PMID- 32563888
OWN - NLM
STAT- MEDLINE
DCOM- 20200901
LR  - 20200901
IS  - 1879-1026 (Electronic)
IS  - 0048-9697 (Linking)
VI  - 740
DP  - 2020 Oct 20
TI  - Inhibition of urea hydrolysis by free Cu concentration of soil solution in 
      microbially induced calcium carbonate precipitation.
PG  - 140194
LID - S0048-9697(20)33715-3 [pii]
LID - 10.1016/j.scitotenv.2020.140194 [doi]
AB  - Urea hydrolysis is an initiating step of microbially induced calcium carbonate 
      precipitation (MICP) which can be used as a stabilization technology in heavy 
      metals contaminated soil. In this study, inhibition of urea hydrolysis was 
      investigated in Cu-contaminated soil. At soil Cu concentration from 0 to 
      1000 mg/kg, the amount of urea hydrolyzed (i.e., initial urea 450 mM) ranged from 
      449.3 +/- 1.4 to 10.5 +/- 0.8 mM. Correspondingly, decrease in calcium carbonate 
      precipitation was commensurate with the inhibition of urea hydrolysis. 
      Interestingly, 2.75 times more urea were hydrolyzed in 350 days-aged soil than in 
      freshly spiked soil even at the same soil Cu concentration of 250 mg/kg, 
      suggesting the inhibitory effect of Cu in soil solution. Indeed, the 
      concentrations of Cu in soil solution were 4.9 +/- 0.1 and 21.0 +/- 0.3 mg/L, 
      respectively. Since MICP application involved an increase in Ca(2+) concentration 
      in soil, its effect was also determined. In the freshly spiked soil with 
      250 mg-Cu/kg, the Cu concentration in the soil solution increased from 7.6 +/- 0.1 
      to 21.0 +/- 0.3 mg/L as the calcium concentration increased from 0 to 450 mM. 
      Accordingly, urea hydrolysis was significantly reduced from 217.5 +/- 59.0 to 
      11.9 +/- 0.2 mM. The effect of pH was also determined, showing that 32.8 +/- 3.4 and 
      205.9 +/- 32.5 mM of urea was hydrolyzed at soil pH of 4.5 and 7.8, respectively. 
      The reason was attributed to the great difference in free Cu concentration in 
      soil solution (i.e., 3.3 and 0.3 mg/L at pH 4.5 and 7.8, respectively). The 
      relationship between amounts of urea hydrolyzed and free Cu concentrations was 
      established and half-maximal inhibition concentration (IC(50)) of free Cu 
      concentration in soil solution was predicted to be 0.39 mg/L.
CI  - Copyright (c) 2020 Elsevier B.V. All rights reserved.
FAU - Chung, Hyeonyong
AU  - Chung H
AD  - Department of Civil and Environmental Engineering, Seoul National University, 
      Seoul 08826, Republic of Korea.
FAU - Kim, Sang Hyun
AU  - Kim SH
AD  - Department of Civil and Environmental Engineering, Seoul National University, 
      Seoul 08826, Republic of Korea.
FAU - Nam, Kyoungphile
AU  - Nam K
AD  - Department of Civil and Environmental Engineering, Seoul National University, 
      Seoul 08826, Republic of Korea. Electronic address: kpnam@snu.ac.kr.
LA  - eng
PT  - Journal Article
DEP - 20200615
PL  - Netherlands
TA  - Sci Total Environ
JT  - The Science of the total environment
JID - 0330500
RN  - 0 (Soil)
RN  - 8W8T17847W (Urea)
RN  - H0G9379FGK (Calcium Carbonate)
SB  - IM
MH  - *Calcium Carbonate
MH  - Chemical Precipitation
MH  - Hydrogen-Ion Concentration
MH  - Hydrolysis
MH  - *Soil
MH  - Urea
OTO - NOTNLM
OT  - Free Cu ion
OT  - Half-maximal inhibition concentration
OT  - Microbially induced calcium carbonate precipitation (MICP)
OT  - Urea hydrolysis
COIS- Declaration of competing interest The authors declare that they have no known 
      competing financial interests or personal relationships that could have appeared 
      to influence the work reported in this paper.
EDAT- 2020/06/22 06:00
MHDA- 2020/09/02 06:00
CRDT- 2020/06/22 06:00
PHST- 2020/04/21 00:00 [received]
PHST- 2020/06/11 00:00 [revised]
PHST- 2020/06/11 00:00 [accepted]
PHST- 2020/06/22 06:00 [pubmed]
PHST- 2020/09/02 06:00 [medline]
PHST- 2020/06/22 06:00 [entrez]
AID - S0048-9697(20)33715-3 [pii]
AID - 10.1016/j.scitotenv.2020.140194 [doi]
PST - ppublish
SO  - Sci Total Environ. 2020 Oct 20;740:140194. doi: 10.1016/j.scitotenv.2020.140194. 
      Epub 2020 Jun 15.