The evolution of stable nanohybrids to complex heteroaggregates between nZVI and soil nanoparticles: The influence of ionic strength and soil components

Wenpei Wu; Xueyan Chen; Lu Han; Lei Yang; Mingyue Gu; Jing Li; Mengfang Chen

doi:10.1016/j.jhazmat.2022.129155

The evolution of stable nanohybrids to complex heteroaggregates between nZVI and soil nanoparticles: The influence of ionic strength and soil components

J Hazard Mater. 2022 Aug 15:436:129155. doi: 10.1016/j.jhazmat.2022.129155. Epub 2022 May 16.

Authors

Wenpei Wu¹, Xueyan Chen¹, Lu Han², Lei Yang¹, Mingyue Gu³, Jing Li⁴, Mengfang Chen⁵

Affiliations

¹ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Science, Beijing 100049, China; Jiangsu Engineering Laboratory for Soil and Groundwater Remediation of Contaminated Sites, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
² Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Jiangsu Engineering Laboratory for Soil and Groundwater Remediation of Contaminated Sites, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: hanlu@issas.ac.cn.
³ Nanjing Kaiye Environmental Technology Co Ltd, 8 Yuanhua Road, Innovation Building 106, Nanjing University Science Park, Nanjing 210034, China.
⁴ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
⁵ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Jiangsu Engineering Laboratory for Soil and Groundwater Remediation of Contaminated Sites, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: mfchen@issas.ac.cn.

PMID: 35596993
DOI: 10.1016/j.jhazmat.2022.129155

Abstract

The heteroaggregation mechanism of nZVI with four types of natural soil nanoparticles (SNPs) extracted from representative soils in northern and southern China was investigated. Heteroaggregation rates between nZVI and SNPs were quantified by dynamic light scattering and evaluated as a function of ionic strength at pH 7. The nZVI-SNPs heteroaggregates were stable with hydrodynamic diameters (D_h) ranging from 400 to 600 nm in 0.1 mM solution. Based on the extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, nZVI underwent heteroaggregation with SNPs to form stable nZVI-SNPs nanohybrid due to the attachment of nZVI on the SNPs. However, with enhanced ionic strength, SNPs accelerated the aggregation of nZVI and formed large heteroaggregates with D_h in the range from 1200 to 2000 nm, owing to insignificant electrostatic repulsions and oppositely charged patches. In addition, the differences in the heteroaggregation rates of nZVI with four SNPs were negligible, caused by the negligible impacts of SNPs components such as soil organic matter and Fe/Al oxyhydroxides on the heteroaggregation of nZVI in the 10 mM NaCl solution. These findings are helpful for understanding the interaction between nZVI and SNPs and of significance to groundwater remediation using nZVI.

Keywords: Heteroaggregation; Ionic strength, Extended DLVO theory; NZVI; Soil nanoparticles.

Publication types

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

MeSH terms

China
Nanoparticles*
Osmolar Concentration
Soil*
Static Electricity

Substances

Soil