The competition of heavy metals between hyporheic sediments and microplastics of driving factors in the Beiluo River Basin

Bingjie Li; Ruichen Mao; Zeyu Chen; Yuting Zhang; Jinxi Song; Nan Li; Bin Tang; Jiayuan Feng; Mingchang Guan

doi:10.1016/j.jhazmat.2024.134538

The competition of heavy metals between hyporheic sediments and microplastics of driving factors in the Beiluo River Basin

J Hazard Mater. 2024 May 11:473:134538. doi: 10.1016/j.jhazmat.2024.134538. Online ahead of print.

Authors

Bingjie Li¹, Ruichen Mao¹, Zeyu Chen¹, Yuting Zhang¹, Jinxi Song², Nan Li¹, Bin Tang¹, Jiayuan Feng¹, Mingchang Guan¹

Affiliations

¹ Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China.
² Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China; Yellow River Institute of Shaanxi Province, Northwest University, Xi'an 710127, China. Electronic address: jinxisong@nwu.edu.cn.

PMID: 38761759
DOI: 10.1016/j.jhazmat.2024.134538

Abstract

Both sediments and microplastics (MPs) are medias of heavy metals (HMs) in river ecosystems. This study investigated HMs (Mn, Cr, V, As, Cu, Co, Cd, Pb, and Ni) concentration and driving factors for competitive enrichment between hyporheic sediments versus MPs. The medias basic characteristics indicated that the sediments were mostly sand and rich in Fe₂O₃; three polymer types were identified, with blue, fragment, less than 500 µm being the main types of MPs. The results have shown that the average content of extracted HMs in MPs was much higher than that of the same metals accumulated in sediments. HMs in sediments and MPs reached heavily polluted at some points, among which As and Cd were ecological risks. Electrostatic adsorption and surface complexation, and biofilm-mediated and organic matter complexation were the interaction mechanism of HMs with sediments and MPs. Further, the driving factors affecting the distribution of HMs in the two carriers were analyzed by multivariate statistical analysis. The results demonstrated that carrier characteristics, hydrochemical factors, and the inherent metal load of MPs were the main causes of the high HMs content. These findings improved our understanding of HMs fate and environmental risks across multiple medias.

Keywords: Driving factors; Heavy metals; Hyporheic zone; Microplastics; Sediments.