PMID- 34888301
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20211211
IS  - 2296-4185 (Print)
IS  - 2296-4185 (Electronic)
IS  - 2296-4185 (Linking)
VI  - 9
DP  - 2021
TI  - Revealing the Enhancement and Degradation Mechanisms Affecting the Performance of 
      Carbonate Precipitation in EICP Process.
PG  - 750258
LID - 10.3389/fbioe.2021.750258 [doi]
LID - 750258
AB  - Given that acid-rich rainfall can cause serious damage to heritage buildings in 
      NW China and subsequently accelerate their aging problem, countermeasures to 
      protect their integrity and also to preserve the continuity of Chinese culture 
      are in pressing need. Enzyme-induced carbonate precipitation (EICP) that modifies 
      the mechanical properties of the soil through enhancing the interparticle bonds 
      by the precipitated crystals and the formation of other carbonate minerals is 
      under a spotlight in recent years. EICP is considered as an alternative to the 
      microbial-induced carbonate precipitation (MICP) because cultivating soil 
      microbes are considered to be challenging in field applications. This study 
      conducts a series of test tube experiments to reproduce the ordinary EICP 
      process, and the produced carbonate precipitation is compared with that of the 
      modified EICP process subjected to the effect of higher MgCl(2), NH(4)Cl, and 
      CaCl(2) concentrations, respectively. The modified EICP, subjected to the effect 
      of higher MgCl(2) concentrations, performs the best with the highest carbonate 
      precipitation. The enhancement mechanism of carbonate precipitation is well 
      interpreted through elevating the activity of urease enzyme by introducing the 
      magnesium ions. Furthermore, the degradation of carbonate precipitation presents 
      when subjected to the effect of higher NH(4)Cl concentration. The decreasing 
      activity of urease enzyme and the reverse EICP process play a leading role in 
      degrading the carbonate precipitation. Moreover, when subjected to the effect of 
      higher CaCl(2) concentrations, the slower rate of urea hydrolysis and the 
      decreasing activity of urease enzyme are primarily responsible for forming the 
      "hijacking" phenomenon of carbonate precipitation. The findings of this study 
      explore the potential use of the EICP technology for the protection of heritage 
      buildings in NW China.
CI  - Copyright (c) 2021 Hu, Cheng, Wen and Yuan.
FAU - Hu, Wenle
AU  - Hu W
AD  - School of Civil Engineering, Xi'an University of Architecture and Technology, 
      Xi'an, China.
FAU - Cheng, Wen-Chieh
AU  - Cheng WC
AD  - School of Civil Engineering, Xi'an University of Architecture and Technology, 
      Xi'an, China.
AD  - Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering (XAUAT), 
      Xi'an, China.
FAU - Wen, Shaojie
AU  - Wen S
AD  - School of Civil Engineering, Xi'an University of Architecture and Technology, 
      Xi'an, China.
FAU - Yuan, Ke
AU  - Yuan K
AD  - School of Civil Engineering, Xi'an University of Architecture and Technology, 
      Xi'an, China.
LA  - eng
PT  - Journal Article
DEP - 20211123
PL  - Switzerland
TA  - Front Bioeng Biotechnol
JT  - Frontiers in bioengineering and biotechnology
JID - 101632513
PMC - PMC8650497
OTO - NOTNLM
OT  - ammonium ions
OT  - enzyme-induced carbonate precipitation
OT  - hijacking mechanism
OT  - magnesium ions
OT  - test tube experiment
COIS- The authors declare that the research was conducted in the absence of any 
      commercial or financial relationships that could be construed as a potential 
      conflict of interest.
EDAT- 2021/12/11 06:00
MHDA- 2021/12/11 06:01
PMCR- 2021/01/01
CRDT- 2021/12/10 06:46
PHST- 2021/08/02 00:00 [received]
PHST- 2021/11/01 00:00 [accepted]
PHST- 2021/12/10 06:46 [entrez]
PHST- 2021/12/11 06:00 [pubmed]
PHST- 2021/12/11 06:01 [medline]
PHST- 2021/01/01 00:00 [pmc-release]
AID - 750258 [pii]
AID - 10.3389/fbioe.2021.750258 [doi]
PST - epublish
SO  - Front Bioeng Biotechnol. 2021 Nov 23;9:750258. doi: 10.3389/fbioe.2021.750258. 
      eCollection 2021.