Plastic Samples Research Articles

Numerical simulation of electron beam depth dose distribution in water phantom passed through modified plastic materials

The aim of the study is to evaluate the feasibility of using modified plastics for 3D printing of boluses for electron beam therapy. Filaments for 3D printing made from plastic materials with an admixture of copper were studied. Test samples were made from these filaments and investigated. Mathematical models of such products were created based on the obtained data. The thicknesses of the boluses made from each modified material were calculated to achieve the same electron beam depth dose distribution in the water phantom as natural plastic. Using a the developed model of a therapeutic electron beam and newly created models of test object materials, the electron beam depth dose distributions in the water phantom that passed through the materials under study were obtained in bolus geometry. The results of the work demonstrate the potential of using modified plastics for creating forming elements in electron beam therapy. The application of this plastic samples for electron beam shaping with individual configuration allows to modify the irradiation field based on the clinical tasks quickly and efficiently and to increase the effectiveness of electron beam radiotherapy procedures.

Feasibility Study for Finding Mathematical Approaches to Describe the Optimal Operation Point of Sensor-Based Sorting Machines for Plastic Waste.

At present, sensor-based sorting machines are usually not operated at the optimal operation point but are either overrun or underrun depending on the availability of waste streams. Mathematical approaches for predefined ideal mixtures can be found based on the input stream composition and the throughput rate. This scientific article compares whether and under what conditions these approaches can be applied to sensor-based sorting machines. Existing data for predefined ideal mixtures are compared with newly generated data of real waste on three sensor-based sorting setups in order to make significant statements. Five samples of 3D plastics at regular intervals were taken in a processing plant for refuse-derived fuels. With the comparison of all these results, four hypotheses were validated, related to whether the same mathematical approaches can be transferred from ideal mixtures to real waste and whether they can be transferred to sensor-based sorting machines individually or depending on the construction type. The developed mathematical approaches are regression models for finding the optimal operation point to achieve a specific sensor-based sorting result in terms of purity and recovery. For a plant operator, the main benefit of the findings of this scientific article is that purity could be increased by 20% without substantially adapting the sorting plant.

Risk Factors and Urogenital Schistomiasis Prevalence among Primary School Children in Makurdi, Nigeria

Urogenital schistosomiasis in humans is an infection of public health importance caused by infection with Schistosoma heamatobium. The study investigated the risk factors and intensity of urogenital schistosomiasis among primary school pupils in Makurdi, Nigeria. Eight hundred (800) school pupils consisting of 200 per school, aged 5 – 20 years in Angwan Jukun, Angwan Reke, Agbo and Ijaha communities, respectively were enrolled for the study. Suitably designed questionnaire was used to document data on the demographics as well as relevant information of the participants. Urine samples were collected from consented participants between 10 am – 2 pm, into pre-labelled plastic sample bottles following aseptic techniques. The samples were subjected to standard parasitological techniques for determination and quantification of parasite in the zoology laboratory of Benue State University, Makurdi. Research data was subjected to chi square analysis to ascertain association of the research variables with schistosomiasis prevalence in the study area. The study filed an overall prevalence of 23.75% (190/800). Infection rates were significantly associated with age as age group 16-20 years had the highest prevalence (P<0.000). Males 25.42% (122/800) were slightly more infected than females 21.25% (68/800) (P>0.05). Water contact pattern of participants revealed a highly significant association with schistosomiasis prevalence (p<0.001)). Grazing activity 50% (1/2) displayed higher infection prevalence followed by > 1 activity 34.65% (79/228) while no infection was seen in snail hunters. The association between the presence and type of livestock sharing open water sources with the communities was statistically significant (P<0.05). Makurdi is endemic for urogenital schistosomiasis and related risk factors. The roles of other definitive hosts in ensuring continual disease transmission and possible zoonosis should be investigated

Enhanced performance of eco‐friendly PVC by utilizing halo‐benzothiazole derivatives and glucose/fatty acids esters

AbstractTwo halo‐benzothiazoles, namely, 2‐amino‐6‐bromo‐benzo[d]thiazole and 2‐amino‐6‐fluoro‐benzo[d]thiazole were utilized to modify poly(vinyl chloride) (PVC) and gave two modified PVC samples for biomedical applications. Prepared glucose‐fatty acid esters of palmitic, oleic, and octanoic acids were exploited as plasticizers to produce phthalate‐free eco‐friendly antimicrobial PVC. The chemical structures of all prepared compounds were confirmed via Fourier‐transform infrared spectroscopy. The thermal properties of modified PVC was determined using thermo gravimetric analysis and differential scanning calorimetry while weight loss and degree of discoloration were used to assess the photostability after UV irradiation whereas references heat and UV absorbers were applied for comparison. The plasticizing effect of each glucose‐fatty acid ester at 20% by weight on the mechanical properties of modified PVC was determined and referenced to diethylhexylphthalate. The results revealed that the mechanical properties as well as the thermal stability of plasticized modified PVCs were enhanced. Plasticizers migration from the polymeric matrix was also determined and the results showed low extent of migration of the prepared plasticizers. So, modified plasticized PVC samples exhibited improved physicochemical properties. Antimicrobial properties of all samples, using disc diffusion agar method, were evaluated against some Gram +ve bacteria like Staphylococcus aureus and Streptococcus mutans and Gram −ve bacteria like Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa and fungi strains used were Candida albicans, Aspergillus niger, and Aspergillus ochraceous. All investigated compounds showed improved antibacterial and antifungal activities.Highlights PVC was chemically modified with two halo‐benzothiazoles to obtain antimicrobial PVC. Glucose‐fatty acids esters were prepared as eco‐friendly plasticizers for PVC. Halo‐benzothiazoles improved both the thermal‐ and photo‐stability of PVC. Glucose‐fatty acid plasticizers enhanced the mechanical properties of PVC. The extent of migration of prepared plasticizers is lower than that of reference plasticizer.

Draft genome sequences of six bacteria isolated from polylactic acid samples from the Mediterranean Sea.

Here, we report the draft genome sequences of six marine strains isolated from plastic samples incubated in the Mediterranean Sea. Genomic analyses place these strains within the Alkalihalobacillus, Bacillus, Halomonas, and Marinobacter genera. Examining the genomes of these non-typical environmental bacteria increases our comprehension of microorganism biology and their potential uses.

Quantitative Analysis of Acetyl-CoA, Malonyl-CoA, and Succinyl-CoA in Myocytes.

Several analytical challenges make it difficult to accurately measure coenzyme A (CoA) metaboforms, including insufficient stability and a lack of available metabolite standards. Consequently, our understanding of CoA biology and the modulation of human diseases may be nascent. CoA's serve as lipid precursors, energy intermediates, and mediators of post-translational modifications of proteins. Here, we present a liquid chromatography-mass spectrometry (LC-MS) approach to measure malonyl-CoA, acetyl-CoA, and succinyl-CoA in complex biological samples. Additionally, we evaluated workflows to increase sample stability. We used reference standards to optimize CoA assay sensitivity and test CoA metabolite stability as a function of the reconstitution solvent. We show that using glass instead of plastic sample vials decreases CoA signal loss and improves the sample stability. We identify additives that improve CoA stability and facilitate accurate analysis of CoA species across large sample sets. We apply our optimized workflow to biological samples of skeletal muscle cells cultured under hypoxic and normoxia conditions. Together, our workflow improves the detection and identification of CoA species through targeted analysis in complex biological samples.

The Real-Time Monitoring of the Laser-Induced Functionalization of Transparent Conductive Oxide Films.

Laser-induced functionalization using excimer laser irradiation has been widely applied to transparent conductive oxide films. However, exploring suitable irradiation conditions is time-consuming and cost-ineffective as there are numerous routine film fabrication and analytical processes. Thus, we herein explored a real-time monitoring technique of the laser-induced functionalization of transparent conductive oxide films. We developed two types of monitoring apparatus, electrical and optical, and applied them to magnetron-sputtered, Sn-doped In2O3 films grown on glass substrates and hydrogen-doped In2O3 films on glass or plastic substrates using a picosecond Nd:YAG pulsed laser. Both techniques could monitor the functionalization from a change in the properties of the films on glass substrates via laser irradiation, but electrical measurement was unsuitable for the plastic samples because of a laser-induced degradation of the underlying plastic substrate, which harmed proper electrical contact. Instead, we proposed that the optical properties in the near-infrared region are more suitable for monitoring. The changes in the optical properties were successfully detected visually in real-time by using an InGaAs near-infrared camera.

Comparative Examination of Friction Between Additive Manufactured Plastics and Steel Surface

Nowadays, the increasing use of plastic materials in friction and wear applications, particularly in industrial robotic grippers, is a growing trend in modern industry. Plastics are replacing traditional materials like metals and composites due to their unique properties and significant advantages. Plastic materials used in industrial robotic grippers offer several advantages, such as their low friction coefficient, enabling smooth and precise movement of the gripper and minimizing the risk of damaging the objects being manipulated. This paper presents a comparative study and analysis of the friction coefficient between various plastic materials and the C45 alloy steel, a superior alloy used in industrial applications. The investigated materials include PETG, PLA, PLA with aluminum, ABS, two types of TPU, and two types of UV-sensitive resins. This study aims to evaluate the friction performance of these materials in order to identify the most suitable options for friction and wear applications, such as industrial robotic grippers. To achieve this, dry kinetic friction tests were conducted between 3D printed plastic material samples manufactured by using FDM and SLA technologies, and the C45 alloy steel on the CETR UMT-2 tribometer. The friction coefficient was measured by recording the force required for displacement in two horizontal directions.

Discovery and occurrence of organophosphorothioate esters in food contact plastics and foodstuffs from South China: Dietary intake assessment

A recent study revealed the presence of non-pesticide organothiophosphate esters (OTPEs) — precursors to organophosphate esters (OPEs) contaminants — in river water. Since OPEs have demonstrated adverse reproductive outcomes in humans, this accentuates the urgency to explore the prevalence of non-pesticide OTPEs in other potential human exposure matrices. In this study, a nontarget screening method based on high-resolution mass spectrometry was used to identify OTPEs in food contact plastic (FCP) samples collected from South China. O,O,O-triphenyl phosphorothioate (TPhPt) and O,O,O-tris(2,4-di-tert-butylphenyl) phosphorothioate (AO168 = S) were unequivocally identified (Level 1), while O,O-di(di-butylphenyl) O-methyl phosphorothioate (BDBPMPt) was tentatively identified (Level 2b, indicating probable structure based on diagnostic evidence). Among n = 70 FCP samples, AO168 = S emerged with the highest detection frequency and median concentration of 74 % and 111 ng/g, respectively. Significant Pearson correlations were observed in log-transformed peak areas of AO168 = S and TPhPt in FCPs with their respective oxons, respectively. Occurrences of AO168 = S and TPhPt were further investigated in n = 100 foodstuff samples using a market basket method. AO168 = S and TPhPt exhibited detection frequencies of 43 % and 44 % in all food items with mean concentrations of 2.17 ng/g wet weight (ww) (range: <0.53–67.8 ng/g ww) and 0.112 ng/g ww (range: <0.006–2.39 ng/g ww), respectively. The highest mean concentrations for AO168 = S and TPhPt were found in vegetables (4.62 ng/g ww) and oil (3.00 ng/g ww), respectively. The median estimated daily intakes (EDIs) of AO168 = S and TPhPt via diet were calculated as 10.4 and 1.51 ng/kg body weight/day, respectively. For AO168 = S, only meat and vegetables contributed to the median EDI, whereas for TPhPt, oil was identified as the principal contributor to the median EDI. This study for the first time evaluated human exposure to OTPEs via diet, providing new insights to overall human exposure to OPEs.

Extreme weather events as an important factor for the evolution of plastisphere but not for the degradation process

Marine plastics, with their negative effects on marine life and the human health, have been recently recognized as a new niche for the colonization and development of marine biofilms. Members of the colonizing communities could possess the potential for plastic biodegradation. Thus, there is an urgent need to characterize these complex and geographically variable communities and elucidate the functionalities. In this work, we characterize the fungal and bacterial colonizers of 5 types of plastic films (High Density Polyethylene, Low Density Polyethylene, Polypropylene, Polystyrene and Polyethylene Terepthalate) over the course of a 242-day incubation in the south-eastern Mediterranean and relate them to the chemical changes observed on the surface of the samples via ATR-FTIR. The 16s rRNA and ITS2 ribosomal regions of the plastisphere communities were sequenced on four time points (35, 152, 202 and 242 days). The selection of the time points was dictated by the occurrence of a severe storm which removed biological fouling from the surface of the samples and initiated a second colonization period. The bacterial communities, dominated by Proteobacteria and Bacteroidetes, were the most variable and diverse. Fungal communities, characterized mainly by the presence of Ascomycota, were not significantly affected by the storm. Neither bacterial nor fungal community structure were related to the polymer type acting as substrate, while the surface of the plastic samples underwent weathering of oscillating degrees with time. This work examines the long-term development of Mediterranean epiplastic biofilms and is the first to examine how primary colonization influences the microbial community re-attachment and succession as a response to extreme weather events. Finally, it is one of the few studies to examine fungal communities, despite them containing putative plastic degraders.

Fiber-delivered heterodyne spectroscopy with a mid-infrared frequency comb.

By exploiting the excellent short-term phase stability between consecutive pulses from a free-running optical parametric oscillator frequency comb, we report the first example of hollow-core fiber-delivered heterodyne spectroscopy in the 3.1-3.8 µm wavelength range. The technique provides a means of spectroscopically interrogating a sample situated at the distal end of a fiber, with all electronics and light sources situated at the proximal end and with an inherent capability to suppress spectroscopically interfering features present in the free-space and in-fiber delivery path. Using a silica anti-resonant, hollow-core delivery fiber, we demonstrate high quality transmission and attenuated total reflectance spectroscopy of a plastic sample for fiber lengths of up to 40 m, significantly exceeding the few-meter lengths typically possible using solid-core fibers. The technique opens a route to implementing multi-species spectroscopic monitoring in remote and / or hostile industrial environments and medical applications.

Thermal degradation of virgin and waste plastics: Estimation of kinetic and thermodynamic parameters using model‐free iso‐conversional methods

AbstractKinetic triplets—apparent activation energy (Ea), pre‐exponential factor (A), and the reaction model—were estimated for the thermal degradation of three primary virgin and waste plastics, as well as mixed plastics waste. Model‐free iso‐conversional FWO, KAS, Starink, Kissinger and Vyzovkin and Friedman methods were employed for the kinetic analysis. The apparent activation energy was determined by the integral methods as 206.5‐209.1 kJ mol−1 and 195.6‐198.8 kJ mol−1 for the virgin and waste high‐density polyethylene (HDPE), 211.6‐214.1 kJ mol−1 and 183.1‐186.6 kJ mol−1 for the virgin and waste polypropylene (PP), 144.0‐163.1 kJ mol−1 and 159.7‐167.1 kJ mol−1 for the virgin and waste polystyrene (PS), and 173.6‐178.9 kJ mol−1 for the mixed plastics waste respectively. Ea was found to follow the trend HDPE &gt; PP &gt; PS with higher values for HDPE and PP virgin samples than that for their waste and marginally smaller for the virgin PS than its waste. Degradation of all plastic samples followed Avrami‐Erofeev equation with n varying between 1.0 and 1.8. The effect of conversion on Ea suggested the degradation of both virgin and waste HDPE to consist of multiple parallel reactions while that of others to be more complex. FTIR analysis of the evolved gases was used to explain the possible reaction mechanism. A small difference between the enthalpy change and the apparent activation energy (6‐7 kJ mol−1) for all plastic samples indicated favourable pyrolysis reactions. The estimated kinetic parameters and thermodynamic properties showed the stability of different plastics as HDPE &gt; PP &gt; PS.

Novel composite materials with high near-infrared reflectance properties to retard the thermal aging of polyethylene: Pr3+ and Er3+ doped La2Zr2O7 compounds

In this paper, Er3+ and Pr3+ successfully replaced La3+ in the lattice without changing the structure of La2Zr2O7 pyrochlore, and finally formed the substituted solid solution La2-xMxZr2O7+δ (M = Er, Pr; x = 0–0.25). SEM analysis shows that the pigments were in the shape of nearly spherical particles with a particle size between 10 and 60 nm. La2-xPrxZr2O7+δ and La2-xErxZr2O7 materials have high NIR reflectance properties, with the NIR reflectance of 68.46%–92.51% and 82.79%–90.89%, which are related to the variation of free carrier concentration due to doping content. Compared with pure polyethylene material, the polyethylene plastic samples containing La2-xPrxZr2O7+δ and La2-xErxZr2O7+δ not only had lower internal surface temperatures, 5.9–11.4 °C and 6.9–13.2 °C lower but also had significantly lower thermal aging. In conclusion, the use of synthetic pigments with high NIR reflectivity as additives can delay the thermal aging of plastics and increase the aging resilience of plastic.

Development of a plastic waste treatment process by combining deep eutectic solvent (DES) pretreatment and bioaugmentation with a plastic-degrading bacterial consortium

Polyethylene terephthalate (PET), a petroleum-based plastic, and polylactic acid (PLA), a biobased plastic, have a similar visual appearance thus they usually end up in municipal waste treatment facilities. The objective of this project was to develop an effective PET and PLA waste treatment process that involves pretreatment with deep eutectic solvent (DES) followed by biodegradation with a plastic-degrading bacterial consortium in a composting system. The DES used was a mixture of choline chloride and glycerol, while the bacterial strains (Chitinophaga jiangningensis EA02, Nocardioides zeae EA12, Stenotrophomonas pavanii EA33, Gordonia desulfuricans EA63, Achromobacter xylosoxidans A9 and Mycolicibacterium parafortuitum J101) used to prepare the bacterial consortium were selected based on their ability to biodegrade PET, PLA, and plasticizer. The plastic samples (a PET bottle, PLA cup, and PLA film) were pretreated with DES through a dip-coating method. The DES-coated plastic samples exhibited higher surface wettability and biofilm formation, indicating that DES increases the hydrophilicity of the plastic and facilitates bacterial attachment to the plastic surface. The combined action of DES pretreatment and bioaugmentation with a plastic-degrading bacterial consortium led to improved degradation of PET and PLA samples in various environments, including aqueous media at ambient temperature, lab-scale traditional composting, and pilot-scale composting.

Advanced condition-based monitoring of CFRP under multiple impacts using monte carlo based prognostics and real-time self-sensing data

Studies on self-sensing system under multiple impacts are limited. Furthermore, real-time prognostics research using electromechanical behavior for impact-damage growth is rare and the impact-damaged area analysis has limited in self-sensing. In this paper, the health state of the carbon-fiber-reinforced plastic samples were monitored in real time utilizing self-sensing data. In-depth damage analysis using C-scan and cross-sectional analysis were conducted to investigate the correlation between the electromechanical behavior analysis. Moreover, the relationship between electromechanical behavior and the impact-damaged area was investigated. The damage propagation during multiple impacts was identified in real time. Furthermore, the electromechanical behavior was predicted to prognosticate the damage propagation in the samples under multiple impacts using a particle filter. The impact damage area was determined based on the predicted electromechanical behavior. Moreover, the prediction accuracy according to data acquired was investigated. An advanced condition-based monitoring methodology can monitor current and future health states and damage propagation under multiple impacts that overcomes the previous self-sensing research. Therefore, this study showed high applicability and guidelines for future self-sensing research fields.

Enhancing properties of bio-oil produced from plastic waste: A case study utilized plastic waste from Dar-es-Salaam dump sites

This study investigated the potential of producing and upgrading bio-oil from plastic waste through a catalytic pyrolysis process. Plastic waste samples composed of polystyrene, polyethylene, and low-density polyethylene, shredded to sizes of 1.5–2.5 mm and blended in a ratio of 50/25/25, respectively, were pyrolyzed in a fluidized bed reactor at optimal conditions of 560–650 °C, a heating rate of 15 °C/min, and N2 gas flow rate of 100 ml/min in the presence of zeolite catalysts. The produced bio-oil was treated with fossil diesel, calcium hydroxide, and sodium sulfate to enhance its properties. The results showed that bio-oil production was increased to 65 wt. %, while char was reduced to 3.5 wt. %. Treatment with 20 wt. % diesel reduced bio-oil kinematic viscosity by 58% and improved stability from 20% to 50%. The addition of 16 g calcium hydroxide reduced the bio-oil acidity by 51% from a pH of 3.2–4.85. Furthermore, the bio-oil moisture content was reduced from 10 to 5.2 wt. % through the addition of 10 g of sodium sulfate, while the lower heating value was improved to 39.0 MJ/kg. Therefore, the catalytic pyrolysis of plastic waste in a fluidized bed reactor, and the various treatments performed on the generated bio-oil proved to be an effective technique to enhance the economic value of plastic waste and its environmental management at large.

Optimisation of the analysis procedure of polybrominated diphenyl ethers (PBDEs) in plastic waste from household products

Polybrominated diphenyl ethers (PBDEs) are one group of flame retardants used as additives in many household products, in-cluding plastic products. Determining the residues of PBDEs in household plastic products is required to control their effects on human health and leach into the environment after disposal. This study was conducted to optimise sample preparation conditions for analysing PBDEs in plastic waste from household products. The study results are given that the instrument detection and quantification limits (IDL and IQL) ranged from 4.19 to 28.4 ppb and 14.0 to 94.8 ppb, respectively. In addition, the method detec-tion limit (MDL) and method quantification limit (MQL) were the lowest at 2.20 and 7.35 ng/g (BDE 99) and the highest at 24.1 and 80.3 ng/g (BDE 209), respectively, while the recovery val-ues for spiking samples at different concentrations ranged from 89.1 to 104.5%. The results of the method validation can confirm that the soxhlet extraction and solid phase extraction (SPE) tech-niques combined with gas chromatography mass spectrometry (GC/MS) equipment can be applied to determine the PBDEs in plastic waste samples.

In-line quantitative estimation of ammonium polyphosphate flame retardant in polyolefins via industrial hyperspectral imaging system and machine learning

Due to developments in European legislation, several halogenated flame retardants are banned due to their toxicity, and the use of phosphor-based flame retardants in plastics is increasing. A revision of ammonium polyphosphate (APP) flame retardant revealed that it is an eye irritant and toxic, thus posing a health issue. Hence APP identification is needed for enabling safe recycling of plastic waste streams. Herein an industrial in-line method for quantitative estimation of APP in low density polyethylene (LDPE) and polypropylene (PP) is demonstrated, by using an industrial hyperspectral imaging system (955 to 1700 nm) and principal component analysis (PCA). Spectra of plastic samples with varying concentrations of APP were applied to build and calibrate a quantitative determination method. PCA and band area ratios (of selected bands) were made and fitted with continuous functions for concentration determination. The plastic samples were characterised by elemental analysis, attenuated total reflection, differential scanning calorimetry, and thermogravimetric analysis. The PCA model outperforms the band area ratio model and predicts APP concentrations between 24.3 and 1.5 wt% in LDPE (R2 = 0.98) and 20.0 and 1.7 wt% in PP (R2 = 0.97). Unknown samples with APP ranging from 23.7 to 2.7 wt% in LDPE and from 18.6 to 2.3 wt% in PP were predicted and correlated to the actual concentrations. The proposed approach is valuable for the plastic recyclers and waste management industries where inline concentration determination of flame retardants is key.

Toxicity assessment of bioplastics on brine shrimp (Artemia franciscana) and cell lines

Polylactic acid (PLA) and polybutylene succinate (PBS), are categorized as biodegradable bioplastics that have progressively being utilized as food packaging replacing the obtrusive petroleum plastic. This study aims to evaluate the toxicity of bioplastics and petroleum-based plastic polyethylene (PE) on Artemia franciscana and animal cell lines. Each plastic sample was assessed in its powdered form, and the size distribution of PE, PLA, and PBS microplastic particles was observed by optical microscopy. Additionally, the toxicity of hatching percentage and mortality rate was investigated. The results demonstrated that the percentage of hatching and the mortality rate post treatment with PLA and PBS particles for 24 and 48 h did not significantly alter in comparison to those treated with PE particles. However, the percentage of Artemia hatching reduced post treatment with plastic particles in comparison to the control, as well as the mortality rate increased with a high concentration of plastic particles. The morphology of Artemia after ingesting microplastic particles was obtained using phase contrast inverted microscopy. The accumulation of plastic in the Artemia gut was observed succeeding its exposure to PE, PLA, and PBS particles. In addition, the cytotoxicity of plastics on human keratinocyte (HaCaT), normal human dermal fibroblast (NHDF), and African green monkey kidney (Vero) cell lines were determined by MTT assay. The result exhibited that increasing concentrations of microplastic particles had substantially less toxic to practically nontoxic effect on the cells. The biomolecule profile by synchrotron-IR technique displayed that plastics potentially have more alteration effect in epithelial kidney cells (Vero) than fibroblasts (NHDF) and keratinocytes (HaCaT). Our results demonstrate that PE, PLA, and PBS had toxicity on Artemia following ingestion, in accordance with the concentration and duration tests. Moreover, microplastic particles were nontoxic or harmless to animal cell lines and altered some intracellular biomolecule profiles. These discoveries are essential not only for environmental health risk assessment but also in order to establish recommendations toward safer utilization of bioplastics-based materials for a robust lifestyle.

Thermo-chemical recycling of plastics retrieved from waste electric and electronic equipment (WEEE) by pyrolysis: Identification of the polymer type, removal of bromine compounds from plastics based on an environmentally-friendly process and characterization of the pyrolysates

The increased amounts of plastics originating from waste electric and electronic equipment (WEEE) necessitates finding environmentally friendly solutions for their handling. Taking into account the importance of the aforementioned issue, in this work attention is paid to the recycling of various plastic materials coming from WEEE. Plastic samples including parts from televisions, computers, printers, remote controls and a calculator, were collected from a recycling plant and from end-of-life household appliances. After collection and size reduction, they were analysed by various techniques, including Fourier transform Infra-Red spectroscopy (FTIR) measurements, for the identification of the polymers present in each device, since they were unknown. Their degradation behaviour was investigated via Evolved Gas Analysis (EGA), by heating them from 100 to 700 °C. Thermal pyrolysis was applied with the aim of recovering the monomers or secondary useful products during the samples’ degradation. X-ray fluorescence (XRF) analysis was applied to all samples collected in order to identify the possible presence of bromine, in case those plastics were brominated flame retarded; and it was found that 41% (7/17) of the samples contained bromine. The brominated samples were subjected to Soxhlet extraction aiming to reduce the bromine incorporated into them. Results showed that bromine was reduced in all cases tested, reaching up to 35% reduction. According to EGA analysis, the thermal degradation in most cases followed a one-step mechanism. FTIR and thermal pyrolysis results revealed that most samples consisted of high-impact polystyrene (HIPS), while some of them were blends of polycarbonate (PC)/acrylonitrile-butadiene-styrene (ABS) or ABS. The chemical recycling of the samples, via pyrolysis, led to monomers (e.g., styrene), or other valuable compounds, including hydrocarbons or phenols, depending on the type of the polymer present in each sample.