We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Effect of aging on the release of di-(2-ethylhexyl) phthalate from biodegradable and petroleum-based microplastics into soil
Summary
This study found that aging processes like UV exposure and chemical oxidation cause microplastics to release more of the plasticizer DEHP, a potential carcinogen, into surrounding soil. Biodegradable PLA plastic released DEHP faster than conventional PVC or polystyrene when aged, suggesting that so-called eco-friendly plastics may not be safer in terms of chemical leaching. The findings are concerning because DEHP is known to disrupt hormones, and this study shows that weathered microplastics in soil could be a greater source of exposure than previously thought.
Due to microplastics (MPs) being widely distributed in soil, the use of advanced oxidation to remediate organic-contaminated soils may accelerate the aging of MPs in soil and impact the release of di-(2-ethylhexyl) phthalate (DEHP), a potential carcinogen used as a plasticizer in plastics, from MPs. In this study, persulfate oxidation (PO) and temperature treatment (TT) were used to treat biodegradable and petroleum-based MPs, including polylactic acid (PLA), polyvinyl chloride (PVC), and polystyrene (PS). The methods used for evaluating the characteristics changes of MP were X-ray diffraction (XRD) analysis and water contact angle measurement. The effects of aging on DEHP release from MPs were investigated via soil incubation. The results showed PO and TT led to increased surface roughness, oxygen-containing functional group content, and hydrophilicity of the MPs with prolonged aging, consequently accelerating the release of DEHP from the MPs. Interestingly, PLA aged faster than PVC and PS under similar conditions. After 30 days of PO treatment, DEHP release from PLA into the soil increased 0.789-fold, exceeding the increase from PVC (0.454-fold) and PS (0.287-fold). This suggests that aged PLA poses a higher ecological risk than aged PVC or PS. Furthermore, PO treatment resulted in the oxidation and degradation of DEHP on the MP surface. After 30 days of PO treatment, the DEHP content in PLA, PVC, and PS decreased by 19.1%, 25.8%, and 23.5%, respectively. Specifying the types of MPs studied and the environmental conditions would provide a more precise context for the results. These findings provide novel insights into the fate of biodegradable and petroleum-based MPs and the potential ecotoxicity arising from advanced oxidation remediation in contaminated soils.
Sign in to start a discussion.
More Papers Like This
Photoaging enhances the leaching of di(2-ethylhexyl) phthalate and transformation products from polyvinyl chloride microplastics into aquatic environments
This study found that sunlight aging of PVC microplastics accelerates the release of DEHP, a hormone-disrupting plasticizer, by 1.5 times compared to new plastics. The aging process also creates harmful breakdown products like MEHP and phthalic acid that leach into water. Since most microplastics in the environment have been exposed to sunlight, the actual release of toxic chemicals from plastic pollution is likely much higher than estimates based on new plastic suggest.
Leaching of di-2-ethylhexyl phthalate from biodegradable and conventional microplastics and the potential risks
Researchers compared the leaching of the plasticizer DEHP from biodegradable and conventional microplastics into seawater. They found that conventional polyethylene mulch film released the most DEHP, at about six times the amount leached from biodegradable alternatives. The study suggests that while all tested microplastics released some DEHP, the pollution risk from the leached amounts was assessed as low based on phthalate pollution indices.
Kinetics of plasticiser release and degradation in soils
Researchers measured the release of the plasticizer DEHTP from PVC microplastics in soil over three months and also assessed degradation rates of 12 phthalate and non-phthalate plasticizers. DEHTP was released rapidly from PVC pellets within two hours, and seven of the twelve plasticizers showed half-lives under 30 days in soil, suggesting most emerging plasticizers degrade relatively quickly but initial release is fast.
Effect of particle size and environmental conditions on the release of di(2-ethylhexyl) phthalate from microplastics
Researchers studied how the plasticizer DEHP leaches out of microplastics under different environmental conditions, finding that smaller particles release more of the chemical due to their greater surface area. Higher temperatures, lower pH, and higher salt concentrations all increased the rate of DEHP release. The study suggests that environmental conditions can significantly influence how much potentially harmful chemical is released from microplastic debris in soil and water.
Microplastic formation and simultaneous release of phthalic acid esters from residual mulch film in soil through mechanical abrasion
Researchers found that mechanical abrasion of residual mulch film in soil simultaneously generates microplastics and releases phthalic acid esters like DEHP, with film thickness, polymer type, and aging all influencing the rate of microplastic formation and plasticizer release.