Natural Degradation Processes Research Articles

UVB-Aged Microplastics and Cellular Damage: An in Vitro Study.

Plastics are synthetic organic compounds whose widespread use generates enormous waste. Different processes, such as mechanical abrasion, microbiological activity, and UVB irradiation, can fragment the plastic material and generate microplastics (MPs). MPs are ubiquitous, and various organisms, including humans, can ingest or inhale them, with potential adverse health effects. The differences between UV-aged and virgin particles were studied to evaluate the genotoxic damage and oxidative stress induced by polystyrene MPs with 1 and 5µm sizes on the monocyte-like cell line (THP-1). Fourier transform infrared spectroscopy and Ζ-potential measurements were used to characterise MP particles after UVB exposure. Cells exposed to MPs show a widespread change in the cellular environment with the generation of reactive oxidative species (ROS), as indicated by the increased malondialdehyde level. The occurrence of genotoxic damage is correlated to the smaller size and ageing state of the MPs. The biochemical and genomic alterations observed in this in vitro study suggest that MPs, ubiquitous pollutants, following natural degradation and oxidation processes can cause various adverse effects on the health of the exposed population, making it necessary to carry out further studies to better define the real risk.

Artificial cellulosic leaf with adjustable enzymatic CO2 sequestration capability

Developing artificial leaves to address the environmental burden of CO2 is pivotal for advancing our Net Zero Future. In this study, we introduce EcoLeaf, an artificial leaf that closely mimics the characteristics of natural leaves. It harnesses visible light as its sole energy source and orchestrates the controlled expansion and contraction of stomata and the exchange of petiole materials to govern the rate of CO2 sequestration from the atmosphere. Furthermore, EcoLeaf has a cellulose composition and mechanical strength similar to those of natural leaves, allowing it to seamlessly integrate into the ecosystem during use and participate in natural degradation and nutrient cycling processes at the end of its life. We propose that the carbon sequestration pathway within EcoLeaf is adaptable and can serve as a versatile biomimetic platform for diverse biogenic carbon sequestration pathways in the future.

Isolation and screening of microplastics from Nodularia spumigena and Phaeodactylum tricornutum and determining the efficacy of biodegradation of microplastics obtained using the synergistic consortium

Microplastics are a form of plastics which are less than 5mm in size. They are the major threat for the environment and mankind, as they critically influence the food chain. The best way to extinct them from the environment is to degrade them in eco-friendly manner where biodegradation is the optimal therapy. Phytoplanktons play a vital role in phytoremediation. They are capable of in taking certain water pollutants such as micro plastics. Nodularia spumigena and Phaeodactylum tricornutum were screened and the microplastics were extracted using optimized enzymatic or alklanized digestion process and then dried. The micro plastics obtained were weighed and the concentration of microplastic present per gram of the sample was calculated. UV- VIS spectroscopy and FTIR instrumental analysis were used to analyse the digestion process. In order to formulate a synergistic consortium to degrade the thus obtained microplastic, plastic undergoing the natural degradation process from the dump yard was collected and crowded plate technique was performed and the strains involved in the degradation were thus isolated and identified and sequenced. Synergistic consortium was formulated and then incubated with the microplastics screened. The incubation period was of about 60 days. UV- Spectroscopic analysis was done on 0th day, 30th day and 60th day. The graph evidently illustrates the difference as the incubation time progresses. The peak depicts the microplastic degradation based on the turbidity. As the microplastic gets degraded, the growth of the organism in the consortium also gets limited because the microplastics are the only source of carbon.

Spatial distribution characteristics of carbazole and polyhalogenated carbazoles in water column and sediments in the open Western Pacific Ocean

Polyhalogenated carbazoles (PHCZs), an emerging persistent halogenated organic pollutant, have been detected in the environment. However, our understanding of PHCZs in the ocean remains limited. In this study, 47 seawater samples (covering 50 – 4000 m) and sediment samples (49 surface and 3 cores) were collected to investigate the occurrence and spatial distribution patterns of carbazole and its halogenated derivants (CZDs) in the Western Pacific Ocean. In seawater, the detection frequencies of CZ (97.87%) and 3-CCZ (57.45%) were relatively high. In addition, the average concentration of ΣPHCZs in the upper water (< 150 m, 0.23 ± 0.21 ng/L) was significantly lower than that in the deep ocean (1000 – 4000 m, 0.65 ± 0.56 ng/L, P < 0.05), which may indicate the vertical transport of PHCZs in the marine environment. The concentration of ΣCZDs in surface sediment ranges from 0.46 to 6.48 ng/g (mean 1.54 ng/g), among which CZ and 36-CCZ were the predominant components. Results from sediment cores demonstrate a noteworthy negative correlation between the concentration of CZDs and depth, indicating the ongoing natural degradation process occurring in sediment cores over a long period. This study offers distinctive insights into the occurrence, composition, and vertical features of CZDs in oceanic environments.

Accelerated Weathering Testing (AWT) and Bacterial Biodegradation Effects on Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/Rapeseed Microfiber Biocomposites Properties.

In the context of sustainable materials, this study explores the effects of accelerated weathering testing and bacterial biodegradation on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/rapeseed microfiber biocomposites. Accelerated weathering, simulating outdoor environmental conditions, and bacterial biodegradation, representing natural degradation processes in soil, were employed to investigate the changes in the mechanical, thermal and morphological properties of these materials during its post-production life cycle. Attention was paid to the assessment of the change of structural, mechanical and calorimetric properties of alkali and N-methylmorpholine N-oxide (NMMO)-treated rapeseed microfiber (RS)-reinforced plasticized PHBV composites before and after accelerated weathering. Results revealed that accelerated weathering led to an increase in stiffness, but a reduction in tensile strength and elongation at break, of the investigated PHBV biocomposites. Additionally, during accelerated weathering, the crystallinity of PHBV biocomposites increased, especially in the presence of RS, due to both the hydrolytic degradation of the polymer matrix and the nucleating effect of the filler. It has been observed that an increase in PHBV crystallinity, determined by DSC measurements, correlates with the intensity ratio I1225/1180 obtained from FTIR-ATR data. The treatment of RS microfibers increased the biodegradation capability of the developed PHBV composites, especially in the case of chemically untreated RS. All the developed PHBV composites demonstrated faster biodegradation in comparison to neat PHBV matrix.

An investigation into the stability and degradation of plastics in aquatic environments using a large-scale field-deployment study

The fragmentation of plastic debris is a key pathway to the formation of microplastic pollution. These disintegration processes depend on the materials' physical and chemical characteristics, but insight into these interrelationships is still limited, especially under natural conditions. Five plastics of known polymer/additive compositions and processing histories were deployed in aquatic environments and recovered after six and twelve months. The polymer types used were linear low density polyethylene (LLDPE), oxo-degradable LLDPE (oxoLLDPE), poly(ethylene terephthalate) (PET), polyamide-6 (PA6), and poly(lactic acid) (PLA). Four geographically distinct locations across Aotearoa/New Zealand were chosen: three marine sites and a wastewater treatment plant (WWTP). Accelerated UV-weathering under controlled laboratory conditions was also carried out to evaluate artificial ageing as a model for plastic degradation in the natural environment. The samples' physical characteristics and surface microstructures were studied for each deployment location and exposure time. The strongest effects were found for oxoLLDPE upon artificial ageing, with increased crystallinity, intense surface cracking, and substantial deterioration of its mechanical properties. However, no changes to the same extent were found after recovery of the deployed material. In the deployment environments, the chemical nature of the plastics was the most relevant factor determining their behaviours. Few significant differences between the four aquatic locations were identified, except for PA6, where indications for biological surface degradation were found only in seawater, not the WWTP. In some cases, artificial ageing reasonably mimicked the changes which some plastic properties underwent in aquatic environments, but generally, it was no reliable model for natural degradation processes. The findings from this study have implications for the understanding of the initial phases of plastic degradation in aquatic environments, eventually leading to microplastics formation. They can also guide the interpretation of accelerated laboratory ageing for the fate of aquatic plastic pollution, and for the testing of aged plastic samples.

Dynamics of desertification of arid ecosystems of Kizlyar pastures

The authors conducted research to identify the sources of formation of sand massifs, which then become the main cause of desertification of the territories of Kizlyar pastures, in order to carry out protective measures. In the article, the authors present materials confirming desertification and its ecological aspects. The ecological state of arid territories of Russia is one of the most acute problems that requires constant monitoring. Global changes in climatic conditions have a significant impact on the functioning of terrestrial ecosystems, including the soil cover. With the warming of the climate, the development of the processes of wind erosion and soil salinization increases. As a result, the pastures of Kizlyar were driven into extreme conditions. Pastures have come to an extremely critical state, and the degree of degradation of damage caused by these processes is much higher than other regions of the European South of Russia. The ecological situation of the territory is deteriorating rapidly. According to various estimates, large areas of them are occupied by open sands – 60.0 - 71.3 thousand hectares. As the analysis of the experience of the work carried out on the Kizlyar pastures shows, their effectiveness was extremely low, and in some places they contributed to the strengthening of the development of natural degradation processes. As a result, destabilizing factors have emerged that ensure the production of established phytocenoses, worsening conditions and progressing every year. At present, there are practically no improved pasture lands with natural vegetation in the Tersk-Kum lowland. In the current situation, the priority is to stop the activity of moving sands, as well as to improve the state of the species diversity of vegetation, otherwise, if these processes continue at the same pace, it may endanger the very existence of pastures and the basis of life in this territory.

Oxidation 1-methyl naphthalene based on the synergy of environmentally persistent free radicals (EPFRs) and PAHs in particulate matter (PM) surface

Studies of the environmental fate through the interactions of particle-associated polycyclic aromatic hydrocarbons (PAHs) with environmentally persistent free radicals (EPFRs) are presented. The formation of PAHs and EPFRs typically occurs side by side during combustion-processes. The laboratory simulation studies of the model PAH molecule 1-Methylnaphthalene (1-MN) interaction with model EPFRs indicate a transformational synergy between these two pollutants due to mutual and matrix interactions. EPFRs, thorough its redox cycle result in the oxidation of PAHs into oxy-/hydroxy-PAHs. EPFRs have been shown before to produce OH radical during its redox cycle in aqueous media and this study has shown that produced OH radical can transform other PM constituents resulting in alteration of PM chemistry.In model PM, EPFRs driven oxidation process of 1-MN produced 1,4-naphthoquinone, 1-naphthaldehyde, 4-hydroxy-4-methylnaphthalen-1-one, and various isomers of (hydroxymethyl) naphthalene. Differences were observed in oxidation product yields, depending on whether EPFRs and PAHs were cohabiting the same PM or present on separate PM. This effect is attributed to the OH radical concentration gradient as a factor in the oxidation process, further strengthening the hypothesis of EPFRs’ role in the PAH oxidation process.This finding is revealing new environmental role of EPFRs in a natural degradation process of PAHs. Additionally, it points to implications of such PM surface chemistry in the changing mobility of PAHs into an aqueous medium, thus increasing their bioavailability.

Update on Autophagy Inhibitors in Cancer: Opening up to a Therapeutic Combination with Immune Checkpoint Inhibitors.

Autophagy is a highly conserved and natural degradation process that helps maintain cell homeostasis through the elimination of old, worn, and defective cellular components, ensuring proper cell energy intake. The degradative pathway constitutes a protective barrier against diverse human diseases including cancer. Autophagy basal level has been reported to be completely dysregulated during the entire oncogenic process. Autophagy influences not only cancer initiation, development, and maintenance but also regulates cancer response to therapy. Currently, autophagy inhibitor candidates mainly target the early autophagy process without any successful preclinical/clinical development. Lessons learned from autophagy pharmaceutical manipulation as a curative option progressively help to improve drug design and to encounter new targets of interest. Combinatorial strategies with autophagy modulators are supported by abundant evidence, especially dealing with immune checkpoint inhibitors, for which encouraging preclinical results have been recently published. GNS561, a PPT1 inhibitor, is a promising autophagy modulator as it has started a phase 2 clinical trial in liver cancer indication, combined with atezolizumab and bevacizumab, an assessment without precedent in the field. This approach paves a new road, leading to the resurgence of anticancer autophagy inhibitors as an attractive therapeutic target in cancer.

Novel Simarouba glauca extract mediated biocompatible reduction of graphene oxide for robust scavenging of dyes and promising electrochemical applications

Dyes and pharmaceutical products are major environmental contaminants in the effluent of various industries such as cosmetics, textiles, pharmaceuticals, etc. Moreover, these non-biodegradable pollutants are frequently discharged into the water media without adequate precautions. Because of their intricate aromatic structures, dyes are resistant to natural degradation processes. As a result, various treatment techniques have been developed to remove dyes. Green synthesis is one such environmental technique regarding an alternative perception for the degradation of harmful materials like heavy metals, dyes etc. by exploiting biological samples. Therefore, in the present study dye adsorption and desorption studies of the green synthesised reduced graphene oxide (RGO) were investigated. The study presents an effective green reduction method for the facile synthesis of RGO using novel Simarouba/(Lakshmi Taru) extract through the reflux method at a temperature of 90 °C. As synthesised RGO has been analysed by SEM, XRD, Raman, UV–visible, Photoluminescence, TGA analysis, and FTIR studies. Cyclic voltammetry study exhibited a substantial improvement in current density for the RGO-3 hr sample. The maximum reduction efficiency of RGO accomplished using 100 ml of Simarouba extract was found to be 80% and it exhibits an outstanding capacity for the removal of dye with 94% efficiency. It was reported that Rhodamine B dyes were completely adsorbed within 10 min using 20 mg of RGO. It is investigated that adsorption follows langmuir isotherm model and pseudo-second-order kinetics. The thermodynamic studies specified that the whole adsorption is spontaneous, endothermic and physisorption in nature. The electrostatic interaction between the negatively charged surface of graphene oxide and reduced graphene oxide and positively charged surface of rhodamine B is responsible for the high affinity of adsorption of the graphene oxide and reduced graphene oxide. The proposed study reports the synthesis of highly stable and recyclable green-reduced GO by a cost-effective and eco-friendly technique.

A STUDY ON THE EFFECTS OF PLASTIC ON MARINE LIFE &amp; ITS POSSIBLE SOLUTIONS

When natural degradation processes are slow and technological cleanup methods are ineffective, plastic pollution is considered "poorly reversible" in that particular ecosystem. In areas where plastic pollution has had a harmful impact, it may be nearly impossible to reverse the damage. Weakly reversible plastic pollution can result in changes to the carbon and nitrogen cycles, alterations to soil and habitat, sedimentation, and effects on aquatic ecosystems and rare or keystone species. Additionally, there are potential effects on ecotoxicity and related societal impacts. The best solution to the threat of plastic pollution is to quickly reduce environmental emissions by decreasing the use of virgin polymers and implementing globally coordinated waste management strategies. Keywords: Plastic Debris, Marine, GDP, Polymer, Discharge.

Medical image blind super‐resolution based on improved degradation process

AbstractClinical diagnosis has high requirements for the resolution of medical images, but most existing medical images super‐ resolution (SR) methods are performed under a known or specific degradation kernel. However, the difference between the actual degradations and their assumed degradation kernels results in a severe performance drop for the advanced SR methods in real applications. This paper proposes a medical image blind super‐resolution model (Med‐BSR) based on an improved degradation process to handle this issue. The model makes each of the degradation factors in medical image blind SR, such as blur, noise, and downsampling, more complex and practical. Specifically, the authors use the random select/combine strategy to randomly arrange and combine the type and order of each degradation factor, which significantly expands the degradation space. The authors also improved the loss function of the primary enhanced super‐resolution generative adversarial networks (ESRGAN) network. The extensive experimental results demonstrate that the authors’ designed model can accurately restore the natural degradation process, which can reconstruct high‐quality SR medical images. It also has a good generalization ability to realistic images simultaneously.

Elements of hydraulic calculation of permanent movement at non-standard sewer collectors

An important issue in the design of the main visitable sewer collectors is the hydraulic calculation in permanent movement and non-permanent movement. Some main collectors that can be visited have non-standard flow sections, a situation that complicates the hydraulic calculation. Non-standard flow sections derive from standard sections (circular, ovoid, bell, rectangular and mixed) through natural and anthropogenic degradation processes. The initially designed section changes over time in terms of shape, dimensions and roughness, a situation in which determining the hydraulic parameters becomes very difficult. The research carried out on a series of visitable main collectors revealed that the flow section has geometrically transformed from curved shapes to mixed shapes (curves + right-hand segments).The hydraulic rehabilitation of degraded collectors requires the analysis of flow parameters in the case of geometrically modified sections. The non-standardized flow section can be considered as a “single bed”, or as a “multiple bed”. At the same time, the “single bed” type sections composed of both circular arcs and straight line segments can be hydraulically analyzed with a customized calculation program. The paper presents a model for calculating the geometric and hydraulic parameters of a sewer collector with a non-standard shape and in permanent uniform motion.

Natural degradation process of Salix psammophila sand barriers regulates desert soil microbial biomass C:N:P stoichiometry and homeostasis

The Salix psammophila sand barrier is widely used to control wind-sand disasters in desert areas. Importantly, the means through which the natural degradation of the sand-buried section of these sand barriers contributes to the community-level microbial elemental homeostasis of desert soils remains elusive. In this study, we conducted long-term field in situ sampling experiments over a nine-year period in a typical study area in the desert region of northwest China. Chloroform fumigation and high-throughput sequencing were used to determine soil microbial biomass and the diversity of fungi and bacteria. Combined with sand barrier decay characteristics, soil physicochemical factors, and extracellular enzyme activities, we explored the dynamic balance of soil microbial element ratios and key driving factors. The results show that natural degradation of S. psammophila sand barriers increased microbial biomass C and N contents in desert soil, with seven years being the most important turning point. The consistent increase in the soil microbial C:N:P stoichiometry ratios was primarily directly caused by an increase in the mass loss and changes in the fungal diversity. Microbial C:N and N:P ratios were well limited over time, suggesting homeostatic regulation of microorganisms, but the C:P ratio was not homogenized at the community level. The higher microbial C:P and N:P ratios indicated that microorganisms were limited by P after five years of sand barrier degradation. This was primarily related to a decrease in the soil alkaline phosphatase activity. However, microorganisms mitigated P limitation by altering the fungal community structure. These results constitute new evidence in our understanding of the relationships between S. psammophila sand barriers and soil element stoichiometry and the subsequent effects on microorganisms and community-level elemental homeostasis. This work advances the current understanding of artificial interventions in ecological restoration and desertification control.

Creep-fatigue reliability assessment for high-temperature components fusing on-line monitoring data and physics-of-failure by engineering damage mechanics approach

A new framework for creep-fatigue reliability assessment of high-temperature components is proposed in this paper, during which the monitoring data and physics-of-failure are integrated into the natural degradation process on the basis of engineering damage mechanics approach. Firstly, the surrogate model is constructed to establish the mapping from on-line monitoring data to elastic loads spectrum. Then, the plastic stress is corrected by Neuber rule, and thus the creep-fatigue life prediction models are combined with the linear damage summation rule to calculate the damage accumulations of components at dangerous positions in service. Secondly, uncertainty quantification is performed to reveal the probabilistic damage accumulations and modeled by stochastic process. Finally, the component-level reliability assessment of steam turbine rotor considering the correlation of damage accumulations at dangerous positions is explored by using the copula function. It shows that the combination of inverse Gaussian process model and Gumbel copula are appropriate to describe the damage accumulations and to analyze the dependencies at dangerous positions. Furthermore, the comparative research is also performed with respect to the independent assumption and hotspot method. The independent treatment tends to be conservative and hotspot method may be non-conservative in reliability assessment, which demonstrates the applicability of the proposed framework and is expected to be promoted in other high-temperature components.

Evaluation of a graphitic porous carbon modified with iron oxides for atrazine environmental remediation in water by adsorption

In the last decades, the growth of world agricultural activity has significantly contributed to the increased presence of emerging pollutants such as atrazine (ATZ) in aquatic ecosystems. Due to its high stability to the natural or artificial degradation processes, the ATZ environmental remediation by adsorption has been investigated. In this study, a graphitic-porous-carbon- (GPC) based material with magnetic domains was applied to remove ATZ from aqueous solution. ATZ high adsorption efficiency in a reduced time was achieved in the presence of the GPC adsorbent, leading to a detailed investigation of the mechanisms involved in the adsorption processes. Pseudo-first-order (PFO), pseudo-second-order (PSO), Ritchie, Elovich, and Weber-Morris models were applied to calculate the kinetic process efficiency. Likewise, adsorption isotherms based on Langmuir, Freundlich, Temkin, and Redlich-Peterson models were applied for a detailed understanding of the adsorption mechanisms. GPC was successfully applied for ATZ remediation in natural waters, confirming its high potential for treating natural waters contaminated by ATZ using adsorption process. The material can also be recovered and reused for up to 4 application cycles due to its magnetic properties, showing that in addition to ATZ adsorption efficiency, its sustainable use can be achieved.

Natural blood plasma-based hydrogels as tumor vaccines delivery systems to enhance biomimetic recruitment of antigen presenting cells for tumor immunotherapy.

Tumor vaccines can inhibit or eliminate tumors by vaccinating hosts with tumor antigens to activate antigen-specific immune responses and have gained wild attention. However, their clinical application efficacy is often comprised due to the low safety and poor efficiency of vaccine adjuvants/carriers. Specifically, the adjuvants/carriers usually could not efficiently recruit antigen presenting cells (APCs) to capture the vaccines or directly damage these cells. Therefore, ideal tumor vaccine adjuvants/carriers should effectively recruit APCs and be friendly to the cells for well keeping their bio-functions. In this work, injectable natural blood plasma hydrogel was used for the first time to encapsulate tumor antigens and adjuvant (Mn2+) for the construction of a personalized tumor vaccine. This kind of natural hydrogel with extremely high bio-safety has great potential to friendly recruit APCs in a biomimetic manner by simulating the natural degradation process of subcutaneous blood stasis. The obtained results show that the natural blood plasma hydrogel-based tumor vaccines could significantly promote the recruitment of APCs, well maintain the immuno-functions of the cells, and finally induce efficient anti-tumor immune responses. Compared with traditional tumor vaccines, this natural blood plasma-based hydrogel provides a new strategy for the development of safe and effective tumor vaccines.

Nitrocellulose Propellants Standard Stability Tests Enhancement Employing Semiconductor Sensors

AbstractNowadays, solid propulsion is the workhorse of a wide range of applications, from gun ammunition to missiles; and Nitrocellulose, NC, is still widely used in propellant compositions. However, its long‐time storage represents a serious risk due to NC natural autocatalytic degradation process, that may lead to severe accidents. Some National Surveillance Programs continue using the so‐called Stability Tests to monitor Nitrocellulose condition and storage risks; nevertheless, most users consider these tests technologically outdated and difficult to achieve a precise interpretation. This manuscript deals with this NC stability challenge, developing an innovative technology but maintaining Stability Tests phenomenological behaviour, in order to quantify naturally emitted nitrogen oxides, NOx, from Nitrocellulose vapours, as the main indicator for propellants degradation degree. However, accurate NOx quantification is usually strongly interfered by other naturally emitted vapours from gunpowder components, both in Stability Tests and in the technological proposal. Consequently, this document not only describes the technology and main development milestone, but individual components are also studied to reach a proper essay validation, employing Metal Oxide sensors, MOx. Additionally, signal deconvolution is presented to sharpen the NOx determination from interferences with two real samples (NC gunpowder), which are natural and artificially aged, determining performance of sensors and comparing conclusions with those from classical tests. Finally, presented results have shown insignificant interference of other chemicals present in the gunpowder over NOx quantification. According to these conclusions, this technology can be considered a technological improvement on NC Stability Tests.

Declined peat heterotrophic respiration as consequences from zeolite amendment simulation: coupling descriptive and predictive modelling approaches

Nowadays, halting greenhouse gasses (GHG) emission is the world's major concern to mitigate global climate change. In oil palm cultivated tropical peatland, GHG emission is primarily constituted of CO&lt;sub&gt;2&lt;/sub&gt; flux emitted from aerobic heterotrophic respiration (R&lt;sub&gt;h&lt;/sub&gt;), the natural degradation process of organic material in an oxidative environment. By coupling descriptive and predictive statistical approaches, this study attempt to gain an in-depth understanding of the effects of zeolite rates and incubation time on CO&lt;sub&gt;2&lt;/sub&gt; emission that came from aerobic R&lt;sub&gt;h&lt;/sub&gt; in peat, as well as their decomposition process. This study found that zeolite amelioration up to 30% of the peat at field capacity and starting from the first month of observation (month-1) significantly restricted peat R&lt;sub&gt;h&lt;/sub&gt;, denoted by a reduced amount of observed CO&lt;sub&gt;2&lt;/sub&gt; flux (0.021 and 0.019-0.012 mg m&lt;sup&gt;-2&lt;/sup&gt; sec&lt;sup&gt;-1&lt;/sup&gt;, respectively). Both factors and several soil variables exhibited some non-linear relationships with R&lt;sub&gt;h&lt;/sub&gt; at different magnitudes and importance, showing the limitation of the traditional linear-based approach to interpreting their complex interrelationships, as well as predicting CO&lt;sub&gt;2&lt;/sub&gt; flux. This study highlights the vital role of a polynomial (GAM) and artificial intelligence (Cubist and GBM) -based pedotransfer models in improving our understanding regarding the dynamic of the peat decomposition process as affected by zeolite amendment.

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.