Arsenic removal by iron-modified activated carbon

Weifang Chen, Robert Parette, Jiying Zou, Fred S. Cannon, Brian A. Dempsey

Research output: Contribution to journalArticle

290 Scopus citations

Abstract

Iron-impregnated activated carbons have been found to be very effective in arsenic removal. Oxyanionic arsenic species such as arsenate and arsenite adsorb at the iron oxyhydroxide surface by forming complexes with the surface sites. Our goal has been to load as much iron within the carbon pores as possible while also rendering as much of the iron to be available for sorbing arsenic. Surface oxidation of carbon by HNO3/H2SO4 or by HNO3/KMnO4 increased the amount of iron that could be loaded to 7.6-8.0%; arsenic stayed below 10 ppb until 12,000 bed volumes during rapid small-scale tests (RSSCTs) using Rutland, MA groundwater (40-60 ppb arsenic, and pH of 7.6-8.0). Boehm titrations showed that surface oxidation greatly increased the concentration of carboxylic and phenolic surface groups. Iron impregnation by precipitation or iron salt evaporation was also evaluated. Iron content was increased to 9-17% with internal iron-loading, and to 33.6% with both internal and external iron loading. These iron-tailored carbons reached 25,000-34,000 bed volumes to 10 ppb arsenic breakthrough during RSSCTs. With the 33.6% iron loading, some iron peeled off.

Original languageEnglish (US)
Pages (from-to)1851-1858
Number of pages8
JournalWater Research
Volume41
Issue number9
DOIs
StatePublished - May 2007

All Science Journal Classification (ASJC) codes

  • Ecological Modeling
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution

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