II), the highest pseudo-first-order rate constant (kobs) and % removal was achieved by adding Cl− (2.723 h−1, 75.2%) followed by SO42− (1.753 h−1, 63.9 %) and HCO3− (0.047 h−1, 3.3%). Addition of Cl− played a critical role in improving the removal efficiency by inducing [rad]OH and SO4[rad]− oxidations, while SO42– reduced the efficiency due to non-radical oxidation, as elucidated by electron spin resonance (ESR). Furthermore, in the PSC/ECO/Fe(II) + Cl−, dominant radical was changed from SO4[rad]− to [rad]OH. Scavenger experiments also confirmed that Cl− and SO42− ions are controlling the oxidation reaction. Two chlorinated byproducts analyzed by LC–MS were identified in PSC/ECO/Fe(II) + Cl− system.
AB - Slow-release persulfate candle (PSC)-assisted electrochemical oxidation (ECO) of 2-methylnaphthalene (2-MNA) in an undivided cell using graphite-sheet electrodes was investigated using Fe(II) as an activator. The effects of anions (Cl−, SO42−, and HCO3−) were investigated. In the PSC/ECO/Fe(II), the highest pseudo-first-order rate constant (kobs) and % removal was achieved by adding Cl− (2.723 h−1, 75.2%) followed by SO42− (1.753 h−1, 63.9 %) and HCO3− (0.047 h−1, 3.3%). Addition of Cl− played a critical role in improving the removal efficiency by inducing [rad]OH and SO4[rad]− oxidations, while SO42– reduced the efficiency due to non-radical oxidation, as elucidated by electron spin resonance (ESR). Furthermore, in the PSC/ECO/Fe(II) + Cl−, dominant radical was changed from SO4[rad]− to [rad]OH. Scavenger experiments also confirmed that Cl− and SO42− ions are controlling the oxidation reaction. Two chlorinated byproducts analyzed by LC–MS were identified in PSC/ECO/Fe(II) + Cl− system.
KW - 2-methylnaphthalene
KW - Electrochemical oxidation
KW - PS candle
KW - Radical
KW - Slow release
UR - http://www.scopus.com/inward/record.url?scp=85086732344&partnerID=8YFLogxK
U2 - 10.1016/j.jhazmat.2020.123196
DO - 10.1016/j.jhazmat.2020.123196
M3 - Article
C2 - 32593020
AN - SCOPUS:85086732344
SN - 0304-3894
VL - 400
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
M1 - 123196
ER -