Advanced oxidation and reduction process chemistry of methyl tert-butyl ether (MTBE) reaction intermediates in aqueous solution: 2-methoxy-2-methyl-propanal, 2-methoxy-2-methyl-propanol, and 2-methoxy-2-methyl-propanoic acid.
Absolute rate constants for the reaction of three important degradation products of methyl-tert-butyl ether (MTBE) with the hydroxyl radical, hydrated electron and hydrogen atom were determined in aqueous solution at room temperature. These three intermediate species; 2-methoxy-2-methyl propanal (MMP), 2-methoxy-2-methyl-propanol (MMP-OH) and 2-methoxy-2-methyl-propionic acid (MMP-acid), are formed in the degradation of MTBE under advanced oxidation and reduction process conditions. The rate constants for their hydroxyl radical oxidation of (3.99+/-0.29)x10(9), (8.02+/-0.53)x10(8), and (7.73+/-0.48)x10(8)M(-1)s(-1), respectively, show that this reaction would be the overall dominant degradation pathway for these three compounds, relative to their corresponding hydrated electron reduction values of (3.11+/-0.32)x10(7), (7.8+/-1.8)x10(6) and (1.40+/-0.10)x10(9)M(-1)s(-1), and hydrogen atom rate constants of (1.65+/-0.14)x10(7), (1.30+/-0.13) x10(8) and <1.2 x 10(6)M(-1)s(-1).
Department of Chemistry and Biochemistry, California State University at Long Beach, Long Beach, CA 90840, USA. smezyk@csulb.edu
Stephen P
SP
Mezyk
D Rance
DR
Hardison
Weihua
W
Song
Kevin E
KE
O'Shea
David M
DM
Bartels
William J
WJ
Cooper
D000447:Aldehydes / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D006859:Hydrogen / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry; D008738:Methyl Ethers / Q000737:chemistry*; D010084:Oxidation-Reduction; D011412:Propanolamines / Q000737:chemistry*; D011422:Propionates / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
C456585:2-hydroxy-2-methylpropanal; C546864:2-methoxy-2-methyl-propanoic acid; D000447:Aldehydes; D008738:Methyl Ethers; D011412:Propanolamines; D011422:Propionates; D014867:Water; C043243:methyl tert-butyl ether; D017665:Hydroxyl Radical; D006859:Hydrogen; C006551:2-amino-2-methyl-1-propanol