MICROBIAL-INDUCED CALCITE PRECIPITATION" AS A POTENTIAL SUSTAINABLE TECHNIQUE FOR POLLUTED SOIL BIOREMEDIATION: A REVIEW

الملخص

Industrialization and population growth have increased the emission and buildup of environmental heavy metals. These components' bioaccumulation as exposure have been related to a range of illnesses and cancer, and the mechanical and physical properties of soil are altered. The "Microbial Induced Calcite Precipitation" is an environmentally green, friend, and sustainable method. This review focused on the metal remediation technology's effects and how to make them sustainable and more environmentally friendly. Many bacteria produce urease, the bacillus is a more common type. Bacteria, with sizes ranging from 0.5 to 3.0µm, are the most common microbes found in soils. It is critical to examine the type of soil, Bacterial size, and size of pore throat. The calcium carbonate majority tends to coat the surface of soils with coarse particles in the state of the contact points in soils with particles smaller than bacterial size (heterogeneous and limited precipitation). The bacterial concentration appears to affect crystal shape, calcium carbonate formation, and the cementation effect of geomaterials. Calcite precipitation takes place most when the pH is between 7.5 and 9.5. Calcite is formed three times at 50°C, while the unconfined compressive strength is only 60% of that at 25°C. Calcium carbonate can be immobilized or formed into undissolved compounds by binding free ions to the calcium carbonate's surfaces, resulting in a form of non-toxic and chemically stable.