Metals and suspended solids in the effluents from in-water hull cleaning by remotely operated vehicle (ROV): Concentrations and release rates into the marine environment

Zhi Yang Soon; Taekhyun Kim; Jee-Hyun Jung; Moonkoo Kim

doi:10.1016/j.jhazmat.2023.132456

Metals and suspended solids in the effluents from in-water hull cleaning by remotely operated vehicle (ROV): Concentrations and release rates into the marine environment

J Hazard Mater. 2023 Oct 15:460:132456. doi: 10.1016/j.jhazmat.2023.132456. Epub 2023 Sep 1.

Authors

Zhi Yang Soon¹, Taekhyun Kim², Jee-Hyun Jung², Moonkoo Kim³

Affiliations

¹ Risk Assessment Research Center, Korea Institute of Ocean Science and Technology, 41 Jangmok 1-gil, Geoje 53201, Republic of Korea; Ocean Science, University of Science and Technology, 217 Gajeong-ro, Daejeon 34113, Republic of Korea; Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, 146 Williams St., Solomons, MD 20688, United States.
² Risk Assessment Research Center, Korea Institute of Ocean Science and Technology, 41 Jangmok 1-gil, Geoje 53201, Republic of Korea; Ocean Science, University of Science and Technology, 217 Gajeong-ro, Daejeon 34113, Republic of Korea.
³ Risk Assessment Research Center, Korea Institute of Ocean Science and Technology, 41 Jangmok 1-gil, Geoje 53201, Republic of Korea; Ocean Science, University of Science and Technology, 217 Gajeong-ro, Daejeon 34113, Republic of Korea. Electronic address: mkim@kiost.ac.kr.

PMID: 37708650
DOI: 10.1016/j.jhazmat.2023.132456

Abstract

An increase in the use of ROVs for in-water hull cleaning (IWC) has led to the need to understand the risks to the marine environment posed by the release of IWC effluents. The primary objective of this research is to investigate the characteristics of wastewater generated during IWC, specifically concerning suspended solids (SS) and metal concentrations, and their release rates and total load to the environment. The IWC effluents contain substantial amounts of SS and metals, with Cu and Zn being the most prevalent. These metals are predominantly associated with fine antifouling paint particles, posing a potential risk of secondary pollution upon release into the marine environment. While the treatment systems demonstrated effectiveness in reducing SS and particulate metals, achieving complete removal of dissolved and particulate metals below ambient levels proved to be challenging. To mitigate environmental risks, this study proposes, based on the particle size analysis, the implementation of multistage filtration systems with an optimal filtration pore size for the effluent treatment. In conclusion, we highlight the potential environmental risks of IWC activities. As most metals have a strong affinity towards particles in wastewater, effective removal of particles is essential to alleviate environmental stress at IWC sites.

Keywords: Antifouling paint particle; Environmental risk; Leaching; Marine ecosystem; Particle size distribution.