Immobilisation remediation of arsenic-contaminated soils with promising CaAl-layered double hydroxide and bioavailability, bioaccessibility, and speciation-based health risk assessment

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Arsenic (As)-contaminated soil poses great health risk to human mostly through inadvertent oral exposure. We investigated CaAl-layered double hydroxide (CaAl-LDH), a promising immobilising agent, for the remediation of As-contaminated Chinese soils. The effects on specific soil properties and As fractionation were analyzed, and changes in the health risk of soil As were accurately assessed by means of advanced in vivo mice model and in vitro PBET-SHIME model. Results showed that the application of CaAl-LDH significantly increased soil pH and concentration of Fe and Al oxides, and effectively converted active As fractions into the most stable residual fraction, guaranteeing long-term remediation stability. Based on in vivo test, As relative bioavailability was significantly reduced by 37.75%. Based on in vitro test, As bioaccessibility in small intestinal and colon phases was significantly reduced by 25.65% and 28.57%, respectively. Furthermore, As metabolism (reduction and methylation) by the gut microbiota inhabiting colon was clearly observed. After immobilisation with CaAl-LDH, the concentration of bioaccessible As(Ⅴ) in the colon fluid was significantly reduced by 61.91%, and organic As (least toxic MMA(V) and DMA(V)) became the main species, which further reduced the health risk of soil As. In summary, CaAl-LDH proved to be a feasible option for immobilisation remediation of As-contaminated soils, and considerable progress was made in relevant health risk assessment.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:469

Enthalten in:

Journal of hazardous materials - 469(2024) vom: 05. Apr., Seite 134096

Sprache:

Englisch

Beteiligte Personen:

Chen, Xiao-Chen [VerfasserIn]
Huang, Zhen-Jia [VerfasserIn]
Wang, Ao [VerfasserIn]
Yu, Jian-Ying [VerfasserIn]
Zhang, Jian-Yu [VerfasserIn]
Xiao, Zi-Jun [VerfasserIn]
Cui, Xiao-Yu [VerfasserIn]
Liu, Xian-Hua [VerfasserIn]
Yin, Nai-Yi [VerfasserIn]
Cui, Yan-Shan [VerfasserIn]

Links:

Volltext

Themen:

Arsenic
CaAl-layered double hydroxide
Health risk
Immobilisation
Journal Article
N712M78A8G
Soil
Soil Pollutants
Soil remediation

Anmerkungen:

Date Completed 08.04.2024

Date Revised 08.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.jhazmat.2024.134096

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM370117611