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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 global adoption of biodegradable and compostable plastics obtained from biomass-derived monomers, we argue in this account, is now close to the inflection point. The first industrially significant impact will affect the packaging segment of the global chemical industry. In this process, China and India will play a pivotal role. Selected guidelines aiming to foster development of bioplastics industry in both developed and developing nations are provided. [ABSTRACT FROM AUTHOR]

Trade drives increased life-cycle carbon dioxide (CO 2) emissions and carbon leakage from plastics, increasing the environmental burden on the supply chain. Therefore, assessing the characteristics and drivers of plastic carbon emissions will help develop emission reduction strategies from a supply chain perspective. In this study, we present a model framework for life-cycle assessment, optimized input-output analysis, and structural decomposition analysis. Specifically, for the first time, we assess the life-cycle CO 2 emissions of plastics in China, the world's largest producer and consumer, and consider the input, production, consumption, and income stages of the plastic supply chain. China's plastic CO 2 emissions increased by 38.07% from 2010 to 2021 and, under a business-as-usual path, will consume 4.2–5.4% of the global carbon budget by 2050. From a supply chain perspective, each economic sector assumes different responsibilities for emissions at different stages. Despite increasing emissions, China's economic structure has potentially improved the embodied carbon leakage from the intersectoral and international trade in plastics. Furthermore, regarding socioeconomic factors, the levels of final demand (63%) and primary input (61%) dominated the increase in plastic CO 2 emissions from 2012 to 2020, and the intensity of emissions was the key to reducing emissions. The novelty of this study is that the model we proposed can solve the data limitations of the global plastics supply chain and focuses for the first time on the input and income stages and their drivers. [Display omitted] • An optimized input-output approach is applied to study plastic CO 2 emissions. • The importance of inputs and income on plastic CO 2 emissions is revealed. • Characteristics and drivers of plastic CO 2 emissions in the economic sector are investigated. • The potential impact of the economic structure on plastic-embodied carbon leakage is analyzed. • Measures to reduce CO 2 emissions from different trade supply chain perspectives are proposed. [ABSTRACT FROM AUTHOR]

China government has implemented regulations to completely ban the use of disposable plastics with about 54 million kt, resulting in tremendous controversies about non-degradable and biodegradable plastics. However, there is still a lack of direct evidence to elucidate the difference of degradation mechanisms among them, which limits the development of applications for biodegradable materials. In this work, we provide direct evidence to clarify the degradation mechanisms between bio- and non-degradable materials. Cellulose, polybutylene adipate terephthalate (PBAT), and polyethylene (PE) film were subjected to phosphate-buffered solution (PBS) degradation, ultraviolet (UV) aging, and soil degradation, and the possible degradation mechanism analysis was carried out. The results exhibited that the cellulose film possessed the shortest degradation cycles whether in PBS degradation, UV aging, or soil degradation, moreover, the cellulose film showed a much higher weight loss of 99.1% after 98 days of soil degradation compared with PBAT film (2.1%) and PE film (1.7%). Additionally, we proposed possible degradation mechanisms to pave the way for the fabrication of green and degradable packaging plastics. • Diverse degradation behaviors of non-degradable and biodegradable materials were evaluated. • Cellulose film possessed a better degradation ability than PBAT and PE film. • The possible degradation mechanisms of the three kinds of films were demonstrated. [ABSTRACT FROM AUTHOR]