Impact of Microplastics on Oil Dispersion Efficiency in the Marine Environment

Min Yang,Yifu Chen,Xiaying Xin,Baiyu Zhang,Kenneth Lee,Bing Chen

doi:10.3390/su132413752

Min Yang, Yifu Chen + Show 4 more

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https://doi.org/10.3390/su132413752

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Abstract

Oil spill and microplastics (MPs) pollution has raised global concerns, due to the negative impacts on ocean sustainability. Chemical dispersants were widely adopted as oil-spill-treating agents. When MPs exist during oil dispersion, MP/oil-dispersant agglomerates (MODAs) are observed. This study explored how MPs affect oil-dispersion efficiency in oceans. Results showed that, under dispersant-to-oil volumetric ratio (DOR) 1:10 and mixing energy of 200 rpm, the addition of MPs increased the oil droplet size, total oil volume concentration, and oil-dispersion efficiency. Under DOR 1:25 and mixing energy of 120 rpm, the addition of MPs increased the oil droplet size but resulted in a decrease of total oil volume concentration and dispersion efficiency. Compared with the oil volume concentration, the oil droplet size may no longer be an efficient parameter for evaluating oil-dispersion efficiency with the existence of MODAs. A machine learning (ML)-based XGBRegressor model was further constructed to predict how MPs affected oil volume concentration and oil-dispersion efficiency in oceans. The research outputs would facilitate decision-making during oil-spill responses and build a foundation for the risk assessment of oil and MP co-contaminants that is essential for maintaining ocean sustainability.

Highlights

Accepted: 11 December 2021Microplastics (MPs), defined as plastic particles between 1 and 5000 μm in size, have been widespread in the marine environment [1,2]
The surface morphology of MPs and MP/oil-dispersant agglomerates (MODAs) was observed through an scanning electron microscopy (SEM)
The results showed that, under dispersant-to-oil volumetric ratio (DOR) 1:10 and mixing energy of 200 rpm, the oil droplet size and volume concentration decreased first and increased with the addition of MPs

Summary

Introduction

Microplastics (MPs), defined as plastic particles between 1 and 5000 μm in size, have been widespread in the marine environment [1,2]. They can transfer from the seawater surface to deep-sea [3,4,5]. MPs could serve as vectors for organic contaminants owing to their strong hydrophobicity and large specific surface area [8]. Rainbowfish (Melanotaenia fluviatilis) could accumulate the MPs and sorbed polybrominated diphenyl ethers (PBDEs) co-contaminants to a high concentration after 21 days of exposure [10]. The larvae growth of zebrafish was negatively affected by the accumulation of the MPs and butylated hydroxyanisole (BHA)

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