Interactive effects of rice straw biochar and γ-Al2O3 on immobilization of Zn

Ping Wu; Peixin Cui; Marcelo E Alves; Willie J G M Peijnenburg; Cun Liu; Dongmei Zhou; Hailong Wang; Yong Sik Ok; Yujun Wang

doi:10.1016/j.jhazmat.2019.03.076

Interactive effects of rice straw biochar and γ-Al₂O₃ on immobilization of Zn

J Hazard Mater. 2019 Jul 5:373:250-257. doi: 10.1016/j.jhazmat.2019.03.076. Epub 2019 Mar 19.

Authors

Ping Wu¹, Peixin Cui², Marcelo E Alves³, Willie J G M Peijnenburg⁴, Cun Liu², Dongmei Zhou², Hailong Wang⁵, Yong Sik Ok⁶, Yujun Wang⁷

Affiliations

¹ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China.
² Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, PR China.
³ Departamento de Ciencias Exatas, Escola Superior de Agricultura "Luiz de Queiroz", 13418-900, Piracicaba, SP, Brazil.
⁴ National Institute of Public Health and the Environment, Center for Safety of Substances and Products, 3720 BA, Bilthoven, the Netherlands; Institute of Environmental Sciences (CML), Leiden University, 2300 RA, Leiden, the Netherlands.
⁵ Biochar Engineering Technology Research Center of Guangdong Province, School of Environment and Chemical Engineering, Foshan University, Foshan, Guangdong, 528000, PR China; School of Environmental and Resource Sciences, Zhejiang A & F University, Hangzhou, Zhejiang, 311300, PR China.
⁶ Korea Biochar Reseach Center & Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea.
⁷ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, PR China. Electronic address: yjwang@issas.ac.cn.

PMID: 30921576
DOI: 10.1016/j.jhazmat.2019.03.076

Abstract

Biochar system technology has been proved as a sustainable remediation method for metal contaminated soils. However, little attention has been paid to the interaction between biochar and oxide minerals and their influence on metal immobilization in soils. In this study, batch-type Zn sorption experiments were conducted using the mixture of γ-Al₂O₃ and rice straw biochar as a model binary geosorbent systems. In addition, advanced spectroscopic technics such as EXAFS, FTIR and XRD were performed to reveal the mechanism. EXAFS spectroscopy revealed that 62% of Zn existed as Zn-Al layered double hydroxide (LDH) on γ-Al₂O₃ at pH 7.5 (for 2 mM Zn loading) within 24 h, which was 19% in the mixture. The Zn in biochar samples mainly existed as Zn-OM (53%-76%) and Zn₂SiO₄ (21%-47%), while the proportion of Zn₂SiO₄ (0-6%) was negligible compared with Zn-Al silicate (26-48%) in the mixtures. The overall findings confirmed that Al released from γ-Al₂O₃ was sorbed in parallel with Zn on biochar to form Zn-Al silicate, rather than Zn-Al LDH on the γ-Al₂O₃ surface. These results unveiled the dynamic interactions between amended biochar and soil oxide minerals which can significantly affect the immobilization pathways of metals in contaminated soils.

Keywords: Black carbon; Chemical stabilization; Soil remediation; Synchrotron; Zinc immobilization.

Publication types

Evaluation Study
Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Aluminum Oxide / analysis
Aluminum Oxide / chemistry*
Charcoal / analysis
Charcoal / chemistry*
Microscopy, Electron, Scanning
Oryza
Zinc / isolation & purification*

Substances

biochar
Charcoal
Zinc
Aluminum Oxide