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Plastic imposes a critical threat to the environment, ecosystems and human health, because of low utilization efficiency of plastics. Here, we demonstrate a sustainable highly efficient cascade photocatalysis for upcycle plastics to value-added acetic acid using Fe single atom catalysts (Fe@C3N4 SAC) at ambient conditions. Inspired by Phanerochaete chrysosporium microbial, the defected Fe@C3N4 SAC acts as a as a bifunctional cascade photocatalyst for both Fenton-like and CO2 reduction reactions. During the reaction, hydroxyl radicals (*OH) form and subsequently oxidize plastics into CO2 intermediates. These CO2 intermediates were then photo-reduced to CH3COOH on the same catalyst via cascade photocatalysis. The mechanismmore » was confirmed by in situ multimodal microscopy and spectroscopies, with density functional theory calculations. A state-of-art CH3COOH yield of 63.8 mg h-1 gcat-1 from PVC, 12.7 mg h-1 gcat-1 from PE, 5.4 mg h-1 gcat-1 from PET, and 5.3 mg h-1 gcat-1 from PP were directly obtained under AM1.5G solar irradiation and further validated under real sunlight (~ 0.6 sun), achieving 5.6 mg h-1 gcat-1 from PET, using low-cost Fe@C3N4 SAC in a sealed reactor by enhancing the photon transport and utilization efficiency. The techno-economic analysis shows it is promising to practically mitigate plastic based on broader social welfare assessments.« less

Microplastics cause negative environmental consequences such as the release of toxic additive leachates, increased greenhouse gas emissions during degradation, and threaten food chains . Microplastic particles are known to serve as a vector for transport of microbes (fungi and bacteria) to new environments, threatening biodiversity. Robust biofilm formation makes fungi a candidate to collect and remediate environmental microplastics. However, fungal-microplastic colonization mechanisms have yet to be explored. In this work, we aim to understand which fungal molecules mediate microplastics binding. We examine common fungal genus Aspergillus , which we found binds microplastics tightly, removing particles from suspension. Upon inoculation ofmore » Aspergilli with microplastics particles, up to 3.85 ± 1.48 g of microplastics were flocculated per gram of dry fungal biomass; this phenomenon was observed across various plastics ranging in size from 0.05 to 5 mm. Gene knockouts revealed that hydrophobins drive microplastic-fungi binding, evidenced by a decrease in flocculation relative to wild-type Aspergillus fumigatus. Moreover, purified hydrophobins flocculated microplastics independently of the fungus, validating their ability to bind to microplastics. Furthermore, our work elucidates a role for hydrophobins in fungal colonization of microplastics and highlights a target for mitigating the harm of microplastics through engineered fungal-microplastic interactions.« less

Microplastics (MPs) as emerging contaminants have accumulated extensively in agricultural ecosystems and are known to exert important effects on biogeochemical processes. However, how MPs in paddy soils influence the conversion of mercury (Hg) to neurotoxic methylmercury (MeHg) remains poorly understood. Here, in this study, we evaluated the effects of MPs on Hg methylation and associated microbial communities in microcosms using two typical paddy soils in China (i.e., yellow and red soils). Results showed that the addition of MPs significantly increased MeHg production in both soils, which could be related to higher Hg methylation potential in the plastisphere than in themore » bulk soil. We found significant divergences in the community composition of Hg methylators between the plastisphere and the bulk soil. In addition, the plastisphere had higher proportions of Geobacterales in the yellow soil and Methanomicrobia in the red soil compared with the bulk soil, respectively; and plastisphere also had more densely connected microbial groups between non-Hg methylators and Hg methylators. These microbiota in the plastisphere are different from those in the bulk soil, which could partially account for their distinct MeHg production ability. Our findings suggest plastisphere as a unique biotope for MeHg production and provide new insights into the environment risks of MP accumulation in agricultural soils.« less

Increasing production and use of various novel plastics products, a low recycling rate, and lack of effective recycling/disposal methods have resulted in an exponential growth in plastic waste accumulation in landfills and in the environment. To better understand the effects of plastic waste, Life Cycle Analysis (LCA) was done to compare the effects of various production and disposal methods. LCA shows the specific effects of the cradle-to-grave or cradle-to-cradle scenarios for landfill, incineration, and mechanical recycling. The analysis clearly indicates that increasing recycling of plastics can significantly save energy and eliminate harmful emissions of various carcinogens and GHGs into themore » environment. As recycling increases, the need for virgin-plastic production can be greatly reduced. Furthermore, the results of this study may help improve current mechanical recycling processes as well as potential future recycling methods, such as chemical recycling. Concerns about the current recycling/disposal methods for plastics have brought increasing attention to the waste accumulation problem. However, with the current COVID-19 pandemic, plastic accumulation is expected to increase significantly in the near future. A better understanding of the quantitative effects of the various disposal methods can help guide policies and future research toward effective solutions of the plastic waste problem.« less