Various Types Of Plastics Research Articles

Microbial consortia for multi-plastic waste biodegradation: selection and validation

The accumulation of plastic waste in the environment poses significant ecological and health risks. This study evaluates the effectiveness of microbial consortia in degrading various types of plastics, including low-density polyethylene (LDPE), low linear-density polyethylene (LLDPE), polyethylene terephthalate (PET) and polystyrene (PS). Qualitative enzyme assays for esterases and ligninases, which are related to plastic biodegradation, were conducted in five microbial strains. Four microbial consortia, combining bacterial and fungal strains, were assembled based on the enzyme profile of their components and evaluated for their ability to degrade both virgin and recycled plastics. The results showed that consortia C2 (Bacillus subtilis RBM2, Fusarium oxysporum RHM1, and Alternaria alternata RHM4) and C4 (Bacillus subtilis RBM2 and Pseudomonas alloputida REBP7) exhibited the highest biodegradation efficiency, particularly achieving significant weight loss in recycled LDPE, virgin LLDPE and recycled PET. The biodegradation was further confirmed by FTIR analysis, which revealed changes in the chemical composition and functional groups of the treated plastics, indicating microbial interaction and degradation. This study underscores the potential of microbial consortia in addressing plastic pollution, highlighting the importance of strategic consortia design based on enzymatic profiles and plastic colonization capabilities. These promising results suggest that further optimization of microbial consortia could offer a viable solution for large-scale plastic waste management.

Biodegradation of four polyolefin plastics in superworms (Larvae of Zophobas atratus) and effects on the gut microbiome

Recent studies have demonstrated superworms (larvae of Zophobas atratus) ability to degrade polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), and polypropylene (PP) within their digestive system. This study aimed to compare the ability of superworms to degrade the above four polyolefin plastics over a duration of 30 days. In this study, the degradation rate of PE was the highest, and the final average weight of superworms, as well as the final plastic mass loss consumed by them, significantly increased (73.38 % and 52.33 %, respectively) when PE was fed with wheat bran (1:1 [w/w]). FTIR and TGA indicated the occurrence of oxidation and biodegradation processes in the four polyolefin plastics when exposed to superworms. In addition, the molecular weights (Mw and Mn) of excreted polymer residues decreased by 3.1 % and 2.87 % in PE-fed superworms, suggesting that the depolymerization of PE was not entirely dependent on the gut microbial community. The analysis of the gut microbial communities revealed that the dominant microbial community were different for each type of plastic. The results indicate that the gut microbiome of superworms exhibited remarkable adaptability in degrading various types of plastics, and the intake preferences and efficiency of different plastics are associated with different dominant microbial community species.

Plastic Analysis with a Plasmonic Nano-Gold Sensor Coated with Plastic-Binding Peptides.

Contamination with plastics of small dimensions (<1 µm) represents a health concern for many terrestrial and aquatic organisms. This study examined the use of plastic-binding peptides as a coating probe to detect various types of plastic using a plasmon nano-gold sensor. Plastic-binding peptides were selected for polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), and polystyrene (PS) based on the reported literature. Using nAu with each of these peptides to test the target plastics revealed high signal, at 525/630 nm, suggesting that the target plastic limited HCl-induced nAu aggregation. Testing with other plastics revealed some lack of specificity but the signal was always lower than that of the target plastic. This suggests that these peptides, although reacting mainly with their target plastic, show partial reactivity with the other target plastics. By using a multiple regression model, the relative levels of a given plastic could be corrected by the presence of other plastics. This approach was tested in freshwater mussels caged for 3 months at sites suspected to release plastic materials: in rainfall overflow discharges, downstream a largely populated city, and in a municipal effluent dispersion plume. The data revealed that the digestive glands of the mussels contained higher levels of PP, PE, and PET plastic particles at the rainfall overflow and downstream city sites compared to the treated municipal effluent site. This corroborated earlier findings that wastewater treatment could remove nanoparticles, at least in part. A quick and inexpensive screening test for plastic nanoparticles in biological samples with plasmonic nAu-peptides is proposed.

FAKTOR YANG BERHUBUNGAN DENGAN PENATALAKSANAAN PENANGGULANGAN SAMPAH DENGAN STRATEGI REDUSE, REUSE, RECYCLE DI KECAMATAN BATANGTORU KABUPATEN TAPANULI SELATAN

The 3R method or Reuse, Reduce and Recycle is one of the best ways to manage and deal with various types of plastic waste. The application of this system is also very good for managing waste from various types of plastic from safe to toxic. Types of analytical quantitative research with survey techniques. Analytical surveys are intended to explain a condition. Analytical surveys usually attempt to respond to why. The population totaled 93 respondents in the Batangtoru sub-district, using a proportional random sampling technique. Data analysis was carried out univariately and bivariate with the chi-square test. The basis for decision-making is based on the level of significance (p-value), with the following criteria: ho is rejected if p &lt;α 0.05, then there is a significant correlation or relationship between the variables ho is accepted if p &gt; α 0.05, then there is no significant correlation or relationship between variables. The results of the study using the chi square test obtained a p value of 0.436 (p &lt;0.05) it can be concluded that there is no relationship between knowledge and waste management with last year's 3R strategy, results using the chi square test p value obtained 0.314 (p &lt;0.05) it can be concluded that there is no relationship between education and management of waste management with last year's 3R strategy, results using the chi square test p value value obtained 0.256 (p &lt;0.05) it can be concluded that there is no relationship between perception and management of waste management with the 3R strategy last year, the results using the chi square test p value obtained 0.031 (p &lt;0.05) can be obtained conclude that there is no relationship between income and management of waste management with the 3R strategy last year, the results using the chi square test p value obtained 0.000 (p &lt;0.05) it can be concluded that there is a relationship between the role of government and community leaders with management of management waste management with the 3R strategy last year, the results using the chi square test, the p value was obtained 0.003 (p &lt;0.05) it can be concluded that there is a relationship between facilities and markets with the management of waste management with the 3R strategy last year

Education about various plastic types and its impact to environment for karang taruna group

The Karang Taruna Respect@05 group engages in waste bank management activities, but encounters challenges in sorting plastic waste. Additionally, the plastic product code provides information on the classification of plastic resin types, recommendations for usage, and guidelines for recycling plastic waste. This community service initiative aims to educate members of the youth organization about various types of plastic and their environmental impact, contributing to increased knowledge and enhanced plastic waste management efforts. The activities employ the outreach method, utilizing leaflets and interactive discussions. The results of this program indicate a notable increase in knowledge and support for sustainable plastic waste management.

Review of the global evolution of regulations on single-use plastics and lessons drawn for Canada.

Plastic pollution is a global problem and many countries are strengthening their regulations to mitigate the related environmental degradation and health risks and to support the development and deployment of circular economy for various types of plastics. As Canada also develops its strategy for regulating single-use plastic as one element of the plastic pollution, aligned federal and provincial policies are essential. This study presents an analysis of existing and emerging policies to provide guidance on Canada's future regulations. Qualitative and quantitative data regarding plastic regulations were gathered from similar countries including Australia, the United Kingdom, the European Union, the United States and relevant scientific articles. Analysis was also conducted of current Canadian regulations that both impact and guide the path for plastic regulation, international examples provided guidance for future Canadian regulations. The analysis found that there is a need for public education on the gravity of plastic pollution to gain their support; for establishing pioneering provinces or cities in plastic regulations to learn from and provide other cities with support; and to start with banning items with available alternatives, to be followed by phasing out other items that are more difficult to replace. The study also showed potential areas of improvement in impact data. The need for reliable regulatory performance data against a baseline scenario; consistency in methodology; and proper scoping to reduce the risk of displacement or exclusivity in policy were identified.

The effects of non-functionalized polystyrene nanoparticles of different diameters on the induction of apoptosis and mTOR level in human peripheral blood mononuclear cells

Particles of various types of plastics, including polystyrene nanoparticles (PS-NPs), have been determined in human blood, placenta, and lungs. These findings suggest a potential detrimental effect of PS-NPs on bloodstream cells. The purpose of this study was to assess the mechanism underlying PS-NPs-induced apoptosis in human peripheral blood mononuclear cells (PBMCs). Non-functionalized PS-NPs of three diameters: 29 nm, 44 nm, and 72 nm were studied used in this research. PBMCs were isolated from human leukocyte–platelet buffy coat and treated with PS-NPs at concentrations ranging from 0.001 to 200 μg/mL for 24 h. Apoptotic mechanism of action was evaluated by determining the level of cytosolic calcium ions, as well as mitochondrial transmembrane potential, and ATP levels. Furthermore, detection of caspase-8, -9, and -3 activation, as well as mTOR level was conducted. The presence of apoptotic PBMCs was confirmed by the method of double staining of the cells with propidium iodide and FITC-conjugated Annexin V. We found that all tested NPs increased calcium ion and depleted mitochondrial transmembrane potential levels. The tested NPs also activated caspase-9 and caspase-3, and the smallest NPs of 29 nm of diameter also activated caspase-8. The results clearly showed that apoptotic changes and an increase of mTOR level depended on the size of the tested NPs, while the smallest particles caused the greatest alterations. PS-NPs of 26 nm of diameter activated the extrinsic pathway (increased caspase-8 activity), as well as intrinsic (mitochondrial) pathway (increased caspase-9 activity, raised calcium ion level, and decreased transmembrane mitochondrial potential) of apoptosis. All PS-NPs increased mTOR level at the concentrations smaller than those that induced apoptosis and its level returned to control value when the process of apoptosis escalated.

Occurrence and Effects of Microplastics in Lake Ecosystems: Particular Focus on Migration in Water and Food Chains

Microplastics have become a research hotspot in the environmental field owing to their persistence and complex ecological effects. Although microplastics have attracted public attention only recently, the microplastic pollution in lake, a unique water system characterized by their irreplaceable ecological value and special hydrodynamic conditions, were increasingly documented, calling for a summary of the most recent advance in this research area. Therefore, the sampling and analysis methods, occurrence, sources, and ecological effects of microplastics in lakes were summarized in this review. Various types of plastics are produced and used in large quantities for different purposes, resulting in microplastic pollution being widespread in lakes worldwide, albeit with different levels and characteristics. Microplastics constantly migrate and transform in lake ecosystems, exerting impacts on ecological, including pollution diffusion and biological toxicity. This review focused on the migration of microplastics in water and food chains, which is a different perspective than that considered in previously published reviews. This review also discussed the limitations of existing studies and made recommendations. Future research directions should include the following: 1) improving the baseline database of microplastic pollution in lakes; (2) unifying the sampling and laboratory analysis methods; (3) exploring the quantitative analysis methods of the sources, transportation, and fate of microplastics; (4) considering more factors to explore the effects of microplastics on lake ecosystems.

Application of waste biaxially oriented polypropylene sandwiched graphene to enhance properties of asphalt mixes via a wet process

The global community is concerned about the environmental degradation caused by plastic waste, particularly Biaxially Oriented Polypropylene (BOPP) used in food packaging materials. Utilizing plastic in road construction can conserve energy, reduce pollution, and enhance the performance of asphalt mixes at high temperatures. Many research studies have inspected the impact of various types of plastic, such as LDPE, HDPE, LLDPE, and others, on the physical-rheological and chemical characteristics of the base binder. This study assesses how BOPP and Graphene Oxide (GO) work together to develop the performance of the base binder. The modified binder's physical-rheological and chemical structure was evaluated using different percentages of BOPP and Graphene oxide. Penetration, Softening Point, Rotational Viscosity, Dynamic Shear Rheometer (DSR), and temperature sweep tests were conducted to examine the modified binder's properties changes. The findings indicate that the combination of GO and BOPP significantly improved the physical–chemical and rheologic properties of the base binder. The trial rheological results for 0.4%, 0.5%, 0.6% of GO and 1.5%, 2.0%, and 2.5% of WBOPP (GWBOPP) modified bitumen demonstrate that the modification of the base binder with this combination improved its elastic capacity at higher temperatures and rutting resistance. These results suggest a positive correlation between the chemical-physical-rheological parameters.

Pyrolysis products from various types of plastics using TG-FTIR at different reaction temperatures

Pyrolysis products of low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), and municipal plastic waste at different reaction temperatures were predicted in the current study using a newly developed thermogravimetric analyzer coupled with Fourier transform infrared spectroscopy (TG-FTIR) method. The experiments revealed that pyrolysis products of LDPE and PP at 500 °C were almost wax. Above 600 °C, wax formed from LDPE and PP almost disappeared, while the production of light hydrocarbons was enhanced. In the cases of LDPE and PP, the benzene and toluene formations were clearly observed above 800 and 700 °C, respectively. For PS, styrene was observed as the major component at 500–800 °C. With increasing temperature, the formations of alkenes, benzene, and toluene were enhanced at the expense of styrene. Different from other plastics, PET produced a pyrolysis vapor containing mainly CO2 and CO. FT-IR spectra of PET were almost unchanged despite increasing temperature above 600 °C. In the case of municipal plastic waste, the product distribution was similar to those of LDPE and PP. The new TG-FTIR method turned out to be an effective tool to predict pyrolysis products, especially gases products having low molecular weights.

Floating Riverine Litter Flux to the White Sea: Seasonal Changes in Abundance and Composition

Arctic rivers bring litter from their basins to the sea, but accurate data for the Arctic do not exist yet. This study presents the first assessment of floating macro litter input (&gt;2.5 cm) from the Northern Dvina and Onega rivers to the White Sea. The observations were performed based on the European Marine Strategy Framework Directive (MSFD) methodology and using the mobile application of the Joint Research Centre (Ispra, Italy). The results of observations from May 2021 to November 2021 show that 77% of floating objects were of natural origin (mainly leaves, wood and bird feathers). Of the particles of anthropogenic origin, 59.6% were represented by various types of plastics, 27.7% were processed wood, 8.5% paper/cardboard, 2.7% metal, 1.1% were rubber and &lt;1% textiles. The average monthly input of anthropogenic macro litter by the Northern Dvina varies from 250 to 1700 items/hour, and by Onega from 520 to 2350 items/hour. The level of pollution of the studied rivers was found to be higher than in some Europeans rivers but lower than in China. The mass discharge of macroplastics in the Northern Dvina River was compared with the estimates of the discharge of meso- and microplastics; that allowed us to show that the discharge of macroplastics in mass units is much higher than of micro- and mesoplastics.

Impact of Plastic-Wrap Properties and Cleaning Intervals on the Disinfection of Elevator Buttons.

Fomite transmission is a possible route by which different pathogens spread within facilities. In hospital settings, elevator buttons are widely observed to be covered with various types of plastic wraps; however, limited information is available concerning the impact of different plastic materials on cleaning. Our study aimed to identify which plastic material is suitable for the coverage of elevator buttons and the optimal intervals for their cleaning. We tested six plastic covers, including polyethylene (PE), polymethylpentene (PMP), polyvinyl chloride (PVD), and polyvinylidene chloride (PVDC) plastic wraps; a thermoplastic polyurethane (TPU) keyboard cover; and a polyethylene terephthalate-ethylene vinyl acetate (PET-EVA) laminating film, which are plastic films. The bioburden on the elevator buttons at different time intervals was measured using an adenosine triphosphate (ATP) bioluminescence assay. Our results show that wraps made of PVDC had superior durability compared with those of PMP, PVC, and PVDC, in addition to the lowest detectable ATP levels among the six tested materials. Regarding different button locations, the highest ATP values were found in door-close buttons followed by door-open, and first-floor buttons after one- and three-hour intervals (p = 0.024 and p < 0.001, respectively). After routine disinfection, the ATP levels of buttons rapidly increased after touching and became more prominent after three hours (p < 0.05). Our results indicate that PVDC plastic wraps have adequate durability and the lowest residual bioburden when applied as covers for elevator buttons. Door-close and -open buttons were the most frequently touched sites, requiring more accurate and precise disinfection; therefore, cleaning intervals of no longer than three hours may be warranted.

Potential Bacteria Isolated from Contaminated Sites as Bio-degraders of Various Types of Plastic

The growing demand for plastics and their improper disposal have resulted in a significant environmental pollution problem. While various management strategies have been employed to tackle this issue, the persistence of plastic pollutants in the environment is still a major concern. Therefore, exploring and developing sustainable and environmentally safe techniques, such as biodegradation using potential bacteria, can help mitigate plastic pollution and provide a viable solution. The purpose of this study was to isolate and identify potential bacteria for degrading plastics from six soil samples collected from five plastic-contaminated sites. The population of microorganisms in the soil ranged from 1.9 ×105 to 8.2 × 104 CFU/g. The screening of biodegradation abilities to degrade various types of plastics, including Polypropylene (PP), Polystyrene (PS), Polyethylene (PE), Polyethylene terephthalate (PET), and Polylactic acid (PLA) (Bioplastic), as measured by the diameters of the clear zones surrounding the colonies, revealed that out of 40 strains, only 8 strains could degrade various types of plastics. These bacteria were identified using 16S rRNA genes, which showed that NBI0106, NBI0108, NBI0109, and NBI0111 tend to be Streptomyces ardesiacus with similarity 99%, NBI0113 tend to be Pseudomonas plecoglossicida with similarity 99%, and NBI0305 tend to be Streptomyces cellulosae with similarity 100%. In addition, The Streptomyces ardesiaca strain NBI0111 demonstrated the highest degradation efficiency for PP plastic, with a clear zone diameter of 32.19  0.34 mm. This study shows the importance of identifying bacteria in plastic-contaminated soils and landfills, which may lead to the discovery of more effective bacteria strain with the capacity to degrade various types of plastic in real environmental conditions.

MICROPLASTICS AND THE AMAZON: FROM THE RIVERS TO THE ESTUARY

Plastic pollution is causing worldwide concern, especially after evidence that the various types of plastic degrade into particles of smaller sizes; known as micro- and nanoplastics. The origin of the plastics in the environment is related to human actions. The objective of this review is to describe the main routes of microplastic input in the Amazonian rivers and how local environmental characteristics can affect the transformation of plastics into microplastics until their absorption by aquatic organisms. The current situation regarding the presence of microplastic particles in freshwater is analyzed considering the environmental dynamics of the region, and focuses on rivers, estuaries and sediments, their effects on organisms, especially on fish, followed by the transportation of microplastic particles to the sea. Amapá, Amazonas, Pará and Mato-Grosso are the states of the Brazilian Amazon with scientific reports on the characterization of microplastic particles in sediment, water, and fish. These studies are local and descriptive and most of them highlight the characterization of microplastics. There is a need for field research in the various microregions of the Amazon, as well as actions to mitigate the damage, including to riverine populations, that is caused by these pollutants in the region.

Are Particulate Pollutants Emitted by Open-Burning of Agricultural Plastic Waste (Greenhouse LDPE Film) Harmful?

Background and objective: Agricultural plastic waste (APW), which includes various types of plastics and greenhouse film, accounts for the largest volume of annual average incineration of plastic (Korea Environment Corporation, 2021). Open-burning incineration of such APW emits metallic particulate pollutants, the human hazard of which is widely known. As such, the systematic management of incinerable APW is required. Furthermore, basic physicochemical research on particulate pollutants (PPs) is needed for related policy decision-making.Methods: The U.S. EPA particulate test method (Method 5G) was applied to set up the experimental infrastructure for an open-air incineration simulation. Scanning electron microscopes with SEM-EDS and XRF were used for a chemical species analysis of the generated particulate matter (PM). Low-density polyethylene (LDPE), used as a greenhouse material and collected by the Dangjin plastic collection office of the Korea Environment Corporation, was used as samples and subjected to incineration test three times.Results: Chemical speciation by an XRF analysis showed that the major chemical components of LDPE before incineration, listed in order of their content, were Fe (26.87%, SD = 20.67) &gt; Si (25.91%, SD = 11.29) &gt; Al (16.43%, SD = 7.23), which was changed to Si (44.51%, SD = 0.25) &gt; Zn (16.53%, SD = 0.03) &gt; Ba (15.73%, SD = 0.05) after incineration. An SEM-EDS analysis found the PM emitted as rock-like shapes and cotton-like shapes. Regarding the weight ratio, the rock-shaped particles contained less C (8.94 wt%, SD = 1.90) and more Al (11.77 wt%, SD = 3.08) and Fe (9.58 wt%, SD = 7.14), whereas the cotton-shaped particles contained more C (29.44 wt%, SD = 3.97), less Al (2.34 wt%, SD = 0.19), and an untraceable amount of Fe (ND).Conclusion: This study found that PPs emitted through the incineration of APW such as LDPE can be classified into rock-like shapes and cotton-like shapes, which is related to the difference in weight ratio of non-metals (C), transition metals (Fe), and other metals (Al) in unit particulate matter.

TREATMENT OF COMBAT SURGICAL TRAUMA OF THE LIMBS IN THE CONDITIONS OF MODERN WAR

Among the total number of wounded who entered the Military Medical Clinical Center of the Western Region from February to September 2022, combat injury to the limbs was in 63.3%. Bullet wounds caused combat injury to the limbs in 10.4%, shrapnel and mine-explosive – in 68.1%, explosive injury – in 21.5%. At the second role of medical care, emergency surgical interventions were performed on the wounded, immobilization of bone fractures with an external fixation and anti-shock therapy. At the third and fourth roles – the treatment of the wounded consisted in the use of a multidisciplinary approach with the involvement of doctors of various specialties, first of all, general surgeons, traumatologists, vascular, plastic surgeons and anesthesiologists. The most frequent surgical intervention was repeatened and secondary debridment of gunshot wounds, which was required by 93% of the wounded. The main pathogens that vegetated in wounds were Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter aerogenes, Proteus vulgaris, Enterococcus faecalis with high levels of microbial contamination – 104-108/g in tissues., Various types of plastics were used to close soft tissue defects, according to the rule of the reconstruction ladder. After healing a soft tissue wound to determine the timing of replacing the method of fixing fractures with internal osteosynthesis, were analyzed clinical and laboratory parameters and assessed the risks of complications. The main causes of amputations of the limbs were common defects in soft tissue and bones, which were not subject to reconstruction with no prognosis for bone fusion and progression of the infectious-necrotic process.

Decomposition of microplastics: Emission of harmful substances and greenhouse gases in the environment

Few reports have been reported on the conditions of the decomposition of plastics in the environment and their threats, while the influence of the decomposition of plastics as a potential factor in increasing greenhouse gas emissions has not been investigated. Greenhouse gases from the decomposition of plastics have so far not been considered in the development of models that show the likely climate change in the future. The work described here examined the presence and possibility of emission of phthalic acid esters and greenhouse gases from various plastic materials in daily use in the aquatic environment. The article presents, inter alia, research on the influence of temperature (20, 60, and 90 °C), pH (3, 7, and 10), plastic material, time (1, 3, 5, 7, and 14 d), and ultraviolet radiation on the migration of components present in various types of plastics, such as poly(vinyl chloride) (with high and low content of plasticizers) and polypropylene. No significant effect of pH on the migration of the plasticizers from the polymer matrix was observed. In turn, the influence of temperature on the emission of these susceptibilities was determined by the type of polymer. The highest emission level of plasticizers made of poly(vinyl chloride) was recorded for 60 °C, while from polypropylene for 20 °C. Depending on environmental conditions, the degradation of microplastics leads to a reduction in the mass of the material and conversion to methane and carbon dioxide. Each material was degraded, which resulted in the observed migration of components and methane and carbon dioxide emissions from the analysed materials. The highest degree of bis(2-ethylhexyl) phthalate migration was observed for the material made of poly(vinyl chloride). The amount of greenhouse gas emissions depended on the insolation conditions, and the poly(vinyl chloride) material showed the highest emission of methane and carbon dioxide. The highest concentration of methane at the level of 94 ppm after 360 days was observed for poly(vinyl chloride) with a large amount of plasticizers without access to light.

Hybrid Vibration and UV Fluorescence Technology for Rapid Imaging and Guidance for Manual Removal of Fish Bones from Fish Floss.

The objective of the proposed human-machine cooperation (HMC) workstation is to both rapidly detect calcium-based fish bones in masses of minced fish floss and visually guide operators in approaching and removing the detected fish bones by hand based on the detection of fingernails or plastic-based gloves. Because vibration is a separation mechanism that can prevent absorption or scattering in thick fish floss for UV fluorescence detection, the design of the HMC workstation included a vibration unit together with an optical box and display screens. The system was tested with commonly used fish (swordfish, salmon, tuna, and cod) representing various cooking conditions (raw meat, steam-cooked meat, and fish floss), their bones, and contaminating materials such as derived from gloves made of various types of plastic (polyvinylchloride, emulsion, and rubber) commonly used in the removal of fish bones. These aspects were each investigated using the spectrum analyzer and the optical box to obtain and analyze the fluorescence spectra and images. The filter was mounted on a charge-coupled device, and its transmission-wavelength window was based on the characteristic band for fish bones observed in the spectra. Gray-level AI algorithm was utilized to generate white marker rectangles. The vibration unit supports two mechanisms of air and downstream separation to improve the imaging screening of fish bones inside the considerable flow of fish floss. Notably, under 310 nm ultraviolet B (UVB) excitation, the fluorescence peaks of the raw fillets, steam-cooked meat, and fish floss were observed at for bands at longer wavelengths (500-600 nm), whereas those of the calcium and plastic materials occurred in shorter wavelength bands (400-500 nm). Perfect accuracy of 100% was achieved with the detection of 20 fish bones in 2 kg of fish floss, and the long test time of around 10-12 min results from the manual removal of these fish bones.

CH4 and CO2 Emissions from the Decomposition of Microplastics in the Bottom Sediment—Preliminary Studies

In recent years, a significant new threat to the environment has emerged, namely contamination with microplastics and their degradation products. The decomposition products of microplastics include, among others, greenhouse gases that are responsible for climate change. The article analyzes the emission of carbon dioxide and methane during the decomposition of various types of plastics in the form of microplastics in the bottom sediments in the presence of water. The research covers plastic materials made of polyvinyl chloride with a high and low content of plasticizers, polypropylene, and rubber. All analyzed microplastics generated the tested greenhouse gases. However, the quantity of gases generated depended on the type of polymer used. The highest concentration of methane, at 25,253 ppm after 180 days of incubation, was characterized by high plasticizer polyvinyl chloride, i.e., di (2-ethylhexyl) phthalate. In the case of carbon dioxide emissions, the values were comparable. The maximum value was obtained at 65,662 ppm for polypropylene microplastics. The influence of particle size on the amount of the emissions of these gases was also investigated. During the decomposition of microplastics in the bottom sediments in the presence of water, it was observed that the smaller the microplastic particles are, the greater the production of methane and carbon dioxide.

The possibility of using different types of polymeric and polymer-containing reusable containers (literature review)

The article contains a review of the literature devoted to research the possibility of using polymeric materials as returnable containers for the supply of water to consumers. When conducting a literature search, the following databases were used: Pubmed, Scopus, Web of Science, MedLine, Global Health, RSCI. The purpose of the work was to collect information on the sources of contamination of drinking water packed in polymer containers based on the literature data and evaluate the possibilities of its safe reuse. Conducted information and analytical studies have shown that the repeated use of polymer containers (in particular, PET containers) may be unreliable, both in terms of chemical and microbiological safety. The paper identifies the main chemical components migrating from polymer containers, which have the greatest impact on the quality of drinking water. The influence of storage temperature, the duration of contact of plastic with water, abrasion of the material, the influence of photochemical aging of bottles and the impact of disinfectants are also considered. The conducted studies have shown that at the moment there are no regulatory and methodological documents regulating the possibility and conditions for the reuse of plastic containers (19-liter bottles), the number of cycles of its reuse, the indicators by which the assessment is made, and the criteria by which the already used container cannot be used further. The possibility of multiple reuse of polymer containers for water storage currently needs to be regulated. There is little literature data on the wear resistance of various types of plastic and the maximum number of cycles of detergents and disinfectants that it can withstand without destroying its structure. Taking into account the data on the destructive changes in polymers under the influence of external factors (temperature, sunlight, etc.), and in the process of treating it with detergents, it is necessary to propose and scientifically substantiate documents regulating the use of returnable packaging, taking into account the materials of modern research. It is also necessary to search for safe, simple and effective methods and means of disinfection of polymer containers.