Polystyrene Plastic Research Articles

Polystyrene Bioremediation: A Perspective on Microbial and Environmental Constrained Interventions

The polystyrene is the specific kind of plastics based upon petroleum which is composed of monomers of vinyl benzene (styrene). Regardless of the attraction of polystyrene, multiple organizations and municipalities are enduring an emerging challenge during disposal of polystyrene products and packaging. It is appraised that the products of polystyrene accounts for not more than 1% of the overall burden of landfill resources. It could be a greater health threat for humans also who are on the topmost level of food chain and farsighted styrene monomers of the plastics used in engineering polystyrene has been categorized as a potential humanoid carcinogen by the International Agency for Research on Cancer (IARC) and the US National Institutes of Health (NIH). As a few researchers have been published on the degradation of polystyrene plastic but the key point addressed in this review is the recognition of microbial and fungal enzymes which are known at present to be involved in polystyrene monomer plastic degradation. The major bacterial and fungal enzymes involved within the degradation reaction of vinyl side chain include styrene monooxygenase, styrene oxide isomerase, styrene monooxygenase, flavin adenine dinucleotide (FAD) reductase, styrene isomerase and phenyl acetaldehyde dehydrogenase. Omics”-based approaches revitalized the study of PAH catabolism by permitting for an integrative assessment of the biochemical mechanism in charge to degrade PAH including polystyrene on the polluted locations. The applications of such enzymes in procedures that would permit the degradation of polystyrene plastics contaminating niches is a dare for future cohorts of microbiology experts

Highly Efficient and para-Selective C-H Functionalization of Polystyrene Providing a Versatile Platform for Diverse Applications.

Postpolymerization modification of polystyrene (PS) can afford numerous value-added materials with different functions and applications, but it has been hampered by the lack of efficient methods. We report herein a highly efficient and para-selective conversion of the C-H bonds of the aromatic ring of PS into diverse functional groups using a combination of thianthrenation and thio-Suzuki-Miyaura coupling reaction. Notably, the thianthrenation efficiency of PS is as high as 99% and the degree of thianthrenation can be conveniently controlled using stoichiometric tuning of the amount of thianthrene-S-oxide added, resulting in 24-99 mol % thianthrenation. In the subsequent thio-Suzuki-Miyaura coupling reaction, 18 functionalized PS containing various functional groups (-CH2OH, -OMe, -SMe, -OTBS, -CH3, -NHBoc, -OCOMe, -CHO, -COMe, -Si(Me)3, etc.) were successfully prepared with a high degree of functionalization (64-99 mol %). The obtained functionalized PS can be readily converted into diverse functional materials, including solid-phase synthesis resins, aggregation-induced emission fluorophores, as well as ionomer binders and ion-exchange membranes for energy conversion devices. This method imparts diverse functionality onto PS with extremely high efficiency and selectivity, providing a versatile platform to transform existing commodity PS plastics into high-performance materials.

Scalable Production of Biodegradable, Recyclable, Sustainable Cellulose-Mineral Foams via Coordination Interaction Assisted Ambient Drying.

Heavy reliance on petrochemical-based plastic foams in both industry and society has led to severe plastic pollution (the so-called "white pollution"). In this work, we develop a biodegradable, recyclable, and sustainable cellulose/bentonite (Cel/BT) foam material directly from resource-abundant natural materials (i.e., lignocellulosic biomass and minerals) via ambient drying. The strong resistance to the capillary force-driven structural collapse of the preformed three-dimensional (3D) network during the ambient drying process can be ascribed to the purpose-designed cellulose-bentonite coordination interaction, which provides a practical way for the locally scalable production of foam materials with designed shapes without complex processing and intensive energy consumption. Benefiting from the strong cellulose-bentonite coordination interaction, the Cel/BT foam material demonstrates high mechanical strength and outstanding thermal stability, outperforming commercial plastic polystyrene foam. Furthermore, the Cel/BT foam presents environmental impacts much lower than those of petrochemical-based plastic foams as it can be 100% recycled in a closed-loop recycling process and easily biodegraded in the environment (natural cellulose goes back to the carbon cycle, and bentonite minerals return to the geological cycle). This study demonstrates an energy-efficient ambient drying approach for the local and scalable production of an all-natural cellulose/bentonite foam for sustainable packaging, buildings, and beyond, presenting great potential in response to "white pollution" and resource shortage.

The single and combined effects of mercury and polystyrene plastic beads on antioxidant-related systems in the brackish water flea: toxicological interaction depending on mercury species and plastic bead size

Plastics are considered as a major threat to marine environments owing their high usage, persistence, and negative effects on aquatic organisms. Although they often exist as mixtures in combination with other pollutants (e.g., mercury (Hg)) in aquatic ecosystems, the combined effects of plastics and ambient pollutants remain unclear. Therefore, in the present study, we investigated the toxicological interactions between Hg and plastics using two Hg species (HgCl2 and MeHgCl) and different-sized polystyrene (PS) beads (diameter: 0.05, 0.5, and 6-μm) in the brackish water flea Diaphanosoma celebensis. The single and combined effects of Hg and PS beads on mortality were investigated, and changes in the antioxidant system and lipid peroxidation were further analyzed. After 48-h exposure to single Hg, HgCl2 induced a higher mortality rate than MeHgCl. The combined exposure test showed that 0.05-μm PS beads can enhance the toxicity of both the Hg species. The expression of GST-mu, glutathione S-transferease (GST) activity and malondialdehyde (MDA) content increased significantly after exposure to Hg alone (HgCl2 or MeHgCl) exposure. Combined exposure with PS beads modulated the effects of Hg on the antioxidant system depending on bead size and the Hg species. In particular, the 0.05-μm beads significantly increased the expression level of GST-mu, GST activity and MDA content, regardless of Hg species. These findings suggest that toxicological interactions between Hg and PS beads depend on the type of Hg species and the size of PS beads; nano-sized 0.05-μm PS beads can induce synergistic toxicity with Hg.

Pengaruh Penambahan Serat Kulit Kopi dan PVA terhadap Karakteristik Biodegradable Foam dari Pati Kulit Singkong

Polystyrene plastic or stryrofoam is very popular to be used as a food packaging container even though Styrofoam has a bad impact on health. In addition, Styrofoam also cannot be biodegraded naturally in the environment so that the use of Styrofoam is also a problem for the environment. One alternative to styrofoam is biodegradable foam (biofoam) made from starch and cellulose. It is safe for health and can be broken down naturally.Cassava peel is rich in starch (carbohydrates) but has low cellulose content. Meanwhile coffee peel is rich in cellulose and minimal in carbohydrates. Both types of waste have the potential to become biodegradable foam raw materials. The addition of synthetic PVA polymer is expected to improve the mechanical quality of biodegradable foam. This study aims to obtain the best formulation for the manufacture of biodegradable foam from cassava starch with the addition of coffee peel cellulose and PVA. The quality of biofoam evaluated includes tensile strength, water absorption, and biodegradability. The best biofoam characteristics were obtained at the addition of 15% fiber and 15% PVA, resulted in water absorption of 28.87%, tensile strength of 2.70 N / mm2 and biodegradability of 93.66% for 30 days.

Roles of polystyrene micro/nano-plastics as carriers on the toxicity of Pb2+ to Chlamydomonas reinhardtii

Little information could be consulted on the impacts of micro-plastics as carriers on toxicity of heavy metals, especially for micro-plastics of different sizes. Therefore, this study investigated the adsorption and desorption of Pb2+ on polystyrene plastics with nano- and micro-size (NPs and MPs), and further evaluated the roles of NPs and MPs as carriers on the toxicity of Pb2+ to Chlamydomonas reinhardtii (C. reinhardtii). The results showed that NPs showed higher adsorption capacities and a lower desorption rate for Pb2+ than MPs. The growth inhibitory rates (IR) of mixed and loaded Pb2+ with MPs to C. reinhardtii were 18.29% and 15.76%, respectively, which were lower than that of Pb2+ (22.28%). The presence of MPs decreased the bioavailability of Pb2+ to C. reinhardtii by a competitive adsorption for Pb2+ between MPs and algal cells, and suppressed membrane damage and oxidative stress caused by Pb2+. Maximum IR was observed for the mixture of NPs with Pb2+ (35.64%), followed by Pb2+ loaded on NPs (30.13%), single NPs (26.71%) and Pb2+ (21.01%). The internalization of NPs with absorbed Pb2+ intensified lipid peroxidation. The mixed and loaded microplastics with Pb2+ had more negative effects on C. reinhardtii than the single microplastics. The size-dependent effect was observed in the capacity of heavy metal ions carried by microplastics and the roles of microplastics as carriers on the toxicity of Pb2+. The results showed that the indirect risk of microplastics as 'carriers' could not be ignored, especially for NPs.

Influence of particle characteristics, heating temperature and time on the pyrolysis product distributions of polystyrene micro- and nano-plastics

Pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) has been widely used for the detection of micro- and nanoplastics (MNPs) in the environment. However, there is a lack of thorough investigation on the effects of pyrolysis temperature and time, as well as the particle source, size and mass of MNPs on the pyrolysis efficiency and pyrolysis product distribution of MNPs. Herein, taking the common plastics polystyrene (PS) as a model, we systematically evaluated the influences of the above factors on the pyrolysis of PS MNPs. Results showed that pyrolysis temperature and time significantly affect the pyrolysis efficiency. By measuring the relative response values of the indicator compound styrene trimers to styrene monomer, the optimum condition was determined as the temperature of 510 ℃ and pyrolysis time longer than 18 s. Meanwhile, the mass of MNPs also affected the distribution of PS pyrolysis products. The proportions of styrene dimers and trimers increased slightly with PS MNP mass, while the source, particle size of MNPs have little effect on the pyrolysis product distribution. This work proposed a suitable pyrolysis temperature and time for the determination of PS by Py-GC/MS, which would contribute to the accurate analysis of PS MNPs in the environment.

Cytotoxicity and Genotoxicity of Polystyrene Micro- and Nanoplastics with Different Size and Surface Modification in A549 Cells.

BackgroundMicro- and nano-sized plastics (MPs and NPs) have become an environmental issue of global concern due to their small size, strong bio-permeability and high specific surface area. However, few studies have assessed the effect of polystyrene MPs and NPs on human lung cells. In this research, we evaluated the cytotoxicity and genotoxicity of polystyrene (PS) MPs and NPs with different sizes (2 μm and 80 nm) and surface modification (carboxy and amino functionalized polystyrene, pristine polystyrene) in A549 cells.MethodsThe zeta potential and hydrodynamic particle size of five types of PS plastic solutions were measured by dynamic light scattering, and their morphology and degree of aggregation were observed by scanning electron microscopy. After incubation of the PS plastics with A549 cells, the uptake and toxicity of the cells were assessed by fluorescence microscopy, laser scanning confocal microscopy, flow cytometry, MTT, micronucleus formation assay, and reactive oxygen species.ResultsThe cytotoxicity and genotoxicity of A549 cells caused by nano-level PS is more serious than that of micro-level. Compared with unmodified PS-NPs, more surface-functionalized PS-NPs were found inside the cells, especially the accumulation of PS-NH2. Cell viability and the induction of micronuclei (MN) are appreciably impacted in a dose-dependent way. Compared with pristine PS-NPs, functionalized PS-NPs showed stronger cell viability inhibitory ability, and induced more MN scores.ConclusionThis study shows that the intrinsic size properties and surface modification of PS plastics, the interaction between PS plastics and the receiving medium, intracellular accumulation are critical factors for evaluating the toxicological influences of PS plastics on humans.

Utilization of High Impact Polystyrene(HIPS) Plastic Waste as a Partial Replacement of Fine Aggregates in Lightweight Concrete

Every year, the use of electronic plastic results in the generation of a significant quantity of garbage in India, recycling it into concrete may assist to reduce the amount of waste that must be disposed of. Various percentages of e-waste are added into concrete compositions as fine aggregate to assess whether they are suitable for usage. The goal of this research is to look into the impacts of using plastic trash instead of fine aggregate. Plastic trash absorption into concrete will help to safeguard both the environment and human health. This is because electronic plastic trash is harmful to both the environment and human health. Several research have been conducted in the past to find safe and practicable techniques of plastic trash ejection. However, limited land resources and the environmental risk have pushed us to take a step back and examine safe solutions for the re-use of plastic garbage. One technique among many is to incorporate plastic into the manufacturing of concrete. Concrete, which has a longer service life than other materials, can provide a safe environment for the use of plastic. The goal of this work is to present an overview of the numerous experiments conducted to investigate the influence of plastic inclusion in concrete. In this investigation, M30 grade concrete was employed, and the fine aggregate was substituted with waste High Intensity Polystyrene (HIPS) plastic from medical facilities in varied quantities of 5%, 10%, 15%, 20%, and 25%, respectively. A comparison of the physical and mechanical qualities was performed, as well as an optimization of the replacement value. After evaluating fresh and hardened concrete, 10 percent HIPS plastic substitution in concrete was shown to be ideal for partial fine aggregate replacement as there was no significant changes in the compressive, flexural and bond strength of nominal mix and optimal replacement mix.

Different plastics ingestion preferences and efficiencies of superworm (Zophobas atratus Fab.) and yellow mealworm (Tenebrio molitor Linn.) associated with distinct gut microbiome changes.

Larvae of superworms (Zophobas atratus Fab.) and yellow mealworms (Tenebrio molitor Linn.) can survive on sole plastic diets. However, no side-by-side comparison of plastics degradation by both species is available yet. Here, superworms and yellow mealworms were fed with polystyrene (PS) or polyurethane (PU) foam plastics as sole diets for 35 days with bran as control. Superworms survived 100% on all diets but decreased weights were observed after 20 days with sole plastic diets. In contrast, yellow mealworms survived 84.67% or 62.67% with PS or PU diet, respectively, both plastics diet groups showed increased weights. Cumulative consumption of plastics by superworms were 49.24 mg-PS/larva and 26.23 mg-PU/larva, which were 18 and 11 folds of that of yellow mealworms, respectively. When converted into mg/g-larvae, superworms had a higher PS consumption rate but both species had similar PU consumption rates. Similar changes of the plastic chemical functional groups in frass indicated occurrences of oxidation and biodegradation of plastics in the guts of both species. Changes of gut microbial communities were found associated with plastics feedstocks and larvae species. The increased relative abundances of unclassified Enterobacteriaceae, Klebsiella, Enterococcus, Dysgonomonas and Sphingobacterium were strongly associated with PS diet in superworms, while Hafnia was strongly associated with PS diet in yellow mealworms. Enterococcus and Mangrovibacter were dominant in PU-fed superworm guts, while unclassified Enterobacteriaceae and Hafnia were strongly associated with PU feeding in yellow mealworms. The results demonstrated that different plastics ingestion preferences and efficiencies of both species were associated with distinct dominant microbiomes although similar changes of chemical groups in plastics were observed.

Turning trash into treasure: Metal-free upcycling of polystyrene plastic waste to aromatics

The environmental stress of plastic waste and the high demand of aromatic commodities are both calling for sustainable solutions. In this issue of <i>Chem</i>, Das and co-workers develop an integrated strategy for both dilemmas by upcycling polystyrene plastic waste to low-molecular-weight aromatics via a metal-free catalytic photooxidation pathway.

Catalytic oxidation of polystyrene to aromatic oxygenates over a graphitic carbon nitride catalyst

The continuous increase in manufacturing coupled with the difficulty of recycling of plastic products has generated huge amounts of waste plastics. Most of the existing chemical recycling and upcycling methods suffer from harsh conditions and poor product selectivity. Here we demonstrate a photocatalytic method to oxidize polystyrene to aromatic oxygenates under visible light irradiation using heterogeneous graphitic carbon nitride catalysts. Benzoic acid, acetophenone, and benzaldehyde are the dominant products in the liquid phase when the conversion of polystyrene reaches >90% at 150 °C. For the transformation of 0.5 g polystyrene plastic waste, 0.36 g of the aromatic oxygenates is obtained. The reaction mechanism is also investigated with various characterization methods and procedes via polystyrene activation to form hydroxyl and carbonyl groups over its backbone via C–H bond oxidation which is followed by oxidative bond breakage via C–C activation and further oxidation processes to aromatic oxygenates.

Influencing factors for the persistence of SARS-CoV-2 (COVID-19) exposed in environmental matrices and disinfection methods: systematic review

Since the COVID-19 pandemic has been pestilential over a considerable duration, global deployment and financial crisis could not be reversed as before. It brought up essentials to allow the nations back to work with effective preventive measures. This review intended to evaluate the persistence of SARS-CoV-2 (COVID-19) exposed in the environmental matrices, influencing factors on the virus persistence and disinfection methods. Applying the PRISMA 2009 tool, MEDLINE/PubMed, HINARI, and Google Scholar were primarily explored. Data were extracted, entered into the modified data extraction forms and analysed narratively. Quality appraisal was done by the Mixed-Methods Appraisal Tool. The findings were presented descriptively. Persistence of SARS-CoV-2 was revealed &lt;4 hours on aluminium, 4 hours on copper, 24 hours on cardboard, 44 hours on glass, 48 hours on stainless steel, 72 hours on plastic, 92 hours on polystyrene plastic, 1.1-1.2 hours in the air, 7 days (higher titer) to 3 days (lower titer) in wastewater. Virus decaying was noted 5-10 times faster at 27°C than at 10°C and 2-5 times faster with 65% relative humidity (RH) than with 40% and 100% RH. Virus infectivity was reduced by far-UVC (222 nm) light for 90% (8 minutes), 95% (11 minutes), 99% (16 minutes) and 99.99% (25 minutes). Sodium hypochlorite (800 g/m3) and ammonium-based detergents were remarkably effective for preliminary disinfection. This review identified the duration of SARS-CoV-2 survival in environmental matrices for both healthcare and non-healthcare settings. The study explored the impacts of environmental factors on the virus and effective disinfection methods to be considered accordingly to the findings.

Migration of Styrene in Yogurt and Dairy Products Packaged in Polystyrene: Results from Market Samples.

The European Food Safety Authority is re-evaluating styrene for assessing the safety of food contact materials (FCM) such as polystyrene (PS) and started a systematic review of the data on migration levels in food. A restriction for styrene is expected in the near future. The main food contact application of PS is dairy packaging, mainly at refrigerated storage. In this study, seventeen dairy products packed in PS taken from the Italian and German markets were investigated. Styrene concentrations in the refrigerated dairy products (yogurt, cream) ranged from 5 to 30 µg/kg at the best before date, while in single serving portions of coffee creamer, which were stored at room temperature until the best before date of approx. 190 days, 401 µg/kg were measured. Among several parameters, the ratio between the surface contact area of the package and the quantity of the food packed, the time/temperature conditions of production/filling and storage of the products were identified as the main factors influencing styrene migration into food under realistic conditions. Yogurts fermented in the pots for approximately 8 h at 40–50 °C showed higher styrene levels than those fermented in an incubator and filled at 20 °C. The fat content might influence the styrene level but the effect, if any, was too small in relation to the variability of other parameters. Levels of styrene migrating into 50% ethanol food simulant under standardized condition (10 days/40 °C) were found to be much higher than levels in refrigerated foods. This raises the question as to whether compliance testing for PS plastics should be adapted taking into consideration the correlation between migration testing by laboratory simulations and migration into real food.

Digestion of plastics using in vitro human gastrointestinal tract and their potential to adsorb emerging organic pollutants

Excessive plastic use has inevitably led to its consumption by organisms, including humans. It is estimated that humans consume 20 kg of plastic during their lifetime. The presence of microplastics in the human body can carry serious health risks, such as biological reactions e.g. inflammation, genotoxicity, oxidative stress, apoptosis, as well toxic compounds leaching of unbound chemicals/monomers, free radicals or adsorbed organic pollutants, which mainly depend on the properties of the ingested plastic. Plastics are exposed to different substances (e.g., enzymes and acids) in the digestive system, which potentially affects their properties and structure. By stimulating the human digestive system and applying a set of advanced analytical tools, we showed that the surface of polystyrene and high-density polyethylene plastics frequently in contact with food undergoes fundamental changes during digestion. This results in the appearance of additional functional groups, and consequent increase in the plastic adsorption capacity for hydrophobic ionic compounds (such as triclosan and diclofenac) while reducing its adsorption capacity for hydrophobic non-ionic compounds (such as phenanthrene). Micro- and nanostructures that formed on the flat surface of the plastics after digestion were identified using scanning electron microscopy. These structures became defragmented and detached due to mechanical action, increasing micro- and nanoplastics in the environment. Due to their size, the release of plastic nanostructures after digestion can become an “accidental food source” for a wider group of aquatic organisms and ultimately for humans as the last link in the food chain. This, combined with improved adsorption capacity of digested plastics to hydrophobic ionic pollutants, can pose a serious threat to the environment including human health and safety.

Combined effects of micro-/nano-plastics and oxytetracycline on the intestinal histopathology and microbiome in zebrafish (Danio rerio)

Accumulated evidence has demonstrated that microplastics and oxytetracycline (OTC) affect organisms, but few studies have investigated their combined effects on aquatic organisms. In this study, adult zebrafish (Danio rerio) were exposed to single and binary-combined contamination of micro-, nano-sized polystyrene plastics and OTC for 30 days, and the intestinal histopathology, gut microbiota and antibiotic resistance genes (ARGs) of zebrafish were measured. The results showed that the intestinal epithelial damage increase with the decrease of plastic sizes. Nano-sized plastics, OTC and their combined exposure caused intestinal epithelial damage, and co-exposure with micro-sized plastics reduced the intestinal damage caused by single OTC exposure. The gut microbial communities were affected by the combined exposure to microplastics and OTC. Compared with the blank control, the relative abundance of Fusobacteria increased 12.7 % and 21.1 % in OTC combined with 45–85 μm micro-plastics (MOTC) and 40–54 nm nano-plastics (NOTC), respectively, and that of Bacteroidetes increased 26.2 % and 18.6 % in the MOTC and NOTC treatments, respectively. The effects of MOTC and NOTC on the biodiversity of the zebrafish gut microbiome were different; MOTC increased the biodiversity by 11.3 % compared with the blank control, whereas NOTC decreased the biodiversity by 8.8 % compared with the blank control. Furthermore, the abundance of ARGs in 40–54 nm nano-plastics, MOTC and NOTC treatments was increased 96.9 %, 96.6 % and 68.8 % compared with the control group, respectively. Additionally, significant differences were observed in ARGs characteristics between the micro- and nano-plastics treated groups whether combined with OTC or not. These results are essential to further understand the combined ecotoxicological effects of micro- or nano-plastics and antibiotics on aquatic organisms.

PROSES PIROLOSIS PENGOLAHAN SAMPAH PLASTIK MENJADI BAHAN BAKAR CAIR

The research aims to utilize polyethylene (PET), polypropylene (PP) and polystyrene (PS) plastic waste into liquid fuel by the pyrolysis process, currently, especially in Surabaya, a lot of waste, 13% - 14% is plastic. The results of the sample from this study are to distinguish the temperature of the steam entering the condenser and also the temperature of the water in the condenser. And what will later be tested is that the oil from the plastic is close to the type of gasoline or diesel. The results of this study found that the optimum temperature to get a lot of results in 1 kg of plastic type Polyethylene (PET) is with a steam temperature of 142°C and a time of 90 minutes, while the type of plastic Polypropylene (PP) with a vapor temperature of 180°C and plastic type Polystyrene (PS) with a vapor temperature of 100°C and a condenser temperature of 15°C. The amount of oil produced by Polyethylene (PET) plastic at that temperature is 40 ml. while the plastic type Polypropylene (PP) the amount of oil produced is 100 ml. and this type of polystyrene (PS) plastic can produce 20 ml of oil. This result means that it is worth 75% of the weight of the plastic that has been processed. Meanwhile, the yield of this oil is close to the premium type.. Keywords: plastic waste, pyrolysis, liquid fuel

Oxidative degradation of pre-oxidated polystyrene plastics by dye decolorizing peroxidases from Thermomonospora curvata and Nostocaceae

Biodegradation of PS has attracted lots of public attentions due to its environmental friendliness. However, no specific PS degrading enzyme has been identified yet. Dye decolorizing peroxidases (DyPs) are heme-containing peroxidases named for the ability to degrade a variety of organic dyes. Herein, the abilities of two DyPs from Thermomonospora curvata (TcDyP) and Nostocaceae (AnaPX) to degrade PS were evaluated. Preoxidation methods by ultraviolet (UV) irradiation and chemical oxidants were developed to initially activate C-C bonds in the PS skeleton. DyPs degradation caused obvious etching and enhanced hydrophilicity of UV-PS films, and also generated new CO and C-OH groups. The cleavage of activated C-C bonds by DyPs was experimentally proven by analyzing the degradation products of UV-PS and model substrates. Furthermore, better pre-oxidation was obtained by using chemical oxidants KMnO4/H2SO4 and mCPBA to oxidize PS materials in dissolved state. And AnaPX exhibited stronger degradation effects on KMnO4/H2SO4-PS and mCPBA-PS by causing greater changes in functional groups CO, C-O, -OH groups and substituted benzenes and higher molecular weight reductions of 19.7% and 31.0%, respectively. To our knowledge, this is the first report on the identification of PS-degrading enzymes that provides experimental evidence.

The Effect of Microwave Oven Power Variations on Co-Pyrolysis Process of Oil Palm Shells and Polystyrene

Indonesia has a very large area of ​​oil palm plantations, one of which is the island of Sumatra. However, in processing and handling palm oil product waste in the form of palm shells, it has not been maximized. Therefore, the chemical decomposition process can play an important role in supporting waste management and sustainable energy use in Indonesia which is not yet optimal. In this research, the proper use of power will be tested with the help of microwaves as a reactor for the co-pyrolysis process of oil palm shells and polystyrene plastic. The purpose of this study was to determine the appropriate power to produce maximum co-pyrolysis products and to investigate the physical characteristics of the oil-pyrolytic products. The test uses a microwave oven which has a power variation of 300 W, 450 W, 600 W, and 800 W with the addition of a catalyst. The ratio of the composition of oil palm shells to polystyrene plastic is 1:1 with a total mass of 105 gr and using coconut shell charcoal as an activated carbon absorber. The pyrolysis temperature is 500 ℃, the nitrogen gas flow rate is 1.5 LPM, and the pyrolysis time is 60 minutes. Furthermore, testing the physical properties of the pyrolysis oil product in the form of density, acidity, and viscosity testing. The results showed that the optimal power to obtain oil-pyrolytic was 600 W with a product oil of 17.6%, and from the physical properties it had a low viscosity value of 2.55 mPa.s with a pH level of 6.6.

Nano-sized polystyrene plastic particles affect many cancer-related biological processes even in the next generations; zebrafish modeling

With the ever-increasing plastic pollution, the nano-sized plastic particles that are constantly released from the main materials have a greater potential threat. Studies continue on how to eliminate plastic waste, which has become a global problem, from nature. We are aware that complete elimination is not easy at all, but it is not known clearly that even if it is successful, its effects on organisms will also disappear completely. In this study, zebrafish injected with 20 nm-sized polystyrene particles (PS) only during the embryonic period were grown in an environment without plastic exposure. The effects of PS on their offspring embryo/larvae were examined at morphological, molecular and metabolomic levels. Results showed that parental PNP exposure caused significant malformations, decreased survival rate, increased heart rate and blood flow rate, as well as decreased eye size, height and locomotor activity, which were attributed to growth retardation in the offspring. According to the results of whole-mount immunofluorescence larval staining, cell death and reactive oxygen species were significantly increased, while lipid accumulation was decreased in new generation larvae from zebrafish injected with PNP. In order to elucidate the mechanisms underlying these morphological, physiological and molecular damages, the metabolome analyses were performed by evaluating the Q-TOF MS/MS spectra with chemometric analyses in the offspring larvae. According to the metabolomics results, 28 annotated metabolomes suggested by the OPLS-DA analysis that may vary significantly through a variable in projection scores were detected. In addition, it was detected that the significantly increased histopathological findings and immunopositivity of JNK, H2A.X, PI3 and NOP10 in new generation larvae. In conclusion, it has been shown that exposure to PS, even only during the embryonic period, may affect many cancer-related biological processes in the next generation.