PMID- 36966928
OWN - NLM
STAT- MEDLINE
DCOM- 20230414
LR  - 20230414
IS  - 1879-1298 (Electronic)
IS  - 0045-6535 (Linking)
VI  - 327
DP  - 2023 Jun
TI  - Enhancing lead immobilization by biochar: Creation of "surface barrier" via 
      bio-treatment.
PG  - 138477
LID - S0045-6535(23)00744-0 [pii]
LID - 10.1016/j.chemosphere.2023.138477 [doi]
AB  - The long-term effectiveness of heavy metal immobilization is always a concern. 
      This study proposes a completely novel approach to enhance the stability of heavy 
      metals by combined biochar and microbial induced carbonate precipitation (MICP) 
      technology, to create a "surface barrier" of CaCO(3) layer on biochar after lead 
      (Pb(2+)) immobilization. Aqueous sorption studies and chemical and 
      micro-structure tests were used to verify the feasibility. Rice straw biochar 
      (RSB700) was produced at 700  degrees C, which shows high immobilization capacity of 
      Pb(2+) (maximum of 118 mg g(-1)). But the stable fraction only accounts for 4.8% 
      of the total immobilized Pb(2+) on biochar. After MICP treatment, the stable 
      fraction of Pb(2+) significantly increased to a maximum of 92.5%. Microstructural 
      tests confirm the formation of CaCO(3) layer on biochar. The CaCO(3) species are 
      predominantly calcite and vaterite. Higher Ca(2+) and urea concentrations in 
      cementation solution resulted in higher CaCO(3) yield but lower Ca(2+) 
      utilization efficiency. The main mechanism of the "surface barrier" to enhance 
      Pb(2+) stability on biochar was likely the encapsulation effect: it physically 
      blocked the contact between acids and Pb(2+) on biochar, and chemically buffer 
      the acidic attack from the environment. The performance of the "surface barrier" 
      depends on both the yield of CaCO(3) and their distribution uniformity on 
      biochar's surface. This study shed lights on the potential application of the 
      "surface barrier" strategy combining biochar and MICP technologies for enhanced 
      heavy metal immobilization.
CI  - Copyright (c) 2023 Elsevier Ltd. All rights reserved.
FAU - Hu, Huicong
AU  - Hu H
AD  - School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, 
      China.
FAU - Tang, Chao-Sheng
AU  - Tang CS
AD  - School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, 
      China. Electronic address: tangchaosheng@nju.edu.cn.
FAU - Shen, Zhengtao
AU  - Shen Z
AD  - School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, 
      China. Electronic address: ztshen@nju.edu.cn.
FAU - Pan, Xiaohua
AU  - Pan X
AD  - School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, 
      China.
FAU - Gu, Kai
AU  - Gu K
AD  - School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, 
      China.
FAU - Fan, Xiaoliang
AU  - Fan X
AD  - School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, 
      China.
FAU - Lv, Chao
AU  - Lv C
AD  - School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, 
      China.
FAU - Mu, Wen
AU  - Mu W
AD  - School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, 
      China.
FAU - Shi, Bin
AU  - Shi B
AD  - School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, 
      China.
LA  - eng
PT  - Journal Article
DEP - 20230324
PL  - England
TA  - Chemosphere
JT  - Chemosphere
JID - 0320657
RN  - 0 (biochar)
RN  - 2P299V784P (Lead)
RN  - 0 (Soil Pollutants)
RN  - 16291-96-6 (Charcoal)
RN  - 0 (Metals, Heavy)
RN  - H0G9379FGK (Calcium Carbonate)
RN  - 0 (Soil)
SB  - IM
MH  - Lead
MH  - *Environmental Restoration and Remediation
MH  - *Soil Pollutants/analysis
MH  - Charcoal/chemistry
MH  - *Metals, Heavy/analysis
MH  - Calcium Carbonate
MH  - Soil/chemistry
OTO - NOTNLM
OT  - Bio-treatment
OT  - Lead immobilization
OT  - Long-term effectiveness
OT  - Microbial induced carbonate precipitation (MICP)
OT  - Rice straw biochar
OT  - Surface barrier
COIS- Declaration of competing interest The authors declare the following financial 
      interests/personal relationships which may be considered as potential competing 
      interests: Chao-Sheng Tang reports financial support was provided by National Key 
      Research and Development Program of China. Chao-Sheng Tang reports financial 
      support was provided by National Natural Science Foundation of China. Zhengtao 
      Shen reports financial support was provided by National Natural Science 
      Foundation of China. Chao-Sheng Tang reports financial support was provided by 
      Natural Science Foundation of Jiangsu Province. Zhengtao Shen reports financial 
      support was provided by Natural Science Foundation of Jiangsu Province.
EDAT- 2023/03/27 06:00
MHDA- 2023/04/14 06:42
CRDT- 2023/03/26 20:25
PHST- 2023/01/10 00:00 [received]
PHST- 2023/03/07 00:00 [revised]
PHST- 2023/03/20 00:00 [accepted]
PHST- 2023/04/14 06:42 [medline]
PHST- 2023/03/27 06:00 [pubmed]
PHST- 2023/03/26 20:25 [entrez]
AID - S0045-6535(23)00744-0 [pii]
AID - 10.1016/j.chemosphere.2023.138477 [doi]
PST - ppublish
SO  - Chemosphere. 2023 Jun;327:138477. doi: 10.1016/j.chemosphere.2023.138477. Epub 
      2023 Mar 24.