0
Article Tier 2 Marine & Wildlife Sign in to save

Long-term phototransformation of microplastics under simulated sunlight irradiation in aquatic environments: Roles of reactive oxygen species

Water Research 2020 580 citations

AI summary Read the abstract

Researchers examined the long-term photodegradation of polystyrene microplastics under simulated sunlight in aquatic conditions, finding that reactive oxygen species — particularly hydroxyl radicals and singlet oxygen — were the primary drivers of surface oxidation and fragmentation into nanoplastics.

Polymers

Microplastics may experience photoaging and breakdown into nanoplastics in aquatic environment as a result of long-term light irradiation. However, the underlying mechanisms responsible for the photodegradation of microplastics are largely overlooked. In this study, the photodegradation of microplastics, utilizing polystyrene microplastic (PS-MP) as a model, was investigated under irradiation with simulated solar light for as long as 150 d. A large amount of reactive oxygen species (ROS), including O, O, HO and •OH, were detected in the PS-MP suspension due to light irradiation, which displayed significant relationships with the generated environmentally persistent free radicals (EPFRs). Distinct photoaging of PS-MP was observed with increased surface roughness and decreased particle size. However, these photoaging effects were significantly inhibited by ROS quenchers, suggesting that the generation ROS played a vital role in the PS-MP phototransformation. In addition, ROS induced formation of more oxidative functional groups on the PS-MP, thus enhancing the negative surface potential and the stability of PS-MP in water. This study elucidated the mechanism of formation of ROS by simulated solar light irradiated MPs and their subsequent roles in the phototransformation of MP, thus expanding current knowledge on the fate of MPs in aquatic environments.

More Papers Like This

Article Tier 2

ROS-mediated photoaging pathways of nano- and micro-plastic particles under UV irradiation

AI summary Read the abstract

Researchers investigated the role of reactive oxygen species in the photoaging of nano- and micro-plastic particles under UV irradiation. The study found that bare polystyrene nanoparticles generated hydroxyl radicals and singlet oxygen, while surface coatings and larger particle sizes reduced ROS generation. The findings help explain the mechanisms by which UV exposure breaks down plastic particles in aquatic environments.

Article Tier 2

Dissolved Organic Matter Promotes the Aging Process of Polystyrene Microplastics under Dark and Ultraviolet Light Conditions: The Crucial Role of Reactive Oxygen Species

AI summary Read the abstract

Researchers found that dissolved organic matter commonly present in natural water environments accelerates the aging and degradation of polystyrene microplastics under both dark and ultraviolet light conditions. The study identified reactive oxygen species as the crucial driver of this aging process, with fulvic acid showing a stronger effect than humic acid due to its greater ability to generate semiquinone radicals.

Article Tier 2

Microplastic removal from urban stormwater: Current treatments and research gaps

AI summary Read the abstract

Researchers investigated the phototransformation of polystyrene microplastics under simulated solar radiation, finding surface oxidation and formation of carbonyl groups after UV exposure. Photo-aged particles showed increased release of dissolved organic carbon and greater toxicity to marine copepods.

Article Tier 2

Effects of photochlorination on the physicochemical transformation of polystyrene nanoplastics: Mechanism and environmental fate

AI summary Read the abstract

Researchers studied how sunlight combined with chlorine in water treatment changes the properties of polystyrene nanoplastics. They found that solar irradiation significantly accelerated the chemical breakdown of the nanoplastics, including surface oxidation and the release of organic compounds. The study reveals that nanoplastics leaving wastewater treatment plants undergo rapid transformation in the environment, which could alter both their fate and toxicity.

Article Tier 2

Which factors mainly drive the photoaging of microplastics in freshwater?

AI summary Read the abstract

This study systematically investigated the roles of UV irradiation, oxygen, temperature, and physical abrasion in the photoaging of polystyrene microplastics in freshwater. UV irradiation and mechanical abrasion were identified as the dominant aging factors, and their combined effect caused more extensive surface oxidation and fragmentation than either alone.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper