Work

Transport of Fe‐Based Nanoparticles in Porous Media Facilitated by Xanthan Gum: Non‐Monotonic Relation Between Transport Efficiency and Flow Velocity

Year: 2025

Type: article

Abstract: The transport of Fe‐based nanoparticles (Fe‐NPs) in porous media is of vital importance for application of Fe‐NPs in groundwater remediation, yet their low mobility remains an open question. Here, we conducted column and microfluidic transport experiments combined with rheology experiments and model simulations to investigate the effect of xanthan gum (XG) on the transport of two types of Fe‐NPs (nanoparticles of Fe 3 O 4 ( n Fe 3 O 4 ) and zero‐valent iron ( n ZVI)) in quartz sand at different input concentrations and flow velocities. We observed that the rheological modification of water by XG significantly enhanced the transport of both Fe‐NPs, and the transport of n ZVI was better than that of n Fe 3 O 4 . With the increase of input concentration of Fe‐NPs, the transport of n ZVI slightly declined, whereas the transport of n Fe 3 O 4 initially increased and then decreased. The different responses of transport of n Fe 3 O 4 and n ZVI to input concentrations were attributed to the unique shear‐thinning rheological properties of XG suspensions with each type of Fe‐NPs. We observed a novel non‐monotonic relation between transport efficiency and flow velocity, where the transport of both Fe‐NPs initially weakened and then enhanced as pore‐water velocity rose within a certain range. We demonstrated that the formation of a non‐flowing layer of XG on the surface of the porous medium was identified as the mechanism responsible for the non‐monotonic transport behavior. These findings provide new insights into transport behavior of Fe‐NPs in porous media under the rheological remediation of XG, and have practical implications for application of Fe‐NPs in groundwater remediation.

Source: Water Resources Research

DOI: 10.1029/2024wr039225

Authors: Guansheng Liu, Lili Huo, Yongming Wu, Zhibing Yang, Jiacheng Xia, Hua Zhong

Institutions: Eastern Institute of Technology, Ningbo, Wuhan University, Jiangxi Academy of Sciences

Language: English

Topic: Environmental remediation with nanomaterials

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,000

Funders: National Natural Science Foundation of China, Natural Science Foundation of Hubei Province, Natural Science Foundation of Ningbo