Study of microbially-induced carbonate precipitation for improving coarse-grained salty soil

doi:10.1016/j.jclepro.2022.132788

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	Study of microbially-induced carbonate precipitation for improving coarse-grained salty soil
	Peng, Erxing 2; Hu, Xiaoying 1; Chou, Yaling 1; Sheng, Yu 2; Liu, Shihao 1; Zhou, Fansheng 1; Wu, Jichun 2; Cao, Wei 2
刊名	Journal of Cleaner Production
	2022-09-10
卷号	365
关键词	Calcite Carbonation Chlorine compounds Compressive strength Curing Deterioration Hydrolysis Metabolism Particle size analysis Precipitation (chemical) Scanning electron microscopy Soil testing Soils Urea Carbonate precipitation Chloride salts Coarse-grained Coarse-grained soils Environmental hazards MICP method Saline soil Salt content Treatment modality Urea hydrolysis
ISSN号	0959-6526
DOI	10.1016/j.jclepro.2022.132788
英文摘要	The salinity of soil can result in serious potential environmental hazards such as increased collapsibility and corrosiveness. Microbially induced carbonate precipitation is an upcoming and pollution-free treatment modality that can eliminate environmental and engineering hazards of saline soil. To verify the feasibility of the method of curing saline soils, a series of tests were conducted to investigate the impact of chloride salt on urea hydrolysis, the impact of the method on engineering and mechanical properties of coarse-grained soils containing chloride salt and the deterioration mechanism of curing effect caused by salt. The study demonstrated that, even though the curing effect of the method is excellent, the negative effect of salt cannot be ignored. With increased salt concentration, the hydrolysis rate and calcium carbonate precipitation efficiency sharply decrease at first and tend to be flatter. The unconfined compressive strength and shear strength of the samples can be greatly improved through the application of the method. However, calcium carbonate content reduces with an increase in the salt content, which decreases the strength. Compared to uncured samples, the permeability coefficient of cured samples reduced from 1 to 2 orders of magnitude. On the other hand, as the dominant aperture size increases with a decrease in the calcium carbonate content, the permeability coefficient increases with an increase in the salt content. Furthermore, micro-mechanical tests, such as X-ray diffraction and scanning electron microscope tests, were conducted to analyze the mechanism by which salt degrades the reinforcement. As a guiding agent, while chloride salt can improve the proportion of calcite in calcium carbonate, it decreases the total quantity of calcium carbonate through the limiting urea hydrolysis process. A significant amount of calcium carbonate is deposited on the surface of the particles in each sample, especially the contact surface. In conclusion, even though salt has a certain deterioration effect, microbially-induced carbonate precipitation is still an effective and environment-friendly method to cure saline soil. This study can provide a theoretical basis for using this method to solidify saline soil. © 2022 Elsevier Ltd
WOS研究方向	Science & Technology - Other Topics ; Engineering ; Environmental Sciences & Ecology
语种	英语
出版者	Elsevier Ltd
WOS记录号	WOS:000822566200004
内容类型	期刊论文
源URL	[http://ir.lut.edu.cn/handle/2XXMBERH/159151]
专题	土木工程学院
作者单位	1.School of Civil Engineering, Lanzhou University of Technology, Gansu, Lanzhou; 730050, China 2.State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Gansu, Lanzhou; 730000, China;
推荐引用方式 GB/T 7714	Peng, Erxing,Hu, Xiaoying,Chou, Yaling,et al. Study of microbially-induced carbonate precipitation for improving coarse-grained salty soil[J]. Journal of Cleaner Production,2022,365.
APA	Peng, Erxing.,Hu, Xiaoying.,Chou, Yaling.,Sheng, Yu.,Liu, Shihao.,...&Cao, Wei.(2022).Study of microbially-induced carbonate precipitation for improving coarse-grained salty soil.Journal of Cleaner Production,365.
MLA	Peng, Erxing,et al."Study of microbially-induced carbonate precipitation for improving coarse-grained salty soil".Journal of Cleaner Production 365(2022).