Effects of pH, temperature, and water quality on chloride removal with ultra-high lime with aluminum process

Ahmed Abdel-Wahab, Bill Batchelor

Research output: Contribution to journalArticle

6 Citations (Scopus)


The ultra high-lime with aluminum process (UHLA) has the ability to remove sulfate and chloride in addition to other scale-forming materials from recycled cooling water. Laboratory experiments have demonstrated that the UHLA process can achieve high chloride removal from recycled cooling water, and an equilibrium model was developed to describe chemical behavior during chloride removal. This paper describes the influence of pH, temperature, and initial chloride concentration on chloride removal by UHLA and identifies the precipitated solids formed during treatment. The optimum pH for maximum chloride removal efficiency was found to be 12 ± 0.2. Chloride removal efficiency was higher at a high initial chloride concentration than at a low initial chloride concentration with the chemical doses used. Solids formed during UHLA treatment were identified by x-ray diffraction as calcium chloroaluminate, tricalcium hydroxyaluminate, and tetracalcium hydroxyaluminate. This supports the assumption of the equilibrium model that these compounds are present and form a solid solution.

Original languageEnglish
Pages (from-to)930-937
Number of pages8
JournalWater Environment Research
Issue number9
Publication statusPublished - 1 Jan 2006
Externally publishedYes



  • Aluminum
  • Calcium chloroaluminate
  • Chloride
  • Cooling water
  • Lime softening
  • pH
  • Solid solution
  • Water recycle

ASJC Scopus subject areas

  • Environmental Chemistry
  • Water Science and Technology

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