Nano-ferrihydrite colloidal particles mediated interfacial interactions of arsenate and cadmium: Implications for their fate under iron-rich geological settings

Bingyu Li; Dongning Wei; Miaomiao Jing; Yimin Zhou; Yayuan Huang; Caleb Oppong Mensah; Jiumei Long; Boqing Tie; Ming Lei

doi:10.1016/j.jhazmat.2023.130755

Nano-ferrihydrite colloidal particles mediated interfacial interactions of arsenate and cadmium: Implications for their fate under iron-rich geological settings

J Hazard Mater. 2023 Apr 5:447:130755. doi: 10.1016/j.jhazmat.2023.130755. Epub 2023 Jan 11.

Authors

Bingyu Li¹, Dongning Wei², Miaomiao Jing¹, Yimin Zhou¹, Yayuan Huang¹, Caleb Oppong Mensah¹, Jiumei Long³, Boqing Tie¹, Ming Lei⁴

Affiliations

¹ College of Resource and Environment, Hunan Agricultural University, Changsha 410128, PR China; Hunan Engineering and Technology Research Center for Irrigation Water Purification, Changsha 410128, PR China.
² College of Resource and Environment, Hunan Agricultural University, Changsha 410128, PR China.
³ College of Life Sciences and Environment, Hengyang Normal University, Hengyang 421008, PR China.
⁴ College of Resource and Environment, Hunan Agricultural University, Changsha 410128, PR China; Hunan Engineering and Technology Research Center for Irrigation Water Purification, Changsha 410128, PR China. Electronic address: leiming@hunau.edu.cn.

PMID: 36640511
DOI: 10.1016/j.jhazmat.2023.130755

Abstract

Arsenic (As) and cadmium (Cd) often coexist in paddy soils. Nano-ferrihydrite colloidal particles (NFPs) are ubiquitous at redox active interfaces of the paddy system and are well-known to play a critical role in controlling the solubility and bio-availability of As and Cd. However, the mutual interaction between As and Cd on NFPs remains elusive. Herein, batch experiments and in-situ spectroscopic techniques were used to investigate the effects of the interaction pattern (sequential reaction) of Cd(II) and As(V) on their respective adsorption on the surfaces of NFPs. Two scenarios were designed: Cd(II) pre-saturated NFPs and As(V) pre-saturated NFPs. Adsorption of Cd(II) was increased by 1.67, 4.08, and 5.21 times in As(V)-saturated NFPs, but only by 1.05, 1.11, and 1.15 times for As(V) in Cd(II)-saturated NFPs. Further, we determined the pH-dependent mutually beneficial cooperation pathways as mediated by the surface of NFPs. At lower pH (5), As(V) tended to promote Cd(II) adsorption, whereas Cd(II) tended to enhance As(V) adsorption at higher pH (> 5.5). X-ray photoelectron spectroscopy (XPS) indicated that both pre-saturated Cd(II) and As(V) altered the local coordination environment of their counterpart ions. Furthermore, results from in-situ attenuated total reflection-Fourier-transform infrared spectroscopy (ATR-FTIR) and second derivative peak shape fitting revealed two types of ternary surface complexes, namely Cd(II)-bridged and As(V)-bridged complexes, which were responsible for the distinct Cd(II) and As(V) co-adsorption behavior on the surface of NFPs under different conditions. These findings help us understand how co-presence Cd and As behave in an iron-rich geological setting and will aid in the development of related restoration technologies.

Keywords: Adsorption; Arsenic; Cadmium; Sequential reaction; Ternary surface complexes.