Immobilizing lead and copper in aqueous solution using microbial- and enzyme-induced carbonate precipitation

Frontiers in Bioengineering and Biotechnology

Bioengineering and Biotechnology

Zhong-Fei Xue¹  Lin Wang¹  Wen-Chieh Cheng¹  Wenle Hu¹  Yi-Xin Xie¹  Md Mizanur Rahman² 

[1] School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an, China;Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering (XAUAT), Xi’an, China;UniSA STEM, SIRM, University of south Australia, Adelaide, SA, Australia;

关键词: MICP;    EICP;    heavy metal;    remediation efficiency;    thermodynamic properties;   

DOI  :  10.3389/fbioe.2023.1146858

 received in 2023-01-18, accepted in 2023-03-16,  发布年份 2023

来源: Frontiers

【 摘 要 】

Inappropriate irrigation could trigger migration of heavy metals into surrounding environments, causing their accumulation and a serious threat to human central nervous system. Traditional site remediation technologies are criticized because they are time-consuming and featured with high risk of secondary pollution. In the past few years, the microbial-induced carbonate precipitation (MICP) is considered as an alternative to traditional technologies due to its easy maneuverability. The enzyme-induced carbonate precipitate (EICP) has attracted attention because bacterial cultivation is not required prior to catalyzing urea hydrolysis. This study compared the performance of lead (Pb) and copper (Cu) remediation using MICP and EICP respectively. The effect of the degree of urea hydrolysis, mass and species of carbonate precipitation, and chemical and thermodynamic properties of carbonates on the remediation efficiency was investigated. Results indicated that ammonium ion (NH4+) concentration reduced with the increase in lead ion (Pb2+) or copper ion (Cu2+) concentration, and for a given Pb2+ or Cu2+ concentration, it was much higher under MICP than EICP. Further, the remediation efficiency against Cu2+ is approximately zero, which is way below that against Pb2+ (approximately 100%). The Cu2+ toxicity denatured and even inactivated the urease, reducing the degree of urea hydrolysis and the remediation efficiency. Moreover, the reduction in the remediation efficiency against Pb2+ and Cu2+ appeared to be due to the precipitations of cotunnite and atacamite respectively. Their chemical and thermodynamic properties were not as good as calcite, cerussite, phosgenite, and malachite. The findings shed light on the underlying mechanism affecting the remediation efficiency against Pb2+ and Cu2+.

【 授权许可】

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Copyright © 2023 Wang, Cheng, Xue, Rahman, Xie and Hu.