0
Article Tier 2 Sign in to save

Enhanced alteration of poly(vinyl chloride) microplastics by hydrated electrons derived from indole-3-acetic acid assisted by a common cationic surfactant

Water Research 2020 22 citations

AI summary Read the abstract

Researchers developed a photo-reductive process that uses hydrated electrons under light exposure to break down PVC microplastics by removing chlorine atoms from the polymer. This novel degradation pathway could offer a new approach for treating PVC — one of the most environmentally persistent and problematic plastic types — in contaminated environments.

Polymers

In this study, a new photo-irradiated reductive dechlorination pathway and the underlying transformation mechanism are described for poly(vinyl chloride) microplastics (PVC-MPs). PVC-MPs underwent photo-reductive dechlorination process with the release of chloride ions. This reaction could be facilitated in the presence of indole-3-acetic acid (IAA) and hexadecyltrimethylammonium bromide (CTAB) under neutral pH and simulated sunlight irradiation conditions. Electrostatic interaction between IAA and CTAB produced neutral IAA/CTAB complex, which might account for the enhanced adsorption of IAA on PVC powders. Upon photo-irradiation, the adsorbed IAA was excited to generate hydrated electrons (e), which could pass through a shorter distance to PVC-MP surface than that derived from homogeneous IAA molecules in aqueous solution. Transient spectra of laser flash photolysis provided direct evidence for the generation of e, which supported the proposed dechlorination mechanism. Based on the results of attenuated total reflectance/Fourier transform infrared (ATR/FTIR) and Raman spectra, C-Cl bond cleavage and polyene formation were involved in the structural transformation of PVC-MPs. Due to the hydrophobic effects and π-π interactions between aromatic rings and polyene structures in PVC-MP surface, the PVC-MP powders irradiated in the presence of IAA/CTAB showed an enhanced sorption for both hydrophobic and hydrophilic aromatic chemicals.

More Papers Like This

Article Tier 2

Photo-aging of polyvinyl chloride microplastic in the presence of natural organic acids

AI summary Read the abstract

Researchers described a new photo-aging pathway for polyvinyl chloride microplastics in aquatic environments involving low-molecular-weight organic acids. The study found that natural organic acids and their iron complexes significantly accelerated the degradation of PVC microplastics under sunlight through hydroxyl radical generation, revealing how environmental conditions influence microplastic weathering.

Article Tier 2

The Aging Behavior of Polyvinyl Chloride Microplastics by UV/Sodium Percarbonate Oxidation: Efficiency and Mechanism

AI summary Read the abstract

Researchers investigated how UV-activated sodium percarbonate breaks down PVC microplastics, finding effective dechlorination and fragmentation after 35 hours of treatment. The study identified hydroxyl and carbonate radicals as the primary agents driving the aging process, providing insights into how advanced oxidation could be used to treat microplastic-contaminated wastewater.

Article Tier 2

Degradation of polyvinyl chloride microplastics via an electro-Fenton-like system with a TiO2/graphite cathode

AI summary Read the abstract

Researchers developed an electro-Fenton system using a TiO2/graphite cathode to degrade PVC microplastics in water, demonstrating effective surface oxidation and fragmentation of PVC particles through in situ generation of reactive oxygen species.

Article Tier 2

Elucidating the role of overlooked environmentally persistent free radicals and reactive chlorine species on photoaged chlorine-containing microplastics: New insights into formation mechanisms and health risks

AI summary Read the abstract

Researchers investigated the formation of environmentally persistent free radicals and reactive chlorine species on photoaged chlorine-containing microplastics like PVC and PVDC. The study revealed previously overlooked chemical transformations during microplastic aging that may pose additional health risks beyond the physical presence of the plastic particles themselves.

Article Tier 2

Condensation accelerates polyvinyl chloride microplastics aging via hydrogen radical generation

AI summary Read the abstract

Researchers discovered that natural condensation — water microdroplets forming on plastic surfaces — accelerates PVC microplastic aging in the dark by generating hydrogen radicals at the droplet-plastic interface, which cleave chemical bonds and form conjugated carbon structures, representing a previously overlooked weathering pathway independent of sunlight.

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