Iron-doped hydroxyapatite for the simultaneous remediation of lead-, cadmium- and arsenic-co-contaminated soil

Zhihui Yang; Hangyuan Gong; Fangshu He; Eveliina Repo; Weichun Yang; Qi Liao; Feiping Zhao

doi:10.1016/j.envpol.2022.119953

Iron-doped hydroxyapatite for the simultaneous remediation of lead-, cadmium- and arsenic-co-contaminated soil

Environ Pollut. 2022 Nov 1:312:119953. doi: 10.1016/j.envpol.2022.119953. Epub 2022 Aug 23.

Authors

Zhihui Yang¹, Hangyuan Gong², Fangshu He¹, Eveliina Repo³, Weichun Yang¹, Qi Liao¹, Feiping Zhao⁴

Affiliations

¹ School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Institute of Environmental Engineering, Central South University, Changsha, 410083, Hunan, China.
² School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Institute of Environmental Engineering, Central South University, Changsha, 410083, Hunan, China; Hunan Chemical Geological Engineering Exploration Institute Co., Ltd., Changsha, 410004, Hunan, China.
³ Department of Separation Science, School of Engineering Science, Lappeenranta-Lahti University of Technology LUT, Yliopistonkatu 34, FI, 53850, Finland.
⁴ School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Institute of Environmental Engineering, Central South University, Changsha, 410083, Hunan, China. Electronic address: feiping.zhao@csu.edu.cn.

PMID: 36028081
DOI: 10.1016/j.envpol.2022.119953

Abstract

Since lead, cadmium and arsenic have completely opposite chemical behaviors, it is very difficult to stabilize all these three heavy metals simultaneously. Herein, a novel iron-doped hydroxyapatite composite (Fe-HAP) was developed via an ultrasonic-assisted microwave hydrothermal method for the simultaneous remediation of lead-, cadmium-, and arsenic-co-contaminated soil in Hunan Province, South China. Using DTPA/sodium bicarbonate extractant to extract bioavailable Pb, Cd and As in soil after Fe-HAP remediation for 60 days, the immobilization efficiencies were 79.77%, 51.3% and 37.5% for Pb, Cd and As, respectively. The soil extractable and exchangeable fractions of Pb, Cd and As decreased significantly. In batch experiments, the adsorption kinetics of Pb, Cd and As on Fe-HAP were well described by pseudo-second-order models, indicating that the adsorption is controlled by chemisorption. In the Langmuir adsorption isotherm, the maximum adsorption capacities of Cd²⁺ and As(V) were 476.2 mg g^-1 and 195.69 mg g^-1, respectively, while Pb²⁺ fit the Freundlich model better. The XRD, SEM and XPS analyses indicated that Fe-HAP formed stable minerals of Pb₅(PO₄)₃OH, Cd₃(PO₄)₂·4H₂O, Cd(OH)₂ and Fe₃(AsO₄)₂·6H₂O with Pb, Cd and As. Overall, its facile and efficient immobilization performance indicate that Fe-HAP has potential for practical applications in integrative remediation of Pb-, Cd-, and As- co-contaminated soil.

Keywords: Hydroxyapatite; Iron; Lead-cadmium-arsenic co-contaminated soil; Solidification/stabilization.

MeSH terms

Arsenic* / analysis
Cadmium / analysis
Charcoal
Durapatite
Iron / analysis
Lead / analysis
Metals, Heavy* / analysis
Pentetic Acid
Sodium Bicarbonate
Soil
Soil Pollutants* / analysis

Substances

Metals, Heavy
Soil
Soil Pollutants
Cadmium
Charcoal
Lead
Pentetic Acid
Sodium Bicarbonate
Durapatite
Iron
Arsenic