0
Article Tier 2 Environmental Sources Marine & Wildlife Remediation Sign in to save

Comprehensive Understanding on the Aging Process and Mechanism of Microplastics in the Sediment–Water Interface: Untangling the Role of Photoaging and Biodegradation

Environmental Science & Technology 2024 36 citations

AI summary Read the abstract

Researchers examined how microplastics break down at the boundary between water and sediment in coastal wetlands, comparing the roles of sunlight-driven aging and biological degradation. They found that photoaging was the dominant process, accounting for over 55% of surface changes, and that biodegradable plastics aged faster than conventional ones. The study provides important insights into how microplastics transform in real-world coastal environments.

Study Type Environmental

Microplastics (MPs) in coastal wetlands have been of great concern, but information on the aging behavior of MPs in the sediment-water interface is still lacking. In this study, the contribution of a typical abiotic (photoaging) and biotic (biodegradation) process and the underlying aging pathway of MPs with different degradabilities (including polypropylene, polyethylene terephthalate, and polylactic acid) were studied. With a quantified relative importance of photoaging (>55%) vs biodegradation, the crucial contribution of photoaging on MP aging was highlighted. This was likely attributed to more generation of reactive oxygen species (ROS) under sunlight irradiation conditions, containing O2•- and H2O2. By raising higher the level of malondialdehyde (0.5-3.5 times as high as that in the dark condition), these photochemically formed ROS caused oxidative stress and inhibited the selective attachment of plastic-degrading microbes on the MP surface, thereby weakening the effect of biodegradation. On this basis, the aging characteristics and potential pathway of different MPs were revealed. The functional group of nondegradable polypropylene tends to be broken by ROS first, while biodegradation (Arthrobacter oryzae and Bacillus sp.) played a relatively dominant role in biodegradable polylactic acid. This study provides a new sight for the understanding on the aging behaviors of MPs in the sediment-water interface.

More Papers Like This

Article Tier 2

Novel insight into the aging process of microplastics: An in-situ study in coastal wetlands

AI summary Read the abstract

Scientists tracked how microplastics age and break down in a coastal wetland in China over three months and found that both sunlight and microbial communities work together to degrade the plastic surfaces. Different plastic types broke down at very different rates, with estimated lifespans ranging from 335 to 661 days before significant degradation. This research helps predict how long microplastics persist in coastal environments that are important for fisheries and human food sources.

Article Tier 2

Weathering Processand Characteristics of Microplasticsin Coastal Wetlands: A 24-Month In Situ Study

AI summary Read the abstract

Researchers conducted a 24-month study of microplastic weathering in coastal wetlands, characterizing how wetland-specific conditions including UV exposure, salinity, and biological activity alter plastic surface chemistry, fragmentation, and biofilm colonization over time.

Article Tier 2

Distribution and Biological Response of Nanoplastics in Constructed Wetland Microcosms: Mechanistic Insights into the Role of Photoaging

AI summary Read the abstract

This study looked at how sunlight aging changes the behavior of nanoplastics in wetland ecosystems. Researchers found that sun-aged nanoplastics accumulated differently in plants, water, and soil compared to fresh ones, and caused stronger biological responses in wetland organisms, suggesting that weathered nanoplastics in the environment may be more harmful than previously thought.

Article Tier 2

Photoaging mechanism of microplastics: a perspective on the effect of dissolved organic matter in natural water

AI summary Read the abstract

This perspective paper examines how microplastics in natural water photoage under UV irradiation via reactive oxygen species generation, breaking down polymer bonds, and explores how dissolved organic matter may accelerate or alter these aging pathways. Understanding photoaging is critical because it fragments plastics into smaller and more biologically available nanoplastics while releasing toxic chemical additives into aquatic ecosystems.

Article Tier 2

Progress on the photo aging mechanism of microplastics and related impact factors in water environment

AI summary Read the abstract

This review examined the photo-aging mechanisms of microplastics in aquatic environments, finding that solar UV radiation drives oxidation reactions that alter surface chemistry, fragment particles further, and enhance their capacity to adsorb and release co-occurring pollutants.

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