0
Article Tier 2 Sign in to save

Molecular transformation and photochemical reactivity of microplastic-derived dissolved organic matter on goethite: Implications for persistence and reactive oxygen species dynamics

Water Research 2025 7 citations

AI summary Read the abstract

Researchers investigated how microplastic-derived dissolved organic matter interacts with the mineral goethite and how this affects its photochemical reactivity. They found that different plastic types produced distinct chemical behaviors: polystyrene-derived matter underwent sulfonation that enhanced reactive oxygen species formation, while polyethylene-derived matter remained relatively inert. The study suggests that microplastic-derived organic matter persists differently in soil depending on its polymer origin and mineral interactions.

Polymers

Microplastics (MPs)-derived dissolved organic matter (MPs-DOM) is emerging as a significant contributor to environmental DOM pools. However, the molecular-scale processes governing its interactions with mineral and their effects on photoreactivity remain poorly understood. This study elucidates the structure-dependent molecular transformations and photochemical reactivity of DOM during its interaction with goethite, revealing distinct mechanisms driving reactive oxygen species (ROS) dynamics. Hydroxyl radical (•OH) production universally declined as goethite adsorbed electron-donating groups. Singlet oxygen (O) remained stable due to the presence of persistent aromatic photosensitizers. Triplet-excited DOM (DOM*) exhibited divergent trends: humic acid (HA) and polybutylene adipate terephthalate (PBAT)-DOM showed decreases due to aromatic core adsorption, while fulvic acid (FA) and polystyrene (PS)-DOM exhibited increases driven by humification-stabilized quinoid systems and sulfonation-enhanced conjugation, respectively. The aliphatic inertia of polyethylene (PE)-DOM minimized ROS fluctuations. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) indicated that HA retained lignin-like components and stable sulfur/nitrogen heterocycles, while FA preserved branched quinones. PS-DOM underwent sulfonation, generating benzene sulfonates that enhanced O formation, whereas PBAT-DOM hydrolyzed to nitrogenous metabolites that suppressed •OH production. PE-DOM remained structurally resistant, consistent with its hydrophobic aliphatic chains. These findings emphasize that goethite's selective adsorption enriches redox-active aromatics in natural DOM but promotes the persistence of MPs-DOM through sulfurization and nitrogenization.

More Papers Like This

Article Tier 2

Molecular-Scale Insights into the Surface Structural Transformation and Light-Driven Production of Reactive Oxygen Species of Goethite Induced by Microplastic-Derived Dissolved Organic Matter

AI summary Read the abstract

Researchers investigated how dissolved organic matter released from degrading microplastics interacts with the iron mineral goethite and affects the production of reactive oxygen species under sunlight. They found that microplastic-derived organic matter behaves differently from natural organic matter, producing distinct patterns of chemical reactivity on mineral surfaces. The study reveals a previously unrecognized way that microplastic degradation products can alter environmental chemistry.

Article Tier 2

Molecular-ScaleInsights into the Surface StructuralTransformation and Light-Driven Production of Reactive Oxygen Speciesof Goethite Induced by Microplastic-Derived Dissolved Organic Matter

AI summary Read the abstract

Researchers used molecular-scale analysis to investigate how microplastic-derived dissolved organic matter transforms the surface structure of goethite and alters its light-driven production of reactive oxygen species, revealing previously unclear interactions between plastic-derived organic matter and iron minerals.

Article Tier 2

Phototransformation of microplastic derived dissolved organic matter reduces its adsorption capacity on ferrihydrite: Effects of additive types

AI summary Read the abstract

Researchers studied how sunlight-driven phototransformation of dissolved organic matter released by microplastics affects its ability to bind to iron minerals in sediments. The study found that phototransformation significantly reduced the adsorption capacity of microplastic-derived organic matter on ferrihydrite, with the type of plastic additive playing a key role in determining the extent of this change.

Article Tier 2

Insights into the photosensitivity and photobleaching of dissolved organic matter from microplastics: Structure-activity relationship and transformation mechanism

AI summary Read the abstract

This study investigated the photosensitivity and photobleaching behavior of dissolved organic matter released from microplastics (MPDOM), examining how physicochemical properties of different plastics influence photoactivation and transformation. The structure-activity analysis revealed that MPDOM composition strongly determines its photoreactivity, affecting how microplastic-derived organic compounds interact with sunlight and generate reactive oxygen species in aquatic environments.

Article Tier 2

Photochemistry of microplastics-derived dissolved organic matter: Reactive species generation and organic pollutant degradation

AI summary Read the abstract

Researchers investigated how dissolved organic matter released from degrading polystyrene and PVC microplastics behaves when exposed to sunlight in water. They found that sunlight breaks down the aromatic compounds in this plastic-derived material and generates reactive chemical species, though at lower rates than natural organic matter. Despite this, these reactive species significantly accelerated the breakdown of co-existing pollutants, suggesting that degrading microplastics may act as unexpected natural catalysts in aquatic environments.

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