Field evidence and modeling validation of biogeochemical controls on the deposition of persistent organic pollutants in the deep ocean

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Author(s)

  • Mengyang Liu
  • Haowen Zheng
  • Hongliang Li
  • Fajin Chen
  • Linghao Lou
  • Weimin Wang
  • Haifeng Zhang
  • Chunqing Chen
  • Jiandong Ye
  • Minggang Cai

Detail(s)

Original languageEnglish
Article number136395
Journal / PublicationJournal of Hazardous Materials
Volume480
Online published4 Nov 2024
Publication statusPublished - 5 Dec 2024

Abstract

Deposition in the deep ocean plays a crucial role in the global sink of persistent organic pollutants (POPs), yet observation-based assessments of their biogeochemical cycling are scarce. In this study, surface sediments were collected from deep sea of the Eastern Indian Ocean (2161–4545 m) and analyzed for organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). Long-range atmospheric transport was identified as the dominant pathway for OCPs (36.7–762.0 pg/g) and PCBs (25.5–110.0 pg/g) to reach the basin area from surrounding agricultural, manufacturing, and combustion emissions. Besides the TOC-dependent deposition, unique hydrodynamic conditions in the mid-ocean ridge might influence the transport and accumulation of POPs by altering their resuspension and repartitioning processes. Results of the machine learning analysis suggested that logKOW, TOC content, and pollutant residence time in the ocean are important parameters in determining PCB concentrations in the Indian Ocean. Additionally, concentrations of POPs generally exhibited logarithmic relationships with microplastic abundances, indicating that microplastics act as potential carriers for transporting these pollutants to deep-sea sediments. This study revealed the biogeochemical controls on the deposition of OCPs and PCBs in the Indian Ocean by combining field observation and model simulation. Given the rapid rate of surface warming and various biogeochemical responses in the Indian Ocean, it is recommended to conduct long-term, high-resolution field observations to understand the dynamic fate of POPs in these changing ocean environments. © 2024 Elsevier B.V.

Research Area(s)

  • Bay of Bengal, Marine sediments, Ninetyeast Ridge, Persistent toxic substances (PTSs), Random Forest Model

Citation Format(s)

Field evidence and modeling validation of biogeochemical controls on the deposition of persistent organic pollutants in the deep ocean. / Liu, Mengyang; Zheng, Haowen; Li, Hongliang et al.
In: Journal of Hazardous Materials, Vol. 480, 136395, 05.12.2024.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review