Plastic Mass Research Articles

Microplastics and nanoplastics size distribution in farmed mussel tissues

Microplastics and nanoplastics are hazardous to ecosystems, wildlife, and through seafood, also for human health. Due to biological, chemical, and physical characteristics, nanoplastics can slip through cell membranes, being even more toxicologically important than microplastics. Thermal Desorption - Proton Transfer Reaction - Mass Spectrometry was used to analyze mussels from the Apulian region, Italy. All the analyzed organisms have plastics (values ranging from 10 to 187 ng of microplastics and nanoplastics per dry weight mg). The highest mass of plastics was detected in the size groups >2.2 µm (218 ng per dry weight mg) and 20–200 nm (187 ng per dry weight mg). Upscaling data we estimated that people in Europe could ingest more than 2 mg of nanoplastics per year through seafood consumption. The detected presence of nanoplastics in farmed mussels here presented contributes to establishing a baseline for monitoring these pollutants.

Functional classification and material characterization of plastic packaging in Flemish land litter to support effective reduction policies

Littered plastics are ubiquitous in the environment. This work presents an elaborate functional classification and material characterization of plastic packaging in land litter representatively sampled in Flanders, to support policy makers in taking effective reduction measures. In terms of mass, plastic bottles constituted the largest functional fraction (50.4 %) within plastic packaging found in land litter, followed by packaging films (food and non-food combined, 19.2 %) and rigid packaging (food and non-food combined, 18.2 %). In contrast, in number, plastic bottles were only the third largest fraction (10.1 %), after food (37.9 %) and non-food (26.2 %) packaging films. The difference between mass and number % for plastic packaging films can be explained by the fact that these films largely consisted of small and lightweight items, such as cookie wrappers and fragments of torn-open packaging. On a material level, the bottles fraction consisted almost entirely of PET, whereas non-food packaging films, bags and loose bottle caps consisted mainly of PE. ‘Cups and lids’, food and non-food rigid packaging and food packaging films consisted of a variety of polymer types, with PP, PET and PE being the most abundant in different ratios. Given the relative importance of plastic bottles, the introduction of a deposit return system could considerably reduce the plastic packaging mass littered into the environment. However, since the share of plastic packaging in the total collected land litter was only 14 %, the overall effect of such a measure on the litter mass will be limited. Given the high number share of food and non-food packaging films such as cookie wrappers, indicating their high ‘likeliness-to-get-littered’, effective policies to avoid littering of these types of packaging seem to be key.

Global analysis of marine plastics and implications of control measure strategies

Plastic pollution is a global environmental crisis that threatens marine ecosystems and human health. This study provides a comprehensive analysis of the current state of plastic pollution in oceans worldwide. We examined data on global plastic production, annual estimates of plastic emissions to oceans from different countries, surface plastic mass by ocean basin, the share of global plastic waste emitted to the ocean, the share of ocean plastics that come from the largest emitting rivers, microplastics in the surface ocean, and plastic mass and particles across the world surface ocean. Our analysis revealed alarming trends, such as the significant increase in plastic production since the 1950s and the projected estimate of up to 12,000 million metric tons of plastic waste in the natural environment by 2050. Additionally, we found that more than 1000 rivers account for 80% of global annual emissions, with Asia contributing the highest estimate of plastic emissions, followed by Africa, South America, North America, Europe, and Oceania. Furthermore, our findings showed that the largest contributors to ocean plastic waste are macroplastics, mesoplastics, and microplastics, with small microplastics dominating the percentage of surface ocean plastic by particle count. The recycling and reuse of waste plastics implement the concept of sustainable development of recycling and offsets the carbon emissions in the environment, potentially obtaining more carbon credits. Our findings highlight the urgent need for coordinated global efforts to reduce plastic waste and prevent further harm to our oceans, incorporating recycling and reuse strategies as key components of comprehensive control measures.

Optimizing quality and mixing performance of processed cheese spread using a mechanical universal disperser

Processed cheese spread (PCS) is currently experiencing rapid growth and is recognised as a prominent segment within the cheese‐based product industry worldwide. This type of cheese spread is produced by comminuting and blending natural cheese of varying ages and degrees of maturity, along with other ingredients, to achieve a homogeneous plastic mass. The high viscosity of PCS necessitates thorough mixing and blending, posing a challenge for cheese processors. In this study, a mechanical unit known as a universal disperser was utilised to prepare PCS. The study aimed to evaluate the impact of different processing parameters on the quality of the final product. Response surface methodology (RSM) was employed to design the experiment and optimise the process accordingly. The experiment involved conducting trials at three distinct melting temperatures: 50, 65 and 80 °C. The impeller speed used for blending the content was set at three levels: 10 000, 15 000 and 20 000 r.p.m. Responses, such as mixing index, mixing time, power consumption, spreadability, and overall acceptability, were recorded. Based on the findings, it was concluded that by employing the optimal parameters, a high‐quality PCS with a desirable overall acceptability score of 8.3 could be achieved while also meeting the desired mixing performance.

Polylactic acid film embedded with phosphor nanoparticles: Photochromic and afterglow biodegradable window and concrete

A smart window is a window made of a stimuli-responsive material whose transparency can be switched on and off. However, smart windows are often made of fragile, non-biodegradable and costly glass. Herein, this work presents the preparation of a transparent smart window from the environmentally-friendly polylactic acid (PLA) plastic. The plastic window was prepared by physically immobilizing nanoparticles of lanthanide-doped aluminate (NLdA; 79-112 nm) at different ratios into PLA bulk. The developed plastic showed afterglow emission, photochromism, superhydrophobicity, durability, UV shielding, rigidity, photostability, biodegradability, and excellent optical transmittance. NLdA was produced as nanoparticles to enhance NLdA dispersion in the plastic mass. NLdA must be uniformly disseminated in the PLA matrix without aggregation in order to provide transparent smart PLA window with long-persistent phosphorescence and photochromic properties. Different analytical methods were employed to determine the morphology, chemical composition, photoluminescence and coloration properties of smart films. There was an examination of the hardness characteristics. The transparent PLA window absorbed light at 365 nm and emitted at 435 nm and 517 nm, demonstrating reversible photochromism to green when irradiated with UV and greenish-yellow emission when exposed to darkness. There was a significant improvement in ultraviolet shielding and hydrophobicity upon increasing the phosphor content.

Elastoplastic solution of a circular tunnel in surrounding rock with any nonlinear yield criteria and plastic flow envelopes

Besides the (semi-)linear Mohr-Coulomb and Hoek-Brown criteria, other nonlinear functions are also used to describe the plastic response of rock mass. For a nonlinear yield and plastic flow function in the form of τ=fσn and/or σ1=fσ3, the equivalent cohesive strength and frictional angle corresponding to the Mohr-Coulomb yield criterion were derived. The normal stress was further related to the minimum principal stress using the geometrical relationship of a Mohr circle. The equivalent dilatancy angle was also derived using the same method. According to the solution of a circular tunnel in Mohr-Coulomb rock mass, this paper derived a semi-analytical solution of a circular tunnel in any nonlinear yield and plastic flow rock masses with a form of τ=fσn and/or σ1=fσ3. A numerical procedure was developed for the stresses and displacement using a reserve method. The proposed solution was verified by the results of a circular tunnel in elasto-perfectly(brittle-)-plastic and/or strain-softening rock mass. The strain-softening analysis of a circular tunnel in the assumed two nonlinear yield criteria and/or plastic flow rock masses was studied. For a linear deteriorated material parameters leads to a nonlinear evolution of equivalent cohesive strength, frictional angle and dilatancy angle in the plastic region.

Multi-stakeholder perspective to generate evidence and strategies for sustainable management of ropes from the fishing sector of Norway

Marine plastic pollution is a growing stressor affecting both marine and terrestrial life. Plastic polymers are widespread in oceans, including sparsely populated Nordic countries. Norway, a fishing-dominant region, faces substantial plastic pollution from fishing ropes, which often end up incinerated, landfilled, or lost in the ocean, contributing to the ghost fishing problem.This research employs a static material flow analysis (MFA) to assess plastic mass flows and the recyclability of 15 rope types used in Norway's commercial fishing sector. Findings reveal that approximately 383 tons of ropes are lost annually in Norwegian waters, endangering fish species. Furthermore, only one-third of the rope types can be efficiently recycled using available recycling technologies, highlighting the need for circularity.The MFA and inventory-based ranking approach shows significant potential as a holistic decision support tool for industry and policymakers in exercising sustainable and circular management for ropes.

The estimated environmental impact on the distribution, mass and abundance of plastics in aquatic ecosystems

Plastic began to be manufactured on a commercial scale in the 1950s, and people saw its attractive properties as revolutionary. Plastic has proven to be a very attractive product because it is lightweight, water resistant, heat and electric insulating and extremely durable. It is also very cheap to make. The starting ingredient is the less commonly killed organic raw material of petroleum, natural gas, or plant material - an increasingly attractive option as the rage for fossil fuels grows. Consequently, plastic can remain for hundreds of years up to 400 years for its degradability in the environment (unless recycled or incinerated). More than a third of plastic is manufactured for single use, most of which is disposed of in the environment within one year of manufacture. In particular, about 8 million tons enter the oceans each year. The durable nature of plastic is remarkable because even though it is made of organic matter, living things cannot digest and break it - a stark contrast to the waste of food and paper. Plastic debris can be distinguished into macroplastics and microplastics. Furthermore, exposure to heat an solar UV radiation makes the fragments brittle so that they easily crumble producing secondary microplastics forming persistent organic pollutants. In addition, there is a sizable fraction of primary microplastics, e.g. microbeads. These pollutants are found in terrestrial and marine aquatic ecosystems and are considered a serious problem of high environmental impact.

A promising approach to monitor microplastic masses in composts

Inputs of plastic impurities into the environment via the application of fertilizers are regulated in Germany and the EU by means of ordinances. Robust and fast analytical methods are the basis of legal regulations. Currently, only macro- and large microplastic contents (>1 mm) are measured. Microplastics (1–1,000 µm), are not yet monitored. Thermal analytical methods are suitable for this purpose, which can determine the mass content and can also be operated fully automatically in routine mode. Thermal extraction desorption-gas chromatography/mass spectrometry (TED-GC/MS) allows the identification of polymers and the determination of mass contents in solid samples from natural environments. In accordance with the German or European Commission (EC) Fertiliser Ordinance, composting plants should be monitored for microplastic particles with this method in the future. In this context a compost plant was sampled. At the end of the rotting process, the compost was sieved and separated in a coarse (>1 mm) and a fine fraction (<1 mm). The fine fraction was processed using density separation comparing NaCl and NaI as possible salt alternative and screened for microplastic masses by TED-GC/MS with additional validation and quality assurance experiments. With TED-GC/MS total microplastics mass contents of 1.1–3.0 μg/mg in finished compost could be detected with polyethylene mainly. What differs much to the total mass of plastics in the coarse fraction with up to 60 μg/mg, which were visually searched, identified via ATR-FTIR and gravimetrically weighted.

Plastic probe electrospray ionization mass spectrometry developed for rapid fingerprint profile of biological samples without pretreatment.

A triangular-shaped flat plastic substrate probe was prepared for direct electrospray ionization mass spectrometry (ESI-MS) for analysis of untreated chemical and biological samples including liquids (Met-Arg-Phe-Ala peptide, reserpine, and dodecyl aldehyde), solids (biological samples, traditional Chinese medicine), and powders (roasted coffee, rhizoma coptidis, lotus plumule, and Schisandra sphenanthera). Quantitative analysis of reserpine in water yielded a detection limit of 1ngmL-1, dynamic response range within 1-500ngmL-1, and linearity of signal response ˃0.9925. Compared to the conventional capillary ESI, this plastic probe ESI offers lower cost of analysis (US $0.0056 per probe), higher sensitivity, lower sample consumption, longer signal duration (>6min), better reproducibility, signal stability, and higher speed of analysis (<10s per sample, including sample loading). Overall, the results indicate the potential of ESI-MS based on flat plastic probes as a versatile method for simple, sensitive, and stable analysis of untreated biological sample analysis.

Global mass of buoyant marine plastics dominated by large long-lived debris

The fate of plastics that enter the ocean is a longstanding puzzle. Recent estimates of the oceanic input of plastic are one to two orders of magnitude larger than the amount measured floating at the surface. This discrepancy could be due to overestimation of input estimates, processes removing plastic from the surface ocean or fragmentation and degradation. Here we present a 3D global marine mass budget of buoyant plastics that resolves this discrepancy. We assimilate observational data from different marine reservoirs, including coastlines, the ocean surface, and the deep ocean, into a numerical model, considering particle sizes of 0.1–1,600.0 mm. We find that larger plastics (>25 mm) contribute to more than 95% of the initially buoyant marine plastic mass: 3,100 out of 3,200 kilotonnes for the year 2020. Our model estimates an ocean plastic input of about 500 kilotonnes per year, less than previous estimates. Together, our estimated total amount and annual input of buoyant marine plastic litter suggest there is no missing sink of marine plastic pollution. The results support higher residence times of plastics in the marine environment compared with previous model studies, in line with observational evidence. Long-lived plastic pollution in the world’s oceans, which our model suggests is continuing to increase, could negatively impact ecosystems without countermeasures and prevention strategies.

Structural and functional characteristics of the assimilation apparatus of &lt;i&gt;Alisma plantago-aquatica&lt;/i&gt; at different stages of development

This paper deals with the features of the structural and functional organization of the assimilation apparatus of individuals of the plantain fly, which are in five ontogenetic states (juvenile, immature, virginal, young and middle-aged generative). The changes in the morphometric parameters of the assimilation apparatus in j, im, v, g₁ and g₂ individuals of Alisma plantago-aquatica are analyzed. During the ontogenesis of Alisma plantago-aquatica, the length, width, area and mass of the sheet plastic, as well as the growth coefficient, changed along an S-shaped curve. In the middle-aged generative plants of Alisma plantago-aquatica, all morphometric parameters had maximum values. During the pregenerative (three ontogenetic states) and generative (two ontogenetic states) periods of ontogenesis, the number of chlorophylls a and b, carotenoids in the leaves of the helophyte increased. Regardless of the ontogenetic state of plants, the concentration of yellow pigments was 3,06,0 times lower than of the green ones. The degree of functionality of the photosynthetic apparatus in individuals of different ontogenetic states can be judged both by the ratio of chlorophyll a to chlorophyll b, and the ratio of the sum of chlorophylls to carotenoids. With an increase in the total assimilating surface of the leaves, the intensity of photosynthesis and, as a consequence, the amount of organic carbon in the leaves of Alisma plantago-aquatica individuals increased. The structural and functional changes of the photosynthetic apparatus observed in the ontogenesis of Alisma plantago-aquatica can be explained by the peculiarities of adaptation mechanisms to long-acting external environmental factors. Medium-aged generative plants of Alisma plantago-aquatica are promising for assessing carbon accumulation and overall productivity of coastal-aquatic phytocoenoses.

New biophysical rate-based modeling of long-term plasticity in mean-field neuronal population models

The formation of customized neural networks as the basis of brain functions such as receptive field selectivity, learning or memory depends heavily on the long-term plasticity of synaptic connections. However, the current mean-field population models commonly used to simulate large-scale neural network dynamics lack explicit links to the underlying cellular mechanisms of long-term plasticity. In this study, we developed a new mean-field population model, the plastic density-based neural mass model (pdNMM), by incorporating a newly developed rate-based plasticity model based on the calcium control hypothesis into an existing density-based neural mass model. Derivation of the plasticity model was carried out using population density methods. Our results showed that the synaptic plasticity represented by the resulting rate-based plasticity model exhibited Bienenstock-Cooper-Munro-like learning rules. Furthermore, we demonstrated that the pdNMM accurately reproduced previous experimental observations of long-term plasticity, including characteristics of Hebbian plasticity such as longevity, associativity and input specificity, on hippocampal slices, and the formation of receptive field selectivity in the visual cortex. In conclusion, the pdNMM is a novel approach that can confer long-term plasticity to conventional mean-field neuronal population models.

Lack of behavioral effect of surgical mask leachate on the Asian shore crab Hemigrapsus sanguineus: Implications for invasion success in polluted coastal waters

The COVID-19 pandemic generated a new source of plastic mass pollution, i.e. surgical masks, that preferentially accumulate in intertidal environments. Made of polymers, surgical masks are likely to leach additives and impact local intertidal fauna. As typical endpoints of complex developmental and physiological functions, behavioral properties are non-invasive key variables that are particularly studied in ecotoxicological and pharmacological studies, but have, first and foremost, adaptive ecological significance. In an era of ever-growing plastic pollution, this study focused on anxiety behaviors, i.e. startle response, scototaxis (i.e. preference for dark or light areas), thigmotaxis (i.e. preference for moving toward or away from physical barriers), vigilance and level of activity, of the invasive shore crab Hemigrapsus sanguineus in response to leachate from surgical masks. We first showed that in the absence of mask leachates H. sanguineus is characterized by a short startle time, a positive scototaxis, a strong positive thigmotaxis, and an acute vigilance behavior. Specifically, a significantly higher level of activity was observed in white areas, in contrast to the lack of significant differences observed in black areas. Noticeably, the anxiety behaviors of H. sanguineus did not significantly differ after a 6-h exposure to leachate solutions of masks incubated in seawater for 6, 12, 24, 48 and 96 h. In addition, our results were consistently characterized by a high inter-individual variability. This specific feature is discussed as an adaptive behavioral trait, which – through the observed high behavioral flexibility – increases H. sanguineus resilience to contaminant exposures and ultimately contribute to its invasion success in anthropogenically-impacted environments.

Microplastics in sea ice: A fingerprint of bubble flotation

Sea ice is heavily contaminated with microplastics (MPs), with the repeatedly confirmed increased number of larger-sized particles, deficit of fibers, and prevalence of materials denser than the surrounding water. To get insight into the drivers behind such a specific pattern, sets of laboratory experiments were performed on the formation of ice by cooling from the surface of fresh and salty (NaCl, 34 g/L) water, with particles of different sizes from heavy plastics (HPP) distributed initially over the bottom of the experimental volume. After freezing, about 50–60 % of HPP were trapped in ice in all the runs. Vertical distribution of HPP, plastic mass distribution, ice salinity (in saltwater experiments), and bubble concentration (in freshwater experiments) were recorded. Formation of bubbles on hydrophobic surfaces was the main cause of the entrapment of HPP into ice, with convection playing a secondary role. Supplementary bubble formation experiments with the same particles in water demonstrated that at larger fragments and fibers, several bubbles grow at the same time, so particle rising and residing at the surface is stable. Smaller HPP experience rising/sinking cycles with minimum time spent at the surface: one bubble is enough to cause a particle rising, but it is most often lost when colliding with the water surface. Application of the results to oceanic conditions is discussed. Oversaturation with gases due to various physical/biological/chemical processes and liberation of bubbles from methane seeps and melting permafrost are common in Arctic waters. Convective water motions are able to relocate HPP in vertical. Based on applied research, the bubble nucleation and growth, the hydrophobicity of weathered surfaces, the effectiveness of flotation methods for plastic particles are discussed. Interaction of plastic particles with bubbles is an important feature, still completely overlooked in the context of MPs behavior in marine environment.

Modeling atmospheric microplastic cycle by GEOS-Chem: An optimized estimation by a global dataset suggests likely 50 times lower ocean emissions

Modeling atmospheric microplastic cycle by GEOS-Chem: An optimized estimation by a global dataset suggests likely 50 times lower ocean emissions

Rigorous solution for drained analysis of spherical cavity expansion in soils of finite radial extent

This paper revisits the expansion problem of a spherical cavity in an elastic–plastic soil mass with a finite radial extent under drained conditions, which proves to be non-self-similar. Rigorous semi-analytical solutions for the analysis of this problem are developed adopting several well-known soil models. With the small strain assumption, analytical expressions for both elastic stresses and displacements are obtained considering the stress dependency of soil moduli and influences of the outer boundary. In the plastic zone, the non-self-similar expansion process is formulated into a set of first-order partial differential equations (PDEs) based on the innovative combination use of the Lagrangian and Eulerian descriptions, and an efficient algorithm for solving these equations is developed. The solution method is quite general to be extended to many other constitutive models and is validated by comparing with existing solutions in some special cases. Then the cavity expansion behaviours in both clay and sand are discussed with a particular focus on the boundary effect. It is shown that, when the ratio of the outer to inner radius is small, the boundary effect may significantly influence the cavity expansion response. The present solution may provide a useful theoretical method for the validation of relevant finite element calculations and interpretation of some typical geotechnical problems such as cone penetration tests in small-size chambers, considering the boundary effect.

Large variation in Mekong river plastic transport between wet and dry season

Plastic pollution in rivers is of increased global concern. Rivers act both as pathways for land-based plastic waste into the ocean, and as plastic reservoirs for long-term retention. Reliable observations are key to designing, optimizing and evaluating strategies to prevent and reduce plastic pollution. Several measurement methods have been developed to quantify macroplastic (&gt;0.5 cm) storage and transport in rivers, including visual counting from bridges, net sampling, and images-based techniques. Method harmonization is crucial to make sure data collected using different techniques remains consistent. In turn, this would allow for comparative analysis of plastic pollution within and between rivers. In this paper, we present a harmonization approach to estimate floating plastic item and mass transport from data collected using different methods. The approach allows estimating the same values based on different measurement methods and data collection protocols. We applied our approach to the Mekong-Tonlé Sap-Bassac river system around the city of Phnom Penh, Cambodia. We estimated the floating plastic item and mass transport in the wet and dry season by combining data from net sampling and visual counting. During the wet season, plastic transport in the Mekong increased with a factor of up to 170 (item transport) and 294 (mass transport) compared to the dry season. The river plastic mass balance around Phnom Penh changed considerably, which was mainly due to the flow reversal of Tonlé Sap river between the wet and dry season. Downstream of Phnom Penh, the total plastic transport was consistently higher than upstream, although less in the wet season (1.5–1.7 times) compared to the dry season (3.8–5.9 times), emphasizing the city’s role as entry point of plastic pollution into the Mekong. The largest sources of uncertainty are assumed to be caused by key differences between methods, including the size ranges, extrapolation from observation point to full river width, and the contribution of submerged plastic to the total transport. Future work should focus on including data from other methods than net sampling and visual counting, and reducing the uncertainties related to combining data from different methods. Our results show that river plastic transport dynamics are highly variable over time and space, especially around confluences, bifurcations and urban areas. With our paper we aim to contribute to further harmonization of river plastic monitoring.

In-line identification of Pb-based pigments in fishing nets and ropes based on hyperspectral imaging and machine learning

Fishing lines, nets, and ropes represent a significant portion of plastic pollution in marine environments, and can contain hazardous additives. The development of less laborious and faster methods aiming at identifying plastic-related additives is therefore needed, in order to facilitate effective recycling. This work aims to develop an industrial inline method to identify lead-based pigments in fishnets by an industrial hyperspectral imaging (HSI) system working in visible-near-infrared spectral range (Vis-NIR, 450 to 1050 nm) and machine learning. A Vis-NIR spectral sample set comprising un-contaminated and lead contaminated (143 to 2430 mg L−1) plastic classes were used to build the classification model via Principal Component Analysis and clustering. The content of the samples was characterized by X-ray fluorescence (XRF), Attenuated Total Reflection (ATR-FTIR), differential scanning calorimetry, thermogravimetric analysis, and burning in astmospheric air. Fishnets containing lead-based pigments with lead concentrations > 1000 mg L−1 (0.1 wt%) were accurately identified by the industrial HSI, and the lead content was corroborated with ATR-FTIR and XRF measurements. In addition, lead contaminated plastic area and mass can be estimated via calibration curve using the pixels numbers vs mass of fibrous plastics with a detectability of 120 mg (R2 = 0.997).

Defossilization and decarbonization of hydrogen production using plastic waste: Temperature and feedstock effects during thermolysis stage

The replacement of natural gas with plastic-derived pyrolysis gas can defossilize H2 production, while subsequent capture, utilization and storage of carbon in a solid form can decarbonize the process. The objective of this study was to investigate H2 production from three types of plastics using a process comprising pyrolysis (600 °C) and thermolysis stages (1200–1500 °C). Depending on the plastic feedstock and thermolysis temperature, the laboratory-scale setup generated 1000–1350 mL/min product gas with H2 purity of 74.3–94.2 vol%. The recovery of 5–9 wt% molecular H2 per mass of plastics was achieved. Other products included solid residue (0.1–12 wt%) and oil (8–52 wt%) from the pyrolysis reactor, solid carbon (36–53 wt%) and gas impurities (2–16 wt%) from the thermolysis reactor. The purity of H2 gas was detrimentally influenced by polyethylene terephthalate in the feedstock due to the dilution of gas by CO. The decomposition of methane containing in the pyrolysis gas was the limiting reaction step during H2 production and improved at higher thermolysis temperature. Three solid carbon structures were formed during the thermolysis stage regardless of the plastic type: carbon black aggregates, carbon black aggregates coated with a layer of pyrolytic carbon and a carbon film on the inner reactor wall. Among the three types of carbon, the highest valorization potential was identified for carbon black aggregates. Plastic feedstock composition had little if any effect on carbon black properties, while high thermolysis temperature (1500 °C) reduced the particle sizes and increased the surface area of aggregates.