0
Article Tier 2 Remediation Sign in to save

Adsorption and desorption mechanisms of oxytetracycline on poly(butylene adipate-co-terephthalate) microplastics after degradation: The effects of biofilms, Cu(II), water pH, and dissolved organic matter

The Science of The Total Environment 2022 38 citations

AI summary Read the abstract

Researchers found that biodegradation significantly increases the ability of poly(butylene adipate-co-terephthalate) (PBAT) microplastics to adsorb the antibiotic oxytetracycline, and that the presence of copper ions further amplifies this adsorption, raising concerns about how degrading biodegradable plastics transport pharmaceutical contaminants.

As the application of biodegradable polymers has grown, so has the interest in exploring the environmental behaviors of biodegradable microplastics (MPs). In this study, we investigated the interaction of oxytetracycline (OTC) with poly(butylene adipate-co-terephthalate) (PBAT) MPs after biodegradation, and explored the effect of the coexisting Cu(II) on OTC adsorption and desorption processes. The maximum adsorption amounts of virgin PBAT, biofilm PBAT, and degraded PBAT reached 692.05 μg·g, 1396.21 μg·g, and 1869.93 μg·g, respectively, and the presence of Cu(II) increased the OTC adsorption capacities by 431.16 %, 165.99 %, and 132.94 %, respectively. The enhanced adsorption capacities were attributed to the formation of PBAT-Cu-OTC complexes. The remarkable desorption hysteresis of OTC was observed on the degraded PBAT but not on the biofilm PBAT when Cu(II) was present, due to the complexation between Cu(II) and biofilms. The effect of Cu(II) varied depending on the MP physiochemical properties (e.g., surface areas, zeta potentials, and functional groups) and the environmental factors (e.g., the solution pH and coexisting dissolved organic matter). Fourier transform infrared spectroscopy (FTIR) coupled with X-ray photoelectron spectroscopy (XPS) identified the Cu(II) bridging effect, and various interaction forces between PBAT and OTC, including hydrogen-bonding, π-π, cation-π, and electrostatic interactions.

More Papers Like This

Article Tier 2

Adsorption behavior of commercial biodegradable plastics towards pollutants during the biodegradation process: Taking starch-based biodegradable microplastics, oxytetracycline and Cu (II) as examples

AI summary Read the abstract

This study found that microbial colonization on biodegradable starch-based microplastics (PBAT/PLA/TPS blend) actually increases their ability to adsorb the heavy metal copper and the antibiotic oxytetracycline, while further biodegradation reduces that capacity. When both pollutants are present together, however, even partially degraded microplastics can still carry significantly elevated contaminant loads. This reveals that biodegradable plastics are not risk-free — their breakdown in the environment changes, but does not eliminate, their role in transporting harmful chemicals.

Article Tier 2

UV and chemical aging alter the adsorption behavior of microplastics for tetracycline

AI summary Read the abstract

Researchers found that UV and chemical aging significantly increased microplastics' capacity to adsorb tetracycline, with biodegradable PBAT showing more dramatic changes in surface properties and adsorption behavior compared to conventional plastics like polystyrene and polyethylene.

Article Tier 2

Adsorption behavior of aged polybutylece terephthalate microplastics coexisting with Cd(II)-tetracycline

AI summary Read the abstract

Researchers studied how aged polybutylene terephthalate microplastics interact with cadmium and the antibiotic tetracycline in water, finding that weathered microplastics adsorb these pollutants more readily than pristine ones. The study suggests that aging changes the surface properties of microplastics, increasing their capacity to carry heavy metals and antibiotics and potentially amplifying their environmental toxicity.

Article Tier 2

Interfacial interaction between diverse microplastics and tetracycline by adsorption in an aqueous solution

AI summary Read the abstract

Polyethylene microplastics showed the strongest adsorption of the antibiotic tetracycline among three plastic types tested, and the presence of metals like lead and zinc enhanced tetracycline adsorption while copper reduced it. Ion exchange was identified as the primary adsorption mechanism, suggesting that microplastics in aquaculture settings could concentrate antibiotics and increase their environmental persistence.

Article Tier 2

UV-photoaging of degradable microplastics in atmospheric and wastewater: Surface changes and enhanced antibiotic interaction

AI summary Read the abstract

When biodegradable microplastics spend time in wastewater rather than open air, they age much more aggressively — developing biofilms and oxidized surfaces that dramatically increase their ability to absorb antibiotics. This study found that wastewater-aged polybutylene succinate microplastics adsorbed 2.4 times more tetracycline than fresh plastic, and outperformed air-aged plastic by 40%, driven by biofilm chemistry and increased surface area. The implication is that wastewater treatment systems — rather than solving the microplastic problem — may be transforming biodegradable plastics into potent carriers for antibiotic resistance.

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