0
Article Tier 2 Sign in to save

Strong influence of surfactants on virgin hydrophobic microplastics adsorbing ionic organic pollutants

Environmental Pollution 2020 100 citations

AI summary Read the abstract

Researchers found that surfactants cause hydrophobic microplastics to adsorb ionic organic pollutants at much higher rates than previously recognized, revealing that the typical assumption of minimal interaction between hydrophobic plastics and hydrophilic contaminants underestimates real-world pollutant uptake. The findings indicate that surfactant ubiquity in environmental waters substantially alters microplastic pollutant-carrying capacity.

Microplastic (MP) pollution has become an area of increasing concern because MPs accumulate various types of pollutants. Many previous studies have explored the interactions between MPs and hydrophobic pollutants. However, little research has been conducted on hydrophilic pollutants, which are of much higher concentration and ubiquitous in environment. Surfactants cause hydrophobic MPs to become hydrophilic, which may significantly enhance their capacities to adsorb hydrophilic pollutants. This study explored the influence of co-existing surfactants on the adsorption of ionic organic pollutants by MPs, and found that the presence of an ionic surfactant could significantly enhance the capacity of polyvinyl chloride (PVC, 0.2 mm) MPs to adsorb pollutants with opposite charges. The Langmuir methylene blue adsorption capacity of PVC could be increased from 172 to 4417 ppm in the presence of a sodium dodecyl benzene sulfonate surfactant. Nonionic surfactants impeded the adsorption of both cationic and anionic pollutants due to the steric resistance of the hydrophilic polyethelene glycol chains. The electrostatic interaction mechanism dominated the interfacial behaviors of ionic pollutants on surfactant-adsorbed MP interfaces. The effects of the surfactants were further verified using four different model pollutants and six surfactants. The adsorption capacities of real environmental MPs, including PVC, polyethylene (PE), polypropylene (PP), and polystyrene (PS), increased by three to twenty-six times. The adsorption properties of MPs may be determined by the presence of co-existing surfactants, rather than their polymer species or additives.

More Papers Like This

Article Tier 2

Microplastics as a vector of hydrophobic contaminants: Importance of hydrophobic additives

AI summary Read the abstract

This paper examines the role of hydrophobicity in determining whether organic pollutants sorbed to microplastics pose a meaningful additional risk beyond direct water exposure. The authors argue that for most scenarios, the contribution of microplastics to total pollutant exposure is smaller than commonly assumed and depends heavily on the properties of the specific chemical and polymer.

Article Tier 2

Bioavailability of microplastic-bound pollutants in vitro: The role of adsorbate lipophilicity and surfactants

AI summary Read the abstract

Researchers tested how the lipophilicity of microplastic-bound pollutants and the presence of surfactants affect the transfer of those pollutants into fish cells, finding that less lipophilic compounds desorb more readily from polyethylene particles and that surfactants modulate cellular uptake through mechanisms beyond simple desorption.

Article Tier 2

Adsorption behavior and interaction mechanism of microplastics with typical hydrophilic pharmaceuticals and personal care products

AI summary Read the abstract

This study examined how different types of microplastics adsorb hydrophilic pharmaceuticals and personal care products (PPCPs) in aquatic environments, finding that polymer type and surface properties governed the interaction mechanisms. The results indicate that microplastics can act as vectors for these emerging contaminants.

Article Tier 2

Sorption of five organic compounds by polar and nonpolar microplastics

AI summary Read the abstract

Polar and biodegradable microplastics, including polyurethane and polycaprolactone, showed significant sorption of hydrophobic organic contaminants, with hydrogen bonding playing a greater role than for conventional nonpolar plastics. The findings extend understanding of how a wider range of plastic types can act as vectors for environmental pollutants.

Article Tier 2

Evaluating the potential of microplastics and natural organic matter for sorption of hydrophobic organic contaminants based on selected properties

AI summary Read the abstract

This review compared how microplastics and natural organic particles in the environment sorb hydrophobic chemical pollutants, finding that particle properties such as size, surface area, and age all influence their capacity to act as contaminant carriers. The authors conclude that microplastics are just one of many particulate types competing to carry pollutants in aquatic systems.

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