Loose Sand Particles Cemented by Chem/Bio-BaHPO₄ Powder

Abstract

Bacillus subtilis was selected as the suitable microorganism, which could produce alkaline phosphatase and constantly hydrolyzed phosphate monoester in the mixture solution of bacteria with substrate, and then the PO₄ ^3- was obtained. Bio-phosphate cement was prepared by alkaline earth element (Ba) ions reacting with PO₄ ^3- in the mixture solution. Structure, size and thermal properties of the bio-phosphate cement were characterized by energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and particle size analysis. The average crystallite sizes of chem-BaHPO₄ and bio-BaHPO₄ corresponded to 11.99 and 24.13 μm, respectively. Chem-BaHPO₄ and bio-BaHPO₄ were then adopted to bind loose sand particles. The results indicated that loose sand particles can be well cemented by the bio-BaHPO₄ powder into a bio-sandstone with a certain mechanical properties, and the average compressive strength of the bio-sandstones can be up to 0.83 MPa when the curing time was 14 d. Along with the method in future studies, there will be multiple new opportunities for engineering applications, for instance, the treatment of sandy soil foundation, remediation of heavy metals in contaminated soil, and so on.

Keywords

Bacillus subtilis / bio-phosphate cement / X-ray techniques / scanning electron microscope / compressive strength

References

[1] Veis A. A Window on Biomineralization[J]. Science, 2005, 307: 1419-1420.

[2] Mann S. Molecular Recognition in Biomineralization[J]. Nature, 1988, 332: 119-124.

[3] Schüler D, Frankel R B. Bacterial Magnetosomes: Microbiology, Biomineralization and Biotechnological Applications[J]. Appl. Microbiol. Biot., 1999, 52(4): 464-473.

[4] Schüler D, Baeuerlein E. Dynamics of Iron Aptake and Fe₃O₄ Biomineralization during Aerobic and Microaerobic Growth of Magnetospirillum Gryphiswaldense[J]. J. Bacteriol., 1998, 180(1): 159-162.

[5] Fu G, Valiyaveettil S, Wopenka B, et al. CaCO₃ Biomineralization: Acidic 8-kDa Proteins Isolated from Aragonitic Abalone Shell Nacre Can Specifically Modify Calcite Crystal Morphology[J]. Biomacromolecules, 2005, 6(3): 1289-1298.

[6] Ma Y F, Qiao L, Feng Q L. In-vitro Study on Calcium Carbonate Crystal Growth Mediated by Organic Matrix Extracted from Fresh Water Pearls[J]. Mat. Sci. Eng. C, 2012, 32(7): 1963-1970.

[7] Yao Y, Wang D, Han L, et al. Self-assembly of a-helices to Form Rare Two-dimensional Square P4mm Symmetry via Silica Mineralization[J]. Chem. Eur. J., 2013, 19(46): 15489-15492.

[8] Zhu W K, Luo X G, Zhang C, et al. Microbiological Precipitation of Barium Carbonate[J]. Chinese J. Inorg. Chem., 2011, 27(10): 2053-2060.

[9] Zhang X D, He W, Yue Y Z, et al. Bio-synthesis Participated Mechanism of Mesoporous LiFePO₄/C Nanocomposite Microspheres for Lithium Ion Battery[J]. J. Mater. Chem., 2012, 22(37): 19948-19956.

[10] Wang F, Xu G Y, Zhang Z Q. The Effect of pH on Morphological Control of Barium Hydrogen Phosphate Crystal by a Double-hydrophilic Copolymer[J]. Mater. Lett., 2005, 59(7): 808-812.

[11] Arora S K, Oza A T, Trivedi T R, et al. Dielectric Properties of Barium Hydrogen Phosphate (BHP)[J]. Mat. Sci. Eng. B, 2005, 77(1): 131-134.

[12] Trivedi T R, Oza A T, Patel V A, et al. DC and AC Conductivity of Barium Hydrogen Phosphate(BaHPO4)[J]. Cryst. Res. Technol., 2000, 35(5): 615-624.

[13] Nallamuthu D, Selvarajan P, Freeda T H. Studies on Various Properties of Pure and Li-doped Barium Hydrogen Phosphate (BHP) Single Crystals[J]. Physica B, 2010, 405(24): 4908-4913.

[14] Chen Y G, Luan B L, Song G L, et al. An Investigation of New Barium Phosphate Chemical Conversion Coating on AZ31 Magnesium Alloy[J]. Surf. Coat. Tech., 2012, 210: 156-165.

[15] Yu X N, Qian C X, Wang X. Cementing Mechanism of Bio-phosphate Cement[J]. Sci. China Tech. Sci., 2015, 58(6): 1112-1117.

[16] Yu X N, Qian C X, Wang X. Study on Morphology of Barium Hydrogen Phosphate Formation Induced by Phosphate-mineralization Microbe[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed., 2016, 31(1): 227-230.

[17] Wang J, Cai Y Q, Ma J J, et al. Improved Vacuum Preloading Method for Consolidation of Dredged Clay-slurry Fill[J]. J. Geotech. Geoenviron., 2016, 142(11): 06016012

[18] Cai Y, Qiao H, Wang J, et al. Experimental Tests on Effect of Deformed Prefabricated Vertical Drains in Dredged Soil on Consolidation via Vacuum Preloading[J]. Eng. Geol., 2017, 222: 10-19.

[19] Wang J, Ni J, Cai Y, et al. Combination of Vacuum Preloading and Lime Treatment for Improvement of Dredged Fill[J]. Eng. Geol., 2017, 227: 149-158.

[20] Yu X N, Qian C X, Sun L Z. The Influence of the Number of Injections of Bio-composite Cement on the Properties of Bio-sandstone Cemented by Bio-composite Cement[J]. Constr. Build. Mater., 2018, 164: 682-687.

[21] Qian C X X Y, Wang X. A Study on the Cementation Interface of Bio-cement[J]. Mater. Charact., 2018, 136: 122-127.

[22] Yu X N, Jiang J J. Mineralization and Cementing Properties of Bio-canbonate Cement, Bio-phosphate Cement, and Bio-canbonate/phosphate Cement: A Review[J]. Environ. Sci. Pollut. Res., 2018, 25(13): 12764-12779.

[23] Yu X N, Qian C X, Sun L Z, et al. Preparation of Biological Magnesium Phosphates Nanoparticles and Their Binding Properties[J]. Rev. Rom. Mater., 2017, 47(2): 71-77.