were used to catalyse the hydrolysis of urea and
produce ammonium and carbonate ions leading to an
increase of pH level and precipitation of CaCO3.
Biocementation (or biocalcification) through
ureolysis presents several advantages over the other
carbonate generating pathways, as it can be easily
controlled and it has the potential to produce large
quantity of carbonate within a short period of time
[10]. Fig. 1 illustrates bio-chemical reactions involving
the induction of CaCO3 precipitation. Bacteria produce
enzyme urease that hydrolyzes urea (CO(NH2)2 or
NH2-CO-(NH2) to ammonium (NH4
+) and carbonate
(CO3
2-) ions.