High-efficiency Ce-modified ZSM-5 nanosheets for waste plastic upgrading

Zeolite-based catalyst hydrocracking of plastics is a potential strategy for mitigating the environmental impacts of plastic wastes and recycling valuable resources,but difficult mass transfer,low concentration of acid sites,and high cost are still barriers to their practical applications.In this paper,we report an excellent hydrocracking catalyst of ZSM-5 nanosheets(Ce/b-ZSM-5)modified by Ce species with high conversion up to 96.3%,C_(3)−C_(5)selectivity up to 80.9%,and good stability during the hydrogenation of low-density polyethylene.Through comprehensive studies,b-ZSM-5 shows higher molecular diffusion efficiency and acid site concentrations compared with normal ZSM-5(n-ZSM-5)and hollow ZSM-5(h-ZSM-5).The introduction of Ce species into b-ZSM-5 further increases the density of Brønsted(B)and Lewis(L)acid sites as active sites,which enhances the adsorption of substrates and facilitates the formation of intermediates and desorption of products.As a result,the hydrocracking activity of Ce/b-ZSM-5 is significantly improved.

Base-or acid-assisted polystyrene plastic degradation in supercritical CO_(2)

Plastic has caused serious"white pollution"to the environment,and the highly inert characteristics of plastic bring a major challenge for degradation.Supercritical fluids have unique physical properties and have been widely used in various fields.In this work,supercritical CO_(2)(Sc-CO_(2))with mild conditions was selected and assisted by NaOH/HCl solution to degrade polystyrene(PS)plastic,and the reaction model was designed using response surface methodology(RSM).It was found that,regardless of the types of assistance solutions,the factors affecting PS degradation efficiencies were reaction temperature,reaction time,and NaOH/HCl concentration.At the temperature of 400℃,time of 120 min,and base/acid concentration of 5%(in weight),0.15 g PS produced 126.88/116.99±5 mL of gases with 74.18/62.78±5 mL of H2,and consumed 81.2/71.5±5 mL of CO_(2).Sc-CO_(2)created a homogeneous environment,which made PS highly dispersed and uniformly heated,thus promoting the degradation of PS.Moreover,Sc-CO_(2)also reacted with the degradation products to produce new CO and more CH_(4)and C_(2)H_(x)(x=4,6).Adding NaOH/HCl solution not only improved the solubility of PS in Sc-CO_(2),but also provided a base/acid environment that reduced the activation energy of the reaction,and effectively improved the degradation efficiencies of PS.In short,degrading PS in Sc-CO_(2)is feasible,and better results are obtained with the assistance of base/acid solution,which can provide a reference for the disposal of waste plastics in the future.

Plastic materials and water sources actively select and shape wastewater plastispheres over time

The daily use of plastics presents a serious pollution issue due to their extremely slow degradation.Microplastics and the biofilm that grows on plastics(i.e.,the plastisphere)are important subsets of plastic wastes.Many studies have been conducted to reveal the structures of the plastispheres,the driving factors for the formation of the plastisphere,and the ability of the plastispheres to degrade plastics in a variety of water bodies.However,the plastispheres related to wastewater are understudied.In this study,we used a microcosmic strategy to study the evolution of the plastispheres associated with microplastics(MPs)over time in wastewater.We found that plastic materials and water sources did not actively select and shape the plastispheres at an early stage,but the active selection for a unique niche of the plastisphere occurred after 14 d of growth.In addition,we confirmed that the alkB gene was densely present,and metagenomics showed some additional chemical reactions,which suggests that MPs are consumed by the microbes in the plastispheres.Additionally,metagenomics identified some metagenome-assembled genomes(MAGs)associated with high-density polyethylene(HDPE)and polyethylene terephthalate(PET).The identification of HDPE-associated MAGs and PET-associated MAGs further supports the notion that the selection for a unique niche of the plastisphere is driven by plastic materials and water sources(in this study,after 14 d of growth).Our discoveries bring new views on the behavior of the wastewater-associated plastisphere,especially how long it takes a wastewater plastisphere to form.

Ten decadal advances in fungal biology leading towards human well‑being

Fungi are an understudied resource possessing huge potential for developing products that can greatly improve human well-being.In the current paper,we highlight some important discoveries and developments in applied mycology and interdisciplinary Life Science research.These examples concern recently introduced drugs for the treatment of infections and neurological diseases;application of–OMICS techniques and genetic tools in medical mycology and the regulation of mycotoxin production;as well as some highlights of mushroom cultivaton in Asia.Examples for new diagnostic tools in medical mycology and the exploitation of new candidates for therapeutic drugs,are also given.In addition,two entries illustrating the latest developments in the use of fungi for biodegradation and fungal biomaterial production are provided.Some other areas where there have been and/or will be significant developments are also included.It is our hope that this paper will help realise the importance of fungi as a potential industrial resource and see the next two decades bring forward many new fungal and fungus-derived products.