Biomineralization of soil with crude soybean urease using different calcium salts  

作　　者：Yajie Weng Junjie Zheng Hanjiang Lai Mingjuan Cui Xingzhi Ding 

机构地区：[1]School of Civil and Hydraulic Engineering,Huazhong University of Science and Technology,Wuhan,430074,China [2]Zijin School of Geology and Mining,Fuzhou University,Fuzhou,350108,China [3]College of Civil Engineering,Fuzhou University,Fuzhou,350116,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第5期1788-1798,共11页岩石力学与岩土工程学报（英文版）

基　　金：the financial support by the National Natural Science Foundation of China(NSFC)(Grant Nos.52178319 and 52108307);the Natural Science Foundation of Fujian Province,China(Grant No.2022J05127).

摘　　要：Calcium salt is an important contributing factor for calcium-based biomineralization.To study the effect of calcium salt on soil biomineralization using crude soybean urease,the calcium salts,including the calcium chloride (CaCl_(2)),calcium acetate ((CH_(3)COO)_(2)Ca) and calcium nitrate (Ca(NO_(3))_(2)),were used to prepare the biotreatment solution to carry out the biomineralization tests in this paper.Two series of biomineralization tests in solution and sand column,respectively,were conducted.Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were performed to determine the microscopic characteristics of the precipitated calcium carbonate (CaCO_(3)) crystals.The experimental results indicate that the biomineralization effect is the best for the CaCl2 case,followed by (CH_(3)COO)_(2)Ca,and worst for Ca(NO_(3))_(2) under the test conditions of this study (i.e.1 mol/L of calcium salt-urea).The mechanism for the effect of the calcium salt on the biomineralization of crude soybean urease mainly involves: (1) inhibition of urease activity,and (2) influence on the crystal size and morphology of CaCO_(3).Besides Ca^(2+) ,the anions in solution can inhibit the activity of crude soybean urease,and NO_(3)− has a stronger inhibitory effect on the urease activity compared with both CH_(3)COO^(−) and Cl^(−) .The co-inhibition of Ca^(2+) and NO_(3)− on the activity of urease is the key reason for the worst biomineralization of the Ca(NO_(3))_(2) case in this study.The difference in biomineralization between the CaCl_(2) and (CH_(3)COO)_(2) Ca cases is strongly correlated with the crystal morphology of the precipitated CaCO_(3).

关 键 词：BIOMINERALIZATION Crude soybean urease Calcium salt Influence mechanism 

分 类 号：TU443[建筑科学—岩土工程]