Poorly crystalline Fe(Ⅱ) mineral phases induced by nano zero-valent iron are responsible for Cd stabilization with different soil moisture conditions and soil types

Mengjiao Liu; Meng Xu; Xin Zhang; Jingjie Zhou; Qingxu Ma; Lianghuan Wu

Ecotoxicology and Environmental Safety (Oct 2021)

Poorly crystalline Fe(Ⅱ) mineral phases induced by nano zero-valent iron are responsible for Cd stabilization with different soil moisture conditions and soil types

Mengjiao Liu,
Meng Xu,
Xin Zhang,
Jingjie Zhou,
Qingxu Ma,
Lianghuan Wu

Affiliations

Mengjiao Liu: Zhejiang Provincial Key Laboratory of Agricultural Resource and Environment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
Meng Xu: Zhejiang Provincial Key Laboratory of Agricultural Resource and Environment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
Xin Zhang: Zhejiang Provincial Key Laboratory of Agricultural Resource and Environment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
Jingjie Zhou: Zhejiang Provincial Key Laboratory of Agricultural Resource and Environment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
Qingxu Ma: Corresponding authors.; Zhejiang Provincial Key Laboratory of Agricultural Resource and Environment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
Lianghuan Wu: Corresponding authors.; Zhejiang Provincial Key Laboratory of Agricultural Resource and Environment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China

Journal volume & issue: Vol. 223
p. 112616

Abstract

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Nano zero-valent iron (nZVI) is a promising remediation material for Cd-contaminated soil, but questions remain regarding the effects of nZVI-induced Fe oxides on Cd availability with different soil types and moisture conditions. To identify the changes in Cd availability and Fe mineral phases resulting from the application of nZVI, three types of Cd-spiked soils with 0.1% nZVI amendment were incubated under different moisture conditions with water-holding capacities (WHCs) of 30%, 60%, and 180%. The availability of Cd was significantly decreased in yellow and black soils amended with nZVI, with fewer changes being observed in cinnamon soil. The limited effect of nZVI on Cd stabilization was due to the extremely low content of poorly crystalline Fe phases in cinnamon soil. The Cd stabilization efficiency of nZVI was higher in the flooding soils (180% WHC) than in the non-flooding yellow and black soils (30% and 60% WHC, respectively). Moreover, the addition of nZVI promoted the formation of less-available forms of Cd (Fe-oxide-bound Cd in yellow soil and Fe-oxide-bound and organic-material-bound Cd in black soil) under the flooding condition. The decrease in extractable Cd was strongly related to the increase in poorly crystalline Fe(Ⅱ) mineral phases among the three soils and various soil moisture contents. Although 0.1% nZVI amendment induced the dissolution of Mn oxides, it did not hinder the Cd stabilization in the three soils. Overall, this study indicates that increased amounts of poorly crystalline Fe(Ⅱ) compounds due to nZVI amendment play a critical role in the stabilization of Cd in soils.

Published in Ecotoxicology and Environmental Safety

ISSN: 0147-6513 (Print); 1090-2414 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Technology: Environmental technology. Sanitary engineering: Environmental pollution; Geography. Anthropology. Recreation: Environmental sciences
Website: https://www.journals.elsevier.com/ecotoxicology-and-environmental-safety

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