Micromorphological and Biocalcification Effects of Sporosarcina pasteurii and Sporosarcina ureae in Sandy Soil Columns

Microbial calcium carbonate, by bridging sand particles, can play an important role in sand dune stability. A study was carried out on the cementation of sand grains and infilling of pore spaces by CaCO۳. Two bacterial species (Sporosarcina pasteurii and Sporosarcina ureae), three reactant concentrations (۰.۵, ۱ and ۱.۵M), and six reaction times (۱۲, ۲۴, ۴۸, ۹۶, ۱۹۲ and ۲۸۸ hours) were tested in factorial experiment. Bacterial inocula and reactant solutions were added daily to sandy soil columns (۶.۵ cm height and inner diameter of ۷.۷ cm), while precipitation of CaCO۳ being investigated within ۰-۱.۵, ۱.۵-۳, ۳-۴.۵ and ۴.۵-۶ cm intervals. Chemical and micromorphological analyses revealed that CaCO۳ formation, inorganic C sequestration, and depth of cementation were more profound for S. pasteurii as compared with S. ureae. Both microbial CaCO۳ precipitation and inorganic C sequestration increased with increase in reaction time from ۱۲ to ۲۸۸ hours. Increase in reactant concentration also caused an increase in CaCO۳ precipitation (by ۱۲%). Micromorphological observations showed a high degree of calcite crystals’ bridging, coating on sand particles and as well infilling of pore spaces. S. pasteurii is thus recommended for being used in stabilization of sand dunes; due to its significant effects on CaCO۳ deposition and as well on sand grain cementation.

کلیدواژه ها:

Biomineralization ، Inorganic C sequestration ، Sand dune fixation ، Ureolytic bacteria