TY - JOUR
T1 - Zeolite-supported nanoscale zero-valent iron for immobilization of cadmium, lead, and arsenic in farmland soils
T2 - Encapsulation mechanisms and indigenous microbial responses
AU - Li, Zhangtao
AU - Wang, Lu
AU - Wu, Jizi
AU - Xu, Yan
AU - Wang, Fan
AU - Tang, Xianjin
AU - Xu, Jianming
AU - Ok, Yong Sik
AU - Meng, Jun
AU - Liu, Xingmei
N1 - Funding Information:
This work was financially supported by the National Natural Science Foundation of China (41722111 and 41571477), the National Key Research Program of China (2016YFD0801105), the Hangzhou Science and Technology Project (20162013A07), and the Agriculture Research System of China (CARS-01-30).
Funding Information:
This work was financially supported by the National Natural Science Foundation of China ( 41722111 and 41571477 ), the National Key Research Program of China ( 2016YFD0801105 ), the Hangzhou Science and Technology Project ( 20162013A07 ), and the Agriculture Research System of China ( CARS-01-30 ).
PY - 2020/5
Y1 - 2020/5
N2 - Zeolite-supported nanoscale zero-valent iron (Z-NZVI) has great potential for metal(loid) removal, but its encapsulation mechanisms and ecological risks in real soil systems are not completely clear. We conducted long-term incubation experiments to gain new insights into the interactions between metal(loid)s (Cd, Pb, As) and Z-NZVI in naturally contaminated farmland soils, as well as the alteration of indigenous bacterial communities during soil remediation. With the pH-adjusting and adsorption capacities, 30 g kg−1 Z-NZVI amendment significantly decreased the available metal(loid) concentrations by 10.2–96.8% and transformed them into strongly-bound fractions in acidic and alkaline soils after 180 d. An innovative magnetic separation of Z-NZVI from soils followed by XRD and XPS characterizations revealed that B-type ternary complexation, heterogeneous coprecipitation, and/or concurrent redox reactions of metal(loid)s, especially the formation of Cd3(AsO4)2, PbFe2(AsO4)2(OH)2, and As0, occurred only under specific soil conditions. Sequencing of 16S rDNA using Illumina MiSeq platform indicated that temporary shifts in iron-resistant/sensitive, pH-sensitive, denitrifying, and metal-resistant bacteria after Z-NZVI addition were ultimately eliminated because soil characteristics drove the re-establishment of indigenous bacterial community. Meanwhile, Z-NZVI recovered the basic activities of bacterial DNA replication and denitrification functions in soils. These results confirm that Z-NZVI is promising for the long-term remediation of metal(loid)s contaminated farmland soil without significant ecotoxicity.
AB - Zeolite-supported nanoscale zero-valent iron (Z-NZVI) has great potential for metal(loid) removal, but its encapsulation mechanisms and ecological risks in real soil systems are not completely clear. We conducted long-term incubation experiments to gain new insights into the interactions between metal(loid)s (Cd, Pb, As) and Z-NZVI in naturally contaminated farmland soils, as well as the alteration of indigenous bacterial communities during soil remediation. With the pH-adjusting and adsorption capacities, 30 g kg−1 Z-NZVI amendment significantly decreased the available metal(loid) concentrations by 10.2–96.8% and transformed them into strongly-bound fractions in acidic and alkaline soils after 180 d. An innovative magnetic separation of Z-NZVI from soils followed by XRD and XPS characterizations revealed that B-type ternary complexation, heterogeneous coprecipitation, and/or concurrent redox reactions of metal(loid)s, especially the formation of Cd3(AsO4)2, PbFe2(AsO4)2(OH)2, and As0, occurred only under specific soil conditions. Sequencing of 16S rDNA using Illumina MiSeq platform indicated that temporary shifts in iron-resistant/sensitive, pH-sensitive, denitrifying, and metal-resistant bacteria after Z-NZVI addition were ultimately eliminated because soil characteristics drove the re-establishment of indigenous bacterial community. Meanwhile, Z-NZVI recovered the basic activities of bacterial DNA replication and denitrification functions in soils. These results confirm that Z-NZVI is promising for the long-term remediation of metal(loid)s contaminated farmland soil without significant ecotoxicity.
KW - Bacterial community
KW - Encapsulation mechanism
KW - Metal(loid)s
KW - Nanoscale zero-valent iron
KW - Soil remediation
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U2 - 10.1016/j.envpol.2020.114098
DO - 10.1016/j.envpol.2020.114098
M3 - Article
C2 - 32041084
AN - SCOPUS:85078928913
VL - 260
JO - Environmental Pollution
JF - Environmental Pollution
SN - 0269-7491
M1 - 114098
ER -