Removal of 2-MIB and geosmin using UV/persulfate: contributions of hydroxyl and sulfate radicals.

Published

Journal Article

2-methylisoborneol (2-MIB) and geosmin are two odor-causing compounds that are difficult to remove and the cause of many consumer complaints. In this study, we assessed the degradation of 2-MIB and geosmin using a UV/persulfate process for the first time. The results showed that both 2-MIB and geosmin could be degraded effectively using this process. The process was modeled based on steady-state assumption with respect to the odor-causing compounds and either hydroxyl or sulfate radicals. The second order rate constants for 2-MIB and geosmin reacting with the sulfate radical (SO4(-)) were estimated to be (4.2 ± 0.6) × 10(8) M(-1)s(-1) and (7.6 ± 0.6) × 10(8) M(-1)s(-1) respectively at a pH of 7.0. The contributions of the hydroxyl radical (OH) to 2-MIB and geosmin degradation were 3.5 times and 2.0 times higher, respectively, than the contribution from SO4(-) in Milli-Q water with 2 mM phosphate buffer at pH 7.0. The pseudo-first-order rate constants (ko(s)) of both 2-MIB and geosmin increased with increasing dosages of persulfate. Although pH did not affect the degradation of 2-MIB and geosmin directly, different scavenging effects of hydrogen phosphate and dihydrogen phosphate resulted in higher values of ko(s) for both 2-MIB and geosmin in acidic condition. Bicarbonate and natural organic matter (NOM) inhibited the degradation of both 2-MIB and geosmin dramatically through consuming OH and SO4(-) and were likely to be the main radical scavengers in natural waters when using UV/persulfate process to control 2-MIB and geosmin.

Full Text

Duke Authors

Cited Authors

  • Xie, P; Ma, J; Liu, W; Zou, J; Yue, S; Li, X; Wiesner, MR; Fang, J

Published Date

  • February 2015

Published In

Volume / Issue

  • 69 /

Start / End Page

  • 223 - 233

PubMed ID

  • 25486622

Pubmed Central ID

  • 25486622

Electronic International Standard Serial Number (EISSN)

  • 1879-2448

International Standard Serial Number (ISSN)

  • 0043-1354

Digital Object Identifier (DOI)

  • 10.1016/j.watres.2014.11.029

Language

  • eng