Effects of selected good's pH buffers on nitrate reduction by iron powder

Tian C. Zhang, Yong H. Huang

Research output: Contribution to journalArticle

31 Scopus citations

Abstract

The effects of three selected Good's pH buffers on the performance of an Fe0/nitrate/H2O system were evaluated. The Good's ph buffer itself did not reduce nitrate directly. Nitrate reduction by iron powder at near-neutral ph was negligible in an unbuffured system but it was greatly enhanced with the presence of the buffer. A significant amount of aqueous Fe2+ (or Fe3+) was released after adding the Good's pH buffer into the Fe0/H2O system with or without nitrate. In general, the Ph of the buffered solution increased from the initial ph (=∼4.6-5.3, depending on buffer's pKa) to near-neutral pH. After the initial hiking, the pH in the system was more or less stable for a period of time (∼5-10 h, usually concurrent with a fairly stable aqueous fe2+). The ph then drifted to ∼7.1 to 8.6 depending on the buffer's initial concentration, the buffer's pKa, and the consumption of Fe2+ concurrent with nitrate reduction. While a common assumption made by researchers is that Good's ph buffers do not directly participate in reaction processes involved in contaminant remediation, this study shows that as side effects, the Good's ph buffer may react with iron powder.

Original languageEnglish (US)
Pages (from-to)461-470
Number of pages10
JournalJournal of Environmental Engineering
Volume131
Issue number3
DOIs
StatePublished - Mar 1 2005

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Keywords

  • Iron
  • Nitrates
  • Remedial action
  • Water pollution
  • Water treatment

ASJC Scopus subject areas

  • Environmental Engineering
  • Civil and Structural Engineering
  • Environmental Chemistry
  • Environmental Science(all)

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