Mechanisms of propeller jet-induced migration, release, and distribution of perfluoroalkyl acids in sediment-water systems

Yixin Ma; Zulin Hua; Peng Wang; Yundong Yang; Yueyang Dong; Liang Yu

doi:10.1016/j.watres.2023.120048

Mechanisms of propeller jet-induced migration, release, and distribution of perfluoroalkyl acids in sediment-water systems

Water Res. 2023 Jun 30:238:120048. doi: 10.1016/j.watres.2023.120048. Epub 2023 May 4.

Authors

Yixin Ma¹, Zulin Hua², Peng Wang³, Yundong Yang⁴, Yueyang Dong¹, Liang Yu¹

Affiliations

¹ Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China.
² Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; Yangtze Institute for Conservation and Development, Hohai University, Nanjing 210098, PR China.
³ Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China. Electronic address: hhwp@hhu.edu.cn.
⁴ Jiangsu Environmental Engineering Technology Co., Ltd, Nanjing 210098, PR China.

PMID: 37159963
DOI: 10.1016/j.watres.2023.120048

Abstract

Perfluoroalkyl acids (PFAAs) are continuously accumulated in surface sediments due to extensive and long-term application. However, the mechanisms through which disturbances induced by ship propeller jets at the riverbed cause secondary release of PFAAs from sediments remain unclear. In this study, the effects of different propeller rotational speeds on PFAA migration, release, and distribution in multiphase media were investigated by performing indoor flume experiments combined with particle tracking velocimetry. Moreover, key factors influencing PFAA migration and distribution were identified, and partial least squares regression (PLS) method was applied to develop quantitative prediction models of relationships among hydrodynamics, physicochemical parameters, and PFAA distribution coefficients. The total PFAA concentrations (ΣPFAAs) in overlying water under propeller jet action exhibited transient characteristics and hysteresis with time after the disturbance. In contrast, the ΣPFAAs in suspended particulate matter (SPM) exhibited an upward trend throughout the process with consistent characteristics. The spatial distribution trends of PFAAs in overlying water and SPM at different propeller rotational speeds featured vertical variability and axial consistency. Furthermore, PFAA release from sediments was driven by axial flow velocity (V_x) and Reynolds normal stress R_yy, while PFAA release from porewater was inextricably linked to Reynolds stresses R_xx, R_xy, and R_zz (p < 0.05). PLS regression models showed that variations in Vorticity, dissolved organic carbon, and pH influenced the decreases in PFAA distribution coefficients between SPM and overlying water (K_D-SW) as propeller rotational speed increased, except for very long-chain PFAAs (C > 10). The increases in PFAA distribution coefficients between sediment and porewater (K_D-SP) were mainly determined by physicochemical parameters of sediments, and the direct effect of hydrodynamics was relatively weak. Our study provides valuable information regarding the migration and distribution of PFAAs in multiphase media under propeller jet disturbance (both during and after disturbance).

Keywords: Environmental fate; Hydrodynamic disturbance; Multiphase distribution; PFAAs; Particle tracking velocimetry.

MeSH terms

Alkanesulfonic Acids* / analysis
Environmental Monitoring
Fluorocarbons* / analysis
Hydrodynamics
Particulate Matter
Water
Water Pollutants, Chemical* / analysis

Substances

Water
Water Pollutants, Chemical
Fluorocarbons
Particulate Matter
Alkanesulfonic Acids