Impact of humic acid on iron (oxyhydr)oxide transport in the presence of phosphate in saturated porous media.

Autor: Shah T; College of Land Science and Technology, China Agricultural University, Beijing 100193, PR China., Zhao K; College of Land Science and Technology, China Agricultural University, Beijing 100193, PR China; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China. Electronic address: zhaok3@sustech.edu.cn., Yin Y; College of Land Science and Technology, China Agricultural University, Beijing 100193, PR China., Shang J; College of Land Science and Technology, China Agricultural University, Beijing 100193, PR China. Electronic address: jyshang@cau.edu.cn.
Jazyk: angličtina
Zdroj: Journal of contaminant hydrology [J Contam Hydrol] 2024 Nov; Vol. 267, pp. 104444. Date of Electronic Publication: 2024 Oct 11.
DOI: 10.1016/j.jconhyd.2024.104444
Abstrakt: The subsurface flow of particular phosphate (P) has been recently regarded as a vital P transport path. Humic acid (HA) and P usually coexist in the natural environment and show a strong affinity to iron (Fe) (oxyhydr)oxide. The impact of P and HA on Fe (oxyhydr)oxide stability and transport is critical for evaluating the vertical transport of particular P and biogeochemical processes of Fe and P. This study investigated the effect of inorganic (IP) and organic (OP) phosphate on the stability and transport of ferrihydrite and goethite with HA through stability tests and column experiments. The adsorption of IP or OP on Fe (oxyhydr)oxide enhanced the stability and transport of Fe (oxyhydr)oxide, and OP showed a stronger enhancement than IP due to its stronger binding capacity and more negative surface. Compared with ferrihydrite, goethite had fewer adsorption sites for IP or OP and showed strong stability and transport at low IP (50 μM) or OP (10 μM) concentration. HA decreased IP or OP adsorption on Fe (oxyhydr)oxide through competition adsorption and electrostatic repulsion. The formed ternary phosphate-Fe (oxyhydr)oxide-HA complex showed a more negative surface and strong stability and transport. Our findings provide direct insights into the distinct role of IP and OP on Fe (oxyhydr)oxide stability and transport in the presence of HA, which provides essential information for evaluating the transport of particular Fe (oxyhydr)oxide-facilitated P in soils and subsurface environments rich in iron, phosphate, and dissolved carbon.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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