Chen Minjie, Cao Dan, Li Bowen, Pang Hao, Zheng Chunli
School of Energy and Environment, Inner Mongolia University of Science and Technology, Baotou, 014010, People's Republic of China; Inner Mongolia Engineering Research Center of Evaluation and Restoration in the Mining Ecological Environments, Baotou, 014010, People's Republic of China.
School of Energy and Environment, Inner Mongolia University of Science and Technology, Baotou, 014010, People's Republic of China; Inner Mongolia Engineering Research Center of Evaluation and Restoration in the Mining Ecological Environments, Baotou, 014010, People's Republic of China; School of Resource and Environmental Engineering, Shanghai Polytechnic University, Shanghai, 310014, People's Republic of China.
Environ Res. 2023 May 1;224:115479. doi: 10.1016/j.envres.2023.115479. Epub 2023 Feb 14.
The microbially induced carbonate precipitation (MICP) technique is widely used in soil heavy metal pollution control. Microbial mineralization involves extended mineralization times and slow crystallization rates. Thus, it is important to discover a method to accelerate mineralization. In this study, we selected six nucleating agents to screen and investigated the mineralization mechanism using polarized light microscopy, scanning electron microscopy, X-ray diffraction and Fourier-transform infrared spectroscopy. The results showed that sodium citrate removed 90.1% Pb better than traditional MICP and generated the highest amount of precipitation. Interestingly, due to the addition of sodium citrate (NaCit), the rate of crystallization increased and vaterite was stabilized. Moreover, we constructed a possible model to explain that NaCit increases the aggregation capacity of calcium ions during microbial mineralization to accelerate the formation of calcium carbonate (CaCO). Thus, sodium citrate can increase the rate of MICP bioremediation, which is important for improving MICP efficiency.
微生物诱导碳酸盐沉淀（MICP）技术在土壤重金属污染控制中得到广泛应用。微生物矿化涉及较长的矿化时间和较慢的结晶速率。因此，发现一种加速矿化的方法很重要。在本研究中，我们选择了六种成核剂进行筛选，并使用偏光显微镜、扫描电子显微镜、X射线衍射和傅里叶变换红外光谱研究了矿化机制。结果表明，柠檬酸钠去除铅的效果比传统MICP好90.1%，且产生的沉淀量最高。有趣的是，由于添加了柠檬酸钠（NaCit），结晶速率增加，球霰石得以稳定。此外，我们构建了一个可能的模型来解释NaCit在微生物矿化过程中增加钙离子的聚集能力，以加速碳酸钙（CaCO）的形成。因此，柠檬酸钠可以提高MICP生物修复的速率，这对提高MICP效率很重要。
