Microplastics in Brazilian rivers: An overview and a study of floating particle accumulation on the coast of Santa Catarina state.

Are mangrove ecosystems plastic accumulation zones?

This research provides an intensive experimental investigation of the energy issues with respect to tensile strength and energy consumption during ultrasonic welding of thermoplastic PP and Electrostatic Discharge ABS polymers. A scheduled set of 27 experiments were performed through varying amplitude, weld pressure, and weld time that led to the identification of the effect of process parameters on joint quality and energy usage. Quantitative data were gathered and analysed to recognize patterns to improve efficiency. The Pearson correlation coefficient was applied to confirm relations between the input variables and the response variables. The analysis indicated a strong positive correlation of weld time with energy consumed, and with the tensile strength and amplitude of the weld. The findings can help create energy-efficient welding methods for polymer materials used in energy systems. Power signals and harmonics analysis is performed using MATLAB to understand its variation when the process is ON and it provides an insight into signals and control mechanism to be fine-tuned for ultrasonic welding process.

This study aims to assess the relationship between marine pollution exposure levels and the risk of gastrointestinal health disorders in coastal fishing communities in Semarang City, Indonesia. A cross-sectional study was conducted from May to October 2025 in the Tambaklorok and Tanjung Emas areas, which are areas with high seafood consumption patterns and exposure to marine environments. Data were collected through a structured questionnaire covering respondent characteristics, seafood consumption habits, and gastrointestinal complaints using the Gastrointestinal Symptom Rating Scale (GSRS). All respondents (100%) tested positive for microplastic exposure in feces with an average concentration of 18.4 6.7 particles/gram, dominated by PE, PP, and PS polymers, as well as heavy metal levels (Hg, Pb, Cd) through AAS or ICP-MS. Microplastics were the strongest predictor of increased GSRS scores (=0.37, p0.001), followed by blood mercury levels and inadequate sanitation conditions, with the model able to explain 43-47% of the variation in symptoms. This research fills a gap in the literature regarding marine pollution risk in Indonesia and provides a scientific basis for developing environmental health policies, coastal waste management, and more targeted public health intervention programs for fishing communities.

Occurrence, trophic transfer and risk assessment of microplastics in fishery organisms from the Bohai Sea, China.

Microplastics (MPs) are tiny plastic particles that persist in nature for more than 100 years. This review aimed to illustrate the scenario of global microplastic pollution in various rivers and their ecological impacts. The study collected data from journals, books, and reports published within the last twenty years using multiple search engines such as Google Scholar, ResearchGate, etc. Microplastics (MPs) were found in high abundance in river systems, which act as pathways for from terrestrial to marine ecosystems. FTIR, or Raman spectroscopy, Py-GC-MS, and SEM-EDS were the major instruments to identify MPs. Green or blue-colored fibers or fragments like PE or PP polymers were dominant MPs in rivers. This review found the highest 120 ± 43 MPs/L in water samples collected from Nakdong River, South Korea, whereas the highest 13607 MPs/kg in sediment samples collected from peripheral rivers of Dhaka, Bangladesh, and MPs abundance ranged from 6.3 to 22.21 MPs/fish and 40 MPs/bird. Ingested microplastics can block digestive tracts, reduce nutrient absorption, and lead to starvation, and they can cause exposure to toxins and pathogens. However, it causes bioaccumulation and disrupts food chains and habitats. Therefore, effective mitigation strategies should be adopted to address the microplastic pollution in rivers.

Several studies have focused on quantifying microplastics (MP) in the environment using μ-FTIR and Py-GC/MS, the most common analytical methods. However, their application to complex matrices like sediments is affected by interferences specific to each method. In this study, we developed a protocol combining μ-FTIR and Py-GC/MS for sequential analysis of MP (10-500 μm) in 16 river sediment samples, targeting PE, PP, and PS polymers. Mass concentrations were estimated from the particle volume in μ-FTIR and measured directly by Py-GC/MS using internal calibration. Results show consistency between the two methods across different sites, with variability of two orders of magnitude in concentration ranges from 0.3 to 50 items g-1 and 0.2 to 17 μg g-1 for μ-FTIR, and 0.8 to 21 μg g-1 for Py-GC/MS. Replicate analyses (2 to 6 per site) revealed that intra-site variability was mainly influenced by sample preparation and, to a lesser extent, by the measurement technique. While estimated and measured concentrations were similar, discrepancies were observed in polymer proportions: PP predominated in μ-FTIR, while PS was more prevalent in Py-GC/MS. These differences are explained by the specific limitations of each method, especially the limited detection of synthetic fibres and tyre or road abrasion particles by μ-FTIR, which are detected as MP by Py-GC/MS. This comparative study provides recommendations for evaluating compatibility between studies using either technique and offers guidelines for selecting the most appropriate method based on research interests.

Polymer-based compounds such as PVC, HFFR, PE, PP, and engineering polymers are widely used in the cable industry as sheath, insulation, and filling materials due to their mechanical, electrical, and environmental advantages. However, in their processing, challenges such as mixing homogeneity and production efficiency remain significant limitations in conventional systems. Inadequate mixing or uneven dispersion of additives not only reduces production efficiency but also directly affects the mechanical properties of the final product such as tensile strength, elongation value and flexibility. In this study, a multi-purpose compound production machine equipped with intermeshing and co-rotating counter-conical screws was designed, manufactured, and tested. The system consists of six main components: ribbon mixer, feeding unit, twin conical screws, transfer screw, granule cutting and cooling unit, and a PLC-based main control panel (HMI). The homogeneity and desired dispersion of the compound were confirmed by microscopic examinations, SEM analysis, and mapping analysis. Mechanical tests demonstrated that the compound had a tensile strength of 14.72 N/mm² and an elongation value of 173%, along with hardness, density, and moisture measurements, all meeting industrial standards. The developed machine provides significant advantages over conventional systems in terms of mixture homogeneity and production efficiency.

Occurrence and characteristics of microplastics across the watershed of the world’s third-largest river

Primary risk assessment of microplastic pollution in spineless cuttlefish (Sepiella inermis) from the North-East Bay of Bengal: A tissue-based analysis

Microplastics contamination in commercial fish meal and feed: a major concern in the cultured organisms

This paper presents the obtaining and characterization of recycled polypropylene/strontium ferrite (PP/SrFe12O19) polymer composite materials with applications in the electromagnetic shielding of vehicle interiors (mainly automotive electronics-carcasses) from the electromagnetic radiation emitted mainly by exterior sources-electrical lines and supply sources-in terms of the development of the new electrical vehicles. With this aim, suitable polymer composite materials were developed using SrFe12O19 filler in two forms (powder and concentrate). The recycled PP polymer and composite materials with a PP/SrFe12O19 weight ratio of 75/25 and 70/30 were obtained in two stages, i.e., pellets by extrusion and samples for testing through a melt injection process. The characterization of the obtained materials took into account the requirements imposed by the desired applications. It consisted of determining the mechanical and dielectric properties, and microstructure analyses, along with the determination of the resistance to the action of a temperature of 70 °C, which is higher than the temperatures created during the summer inside vehicles. The performance of these materials as electromagnetic shields was assessed through functional tests consisting of the determination of magnetic permeability and the estimation of the electromagnetic shielding efficiency (SE). The obtained results confirmed the improvement of the mechanical, dielectric, and magnetic properties of the PP/SrFe12O19 composites compared to the selected PP polymers. It is also found that all the composite materials exhibited reflective shielding properties (SER from -71.5 dB to -56.7 dB), with very little absorption shielding. The most performant material was the composite made of PP/SrFe12O19 powder with a weight ratio of 70/30. The promising results recommend this composite material for potential use in automotive shielding applications against electromagnetic pollution.

Monocyclic aromatic hydrocarbons production from NaOH pretreatment metallized food plastic packaging waste through microwave pyrolysis coupled with ex-situ catalytic reforming

Abstract The morphological transformation of expanded vermiculite (VC) during injection molding with brittle PLA and ductile PP polymers along with its positive and negative contribution to mechanical response is investigated. Polymer/VC mixtures with 30 wt. % VC are prepared by thermokinetic high shear mixing at 4000 rpm without any ex‐situ exfoliation agents or compatibilizers. Obtained composite mixtures are then injection molded onto three‐point bending and tensile test specimens. Performed mechanical tests suggested a significant increase in tensile (110%) and flexural modulus (112%) of PP30VC samples. Presented fractographic and morphological investigations suggested that the root cause of measured improved tensile (36%) and bending strength (26%) of PP is the fibrillation of VC associated with PP/VC interactions under high shear. A similarly increasing trend for tensile (147%) and bending modulus (137%) was observed for PLA30VC samples. Contrary to PP30VC, a decreasing pattern was present in the case of tensile (−40%) and bending strength (−13%) of PLA30VC. The root cause for such reduction is determined to be (i) in situ exfoliation of VC inside PLA matrix and transformation of VC into micrometer‐sized platelets; (ii) evaporation of trapped water/crystalline water in the interlayer region of VC which caused in situ degradation of PLA during manufacturing.Highlights Vermiculite‐loaded PP and PLA composites are produced at high shear. Composites have superior modulus compared to neat polymers. Fibrillation of platelet vermiculite is observed in only the PP matrix.

Biodegradation of additive-free polypropylene by bacterial consortia enriched from the ocean and from the gut of Tenebrio molitor larvae

Microplastics and mesoplastics as emerging contaminants in Tehran landfill soils: The distribution and induced-ecological risk

Since the start of mass production of plastic materials more than a century ago, the problem of accumulating plastic waste in the environment has reached epic proportions. Recently, the problem of smaller plastic particles (microplastic, MP) in the environment has become a widely studied topic, but the amount and types of MP in karst environments are still poorly known. Thus, the objective of this study was to collect and analyse samples from various karst habitats and to try and determine the scope of pollution in karst springs that are in part used as sources for drinking water. Of the potential pollution sources, we sampled rainwater, two discharges from wastewater treatment plants, and a leachate from a landfill. We conducted polymer analyses of potential MP particles using FTIR-ATR. The results showed that eight samples from the Postojna region (Postojna–Planina Cave System, rainfall sample and surface streams) contain up to 444 MP particles per m3. However, 32 samples taken from the Škocjan–Kačna–Jama 1 v Kanjaducah Cave System contain up to 60,000 MP particles per m3, with the bulk of particles found in the sediment samples from Škocjan Caves – Kačna Cave System. Samples from Postojna region contained mostly PET, PU and PA polymers, with a minor inclusion of polymers of plastic sponge used for cleaning. Samples from Škocjan region contained mostly PP, PET and PE polymers, with some of PA and PU polymers. Sediment samples contained much less MP particles compared to water samples, which indicates fast transport through karst aquifer.

Compression Properties of 3d Printed Honeycomb and Re-Entrant Sandwich Core Materials

Air filtration materials such as protective masks can protect humans from airborne pathogens; however, most of the existing protective filtration materials are aimed to intercept bacteria. Therefore, in this work, modified polypropylene- (PP-) based melt-blown nonwovens with antibacterial property were prepared for reducing the infection rate during the filtering process. Firstly, an N-halamine precursor, 2,4-diamino-6-diallylamino-1,3,5-triazine (NDAM) monomer, was grafted with PP polymers (PP-g-NDAM) by reactive extrusion method, and the grafting effect was confirmed by nitrogen analysis and FTIR spectra. Then, the obtained PP-g-NDAM was mixed with pristine PP resins in different ratios to prepare the filter materials by melt-blown technology. Finally, the new PP-g-NDAM melt-blown filter materials were finishing treated by the chlorination and electrostatic process, which showed a high filtration efficiency with low pressure drop and a potent antibacterial effect against Escherichia coli (E. coli). This work provides an innovative method for manufacturing antibacterial filtration nonwovens, which can improve the quality of conventional filtration products.

Nanotechnology is a perspective manufacturing technology, and in the technical fields, it deals with the production, development and utilization of technologies and materials with dimensions in nanometre sizes (1–100 nm). Nanofilters used in the article for filtration purposes consist from a nanolayer which is applied to a coarse textile backing layer, and they are inserted into the frames as conventional textile filters. The most commonly used materials are PP and PE polymers, as well as carbon, glass and metal filters. With the fabrication of nanotechnology-based filter, it is very important to choose materials, polymers with specific properties, which can be used for filtration function of the product itself. The results given in the main article compare the nanofilters with the main representatives of existing filter products currently available on the market. There is a problem with high pressure loss of the nanomaterial, and when we compare them with traditional filters, it is difficult to use them in technical practice, even if there exists the possibility for us to define the material and the thickness of the layer which are adapted to the application-specific application conditions.