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Microplastics have been widely detected in the natural water environment, which brings inevitable risks to the water ecosystem and human health. However, the understanding of the potential impact of microplastics on aquatic animals, plants, and human health is still limited, and technical methods to control microplastic pollution in natural water are still rare. Hence, this paper summarizes the progress of research on microplastic pollution in water systems in terms of microplastic source, attributes, distribution characteristics, environmental effects, and prevention and control methods according to the relevant research reports on water microplastic pollution. It also expounds the basic ways for the prevention, control, and treatment of water microplastics, and looks forward to the research direction of water microplastic pollution in the future. The results show that the abundance of fresh water microplastics in China is higher than that in other regions, but the pollution level of marine microplastics is at the middle level. Compared with other countries, the pollution degree of microplastics in aquatic organisms in China is at the middle and lower level, but the spatial heterogeneity is more obvious. Through hydraulic control and the substitution of degradable plastic products, water microplastic pollution can be greatly reduced. This paper can provide a reference basis for the formulation of microplastic pollution prevention and control in China. [ABSTRACT FROM AUTHOR]

• MPs were mainly fibrous, blue and in 20–500 μm in industrial mariculture. • Long operating time led to higher MP concentration in RAS. • Occurrence and distribution of MPs was analyzed in long & short operated RAS. • Microfilter removed MP in film, granule, fragment and those > 1000 μm efficiently. • PMF model was used to analyze the source of MP based on the polymer type. Industrial mariculture, a vital means of providing high quality protein to humans, is a potential source of microplastics (MPs) which have recently received increasing attention. This study investigated the occurrence and distribution of microplastics in feed, source water and recirculating aquaculture system (RAS) with long & short operating times as well as in fish from typical industrial mariculture farms in China. Results showed that microplastics occurred in all samples with the average concentration of 3.53 ± 1.39 particles/g, 0.70 ± 0.17 particles/L, 1.53 ± 0.21 particles/L and 2.21 ± 0.62 particles/individual for feed, source water, RAS and fish, respectively. Microplastics were mainly fiber in shape, blue in color and 20–500 μm in size. Compared with short operated RAS, long operating time led to higher microplastic concentration in RAS, especially that of microplastic in 20–500 μm, granular and blue. Regardless of short or long operating time, microplastics in RAS mainly gathered in culture tank, tank before microfilter and fixed-bed biological filter, and the microfilter removed efficiently the microplastic with the shape of film, granule, fragment as well as those with size > 1000 μm. As for the polymer types, polyamide (PA, 71.9 %) and polyethylene terephthalate (PET, 65.7 %) dominated in feed and source water, respectively, which may be the reason for the high proportion of PA (38.8 % and 26.4 %) and PET (31.8 % and 30.2 %) in RAS and fish. In addition, polypropylene (PP) was also detected in RAS (18.7 %) and fish (22.6 %), indicating that other plastic facilities such as PP brush carrier also made a contribution. Positive matrix factorization (PMF) model revealed three sources of MP in RAS, namely plastic facilities, industrial sewage and plastic packaging products. Our results provided a theoretical basis for the management of MP in RAS. [Display omitted] [ABSTRACT FROM AUTHOR]

The Corona Virus disease 2019 (COVID-19) outbreak has changed the lifestyles of billions of people. Face masks, as a daily protective tool, have become a must-have item. The number of masks discarded has soared, making environmental and hygiene problems impossible to ignore. The rapid development of biodegradable materials may be one of the solutions to this issue. In this study, life cycle assessment (LCA) was used as a method to quantitatively analyze the environmental impacts of two disposable medical masks, biodegradable polylactic acid (PLA) and fossil-based polypropylene (PP). The results show that human toxicity (63.93%), acidification (39.93%), global warming potential (36.29%), and abiotic depletion (83.55%) of disposable medical masks mainly made of PLA were significantly lower than those of PP. The photochemical oxidation (4.89%) for PLA masks was slightly higher. The manufacturing cost per unit hour was 0.060 yuan (PP) and 0.0675 yuan (PLA). It was estimated that the replacement could reduce global carbon emissions by 321,392,700 tons and 466,400 tons for China. Furthermore, the process improvements in the raw material acquisition stage could maximize the benefits of carbon reduction. [Display omitted] • Feasibility of PLA as a substitute for PP in the disposable masks production verified by LCA. • The replacement can reduce annual global carbon emissions by about 321 million tons. • The manufacturing cost are 0.06 yuan/h (PP) and 0.0675 yuan/h (PLA). • Raw material acquisition stage has the greatest impact on the carbon emission. [ABSTRACT FROM AUTHOR]

This study explores green credit to promote the green transformation of the plastic supply chain under carbon neutral and plastic ban policies in China. The relationship and strategy among commercial banks, suppliers, and manufacturers are analyzed using a supply chain structure and evolutionary game theory. Incorporate dynamic consumer willingness to recycle and cost-sharing mechanisms for green innovation. The stability and dynamic probability of participants' strategy selection are calculated using empirical data, including financial situation and carbon emission. A genetic algorithm is used to optimize the game parameters for sensitivity analysis. The results suggest that green credit can facilitate the green transformation of the plastics supply chain, but its effectiveness is affected by consumers' willingness to recycle. The effect of green credit has a marginal effect, with higher interest rates reducing the rate of green innovation and manufacturing choices. Suppliers are not able to share the costs of the transition, and only manufacturers bearing or co-bearing the costs are conducive to a green transition. Lower green input costs favor transition but are constrained by market demand. Environmental penalties are too low to create financial pressure, and environmental uncertainty discourages green transformation. [Display omitted] • Green credit boosts eco-innovation, tied to interest and recycling rates. • Moderate eco-uncertainty spurs, while excess hampers, green shifts. • New framework merges evolutionary games with genetic algorithms for eco-strategy. • The cost of greening is borne by the manufacturer instead of the supplier. [ABSTRACT FROM AUTHOR]

The "Carbon Peak and Carbon Neutrality" goal requires China actively explore new ways to supplement the oil supply for Chinese situation of oil shortage. Enormous oil shale reserves and large amount of waste plastics are viable feedstocks for supplementing the oil supply. However, individually pyrolyzing oil shale and waste plastic has its drawbacks, that is, the pyrolysis oil from oil shale contains more O and N heteroatoms and the pyrolysis oil from waste plastic has extremely long carbon chains, which both keep the pyrolysis oil from substituting crude oil. In this study, co-pyrolysis of oil shale and plastic (polypropylene, low-density polyethylene, waste tires) was used to produce oil. It could be found that the inorganic components in oil shale can promote the rupture of plastic, thereby reducing the heavy components in the oil (30 ≤ C < 40) and enhancing the light components (C < 30). Meanwhile, co-pyrolysis can effectively reduce the O and N components in the oil phase. The results of reactive force field molecular dynamics simulations showed that the reactive radicals formed by waste plastics first accelerate the pyrolysis reaction, promote the breakage of aliphatic chains in the oil shale kerogen. and thus, more intermediates, especially gas containing O (C<5), are going to form. Furthermore, intermediates (5 ≤ C) could interact with each other to form char. More O- and N-containing components will remain in the char, further reducing the O and N heteroatom content in the oil. • Co-pyrolysis of oil shale and waste plastics could be a handy way to improve oil quality. • Minerals in Oil shale could favor the decomposition of plastics, resulting in gas promotion. • Heavy fraction (C>30) in oil from co-pyrolysis could be reduced by 50 wt% at most. • Heteroatom components could also be largely reduced by co-pyrolysis. • Radicals of short chain from co-pyrolysis play significant role in improving oil quality. [ABSTRACT FROM AUTHOR]