Systematic development of extraction methods for quantitative microplastics analysis in soils using metal-doped plastics

The inconsistency of available methods and the lack of harmonization in current microplastics (MPs) analysis in soils demand approaches for extraction and quantification which can be utilized across a wide variety of soil types. To enable robust and accurate assessment of extraction workflows, PET MPs with an inorganic tracer (Indium, 0.2% wt) were spiked into individual soil subgroups and standard soils with varying compositions. Due to the selectivity of the metal tracer, MPs recovery rates could be quickly and quantitatively assessed using ICP-MS. The evaluation of different methods specifically adapted to the soil properties were assessed by isolating MPs from complex soil matrices by systematically investigating specific subgroups (sand, silt, clay, non-lignified and lignified organic matter) before applying the workflow to standard soils. Removal of recalcitrant organic matter is one of the major hurdles in isolating MPs for further size and chemical characterization, requiring novel approaches to remove lignocellulosic structures. Therefore, a new biotechnological method (3-F-Ultra) was developed which mimics natural degradation processes occurring in aerobic (Fenton) and anaerobic fungi (CAZymes). Finally, a Nile Red staining protocol was developed to evaluate the suitability of the workflow for non-metal-doped MPs, which requires a filter with minimal background residues for further chemical identification, e.g. by μFTIR spectroscopy. Image analysis was performed using a Deep Learning tool, allowing for discrimination between the number of residues in bright-field and MPs counted in fluorescence mode to calculate a Filter Clearness Index (FCI). To validate the workflow, three well-characterized standard soils were analyzed applying the final method, with recoveries of 88% for MPs fragments and 74% for MPs fibers with an average FCI of 0.75. Collectively, this workflow improves our current understanding of how to adapt extraction protocols according to the target soil composition, allowing for improved MPs analysis in environmental sampling campaigns

Peran Ayah dalam Praktik Menyusui

Background: In Indonesia the prevalence of exclusive breastfeeding in 2007 was 32%. Although breastfeeding is a common practice, exclusive breastfeeding remains unpracticed optimally due to some influential factors. One factor to be considered here is father\u27s role. However, until recently studies regarding father\u27s role in breastfeeding practice have not been fully explored in Indonesia. In Bukittinggi exclusive breastfeeding rate was 63,5% in 2008.Objective: To investigate the relationship between the father\u27s role and breastfeeding practices in Bukittinggi Municipality.Method: This was an observational study with cross-sectional study design. Subjects were families with babies aged 0 – 6 months using non probability sampling. The independent variable was the father\u27s role and the dependent variable was breastfeeding practices. Meanwhile, the extraneous variables included knowledge, attitude, mother\u27s occupation; father\u27s working hours in a day, and income. The data were analyzed using univariable analysis, bivariable analysis with chi-square test, and multivariable analysis with logistic regression.Results: The result of multivariable analysis showed that there was a significant relationship between the father\u27s role and breastfeeding practice, by including father\u27s knowledge, mother\u27s knowledge, father\u27s attitude and mother\u27s attitude that could predict by 12% (RP= 1.93; 95% CI= 1.36 – 2.74).Conclusion: The prevalence of exclusive breastfeeding practices in the supporting father group was greater than in the group that non-supporting father. The recommendations are that fathers should be targeted audience in the breastfeeding promotion

Mechanistic understanding of microplastic fiber fate and sampling strategies: Synthesis and utility of metal doped polyester fibers

The increased use of synthetic textiles in the last decades, coupled with recent emphasis on the accumulation of (micro)plastic across multiple environmental compartments, has garnered interest into how microplastic fibers are released into the environment. In particular, polyester textiles washed in the home have shown to release microplastic fibers but challenges with microplastic fiber analysis, including time and difficulty of sample preparation and measurement, has limited mechanistic studies on fiber fate and transport studies. In this study, we provide a method to synthesize fibers with an embedded inorganic (In) fingerprint which can be used as a tracer for ease of analysis and show the utility of this approach to assess the affinity for heteroaggregation between microplastic fibers and other particles in a heterogeneous suspension, as well as approximate the fate of microplastic fibers in batch studies using activated sludge from a municipal wastewater treatment plant (WWTP). Total In content in the fibers was measured to be 0.2 % by weight, which was low enough to not change fiber dynamics for fate and transport studies (e.g. density, etc.) but provided sensitive detection limits by ICP-MS. Fiber length was 510 μm ± 410 μm and 30 μm in diameter. The incorporated metal remained stable inside the polymer when suspended in water and in activated sludge, with 99.9 %), with a mass balance of > 95 % recovery achieved on average across batches. Fiber removal linearly increased with contact times of up to 10 min, suggesting interactions between plastics and organic matter is a metric that should be considered closely in this and other environmental contexts for fate and transport.ISSN:0043-1354ISSN:1879-244

Hybrid Carbon Nanoparticles in Polymer Matrix for Efficient Connected Networks: Self-Assembly and Continuous Pathways

Functional polymer composites based on hybrid carbon nanoparticles (CNPs) offer synergistic properties and have recently received a lot of attention for various applications including photovoltaic cells. In this context, the size dispersity inherent in CNPs such as carbon nanotubes (CNTs) is still a controversial topic in light of new experimental findings when it comes to the formation of percolating networks. Here, we show how nanotube models with different aspect ratios (ARs) dispersed in polyamide 12 (PA12) matrix differ in their equilibrium nanostructures. To this end, large-scale dissipative particle dynamics simulations are carried out, and CNPs with different ARs representing fullerene-like isomers up to realistic CNTs are studied separately or in hybrids. The continuous pathways in the CNP nanostructures are further assessed in Monte Carlo calculations by random electrons transporting through the network quantifying its continuity for electrical conductivity. The results confirm that the morphology of the composite depends on the AR and, by increasing it, changes from a random dispersion to a self-assembled morphology and eventually to a bridging self-assembled network. The generic behavior predicted in the simulations is compared with the rheological and electrical conductivity measurements performed on PA12/CNT nanocomposites. Based on the results, the dispersion quality, the AR of CNPs, and the continuous pathways in the network are found to be interconnected in contrast to previous interpretations of hybrid nanocomposites

Long-term assessment of nanoplastic particle and microplastic fiber flux through a pilot wastewater treatment plant using metal-doped plastics

In recent years, several studies have investigated the flux of particulate plastic through municipal waste water treatment plants (WWTP). Challenges related to time consuming analytical methods have limited the number of sampling points and detection limits have hampered quantification of nanoplastic and microplastic fiber fluxes through WWTPs. By synthesizing nanoplastic particles and microplastic fibers labeled with a rare metal (Pd and In, respectively) which can be measured as a proxy for the plastic itself, we have circumvented major analytical pitfalls associated with (micro)plastic measurements. In this study, we spiked the labeled materials to a pilot WWTP mimicking the activated sludge process (nitrification, de-nitrification and secondary clarification). Using a mass flow model for WWTP sludge, we assessed the behavior of particulate plastic in relation to the removal of organic matter. Triplicate samples were collected from the mixed liquor and from the effluent at least twice weekly over the entire experimental run time of 40 d. Our findings show that in discrete grab samples during steady state conditions, at least 98% of particulate plastics were associated with the biosolids. A positive correlation between total suspended solids (TSS) and plastic concentrations was observed in the sludge as well as in the effluent. Because of the strong association between particulate plastic and TSS, TSS removal is likely a good indicator of plastic removal in a full scale WWTP. Therefore, additional process steps in a full-scale WWTP which further reduce the TSS load will likely retain nanoplastic particles and microplastic fibers effectively and consequently increase the removal rates.ISSN:0043-1354ISSN:1879-244

Melt-Spun Fibers for Textile Applications

Textiles have a very long history, but they are far from becoming outdated. They gain new importance in technical applications, and man-made fibers are at the center of this ongoing innovation. The development of high-tech textiles relies on enhancements of fiber raw materials and processing techniques. Today, melt spinning of polymers is the most commonly used method for manufacturing commercial fibers, due to the simplicity of the production line, high spinning velocities, low production cost and environmental friendliness. Topics covered in this review are established and novel polymers, additives and processes used in melt spinning. In addition, fundamental questions regarding fiber morphologies, structure-property relationships, as well as flow and draw instabilities are addressed. Multicomponent melt-spinning, where several functionalities can be combined in one fiber, is also discussed. Finally, textile applications and melt-spun fiber specialties are presented, which emphasize how ongoing research efforts keep the high value of fibers and textiles alive

Formation of Fiber Fragments during Abrasion of Polyester Textiles

Fiber fragments are one of the dominant types of microplastics in environmental samples, suggesting that synthetic textiles are a potential source of microplastics to the environment. Whereas the release of microplastics during washing of textiles is already well studied, much less is known about the release during abrasion processes. The abrasion of textiles may induce fibrillation of fibers and therefore result in the formation of much finer fiber fragments. The aim of this study was to investigate the influence of abrasion of synthetic textiles on the formation of microplastic fibers and fibrils. Fleece and interlock textile swatches made of polyester were abraded using abrasion tests with a Martindale tester. The microplastic fibers and fibrils formed during abrasion were extracted from the textiles and characterized in terms of number, length, and diameter. The microplastic fibers demonstrated the same diameter than the fibers found in the textiles (fleece: 12.3 μm; interlock: 12.7 μm), while fibrils with a much smaller diameter (fleece: 2.4 μm; interlock: 4.9 μm) were also found. The number of fibrils formed during abrasion in both textiles was higher than the number of microplastic fibers. The majority of the extracted microplastic fibers had a length between 200 and 800 μm, while most fibrils were between 30 and 150 μm, forming two distinct fiber fragment morphologies. The number of microplastic fibers formed during abrasion was 5 to 30 times higher than the number of microplastic fibers that could be extracted from non-abraded samples. The number of fibrils increased after abrasion by more than a factor of 200 for both fabric types. The fibrils formed during abrasion have diameters that fall within the inhalable size for airborne particles. The potential release of fibrils into air during wear of textiles thus raises questions about the human exposure to these materials. Since the Martindale tester can simulate a daily application scenario of textiles over a prolonged period only in a limited way, future studies are needed to establish the correlation between the test results with a real-world scenario.ISSN:0013-936XISSN:1520-585