Long-term sustainability of microbial-induced CaCO3 precipitation in aqueous media

Research output: Contribution to journalArticlepeer-review

60 Scopus citations

Abstract

Microbially induced CaCO3 precipitation (MICP) via urea hydrolysis is an emerging technique for soil amelioration, building materials rehabilitation and pollutants sequestration amongst other various environmental applications. The successful application of MICP requires the sustainability of the precipitated CaCO3; to which the fate of ammonia, the main by-product of ureolysis, is potentially significante. Ammonia volatilization and biological ammonia oxidation both induce a pH decrease, which, in turn, might cause CaCO3 dissolution. To examine the potential effect of accumulated ammonia on precipitated CaCO3, we conducted a long-term MICP batch experiment, using environmental enrichment cultures of ureolytic bacteria. Here we show that CaCO3 precipitation was completed within 15–27 days, along with a rise in ammonium concentration. Following completion of ureolysis and precipitation, ammonium concentrations decreased, leading to a pH decrease. About 30 days after precipitation was completed, as much as 30% CaCO3 dissolution, was observed. A two-step model, describing urea hydrolysis followed by the removal of ammonia from the precipitation solution, predicted CaCO3 dissolution due to ammonia volatilization. We suggest that ureolytic MICP might result in ammonia volatilization, leading to significant CaCO3 dissolution. These results provide basic insights into the sustainability of ureolytic MICP and should further encourage removal of the accumulated ammonia from the treated site.

Original languageEnglish
Pages (from-to)524-531
Number of pages8
JournalChemosphere
Volume184
DOIs
StatePublished - 1 Jan 2017

Keywords

  • Bio-remediation
  • Calcite
  • Microbial-induced CaCO precipitation (MICP)
  • Ureolysis

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • General Chemistry
  • Pollution
  • Health, Toxicology and Mutagenesis

Fingerprint

Dive into the research topics of 'Long-term sustainability of microbial-induced CaCO3 precipitation in aqueous media'. Together they form a unique fingerprint.

Cite this