Applying the first microcapsule-based self-healing microbial-induced calcium carbonate materials to prevent the migration of Pb ions

Zhong-Fei Xue; Wen-Chieh Cheng; Lin Wang; Peng Qin; Yi-Xin Xie; Wenle Hu

doi:10.1016/j.envres.2023.117423

Applying the first microcapsule-based self-healing microbial-induced calcium carbonate materials to prevent the migration of Pb ions

Environ Res. 2023 Dec 15;239(Pt 2):117423. doi: 10.1016/j.envres.2023.117423. Epub 2023 Oct 18.

Authors

Zhong-Fei Xue¹, Wen-Chieh Cheng², Lin Wang³, Peng Qin⁴, Yi-Xin Xie⁵, Wenle Hu⁶

Affiliations

¹ School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China; Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering (XAUAT), Xi'an, 710055, China. Electronic address: xuezhongfei@xauat.edu.cn.
² School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China; Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering (XAUAT), Xi'an, 710055, China. Electronic address: w-c.cheng@xauat.edu.cn.
³ School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China; Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering (XAUAT), Xi'an, 710055, China. Electronic address: wanglin@xauat.edu.cn.
⁴ School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China; Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering (XAUAT), Xi'an, 710055, China. Electronic address: qinpeng@xauat.edu.cn.
⁵ School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China; Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering (XAUAT), Xi'an, 710055, China. Electronic address: xieyixin@xauat.edu.cn.
⁶ School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China; Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering (XAUAT), Xi'an, 710055, China. Electronic address: wenlehu@xauat.edu.cn.

PMID: 37858687
DOI: 10.1016/j.envres.2023.117423

Abstract

Lead (Pb) accumulation can lead to serious threats to surrounding environments and damage to the liver and kidneys. In the past few years, microbial-induced carbonate precipitation (MICP) technology has been widely applied to achieve Pb immobilization due to its environmentally friendly nature. However, harsh pH conditions can cause the instability of the carbonate precipitation to degrade or dissolve, increasing the potential of Pb²⁺ migration into nearby environments. In this study, microcapsule-based self-healing microbial-induced calcium carbonate (MICC) materials were applied to prevent Pb migration. The highest sporulation rate of 95.8% was attained at 7 g/L yeast extract, 10 g/L NH4Cl, and 3.6 g/L Mn²⁺. In the germination phase, the microcapsule not only prevented the bacterial spores from being threatened by the acid treatment but secured their growth and reproduction. Micro analysis also revealed that cerussite, calcite, and aragonite minerals were present, while extracellular polymeric substances (EPSs) were identified via Fourier transform infrared spectroscopy (FTIR). These results confirm their involvement in combining Pb²⁺ and Ca²⁺. The immobilization efficiency of above 90% applied to MICC materials was attained, while it of below 5% applied to no MICC use was attained. The findings explore the potential of applying microcapsule-based self-healing MICC materials to prevent Pb ion migration when the calcium carbonate degrades under harsh pH conditions.

Keywords: Immobilization efficiency; Lead; Microcapsule; Precipitation kinetics; Spore germination rate.

MeSH terms

Calcium Carbonate* / chemistry
Calcium Carbonate* / metabolism
Capsules
Carbonates
Lead*
Minerals

Substances

Calcium Carbonate
Lead
Capsules
Carbonates
Minerals