Yang Yuanjiang, Li Mingdong, Tao Xueqing, Zhang Shiai, He Jia, Zhu Liping, Wen Kejun
School of Civil and Architectural Engineering, East China University of Technology, Nanchang 330013, China.
College of Civil and Transportation Engineering, Hohai University, No.1, Xikang Road, Nanjing 210098, China.
Materials (Basel). 2022 Aug 23;15(17):5814. doi: 10.3390/ma15175814.
Plant urease has the advantages of high activity and small size in enzyme-induced calcium carbonate precipitation (EICP). However, there area lack of nucleation sites for calcium carbonate in EICP. Sucrose and sorbitol, which are readily available and inexpensive, have the potential to provide nucleation sites for EICP as nucleating agents. To explore the effects of the two nucleating agents on EICP, the productivity of calcium carbonate, unconfined compressive strength (UCS) and microscopic mechanisms were tested. It is found that the productivity of EICP can be increased as much as 5.1% by the addition of sorbitol with an optimal content of 5%, and the productivity of EICP can be increased as much as 12.3% by the addition of sucrose with an optimal of 4%. The UCS of EICP-treated sand increases by 2.2 times after being improved by sorbitol with a content of 5.2%, the CaCO content of EICP-treated sand with sorbitol added increased by 1.5% compared to conventional EICP-treated sand. These results show that the two nucleating agents are effective for improving EICP. The SEM images verify that sorbitol/sucrose can compensate for the lack of nucleating sites in EICP and explicate the effect of nucleating agents on EICP.
在酶诱导碳酸钙沉淀（EICP）过程中，植物脲酶具有活性高和尺寸小的优点。然而，EICP中碳酸钙的成核位点不足。蔗糖和山梨醇容易获得且价格低廉，有潜力作为成核剂为EICP提供成核位点。为了探究这两种成核剂对EICP的影响，对碳酸钙的生成率、无侧限抗压强度（UCS）和微观机制进行了测试。结果发现，添加最佳含量为5%的山梨醇可使EICP的生成率提高多达5.1%，添加最佳含量为4%的蔗糖可使EICP的生成率提高多达12.3%。经含量为5.2%的山梨醇改良后，EICP处理砂的UCS提高了2.2倍，添加山梨醇的EICP处理砂的CaCO含量比传统EICP处理砂增加了1.5%。这些结果表明，这两种成核剂对改善EICP有效。扫描电子显微镜（SEM）图像证实，山梨醇/蔗糖可以弥补EICP中缺乏的成核位点，并阐明成核剂对EICP的作用。
