Using Calcined Waste Eggshells to Remove Sulfate in Nonpotable Concrete Mixing Water

Juan Pablo Gevaudan, Zoey M. Craun, Wil V. Srubar

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

The experimental and theoretical potential of using calcined waste eggshells (CWEs) to remove sulfate from sulfate-laden concrete mixing water was investigated in this work. Waste eggshells were first calcined at 800°C and batch-reacted with sodium sulfate solutions. Laboratory experiments elucidated the effect of initial sulfate concentration, temperature of reaction, and CWE particle size on total sulfate removal. Experimental results indicate a maximum sulfate removal of 29.5%±2.2% via calcium sulfate mineral precipitation in laboratory batch reactions. To quantify the maximum sulfate removal potential of CWEs, batch reactions were simulated using PHREEQC, a geochemical code. After validating the simulation approach with experimental data obtained herein, PHREEQC was used to investigate the maximum sulfate removed as a function of CWE addition (g/L). Results indicate that sulfate-laden waters (≤4,000 ppm) can be decreased to ≤3,000 ppm with CWE additions of ≥3 g/L in order to comply with the standard specification for maximum allowable sulfates in water intended for use in the production of hydraulic cement concrete.

Original languageEnglish (US)
Article number04019074
JournalJournal of Materials in Civil Engineering
Volume31
Issue number6
DOIs
StatePublished - Jun 1 2019

All Science Journal Classification (ASJC) codes

  • Civil and Structural Engineering
  • Building and Construction
  • Materials Science(all)
  • Mechanics of Materials

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