White Pollution Research Articles

Toxic entanglements: Multispecies politics, white phosphorus, and the Iraq War in Alaska

AbstractThis article explores avian experiences with toxic war processes that unfold across space and time. Joining together three evolving areas of interest in global politics – ontologies of war, interspecies relations, and sensory politics – the article develops a view of war that centres ongoing war processes that affect more-than-human life in and outside of international warzones. Advancing a multispecies form of inquiry attentive to local voices, including Upper Cook Inlet Tribes, the article examines how interspecies relations emerge in national security debates about long-lasting ecological costs of war. Specifically, it offers an analysis of US Department of Defense hearings surrounding the controversy over reopening Eagle River Flats – an Alaskan estuary that had been polluted with white phosphorus munitions – for weapons testing and training during the Iraq War. The article also considers the experiences of two migratory avian communities (northern pintails and tundra swans) with toxic white phosphorus pollution, illustrating more-than-human sensory perspectives on the space and time of war processes. These conceptual and empirical moves reposition national security concerns about wartime risk into a much broader post-anthropocentric perspective.

Research Progress of Polyvinyl Alcohol Water-Resistant Film Materials.

Polyvinyl alcohol (PVA) is one of the few biodegradable synthetic resins from petroleum-based sources that can alleviate white pollution in the environment. PVA film materials have excellent properties, such as high barrier, high transparency, high toughness, biocompatibility, and adjustable water solubility. However, due to the presence of hydrophilic hydroxyl groups in the side chain of PVA resin, when PVA film is placed in a humid or water environment, swelling or even dissolution will occur, which greatly limits its application. Therefore, it is necessary to modify PVA resin to improve water resistance without reducing other properties and can also impart various functionalities to it, thereby widening the application range. This paper reviews the water-resistant modification methods of polyvinyl alcohol and the application of water-resistant films and provides an outlook on the development trend of PVA water-resistant films.

Preliminary Findings of Polypropylene Carbonate (PPC) Plastic Film Mulching Effects on the Soil Microbial Community

The farmland residual film pollution caused by traditional PE film has an adverse impact on crops and the environment. Polypropylene carbonate (PPC) film is a fully biodegradable film that can alleviate “white pollution”. In this study, the soil physicochemical properties and the composition and function of the soil community of FM (PPC film mulching) and CK (no film) treatments were determined to explore the effect of PPC film mulching on soil and the soil microbial community. Furthermore, the microorganisms at different time periods during the degradation of PPC mulch film were also analyzed. The results showed that film mulching increased soil pH but decreased the contents of EC and SOC, and there was no significant difference in the contents of AP and AK. The relative abundance of the phyla Acidobacteria was increased with film mulching, and the relative abundance of the genera MB_A2_108 also increased in the film mulched soil. Among the soil physicochemical properties, pH and SOC were the most important factors leading to changes in the composition of the bacterial and fungal communities. PPC film mulching had no significant effect on soil microbial community abundance and diversity. In addition, Pseudomonas, Flavobacterium, and Rhizobacter were dominant in the degradation of PPC film. Our research results provide a scientific theoretical basis for soil safety and the large-scale use of PPC biodegradable mulching films and a research foundation for the degradation of PPC plastics.

Birth cluster simulations of planetary systems with multiple super-Earths: initial conditions for white dwarf pollution drivers

ABSTRACT Previous investigations have revealed that eccentric super-Earths represent a class of planets that are particularly effective at transporting minor bodies towards white dwarfs and subsequently polluting their atmospheres with observable chemical signatures. However, the lack of discoveries of these planets beyond a few astronomical units from their host stars prompts a better understanding of their orbital architectures from their nascent birth cluster. Here, we perform stellar cluster simulations of three-planet and seven-planet systems containing super-Earths on initially circular, coplanar orbits. We adopt the typical stellar masses of main-sequence progenitors of white dwarfs ($1.5\, \mathrm{M}_{\odot }$–$2.5\, \mathrm{M}_{\odot }$) as host stars and include 8000 main-sequence stars following a Kroupa initial mass function in our clusters. Our results reveal that about 30 per cent of the simulated planets generate eccentricities of at least 0.1 by the time of cluster dissolution, which would aid white dwarf pollution. We provide our output parameters to the community for potential use as initial conditions for subsequent evolution simulations.

Facile preparation of self-assembled high-performance cellulose based composite

The huge accumulation of plastic wastes is emerging as a serious threat to the ecological environment and human health. Herein, inspired by the reinforcement principle of lignin-carbohydrate complexes (LCC) in the natural trees, we design a green, highly efficient, and eco-friendly method to prepare cellulose composites with excellent performances. Cationic Guar Gum (CGG) and Lignosulfonate (LS), which are derived from biomass, are employed as raw materials to form LS-CGG complexes (LGC) acted as LCC analogs to improve the performance of the cellulose framework. Based on the principle of electrostatic interactions, a self-assembled and facile infiltrated strategy has been applied in the preparation of the LGC-filter paper complex (LGC-FP), which can be industrial-scale manufactured employing established and mature processes from pulping and papermaking industry. This work provides an eco-friendly, low-cost, and scalable route to prepare bioplastics, which is a promising alternative to address the “white pollution” and reach the carbon neutrality goal to a certain extent.

Plastics-to-syngas photocatalysed by Co-Ga2O3 nanosheets.

ABSTRACTPlastics take hundreds of years to degrade naturally, while their chemical degradation typically requires high temperature and pressure. Here, we first utilize solar energy to realize the sustainable and efficient plastic-to-syngas conversion with the aid of water at ambient conditions. As an example, the commercial plastic bags could be efficiently photoconverted into renewable syngas by Co–Ga2O3 nanosheets, with hydrogen and carbon monoxide formation rates of 647.8 and 158.3 μmol g−1 h−1. In situ characterizations and labelling experiments unveil water is photoreduced into hydrogen, while non-recyclable plastics including polyethylene bags, polypropylene boxes and polyethylene terephthalate bottles are photodegraded into carbon dioxide, which is further selectively photoreduced into carbon monoxide. In-depth investigation illustrates that the efficiency of syngas production mainly depends on the carbon dioxide reduction process and hence photocatalysts of high carbon dioxide reduction activity should be designed to promote the efficiency of plastic-to-syngas conversion in the future. The concept for the photoreforming of non-recyclable plastics into renewable syngas helps to eradicate ‘white pollution’ and alleviate the energy crisis simultaneously.

Spillover Effects of Grocery Bag Legislation: Evidence of Bag Bans and Bag Fees

Spillover Effects of Grocery Bag Legislation: Evidence of Bag Bans and Bag Fees

Toughening and reinforcing waste polypropylene with POE/nano‐SiO2 under elongational flow

AbstractDue to the white pollution, the recycling of waste plastics has attracted more and more attention. In this research, waste polypropylene/Ethylene‐octene elastomer/nano‐SiO2 composites (wPP/POE/SiO2) were melt‐blended using an Eccentric Rotor Extruder (ERE) dominated by elongational flow field and a Torque Rheometer (TR) dominated by shear flow field, respectively. The micromorphology, mechanical, crystallization, thermal and rheological properties of wPP/POE/SiO2 blends were studied. Compared to the blends fabricated by TR, the wPP/POE/SiO2 blends with different compositions fabricated by ERE showed higher tensile strength, flexural strength, and modulus. Particularly, without sacrificing the tensile strength, the notched impact strength of the wPP/POE/SiO2 blends fabricated by ERE increased to 13.53 kJ/m2, a factor of 3 times larger than that of neat wPP. The enhancement of impact strength of the wPP/POE/SiO2 blends fabricated by ERE could be ascribed to the good dispersion of POE under elongational flow and the increase of PP crystallinity. The finding from this work provides an efficient way to recycle wPP.

Improvement of Gas Barrier Properties for Biodegradable Poly(butylene adipate-co-terephthalate) Nanocomposites with MXene Nanosheets via Biaxial Stretching.

In order to ease the white pollution problem, biodegradable packaging materials are highly demanded. In this work, the biodegradable poly (butylene adipate-co-terephthalate)/MXene (PBAT/Ti3C2TX) composite casting films were fabricated by melt mixing. Then, the obtained PBAT/Ti3C2TX composite casting films were biaxially stretched at different stretching ratios so as to reduce the water vapor permeability rate (WVPR) and oxygen transmission rate (OTR). It was expected that the combination of Ti3C2TX nanosheets and biaxial stretching could improve the water vapor and oxygen barrier performance of PBAT films. The scanning electron microscope (SEM) observation showed that the Ti3C2TX nanosheets had good compatibility with the PBAT matrix. The presence of Ti3C2TX acted as a nucleating agent to promote the crystallinity when the content was lower than 2 wt%. The mechanical tests showed that the incorporation of 1.0 wt% Ti3C2TX improved the tensile stress, elongation at break, and Young’s modulus of the PBAT/Ti3C2TX nanocomposite simultaneously, as compared with those of pure PBAT. The mechanical dynamical tests showed that the presence of Ti3C2TX significantly improved the storage modulus of the PBAT nanocomposite in a glassy state. Compared with pure PBAT, PBAT-1.0 with 1.0 wt% Ti3C2TX exhibited the lowest OTR of 782 cc/m2·day and 10.2 g/m2·day. The enhancement in gas barrier properties can be attributed to the presence of Ti3C2TX nanosheets, which can increase the effective diffusion path length for gases. With the biaxial stretching, the OTR and WVPR of PBAT-1.0 were further reduced to 732 cc/m2·day and 6.5 g/m2·day, respectively. The PBAT composite films with enhanced water vapor and water barrier performance exhibit a potential application in green packaging.

It's in the bag? The effect of plastic carryout bag bans on where and what people purchase to eat

AbstractThis paper examines how banning the use of plastic carryout bags at grocery stores affects where and what people purchase to eat. Using quasi‐random variation in local bag ban adoption across California and two data sources (retail scanner data and consumer survey data), I show that banning plastic carryout bags shifted some food sales away from regulated grocery stores toward unregulated grocery stores and restaurants. Specifically, I find that bag bans cause a 1.8% decline in food‐at‐home sales and a 1.9 percentage point increase in consumers' food‐away‐from‐home expenditure share. The decline in food‐at‐home sales is larger in jurisdictions more likely to experience cross‐border shopping, whereas the increase in food‐away‐from‐home expenditures is larger farther from jurisdiction borders. Together these results suggest that a small share of consumers find a way to bypass the bag bans—either by cross‐border shopping if near a border or by shifting to restaurants if not near a border. Heterogeneity analyses reveal the policy effects are strongest for those with higher incomes, those under 65 years, and those with young children, suggesting both income effects and time constraints as mechanisms behind the behavioral change. By quantifying consumer avoidance behaviors, these results enable policymakers to more accurately measure the impacts of their regulations and to understand the potential trade‐offs between their environmental and public health objectives.

Developing highly transparent yet ultraviolet blocking fully biocomposite films based on chitin and lignin using ethanol/water as processing solvents

Developing fully biobased products with functionality in a green fashion is highly desirable to meet the increasing demand for environmental sustainability and mitigate “white pollution” by petroleum-based counterparts. Here, chitin from shrimp shells was propionylated to obtain chitin propionate (CP) with significantly improved solubility in organic solvents, organosolv lignin (OSL) was extracted from the forest harvest residuals. The fully biobased composite consisting of CP as a matrix and OSL as a UV-blocker were successfully prepared using acidic ethanol/water as a green processing solvent. The results indicated that the 5% OSL addition enabled the CP film to block approximately 98% UV light while allowing 71% visible light transmittance; tensile and thermal properties were also retained. Nearly 100% UV light was blocked with 20% OSL addition, but visible light transmittance was moderately sacrificed. This study provides an alternative solution to produce novel fully biobased films with high transparency yet excellent UV protection for potential packaging applications.

Exploring consistency between stated and revealed preferences for the plastic bag ban policy in Chile

This paper exploits individual-level data before the implementation of a national policy to understand the factors driving avoidance of plastic consumption and explore potential inconsistencies between revealed and stated preferences for a plastic bag ban policy. We estimate a bivariate ordered probit model that allows us to account for a potential correlation between these types of preferences. The data reveals that while 71% of respondents take a reusable bag for shopping, only 58% of the sample state to strongly agree with prohibiting plastic bags. We find that gender, age, environmental concerns, environmental efforts, participation in environmental causes and pro-environmental behavior determine avoidance of plastic consumption, but no effects are found for being in favor of the prohibition. We also find inconsistencies decrease for individuals demonstrating higher pro-environmental behavior in related domains. This indicates waste management policies may benefit from local grounded knowledge from related environmental initiatives.

Effects of Biodegradable Film Raw Material Particles on Soil Properties, Wheat Growth, and Nutrient Absorption and Transportation

Biodegradable plastic film is one of the effective ways to solve the problem of white pollution in agriculture. However, its impacts on soil-plant systems are not well documented. In order to provide a basis for the safety evaluation of large-scale application of biodegradable plastic film, pot experiments were conducted to investigate the effects of the types(H, S, and X) and doses(2.5, 10, and 40 g·kg-1) of biodegradable film raw material particles on the soil physiochemical properties, biological properties, growth, and nutrient absorption by wheat (Triticum aestivum L.). The results showed that three types of biodegradable film raw material particles significantly increased soil pH but had no significant effect on soil organic matter content; medium-high doses of H and low-medium doses of S plastic particles had a positive effect on soil nitrification and soil nitrogen availability, whereas X film particles had an inhibitory effect. H film particles increased soil available phosphorus content, and S and X had no significant effect. X film particles increased the content of soil available potassium, but S and H had no significant effect. The effects of three types of biodegradable raw material particles on soil enzyme activities varied with the types and doses of plastic film and enzyme types. With the increase in the doses of plastic film particles, the activities of three kinds of soil enzymes showed a downward trend. Except for the low and medium doses of the S treatment, the other treatments inhibited the growth of wheat, in which X film particles had the greatest inhibitory effect on the biomass of wheat roots, stems, leaves, and grain; with the increase in the doses of film particles, the inhibition effect of wheat biomass was more obvious. For wheat nutrients, the absorption of nitrogen was promoted at low doses and inhibited at high doses, and the three types of film particles inhibited the absorption of phosphorus and potassium. There were significant differences in the distribution ratio of nitrogen and phosphorus between the stems, leaves, and grains of wheat by all the film particles; however, there was no significant difference in the distribution ratio of potassium between those treatments. Correlation analysis showed that wheat biomass was the main factor affecting wheat nutrient accumulation.

Polybutylene succinate, a potential bio-degradable polymer: synthesis, copolymerization and bio-degradation

Biodegradable polymers are advantageous over non-biodegradable polymers in terms of degradation. Fabrication of bio-based polymers to mimic petroleum-based polymers, is believed to be an effective way to overcome the white pollution.

Biodegradation and Bioremediation of Polymer by Microbial Assisted Novel Process

The degradation of polystyrene (PS) and polyurethane (PU), both are foams, is a budding challenge due to increasing white pollution. The present investigation has focused on the microbial assisted biodegradation. Various indigenous microorganisms were isolated from sewage soil. PS – PU foam and bioplastic was used to screen the soil bacteria with biodegradation potential. The screened bacteria were subjected to biodegradation assay such as soil burial and liquid culture in the presence of PS – PU foams and bioplastic in a growth medium. Two microorganism were isolated-- Pseudomonas aeruginosa and Aspergillus niger. The degradation rate based on weight loss is conducted by in vitro assay for 10 and 35 days. The maximum degraded foam was analyzed through Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy and PS – PU foam and bioplastic act as a control without microorganisms. Results of the present study showed that the maximum degradation and weight loss in the polyurethane foam occurred in the soil burial method by Pseudomonas aeruginosa compared with Aspergillus niger. The soil burial method is more significant than liquid culture method. There is no weight reduction in the polystyrene foam in both organism and methods. For the degradation of synthetic polymers the isolated Pseudomonas aeruginosa and Aspergillus niger were encapsulated for future studies.

Using Molecules with Superior Water-Plasticity to Build Solid-Phase Molecular Self-Assembly: Room-Temperature Engineering Mendable and Recyclable Functional Supramolecular Plastics

The brittleness of many supramolecular films in a dry environment has prevented their further application as supramolecular plastics. We report here the fabrication of supramolecular plastics displaying excellent dry-flexibility and mechanical strength through room-temperature solid-phase molecular self-assembly using water-locking polyelectrolyte and surfactant. Aided by mild mechanical pressure of about 0.5 MPa, the locked water enables the polyelectrolyte-bridged surfactant microdomains to merge into large mesophases to reduce the interface energy, which yields a transparent supramolecular film. The film still contains 2% water in a dry environment, which is capable of plasticizing the polyelectrolyte and surfactant; thus, it imparts excellent flexibility to the film. The dry film has a stress of 12 MPa and Young’s modulus of 188 MPa with a strain of 24%. This mechanical strength is comparable to that of the commercial soft polyethylene plastics. Since the noncovalent interactions in the film can be activated by water under mild mechanical pressure within seconds, mending a broken film by pressing a wet patch with mild mechanical force onto the damage becomes possible. Complete recycling can be achieved under the same conditions. We envision the current room-temperature mechanical force driven water-based recyclable and mendable supramolecular plastics would be very promising in reducing white pollution and generating integrated materials.

Farmers Markets and Single-Use Plastic: Why Environmentally Conscious Consumers Don’t Bring Reusable Bags

This study looks at the role of Extension in helping local officials reduce plastic bag use at farmers markets in three Lake County, OH communities. We distributed free reusable bags to shoppers and conducted an education and outreach program. We then took observations to determine if the free reusable bags were being used. We also invited shoppers to take a voluntary survey about their environmental attitudes, why or why not they use the reusable bags, and how best to reduce plastic bag use moving forward. Results from the study suggest that supplying free reusable bags at farmer markets is not an effective strategy for Extension professionals attempting to reduce plastic bag use. Instead, we recommend working with local officials to develop financial incentives and disincentives tied to the type of bag option shoppers use, implement plastic bag bans at markets, and conduct locally-focused education and outreach. Although shoppers’ environmental literacy and desire for sustainability is high, it is shown that behavior change is unlikely to occur without financial or policy incentives.

Ban the Bag: Support for Plastic Bag Reduction Strategies in Northeast Ohio

AbstractSociety's use of plastic is increasing, while the ability to properly manage plastic waste is decreasing. In response, improved waste management systems and the adoption of reusable products made from sustainable materials are needed. Municipal governments in the United States are beginning to institute policies reducing unlimited free access to plastic products such as bags, straws, and Styrofoam. However, some state governments in the Great Lakes region, and elsewhere, have responded by making these pro‐environmental policies illegal. Such policies shift the onus of using less plastic to local businesses and conscious consumers. In response, this project sought to determine the effectiveness of a plastic bag ban, supported by targeted education and outreach, at several local businesses in northeast Ohio. Results suggest that the initial implementation and non‐enforcement phase of the bag ban did not lead to a reduction in the use of plastic bags. However, survey respondents indicate they are supportive of policies reducing accessibility and unlimited availability of plastic bags. Results further show most people have access to their own reusable bags and support businesses who charge for, or no longer offer, plastic bags. In conclusion, voluntary reduction of bag use by customers is not effective and store policies or legislation is needed to reduce the use of plastic bags.

Conversion of Waste Plastics into Value‐Added Carbonaceous Fuels under Mild Conditions (Adv. Mater. 50/2021)

Sustainable Development To address the “white pollution” caused by non-recyclable waste plastics, it is required that eco-friendly strategies for plastic degradation be developed for sustainable development. In article number 2005192, Yongfu Sun, Yi Xie, and co-workers highlight solar-driven, enzyme-driven, and low-temperature-driven catalytic conversion of plastics into value-added carbonaceous fuels under mild conditions.

Photoconverting polyethylene terephthalate into exclusive carbon dioxide by heterostructured NiO/Fe2O3 nanosheets under mild conditions

Degradation of polyethylene terephthalate (PET) plastics by the traditional technologies usually requires high energy consumption and encounters poor product selectivity. Herein, we report the photoconversion of PET into carbon dioxide with 100% selectivity by in-plane heterostructured NiO/Fe2O3 nanosheets in pure water under normal temperature and pressure. High-resolution transmission electron microscopy, X-ray absorption near-edge spectroscopy and X-ray photoelectron spectra demonstrate the construction of the Z-scheme heterojunction, which can help to accelerate the separation of electron-hole pairs for enhanced PET conversion property. Various in-situ characterization techniques and experiments unveil that PET is photodegraded into carbon dioxide by the photogenerated holes, while oxygen is photoreduced into water by the photoexcited electrons. This work will open new avenues toward resolving the white pollution crisis.