PMID- 33731790
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20210913
LR  - 20210913
IS  - 2045-2322 (Electronic)
IS  - 2045-2322 (Linking)
VI  - 11
IP  - 1
DP  - 2021 Mar 17
TI  - The role of bacterial urease activity on the uniformity of carbonate 
      precipitation profiles of bio-treated coarse sand specimens.
PG  - 6161
LID - 10.1038/s41598-021-85712-6 [doi]
LID - 6161
AB  - Protocols for microbially induced carbonate precipitation (MICP) have been 
      extensively studied in the literature to optimise the process with regard to the 
      amount of injected chemicals, the ratio of urea to calcium chloride, the method 
      of injection and injection intervals, and the population of the bacteria, usually 
      using fine- to medium-grained poorly graded sands. This study assesses the effect 
      of varying urease activities, which have not been studied systematically, and 
      population densities of the bacteria on the uniformity of cementation in very 
      coarse sands (considered poor candidates for treatment). A procedure for 
      producing bacteria with the desired urease activities was developed and qPCR 
      tests were conducted to measure the counts of the RNA of the Ure-C genes. Sand 
      biocementaton experiments followed, showing that slower rates of MICP reactions 
      promote more effective and uniform cementation. Lowering urease activity, in 
      particular, results in progressively more uniformly cemented samples and it is 
      proven to be effective enough when its value is less than 10 mmol/L/h. The work 
      presented highlights the importance of urease activity in controlling the quality 
      and quantity of calcium carbonate cements.
FAU - Konstantinou, Charalampos
AU  - Konstantinou C
AUID- ORCID: 0000-0002-4662-5327
AD  - Engineering Department, University of Cambridge, Cambridge, CB2 1PZ, UK. 
      ck494@cam.ac.uk.
FAU - Wang, Yuze
AU  - Wang Y
AUID- ORCID: 0000-0003-3085-5299
AD  - Department of Ocean Science and Engineering, Southern University of Science and 
      Technology, Southern Marine Science and Engineering Laboratory (Guangzhou), 
      Shenzhen, 518055, China. wangyz@sustech.edu.cn.
FAU - Biscontin, Giovanna
AU  - Biscontin G
AUID- ORCID: 0000-0002-4662-5650
AD  - Engineering Department, University of Cambridge, Cambridge, CB2 1PZ, UK.
FAU - Soga, Kenichi
AU  - Soga K
AD  - Department of Civil and Environmental Engineering, University of California, 
      Berkeley, CA, 94720, USA.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20210317
PL  - England
TA  - Sci Rep
JT  - Scientific reports
JID - 101563288
SB  - IM
PMC - PMC7969948
COIS- The authors declare no competing interests.
EDAT- 2021/03/19 06:00
MHDA- 2021/03/19 06:01
PMCR- 2021/03/17
CRDT- 2021/03/18 06:33
PHST- 2020/08/31 00:00 [received]
PHST- 2021/03/03 00:00 [accepted]
PHST- 2021/03/18 06:33 [entrez]
PHST- 2021/03/19 06:00 [pubmed]
PHST- 2021/03/19 06:01 [medline]
PHST- 2021/03/17 00:00 [pmc-release]
AID - 10.1038/s41598-021-85712-6 [pii]
AID - 85712 [pii]
AID - 10.1038/s41598-021-85712-6 [doi]
PST - epublish
SO  - Sci Rep. 2021 Mar 17;11(1):6161. doi: 10.1038/s41598-021-85712-6.