Combined ion exchange treatment for removal of dissolved organic matter and hardness

Jennifer N. Apell, Treavor H. Boyer

Research output: Contribution to journalArticle

Abstract

Dissolved organic matter (DOM) and hardness cations are two common constituents of natural waters that substantially impact water treatment processes. Anion exchange treatment, and in particular magnetic ion exchange (MIEX), has been shown to effectively remove DOM from natural waters. An important advantage of the MIEX process is that it is used as a slurry in a completely mixed flow reactor at the beginning of the treatment train. Hardness ions can be removed with cation exchange resins, although typically using a fixed bed reactor at the end of a treatment train. In this research, the feasibility of combining anion and cation exchange treatment in a single completely mixed reactor for treatment of raw water was investigated. The sequence of anion and cation exchange treatment, the number of regeneration cycles, and the chemistry of the regeneration solution were systematically explored. Simultaneous removal of DOM (70% as dissolved organic carbon) and hardness (>55% as total hardness) was achieved by combined ion exchange treatment. Combined ion exchange is expected to be useful as a pre-treatment for membrane systems because both DOM and divalent cations are major foulants of membranes.

Original languageEnglish (US)
Pages (from-to)2419-2430
Number of pages12
JournalWater Research
Volume44
Issue number8
DOIs
StatePublished - Apr 2010

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Keywords

  • Anion exchange
  • Calcium
  • Cation exchange
  • Dissolved organic matter
  • Magnetic ion exchange
  • Membrane fouling
  • Softening

ASJC Scopus subject areas

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

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