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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]

Purpose: This study aims to present a comprehensive knowledge mapping and an in-depth analysis of plastic and sustainability research to understand better global trends and directions in this field that emerged between 1995 and 2022. Design/methodology/approach: This study presents a visual analysis of 1933 research articles listed in the Web of Science (WoS) databases between the years 1995 and 2022 related to plastic and sustainability. The knowledge mapping based on CiteSpace and VOSviewer presents the current research status, which contains the analysis of the collaboration network, co-citation network, references with citation bursts and keyword analysis. Findings: The results reveal that China and the USA are the most prominent countries in exploring the notion of sustainability and plastic. The Chinese Academy of Science is the most prominent institution. Chai Qiang, Friedrich Daniel, Sahajwalla Veena and Ok Yong Sik are the most prolific authors in this field. Furthermore, circular economy, bioplastic, sustainable development, polyester and bioplastics are the highly discussed issues in recent years. Not surprisingly, COVID-19 is the latest topic of discussion started in 2021 due to its negative impact on plastic pollution and the challenges it posed to sustainability. Originality/value: This study is among the pioneers to shed light on the current research status of plastic and sustainability using the bibliometric method and the newest data. This study also suggests that collaborations between scholars and institutions require to be enhanced for better management of plastic pollution and to contribute to sustainable development. [ABSTRACT FROM AUTHOR]

Copyright of Nachrichten aus der Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bioplastic bags mixed with food waste seem inevitable with the growth of waste classification and the banning of non-biodegradable polymers in China. To solve the asynchronous degradation of both food waste (FW) and bioplastics in the anaerobic digestion process, we investigated to determine the most effective pretreatment method. Among the three treatment options—physical, chemical, and biological—we found that biological pretreatment holds the most promise, primarily due to the efficient catalytic hydrolysis capacity of enzymes. We utilized three types of enzymes—amylases, lipases, and proteinase K—at a concentration of 0.075 g L−1 for pretreatment. The pretreatment process involved subjecting the FW/bioplastics mixture to enzymatic action for a duration of 48 h, at temperatures of 35 °C and 55 °C. We observed that the methane production from anaerobic digestion increased by 22.72%, 32.51%, and 60.95%, respectively, at the temperature of 55 °C when treated with the mentioned enzymes. Additionally, the degradation time of the bioplastic bags decreased from 30 to 24 days. Scanning electron microscopy (SEM) analysis revealed noticeable physical degradation, with the emergence of holes on the surface of the bioplastic following the enzymatic pretreatments and the effect of proteinase K was the most obvious. Further analysis using Fourier-transform infrared spectroscopy (FTIR) indicated that the peak observed at 1700 cm−1 is a characteristic peak of proteinase K depolymerization and the peak sign was significantly weakened after the experiment. This discovery suggests that proteinase K possesses a unique ability to break certain chemical bonds within bioplastics. Furthermore, novel bacterial species were identified in the substrate microbiome after proteinase K pretreatment. Notably, temperature was also a significant factor influencing material degradation. The enzymatic pretreatment enhanced biodegradation, resulting in enhanced methane yield during anaerobic digestion. These findings demonstrated the efficacy of biological pretreatment in effectively addressing the asynchronous degradation issue between food waste and bioplastics. [ABSTRACT FROM AUTHOR]

Evaluating the lifespan of aged biodegradable mulch films from the perspective of realistic outdoor climate conditions is a challenge. However, it is worthwhile to determine the changes in their structure and stability. In this study, a talc-filled black poly (butylene adipate-co-terephthalate)/polylactide (PBAT/PLA) biodegradable mulch film was designed and mulched with shallow overburden soil to improve the anti-weathering characteristics of winter potatoes grown in southern China. This study focused on the weather resistance properties of biodegradable talc-filled PBAT/PLA-based mulch films. After 4 months of outdoor service, the elongation at break and tensile strength of talc-filled black PBAT/PLA films remained at 360 ± 250% and 15 ± 2.5 Mpa, respectively, with the number average molecular weight decreasing by 21.4% and the gel content increasing to 10%. Combining the results of microstructure analyses, molecular weight changes, thermodynamic properties, and mechanical and structural changes due to accelerated ageing under different indoor conditions, it was concluded that the maintenance of the mechanical properties of the mulch films could be attributed to the inhibition of random chain-breaking and heavy photo-crosslinking in the plastic film system. Our results using biodegradable films based on crop growth characteristics provide an effective strategy for extending the service life of biodegradable plastics and reducing the cost of biodegradable mulch films. [ABSTRACT FROM AUTHOR]

• The financial and ecological viability of power from pyrolysis oil is assessed. • The process has high oil yield and power generation potential. • The project is economically feasible and profitable in China. • Power generation from the project contributes to global warming. • Consumption of power from the project reduces coal usage and global warming. The increased plastic waste generation worldwide poses ponderous issues for public health and the environment. China is the highest generator of plastic waste around the world. The current treatment process (incineration) of the increased plastic waste causes dangerous environmental consequences. Pyrolysis has recently surfaced as an ecologically friendly technique for energy and material recovery from plastic waste. The present study assesses the financial and ecological viability of power production from oil derived from the pyrolysis of mixed plastic wastes in China from 2009 to 2028. The prominent findings show that the amount of plastic waste collected in 2020 (24.16 Mt) increased by 53.19% in 2028.The pyrolysis of mixed plastic wastes during the project period yielded 359.29 Mt oil, which has a power potential of 1,060.86 GWh. The economic analysis indicated the project is viable and profitable with a positive net present value (US$8.80 million) and profitability index (1.26) greater than 1. The project has 10.6 y payback period, US$0.0752/kWh levelized cost of energy, 22.5% return on investment, and 13.0% internal rate of return. The life cycle assessment results show that conversion of mixed plastic waste to pyrolysis oil for electricity generation during the project period has a total global warming potential (GWP) of 1,311.4 kt CO 2 eq. The GWP is mainly from conversion of pyrolysis oil to electricity (73.42%), pyrolysis oil production (15.01%) and upgrading of pyrolysis oil (11.38%). The consumption of power from the project could avoid the combustion of 2,659.0 t coal, minimizing global warming by 11,278.8 kt CO 2 eq. Sensitivity analysis, which examines the influence of variation in sensitive factors on the success of the project, is presented. This paper provides scientific strategies for optimal investment and decision-making on the environmental sustainability of plastic waste-to-energy pyrolysis projects. [ABSTRACT FROM AUTHOR]

Microplastic pollution is becoming a major issue for human health due to the recent discovery of microplastics in most ecosystems. Here, we review the sources, formation, occurrence, toxicity and remediation methods of microplastics. We distinguish ocean-based and land-based sources of microplastics. Microplastics have been found in biological samples such as faeces, sputum, saliva, blood and placenta. Cancer, intestinal, pulmonary, cardiovascular, infectious and inflammatory diseases are induced or mediated by microplastics. Microplastic exposure during pregnancy and maternal period is also discussed. Remediation methods include coagulation, membrane bioreactors, sand filtration, adsorption, photocatalytic degradation, electrocoagulation and magnetic separation. Control strategies comprise reducing plastic usage, behavioural change, and using biodegradable plastics. Global plastic production has risen dramatically over the past 70 years to reach 359 million tonnes. China is the world's top producer, contributing 17.5% to global production, while Turkey generates the most plastic waste in the Mediterranean region, at 144 tonnes per day. Microplastics comprise 75% of marine waste, with land-based sources responsible for 80–90% of pollution, while ocean-based sources account for only 10–20%. Microplastics induce toxic effects on humans and animals, such as cytotoxicity, immune response, oxidative stress, barrier attributes, and genotoxicity, even at minimal dosages of 10 μg/mL. Ingestion of microplastics by marine animals results in alterations in gastrointestinal tract physiology, immune system depression, oxidative stress, cytotoxicity, differential gene expression, and growth inhibition. Furthermore, bioaccumulation of microplastics in the tissues of aquatic organisms can have adverse effects on the aquatic ecosystem, with potential transmission of microplastics to humans and birds. Changing individual behaviours and governmental actions, such as implementing bans, taxes, or pricing on plastic carrier bags, has significantly reduced plastic consumption to 8–85% in various countries worldwide. The microplastic minimisation approach follows an upside-down pyramid, starting with prevention, followed by reducing, reusing, recycling, recovering, and ending with disposal as the least preferable option. [ABSTRACT FROM AUTHOR]

A new plastic ban has banned the use of single-use non-degradable plastic drinking straws in China's food and beverage industry by the end of 2020. However, this has caused widespread discussion and complaints on social media. What are consumers' reactions and what factors influence consumers to choose bio-straws (substitutes for plastic straws) are unclear. Therefore, this research collected 4367 effective comments (177,832 words in total) on "bio-straws" from social media and extracted keywords based on grounded theory to generate questionnaires. Structural equation modeling was used to analyze the consumption intention and influencing factors of 348 consumers regarding the ban. The results indicate the following: (1) consumer opinion on straws can be summarized into five main categories, namely, consumers' user experience, consumer subjectivity, policy awareness, policy acceptance, and consumption intention; (2) consumer subjectivity, policy awareness, and policy acceptance directly affect consumption intention significantly, while user experience affects consumption intention indirectly; and (3) user experience and consumer subjectivity play significant roles in mediating these relationships. From the perspective of consumers, this study provides an important basis for policymakers to formulate single-use plastic alternative policies in the future. [ABSTRACT FROM AUTHOR]

To reveal the mechanism of influence of different types of biodegradable plastic film mulching and irrigation combinations on the physiological growth characteristics of rice in cold regions, eight types of film mulching irrigation methods were designed, which combined four types of plastic film mulching and two types of irrigation methods for a total of nine treatments. The study analyzed the degradation law of degradable plastic film in rice fields in cold regions, and the effects of film-mulching irrigation methods on rice photosynthetic characteristics, dry matter transport, and rice yield. The results showed that the three biodegradable plastic films were suitable for the rice fields in the northeast cold region. Except for the jointing stage, mulching irrigation treatments could increase the chlorophyll content and net photosynthetic rate of rice, and the improvement degree showed a downward trend with the growth of rice. The film mulching irrigation treatments improved rice stems and leaves dry matter transport and grain contribution. The comprehensive evaluation based on the comprehensive index method showed that the combination of ridge irrigation and thin black biodegradable mulch is the best combination of biodegradable plastic film mulching and irrigation in the study area. [ABSTRACT FROM AUTHOR]

Microplastics (MPs), emerging as significant pollutants, have been consistently detected in aquatic environments, with the Yangtze River experiencing a particularly severe level of microplastic pollution, exceeding all other watersheds in China. Polypropylene (PP), the plastic most abundantly found in the middle and lower reaches of the Yangtze River Basin, has less comprehensive research results into its toxic effects. Consequently, the present investigation employed zebrafish as a model organism to delve into the toxicological impacts of polypropylene microplastics (PP-MPs) with a diameter of 5 μm across varying concentrations (300 mg/L and 600 mg/L). Using histopathological, microbiota profiling, and transcriptomic approaches, we systematically evaluated the impact of PP-MPs exposure on the intestine and liver of zebrafish. Histopathological analysis revealed that exposure to PP-MPs resulted in thinner intestinal walls, damaged intestinal mucosa, and hepatic cellular damage. Intestinal microbiota profiling demonstrated that, the richness, uniformity, diversity, and homogeneity of gut microbes significantly increased after the PP-MPs exposure at high concentration. These alterations were accompanied by shifts in the relative abundance of microbiota associated with intestinal pathologies, suggesting a profound impact on the intestinal microbial community structure. Concurrently, hepatic transcriptome analysis and RT-qPCR indicated that the downregulation of pathways and genes associated with cell proliferation regulation and DNA damage repair mechanisms contributed to hepatic cellular damage, ultimately exerting adverse effects on the liver. Correlation analysis between the intestinal microbiota and liver transcriptome profiles further highlighted significant associations between intestinal microbiota and the downregulated hepatic pathways. Collectively, these results provide novel insights into the subacute toxicological mechanisms of PP-MPs in aquatic organisms and highlight the need for further research on the ecological and health risks associated with PP-MPs pollution. • Polypropylene microplastic induced significant damage on gut and liver of zebrafish. • Polypropylene exposure led to Cetobacterium decrease and Rhizobiales increase in intestine. • Hepatic transcriptome analysis clarified molecular mechanisms of liver injury. • Correlated linkage between gut microbes and hepatic altered pathways was established. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Plastics around the globe have been a matter of grave concern due to the unavoidable habits of human mankind. Taking waste statistics in India for the year 2019–20 into account, the data of 60 major cities show that the generation of plastic waste stands tall at around 26,000 tonnes/day, of which only about 60 % is recycled. A majority of the non‐recycled plastic waste is petrochemical‐based packaging materials that are non‐biodegradable in nature. Vegetative/food waste is another global issue, evidenced by vastly populated countries such as China and India accounting for 91 and 69 tonnes of food wastage, respectively in 2019. The mitigation of plastic packaging issues has led to key scientific developments, one of which is biodegradable materials. However, there is a way that these two waste‐related issues can be fronted as the analogy of "taking two shots with the same arrow". The presence of various bio‐compounds such as proteins, cellulose, starch, lipids, and waxes, etc., in food and vegetative waste, creates an opportunity for the development of biodegradable packaging films. Although these flexible packaging films have limitations in terms of mechanical, permeation, and moisture absorption characteristics, they can be fine‐tuned in order to convert the biobased raw material into a realizable packaging product. These strategies could work in replacing petrochemical‐based non‐biodegradable packaging plastics which are used in enormous quantities for various household and commercial packaging applications to combat the ever‐increasing pollution in highly populated countries. This paper presents a systematic review based on modern scientific tools of the literature available with a major emphasis on the past decade and aims to serve as a standard resource for the development of biodegradable packaging films from food/vegetative waste. [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]

Large amounts of plastic film residues in soil have posed a negative impact on the crops and environment. Alternatively, the sugarcane bagasse has widely been used as inexpensive, abundant, easily available, and sustainable raw material. In this study, a biodegradable film was developed to treat the sugarcane bagasse, in order to reduce the pollution of plastic film and the seasonal drought in the spring in Yunnan-Guizhou Plateau of South China. A Box-Behnken experiment was designed, where the sizing agent components of sodium silicate, soluble starch, and silicone oil content were chosen as the independent variables, whereas, the response values were the degradation rate, tensile strength, soil temperature, and soil moisture. Field experiments were conducted in the School of Modern Agricultural Engineering, Kunming University of Science and Technology, China from September to November 2017, where ten mulching times (10, 19, 27, 34, 40, 45, 49, 52, 62, and 72 d) were designed. Taking the no film mulching as a control (CK), the influence of the film was determined on the degradation rate, tensile strength of two mulching modes, as well as soil temperature and moisture. Scanning Electron Microscopy (SEM) was used to characterize the fiber structure of biodegradation film under two mulching modes during the test period. A bagasse biodegradable film was verified to regulate the degradation cycle for the high soil temperature and moisture, particularly for the better soil environment of sowing in spring. The results showed that the degradation rate and the intensity of the underground film were higher than that of the surface film after 72 days of mulching, where the mass-loss rates of the two mulching modes were 86.41% and 70.44%, respectively. Under the surface biodegradable film mulching, the average degradation rate in test group 1 was the lowest during the entire degradation period, which was 20.1%. The tensile strength in the surface test groups decreased to 9.77-21.97 N/m after 72 days of degradation, whereas, the mechanical properties in the underground tests group were close to 0 N/m after 49 days. The fiber of the mulch film was outstandingly dispersed, where the short fibers were appeared in the SEM images, indicating an excellent consistence with the biodegradable film holes and the gradual decline in the quality during degradation. There was no significant difference in the daily accumulated temperature of the soil in the two mulching modes (P>0.05), compared with the CK, but the significant differences in the accumulated temperature of the soil in the morning, noon, and evening. In the case of ground surface mulching, the thermal preservation performance in test group 1 was the best, where the accumulated temperature in the morning and evening was higher by 6.1% and 5.4%, respectively, and that lower by 7.9% at noon, compared with the CK. The soil moisture content in each test group was significantly higher than that of the CK (P<0.05) during the entire experimental period. In addition, the water retention capacity in test group 1 was the highest. It infers that the capacity of water retention decreased with the degradation of biodegradable film. However, the soil water content in test group 1 was 11.36%, which was significantly higher by 158.77% than CK. To sum up, considering soil moisture, soil temperature, degradation rate of biodegradable film and tensile strength comprehensively, the sizing agent of test group 1 had the best performance among all test groups, and the contents of which were: sodium silicate 10%, soluble starch 20%, and silicone oil 15%. Therefore, the sugarcane bagasse biodegradable mulching film was feasible to increase the soil temperature and moisture, providing for promising application prospects in agricultural production. [ABSTRACT FROM AUTHOR]

With the rapid development of planting techniques using plastic film mulching, the content of residual plastic film in soil increases year by year, which pollutes the soil and water, endangers the growth of crops and reduces the quality and yield of agricultural products. Therefore, in order to solve the problem that plastic film with a thickness of 0.008 mm, commonly used in China, is difficult to recycle, this study designed the residue film recycling machine based on the existing research results. After harvesting cotton in Xinjiang, the working performance of the residue film recovery machine of plough layer was measured. Through theoretical optimization and field experiments, the effects of conveyor speed, distance between elastic teeth and type of elastic teeth on residual film recovery were studied. The relationship between the parameters of the residual film recovery machine and the recovery effect of the residual film was analyzed. When the rotational speed and inclination angle of the conveying and separating device were 74 rpm, 35° and 120 rpm, 45°, respectively, under the condition that the distance between C-shaped elastic teeth was 59 mm, the recovery and separation rate of residual plastic film were 88.12% and 83.27%, respectively. Based on the study results, it is recommended to accelerate the development of naturally degradable agricultural plastic film or to popularize and apply thickened film. Relevant local standards and policies have been formulated to address the problem of residual film pollution, and a governance system has been established for the benefit of the government, scientific research institutions, enterprises and farmers. This study provides a reference for mechanized recovery of residual plastic film in soil and treatment of soil pollution. [ABSTRACT FROM AUTHOR]

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Following the stipulation to replace nondegradable plastics with biodegradable materials in China, cost-effective and water-resistant packaging materials have become increasingly necessary. In this work, lignin reinforced thermoplastic cassava starch (TPS) pieces were prepared by filling glycerol and lignin powder into starch via a melt blending process and then being pressed into thin pieces. A mechanical properties test showed that following the addition of 3 wt% lignin, the tensile strength of the TPS piece was improved to 16.15 MPa from 3.71 MPa of the original TPS piece. The porous structures of the lignin powder tie the TPS macromolecular chains, induce higher crystallization, and thus provide higher tensile strength and lower elongation at break. After sandwiching two pieces of poly (butylene adipateco-terephthalate) (PBAT)/peanut shell powder composite thin film to each side of the TPS piece, the PBAT/TPS/PBAT sandwich gains excellent water resistance properties. However, as soon as the sandwich piece is cut into smaller ones, they absorb water quickly, implying such pieces can be biodegraded rapidly. These characteristics make it especially suitable for use in the preparation of cabinet waste bags, which are generally stirred into organic fertilizer with the cabinet waste. Slow degradation may negatively affect soil health and farm production. [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]

• The DOC released from plastic that can be used by microorganisms in soil. • Plastic carbon participated in soil carbon cycle was confirmed. • PE plastic farmland in northwest China, 1.39 × 105 tons of excess CO 2 emissions. • Replace PE plastic film with biodegradable film, 7.5-fold more excess CO 2 emissions. Plastic film mulching is an important agricultural practice, but its accumulation in soil threatens soil health. Here, we explored the effects of plastic film on soil carbon cycling through microcosmic incubation and estimated the excess carbon dioxide (CO 2) emissions of farmland soils through Meta-analysis. The results showed that plastic film released dissolved organic carbon (DOC) into the soil, which was rapidly used by microorganisms and accelerated the decomposition of soil organic carbon (SOC), increasing CO 2 emissions. Soil moisture content and soil carbon content affected the rate of DOC release from plastic. We estimated that residual plastic film farmland in six northwest provinces of China, 1.39 × 105 tons of excess CO 2 emissions in 2020. The soil excess CO 2 emissions was influenced by polyethylene (PE) plastic concentration and soil type. Replace PE plastic film with biodegradable film, 1.05 × 106 tons of excess CO 2 emissions, 7.5 times that of PE plastics. [Display omitted] [ABSTRACT FROM AUTHOR]

• The greenhouse gas (GHG) emissions were estimated by material flow analysis. • A total of 5544.0 Mt CO 2 eq GHGs were emitted from 1950 to 2020, with 496.8 Mt emitting in 2020. • Monomer production stage had the highest GHG emissions. • Electricity consumption was a major GHG emission source. • The GHG emissions of baseline and comprehensive scenarios reach a peak in 2040 and 2030, respectively. The unprecedented rise of plastics has caused substantial greenhouse gas (GHG) emissions. In this study, material flow analysis and GHG accounting models were integrated to estimate the GHG emissions of plastics in China from 1950 to 2020, and the dynamic evolution from 2021 to 2060 was tracked. The cumulative GHG emissions were 5544.0 Mt CO 2 eq from 1950 to 2020, and 496.8 Mt CO 2 eq of GHG were emitted in 2020. Monomer production stage had the highest GHG emissions (58.6%) and electricity consumption was the major emission source (69.0%). GHG emissions of baseline and comprehensive scenarios would reach a peak in 2040 and 2030, respectively. Neutral scenario was the only scenario that achieved carbon neutrality by 2060. GHG emission reduction requires reducing plastic demand, improving waste recycling, and adopting bio-based plastics and renewable energy. This study scientifically explored the path of carbon peak and carbon neutrality to combat climate change. [Display omitted] [ABSTRACT FROM AUTHOR]

The use of biodegradable plastic film mulching as a replacement for polyethylene plastic film has gained recognition due to its reduced environmental pollution. However, its impact on soil environment is not yet fully understood. Here, we compared the effects of different plastic film mulching on the accumulation of microbial necromass carbon (C) and its contribution to soil total C in 2020 and 2021. Results showed that biodegradable plastic film mulching decreased the accumulation of fungal necromass C compared to no plastic film mulching and polyethylene film mulching. However, the bacterial necromass C and soil total C were not affected by the plastic film mulching. Biodegradable plastic film mulching decreased the soil dissolved organic carbon content after maize harvest. Random forest models suggested that soil dissolved organic C, soil pH and the ratio of soil dissolved organic C to microbial biomass C were important factors in regulating the accumulation of fungal necromass C. The abundance of the fungal genus Mortierella was also found to have a significant positive contribution to the accumulation of fungal necromass C. These findings suggest that biodegradable plastic film mulching may decrease the accumulation of fungal necromass C by changing substrate availability, soil pH, and fungal community composition, with potential implications for soil C storage., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The interaction between microplastics (MPs) and microorganisms may alter the distribution of antibiotic resistance genes (ARGs) in water and increase the ecological risk of drinking water sources. To investigate the characteristics of MPs geographical distribution and its potential ecological risk in typical urban water, this study was conducted in Zhushan Bay, and we carried out a combination of tests to analyze the distribution of MPs and the migration changes of their surface microbial community composition and ARGs in different media by 16S rRNA gene high-throughput sequencing, non-targeted metabolomics and qPCR genomics in the near-shore (I), middle area (Ⅱ) and near-lake (Ⅲ) of Zhushan Bay. The results showed that MPs in fibrous form were dominant in the aquatic environment of Zhushan Bay; Polyurethane (PU) and Silicone were the main MPs types in Zhushan Bay. The abundance of MPs in the water of Zhushan Bay was winter > summer > autumn > spring; and in the sediment was winter > summer > autumn > spring, respectively. The distribution results of MPs in geographical location are as follows: In the water I > Ⅱ > Ⅲ, sediment exhibited Ⅱ > Ⅲ > I. The results indicate that physicochemical factors will affect the geographical distribution of MPs and their surface microbial community composition in the aquatic environment of Zhushan Bay. More cooperative behaviors and increased metabolically important pathways occurred in the microbial network on water-MPs compared to sediment-MPs. However, the microbial community in the sediment-MPs was more stable and had higher abundance of mobile genetic elements (MGEs). A total of 362 differential metabolites were detected, of which 193 were up-regulated and 19 down-regulated differential metabolites. blaTEM , Sul , and inti1 were prevalent in both the water and sediments of Zhushan Bay. Sul1 was most contaminated in ARGs. This study provides the latest field data and insights into MPs pollution in key aquatic environments. [Display omitted] • MPs abundance is winter > summer > autumn > spring. • MPs shape is mainly fiber; PU and Silicone are the main MPs types. • Water-MPs is near-shore (Ⅰ)> middle area (Ⅱ)> near-lake (Ⅲ), sediment-MPs is Ⅱ > Ⅲ > Ⅰ. • There are significant differences in microbial diversity on MPs in water and sediment. • There was a significant correlation between MPs, metabolites and ARGs. [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]

Microplastics (MPs) are emerging pollutants. Landfills store up to 42% of worldwide plastic waste and serve as an important source of MPs. However, the study of MPs distribution and the plastic biodegradation potential in landfills is limited. In this study, the distribution of abundance, size, morphology and polymer type of MPs and plastics biodegradation species in refuse samples along landfill depths were extensively investigated within a large-scale landfill in Shenzhen, China. In addition, plastics biodegradation enzymes were evaluated in seven Chinese large-scale landfills leachate. MPs distribution pattern was investigated in all refuse samples. The abundance of MPs in refuse samples varied between 81 and 133 items/g. The size of MPs in all samples varied between 0.03 and 5 mm, and the average sizes were 1.2 mm ± 0.1 mm. The main morphology and polymer type were fragments and cellophane, respectively. Landfill depth was significantly negatively correlated with the relative abundance of MPs size 1–5 mm (p < 0.05) and was positively correlated with the relative abundance of MPs size < 0.2 mm (p < 0.05), suggesting that plastics were broken down during municipal solid waste decomposition. The multiple regression on matrices analysis further showed the landfill depths and plastic morphology significantly impact the MPs distribution. The strains, Lysinibacillus massiliensis (with relative abundance of 1.8%) for low-density polyethylene and polystyrene biodegradation, and Pseudomonas stutzeri (0.1%) for low density polythene and polypropylene biodegradation, were detected on the plastic surface with high relative abundance. Furthermore, 75 plastic degradation species and their associated 31 enzymes (breakdown 24 plastics) were discovered in seven landfills leachate samples. [Display omitted] • The abundance of MPs in refuse samples ranged from 81 to 133 items/g. • Landfill depths was correlated with the relative abundance of MPs size (p < 0.05). • Depths and plastic morphology significantly impact the MPs distribution. • Typical plastic degradation strains were detected on the plastic surface. • 75 plastic degradation species and their associated 31 enzymes was discovered. [ABSTRACT FROM AUTHOR]

• Scavenging efficiency of rainfall for airborne MPs extended a period after the rain. • Contributions of airborne MPs to rivers could not be ignored. • Intercepting masses by trees only offset those loading into rivers. • Sparse and lowrise buildings are sensitive areas for airborne MPs. The issue of airborne microplastics (AMPs) pollution is receiving increasing attention, but effective solutions are still limited. In this study, AMPs were collected in pairs from an open space and under a tree (Ficus virens) in the suburb of Chengdu, southwest China, to investigate the current pollution status. The meteorological factors and underlying surface types were analyzed to investigate whether these factors could influence and mitigate the pollution of AMPs. The results showed that the fibrous AMPs accounted for the vast majority and the dominant polymers were polypropylene-polyethylene (PP-PE) and polypropylene (PP), with an average deposition flux of AMPs of 192 n/m2/d (22.41 µg/m2/d). Rainfall was found to have the prolonged scavenging efficiency for AMPs, which could extend to 8 to 48 hours after the end of rainfall, and this is a new insight into the relationship with meteorological factors. Interactions between the key underlying surface types and AMPs were also studied. The representative tree species (Ficus virens) had a low interception rate of 6.25% for AMPs and retained mainly small-sized AMPs and more fibers. The masses of AMPs loaded into Chengdu rivers could reach 1149 kg annually, with the unit mass load of 13.6 kg/km2 in urban rivers and 8.2 kg/km2 in suburban rivers. The masses intercepted by trees and bushes throughout the city only offset the masses loading in rivers, and open or sparse buildings were found to be sensitive areas for AMPs, which indicated the urgent need to control and mitigate the pollution of AMPs, especially in these sensitive areas. This work comprehensively analyzed the AMPs pollution from various perspectives and attempted to find ways to mitigate this pollution. [Display omitted] [ABSTRACT FROM AUTHOR]

The replacement of plastic film with biodegradable film is important for reducing plastic film residual pollution in semi-arid regions of northern China. However, information on biodegradable film improvements based on the hydrothermal requirements of major food crops in the typical plastic film mulching area is limited. This study used a combination of field data measurements and curve fitting to assess the spatiotemporal distribution of soil hydrothermal variation and the corresponding maize yield in the field under biodegradable film mulching (BM), polyethylene film mulching (PM), and without mulching (CT). The warming effect of BM was between those of PM and CT and all treatments differed significantly from each other. The duration of the warming effect of BM was shorter than that of PM, and the warming effect of both disappeared at the early jointing stage of maize. The BM soil moisture was significantly lower compared with PM and CT throughout the soil profile (0–180 cm). Moreover, moisture fluctuations were observed in the 0–40 and 40–120 cm soil layers of BM after degradation, and the timing of fluctuations coincided with the filling period of maize. Consequently, the water use efficiency and yield of BM were lower than those of PM. Hence, we suggest that the conservation effect of biodegradable film mulching on soil moisture should persist until the end of the maize filling period, and that the start-up stage of degradation cannot be based solely on the disappearance of the warming effect. [Display omitted] • The warming effect of BM is between PM and CT. • The warming effect of BM and PM disappeared at early jointing stage of maize. • Soil moisture fluctuations coincided with the filling period of maize under BM. [ABSTRACT FROM AUTHOR]

Freshwater rivers play the key role in providing drinking water sources and building the bridge of oceans and lands. Hence, environmental pollutants can be transferred into drinking water through a water treatment process and transported land-based microplastics into the ocean. Microplastics are considered a new pollutant that is becoming a threat to freshwater ecosystems. The present study investigated the temporal and spatial variation of microplastics abundance and their characteristics of occurrence in surface water, sediment and soil samples of Baotou section of Yellow River in China in March 2021 and September 2021. According to the LDIR analysis, the average abundances of microplastics in wet season (surface water 2510.83 ± 2971.27n/L, sediment 6166.67 ± 2914.56n/kg) were higher than that in dry season（surface water 432.5 ± 240.54n/L, sediment 3766.67 ± 1625.63n/kg), particularly being significant difference in the dry and wet seasons of surface water. The predominant polymer types in surface water (PBS and PET during the dry season, PP during the wet season) demonstrated that the temporal variation of microplastics abundance in surface water could be attributed to the combined effect of the regional precipitation, fishing activities and improper disposal of plastic waste. And the results of spatial abundances of microplastics showed that the microplastics abundance of soil and sediment was higher than that in river water and microplastics abundance in the river of the south side was the higher than other water sampling sites, revealing the differences of microplastics burden at the different sampling sites. Moreover, it is worth noting that a large amount of PAM was detected in sediments and soil, but not in water, and the biodegradable plastics PBS and PLA were also detected in the Yellow River. It was a very useful information for evaluating environmental impacts and ecological effects of degradable plastics compared to the traditional plastics after the implementation of a new environmental policy in the future. Thus, this study provided insights into the temporal-spatial characteristics of microplastics in an urban river and raised environmental management awareness of the long-term threat to drinking water safety by microplastics. [Display omitted] • The temporal and spatial changes of microplastics in Baotou section of Yellow River were reported for the first time. • The abundance of microplastics in water samples in the wet season was higher than that in the dry season. • The abundance of microplastics was higher in soil and sediment than in surface water. • The size of microplastics was mainly distributed in 20–50 μm in all samples. • The composition of microplastics showed spatiotemporal variation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A HRMS-based screening strategy was developed to identify novel OPEs; • Forty-two OPEs were identified in plastic food packaging samples; • Seven novel OPE structures were reported for the very first time; • Oxidation of OPAs could be an important source for OPEs in plastics; • OPEs exhibited great migration potentials from plastic food packaging to isooctane. Organophosphate esters (OPEs) are widely used as plasticizers in plastic food packaging; however, the migration of OPEs from plastic to food is largely unstudied. We do not even know the specific number of OPEs that exist in the plastic food packaging. Herein, an integrated target, suspect, and nontarget strategy for screening OPEs was optimized using ultrahigh-performance liquid chromatography–high-resolution mass spectrometry (UHPLC–HRMS). The strategy was used to analyze 106 samples of plastic food packaging collected in Nanjing city, China, in 2020. HRMS allowed full or tentative identification of 42 OPEs, of which seven were reported for the first time. Further, oxidation products of bis(2,4-di- tert -butylphenyl) pentaerythritol diphosphite (AO626) in plastics were identified, implying that the oxidation of organophosphite antioxidants (OPAs) could be an important indirect source of OPEs in plastics. The migration of OPEs was examined with four simulated foods. Twenty-six out of 42 OPEs were detected in at least one of the four simulants, particularly isooctane, in which diverse OPEs were detected at elevated concentrations. Overall, the study supplements the list of OPEs that humans could ingest as well as provides essential information regarding the migration of OPEs from plastic food packaging to food. [ABSTRACT FROM AUTHOR]

Ultraviolet absorbents (UVAs) in the environment have been of increasing concern because of their potential toxicity. However, data on UVAs in the biodegradable plastics are still limited. In this work, we determined the concentrations of 13 UVAs in 6 different types of biodegradable plastic products from Beijing, China, by an ultra-high-performance liquid chromatography with mass spectrometry and found the total concentrations in the range of 37.21-1,138,526 ng g -1 . These target UVAs, BP (benzophenone), BP-3, BP-12, UV-328, UV-234, UV-326, UV-329, UV-360 and UV-P are prevalent in the plastic bags, garbage bags, food packaging bags, plastic lunch boxes and tableware, product packing bags and mulch films, except for BP-1, UV-320, UV-327 and UV-PS. This finding showed that the total concentrations of the 13 UVAs in biodegradable mulch films (mean: 1,138,527 ng g -1 ) were several orders of magnitude higher than those in the other 5 categories of samples (mean: 37.21-186.9 ng g -1 ). And the UV-328 and BP-1 were the most important components of UVAs in the biodegradable mulch films, with the levels ranging of 726,568-1,062,687 ng g -1 and 317,470-506,178 ng g -1 , respectively. As the majority of UVAs were detected in biodegradable plastics, the potential risk of UVAs exposure may exist in the environment with the large-scale use of biodegradable plastics.

In agricultural production, biodegradable plastic mulching film (Bio-PMF) has the potential to replace conventional plastic mulching film (CPMF) due to its degradability, but their impacts on soil-crop ecology are controversial. In this study, from 2019 to 2021, effects of CPMF and Bio-PMF on the soil-crop ecology and soil pollution were evaluated on a peanut farm. Compared to the Bio-PMF, an overall improvement in the soil-peanut ecology under the CPMF was observed, including an increase of 10.77 ± 4.8% in peanut yield, an amelioration of four soil physicochemical properties (total P and available P in the flowering stage, total P and temperature in the mature stage), an increase of rhizobacterial relative abundances in class level (Bacteroidia, Blastocatellia, Thermoleophilia and Vicinamibacteria in the flowering stage, Nitrospira and Bacilli in the mature stage) and genus level (RB41 and Bacillus in the flowering stage, Bacillus and Dongia in the mature stage), and an enhancement of soil nitrogen metabolism abilities (ureolysis, nitrification and aerobic ammonia in the flowering stage, nitrate reduction and nitrite ammonification in the mature stage). These preserved soil nutrients and temperature, reshaped rhizobacterial communities, and enhanced soil nitrogen metabolism abilities in the mature stage were obviously correlated with peanut yield under CPMF. However, such remarkable relations were not existed under Bio-PMF. In addition, compared with Bio-PMF, CPMF significantly increased the contents of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP) and microplastics (MPs) in soil by 79.93, 44.55, 138.72 and 14.1%, respectively. Thus, CPMF improved soil-peanut ecology and caused serious soil pollution, while Bio-PMF introduced little pollutants into the soil and had little impact on soil-peanut ecology. Based on these, the degradation ability of CPMF or the ecological improvement capacity of Bio-PMF should be improved to obtain the environmentally and soil-crop ecology friendly plastic film in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The detection of microplastics (MPs) in agricultural soils has raised alarms on their potential impacts on agricultural production, particularly in China where agriculture has great importance for domestic consumption and export. This review aims to present the abundance, sources and impacts of MPs in the agricultural soils of China. It has the novelty of synthesizing sustainable agronomic practices to reduce MPs pollution of agricultural soils based on the sources identified. According to the extant study, the abundance of MPs in the agricultural soils in China ranged from 4.94 items/kg in the lower reaches of Yangtze River to 40,800 items/kg in Yunnan Province. The MPs were predominantly ≤1 mm and were mainly composed of fragments, films and fibers. Polyethylene and polypropylene MPs were most reported. Plastic mulching films were the most significant source of MPs in agricultural soils, followed by abandoned greenhouses and the use of organic fertilizers containing fugitive MPs or whose sources were often MPs-polluted. MPs were found to alter soil physicochemical properties for instance, water flow, water-stable aggregates, soil aggregation, soil pH, bulk density and nutrient contents. MPs also affect soil biota through changing the richness and diversity of soil microbial community while retarding growth and disrupting physiological functions of soil macrofauna. The effects of MPs on crops vary and range from alteration of biomass, metabolism and nutrient demands to impacted photosynthesis. Sustainable solutions include the use of grass clippings – straw mix as organic mulches, the use of compost as soil amendment in conjunction with grass-straw mix and incorporation of weed-suppressing biomass into compost, the use of jute and biodegradable plastics for greenhouses, proper decommissioning of abandoned greenhouses as well as setting standards for allowable MPs contents in organic fertilizers and irrigation water. [Display omitted] • Agricultural soil in China contains 4.94 items/kg to 40,800 items/kg microplastics. • Microplastics affect water-stable aggregates, soil nutrient profiles and microbes. • Straw-grass clipping mulch and compost-sawdust mulch are good substitutes. • Jute and bioplastics are better greenhouse materials. • Biosolids may need thermal treatment and regulatory approach. [ABSTRACT FROM AUTHOR]

In recent years, microplastics (MPs) as emerging carriers for environmental pollutants have attracted increasing worldwide attention. However, the adsorption of heavy metals on MPs, especially for biodegradable MPs, has been still poorly understood in estuarine environments. In this study, we investigated the aging of biodegradable and conventional MPs in the Pearl River Estuary after long-term exposure and their impacts on the adsorption of heavy metals from seawater. The results showed that the changes in surface characteristics were more prominent on biodegradable MPs than on conventional MPs after aging. Both biodegradable and conventional MPs could adsorb heavy metals, and their adsorption capacities fluctuated greatly on different MPs and different exposure times. The adsorption capacities of Cu, Pb, and As on biodegradable MPs were higher than those on conventional MPs, whereas Mn, Cr, and Co had lower adsorption on biodegradable MPs after 9–12 months by inductively coupled plasma-mass spectrometry (ICP-MS). The aging characteristics (CI, O/C, and X c) of MPs accounted for a contribution of 51.0% on heavy metal adsorption, while the environmental factors (temperature, salinity, pH, and heavy metal concentration) only contributed to 13.2%. Therefore, the present study can provide important evidence on the environmental behaviors and ecological risks of biodegradable and conventional MPs in estuarine systems. [Display omitted] • Adsorption of heavy metals on biodegradable MPs was first reported in the Pearl River Estuary. • The changes in the physicochemical property of biodegradable MPs were distinct. • Biodegradable MPs tend to particularly adsorb Cu, Pb, and As. • The aging properties of MPs had a strong relationship with heavy metal adsorption. [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]

Soil desiccation is a major challenge faced by subsistence farmers growing alfalfa (Medicago sativa L) in consecutive cultivation in semiarid regions. We hypothesized that alfalfa fodder yield would increase with the length of growing season, growing degree-days, and rainfall. A field experiment was conducted on alfalfa production from 2012 to 2016 to 1) determine the response of fodder yield to rainfall, the length of growing season, and accumulated growing degree day (AGDD) in different growing-cutting stage (GCS)s; 2) obtain the suitable mulching material and the optimum ridge width for ridges with manually compacted soil (MCS), mulched with bio-degradable film (BF), and plastic film (PF). There were 10 treatments (3 ridge widths × 3 ridge-mulching materials + flat planting (FP) as control) with three replications laid in a randomized block design. The ratio of the first GCS to the second GCS in fodder yield ranged from 1.10 to 4.55, which was similar to the ratio of the first GCS to the third GCS in fodder yield ranged from 1.14 to 4.59, although rainfall, the length of growing season, and AGDD were different during the two or three GCSs. The highest fodder yield was obtained from the first GCS in one year and reached the highest level in the second growing year, and maintained a similar level in the subsequent years, although rainfall, the length of growing season, and AGDD varied during the five year periods. Fodder yield was affected by both the rainfall in the GCS and the available soil moisture prior to the GCS. Compared to FP, the increase of evapotranspiration for MCS, BF, and PF was 11, 61, and 63 mm, respectively. Fodder yield for BF and PF increased by 28% and 33%, respectively. Fodder yield for MCS maintained the same level as that for FP. Evapotranspiration increased and fodder yield decreased as ridge width increased. The optimum ridge width for MCS, BF, and PF was 29, 39, and 37 cm, respectively, across five years. Future study should focus on alfalfa-crop rotation to mitigate soil desiccation after alfalfa consecutively production. • High rainfall, growing season length and temperature did not mean high alfalfa fodder yield. • Soil moisture prior to growing-cutting stage and rainfall in the stage had impact on alfalfa fodder yield. • Rainfall had higher effects on alfalfa fodder yield than actual evapotranspiration. • Highest fodder yield was obtained in first growing-cutting stage and reached highest level in second stand year. • Optimum ridge width for ridge compacted with soil, biodegradable and plastic film was 29, 39 and 37 cm, respectively. [ABSTRACT FROM AUTHOR]

• In wet year, the ET under no film mulching was lower than film mulching, but was higher in dry year. • A slight T difference under BFM and PFM occurred in the late crop growth stages. • Max E difference at B station and J station happen in early and late growth stages, respectively. • Water use efficiency and irrigation use efficiency under PFM and BFM were improved. Biodegradable film mulching (BFM) in various crops is a good alternative to plastic film mulching (PFM). However, the difference in field water consumption between BFM and PFM has not been fully investigated. A four-year experiment with an improved evapotranspiration (ET) model (BSW) was performed to systematically evaluate and compare the effects of BFM, PFM, and no film mulching (NFM) on ET dynamics. The experiments were done in the Hetao Irrigation District of China at the Baleng experimental station (B station) with sandy soil in 2016-2017 and the Jiuzhuang experimental station (J station) with sandy loam soil in 2018-2019. The results of multi-year verification illustrated that the model accuracy was well-supported during 2016-2019 with mean absolute error (MAE) of 9.0%-16.9% and 13.1%-19.1% for ET and evaporation (E), respectively. The average cumulative ET (CET) under FM (i.e., BFM and PFM) was 443.5 mm each year and decreased by 13.4% compared to NFM. However, there was an obvious difference in CET during the different hydrological years, especially in the early crop growth stages. In the wet years (2016 and 2018), the average CET under FM increased by 6.2%-7.0% compared to NFM but decreased by 7.1%-11.8% in the dry years (2017 and 2019). The transpiration (T) difference between FM and NFM primarily appeared in the early crop growth stages, and T / ET under FM was significantly higher than with NFM by 46.9%-50.2%. An obvious E difference between BFM and PFM was observed in the later crop growing stages due to a greater area of the disintegrated biodegradable film. Additionally, crop yield under PFM and BFM increased by 35.4% and 28.3% compared with NFM, respectively, and water use efficiency (WUE) increased by 47.1% and 35.8%, respectively. Thus, biodegradable film is recommended to replace plastic film to effectively promote the development of sustainable agriculture. [ABSTRACT FROM AUTHOR]

Plastic polyethylene mulch has been widely used in crop production, but also causes environmental pollution if plastic residues accumulate in soil. Biodegradable plastic mulches (BDM) are a potential solution to problems caused by polyethylene mulches, as BDMs are designed be tilled into the soil after the growing season and then biodegrade. However, the agronomic performance of BDMs still needs to be tested for comparison to polyethylene mulch. We carried out a two-year field experiment in 2018 and 2019 in a typical humid continental climate in Northeast China. Maize was planted in a ridge-furrow pattern, with mulching treatments consisting of no mulch (control), clear BDM, black BDM, clear polyethylene, and black polyethylene. Clear mulches increased soil temperature when compared to no mulch control treatments, while black mulches decreased or did not change soil temperature during the early growing season. Soil temperature and root morphology were similar between BDM and polyethylene mulches for a given type of plastic color. Maize yield did not differ across all the treatments. Maize protein, fat, N and P contents were generally higher for black BDM than other treatments, suggesting that maize quality benefited especially from black BDM. Overall, these results show that, in a humid continental climate, the agronomic performance of clear and black BDMs was equivalent to, or better than, that of polyethylene plastic mulches for maize production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)