Surfactant adsorption onto reservoir rocks remains a critical challenge in chemical enhanced oil recovery (cEOR), as it directly impacts flooding efficiency and chemical costs. This study presents a comprehensive scientometric analysis of research on surfactant adsorption for EOR applications over the period 2005–2025. Based on the Scopus database, 877 publications accounting for more than 22,100 citations were retrieved and analyzed to map the intellectual and conceptual structure of this research field. VOSviewer 1.6.20 software was employed to generate keyword co-occurrence networks, author bibliographic coupling, and country-level contributions. The results reveal a strong growth in scientific output after 2016, with annual publications increasing from fewer than 30 papers per year before 2010 to more than 100 papers per year after 2021. “Enhanced Oil Recovery” (165 occurrences), “Adsorption” (101 occurrences), and “Surfactant” (88 occurrences) emerged as the most frequent and highly interconnected keywords. At the geographical level, China (29.4%), the United States (22.3%), and Iran (9.6%) were identified as the leading contributors, together accounting for more than 60% of the global research output. Bibliographic coupling analysis highlighted a core group of highly influential authors shaping the field through strong collaborative networks. Emerging themes such as nanoparticle-assisted EOR, wettability alteration, and low-salinity surfactant systems were identified as rapidly growing research frontiers. This scientometric analysis provides the first quantitative mapping dedicated specifically to adsorption phenomena in cEOR, while highlighting future opportunities for optimizing adsorption control strategies and improving reservoir performance.

Subchronic exposure to fit-for-purpose polystyrene nanoplastics impairs gut and liver health at low doses with non-monotonic effects in a diet-dependent manner.

Nanoplastics (NPLs) are increasingly recognized as emerging contaminants in terrestrial environments, yet their detection and behavior in complex soil matrices at environmentally realistic concentrations remain poorly understood. In this study, gold-labelled polystyrene nanoplastics (Au-PS NPLs) were synthesized and applied as traceable model particles to investigate their transport, availability, and interactions in a Brazilian sandy clay loam (Latossolo), both alone and in co-occurrence with silver nanoparticles (AgNPs). A comprehensive analytical strategy combining single-particle ICP-MS (SP-ICP-MS), optimized tetrasodium pyrophosphate (TSPP)-assisted extraction (recoveries 89–141%), scanning transmission electron microscopy (s-TEM), and X-ray photoelectron spectroscopy (XPS) was developed to monitor nanopollutants in pore water and soil solid phases over 50 days under different moisture regimes (75% and 100% field capacity) and concentration levels (1010 and 1012 particles L-1). Au-PS NPLs were detected in pore water as early as 24 h after application and persisted throughout the experiment, demonstrating their mobility and availability in soil. AgNPs significantly enhanced Au-PS NPL transport, increasing bottom-to-top ratios in both pore water and solid fractions regardless of moisture conditions. SP-ICP-MS and s-TEM analyses revealed partial attachment of AgNPs onto the NPL surface, likely via surface-mediated interactions such as π–π and electrostatic forces, without inducing significant aggregation. Overall, this work demonstrates the applicability of SP-ICP-MS for tracking NPLs at ng L-1 levels in complex soils and provides mechanistic insight into how co-occurring engineered NPs can modulate NPL fate, mobility, and environmental persistence in tropical soils.

The plastisphere critically modulates interactions among microplastics (MPs), biofilms, and trace metals under environmentally realistic conditions, governing the interfacial reactivity of plastisphere-coated microplastics. Here, we investigated cobalt (Co) adsorption onto large polypropylene (PP) primary microplastics (~4 mm) exposed for 28 days in a flow-through riverine mesocosm across a gradient of Co concentrations (0–60 µg·L−1). A multi-technique analytical approach was employed, combining inductively coupled plasma mass spectrometry (ICP-MS), laser ablation ICP-MS (LA-ICP-MS), quantitative PCR (qPCR), and scanning electron microscopy (SEM). Cobalt accumulation increased linearly with time, consistent with apparent first-order dependence on aqueous Co concentration under constant exposure, reaching 38 ± 3 mg·kg−1 after 28 days at 60 µg·L−1, with no saturation observed. The concentration-dependent Co accumulation was well described by an empirical power-law model (Q = KC0n), with the empirical coefficient K increasing linearly over time, reflecting the progressive increase in Co accumulation at a given aqueous concentration. Microbial colonization developed rapidly on MPs, with 16S and 18S rRNA gene copy numbers stabilizing after 14 days, while surface-normalized Co signals increased sharply after day 21, indicating a time-dependent modification of biofilm properties influencing Co retention. SEM confirmed complex microbial structures, including diatom-like cells. No cobalt adsorption was observed under sterile conditions, confirming the key role of biofilm presence. These findings highlight the dynamic role of the plastisphere as a chemically and biologically active interface under environmentally realistic riverine conditions, with implications for contaminant fate, bioavailability, and risk assessment in freshwater systems affected by plastic pollution.

This study investigated the mesophilic anaerobic digestion (AD) of food waste at a semi-continuous pilot scale, assessing process stability, performance, and microbial dynamics under current and emerging treatment scenarios. With the EU requirement for separate bio-waste collection, food waste streams are expanding from those produced by medium/large-sized producers (FW-ML) to include household food waste (FW-HH), likely to contain biodegradable bags. Envisioning this, four feedstock configurations were evaluated: one representing current FW-ML treatment and three others simulating its treatment alongside FW-HH containing either cellulose-based bags, PBAT/starch-based bags, or thermo-alkaline pre-treated PBAT/starch-based bags. The scenario including untreated PBAT/starch-based bags exhibited the most pronounced acidification, with volatile organic acids reaching 4.1 ± 0.6 gHAc/L and total alkalinity decreasing to 8.3 ± 0.8 gCaCO3/L. System acidification was likely associated with the identified presence of terephthalic acid, a monomer released during PBAT biotransformation. Correspondingly, methane yield declined to 469 ± 10 NLCH4/kgVS, compared to 518 ± 9 NLCH4/kgVS for FW-ML alone. In contrast, thermo-alkaline pretreated bags enhanced buffering capacity and limited performance losses, achieving 504 ± 46 NLCH4/kgVS. Microbial analyses revealed stable overall diversity and a resilient methanogenic community dominated by Methanoculleus sp. Redundancy and discriminant analyses indicated both global and taxon‑specific shifts associated with the presence of untreated and pre-treated PBAT/starch-based bags, notably the enrichment of Defluviitoga under pre‑treated conditions. Conducted at pilot scale, this work offers practical insights into the operational challenges and mitigation strategies for treating FW‑HH when biodegradable plastics are present.

This study investigated the semicontinuous mesophilic anaerobic digestion of food waste, assessing process stability, performance, and microbial communities across emerging treatment scenarios. Following the EU mandate for separate bio-waste collection, food waste streams are expanding from medium/large-sized producers (FW-ML) to household food waste (FW-HH) likely to introduce biodegradable bags. Consequently, four scenarios were evaluated: one representing current FW-ML treatment and three simulating its treatment alongside FW-HH containing cellulose-based bags, PBAT/starch-based bags, or thermoalkaline pretreated PBAT/starch-based bags. The PBAT/starch-based bags led to a progressive acidification, with volatile organic acids reaching 4.1 ± 0.6 gHAc/L and total alkalinity decreasing to 8.3 ± 0.8 gCaCO3/L. Correspondingly, methane yield declined to 469 ± 10 NLCH4/kgVS, compared to 518 ± 9 NLCH4/kgVS for FW-ML alone. The qualitative detection of terephthalic acid, a monomer of PBAT, suggests that incomplete biodegradation may have contributed to acidic stress. Conversely, the thermoalkaline pretreatment (3 M KOH, 70 °C, 4 h) provided the dual benefit of plastic solubilization and alkalinity enhancement (11 ± 1 g CaCO₃/L), minimizing performance losses (504 ± 46 NL CH₄/kg VS). Microbial analyses revealed stable overall diversity and a resilient methanogenic community dominated by Methanoculleus sp. Redundancy and discriminant analyses indicated active community structure shifts associated with the presence of FW-HH and the PBAT/starch-based bags, despite their low concentration (2.2 ± 0.3% of the organic loading rate). This study outlines operational challenges and mitigation strategies for treating FW-HH alongside biodegradable plastics, establishing a baseline that invites future techno-economic and life cycle assessment studies.

The detection and quantification of nanoplastics (NPLs) in complex matrices remain a major analytical challenge. In this study, gold-labelled NPLs consisting of a gold nanoparticle core covered by a polystyrene (PS) shell were designed, enabling sensitive quantification by single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS). Optimized conditions yielded NPLs containing one single gold nanoparticle per NPL and exhibiting surface functionalization. These NPLs fulfill key criteria for realistic NPLs models, combining: the use of an environmentally relevant polymer (PS), the exact control over their chemical composition, a density comparable to that of native PS particles despite gold-labelling, and a strong traceability. The strategy applied here demonstrates unprecedented sensitivity, with a limit of detection of 2.8 × 105 NPL L⁻¹ (0.21 ng of NPLs), enabling detection of environmentally realistic concentrations. The method validation performed with NPLs-spiked Daphnia magna achieved recovery rates close to 100%. Exposure experiments revealed a dose-dependent increase in the body burden of NPLs, up to 8.5 × 105 particles/daphnid (64 ng of NPLs) after 48 h. This study combines gold-labelling, precise chemical control, and environmental relevance to enable accurate NPLs quantification in organisms at low, realistic concentrations, paving the way for robust ecotoxicological assessments.

This study assessed the chemical composition and mesophilic anaerobic biodegradability (BI) of 34 commercial compostable food packaging products, including sixteen bags, twelve coffee capsules, and six other products (cups, forks and straws). Thermogravimetric analysis and spectroscopy techniques allowed to determine the proportions of polymers (PLA, PBAT, PBS, PHBV, PE, cellulose, and starch) and additives (inorganic and organic). Six compositional clusters were identified: PHBV-based products (BI = 92 f 1 %), cellulose-based products (BI = 85 f 9 %), PLA-based products (BI = 30 f 20 %), PBAT/starch-based bags (BI = 25 f 8 %), PE/starch-based bags (BI = 9.5 f 0.5 %), and PBS/PLA-based capsules (BI = 6.6 f 3.0 %). Only select cellulosebased products (three bags, one cup, and one capsule) and the PHBV-based products (five capsules and one straw) exhibited a biodegradability over 80 %. Analyzing product composition reveals components that affect biodegradability in anaerobic digestion, thus aiding manufacturers to eco-design more sustainable food packaging.

Considerable advances have been made recently to quantify nanoplastics in the environment but their analyses in complex matrices such as biota remain a challenge. Here, we present a novel labeling strategy for quantifying nanoplastics in complex matrices, without interferences or extensive sample preparation (Limit Of Detection ranging from 2 and 50 mg kg-1 in Artemia sp.). The approach is based on the use of stable isotopes combined with elemental analysis - isotope ratio mass spectrometry (EA-IRMS), as a way to minimize any labeling effects onto the nanoplastic composition and properties, while enabling accurate quantification in complex organic. This quantification method was compared to pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS) to quantify 13C-labeling nanoplastics in relevant matrices. 13C-labeled nanoplastic model materials, with 214 ± 2 nm diameter, were synthesized without additives (including surfactants). Aquatic crustaceans (Artemia sp.) were exposed to these nanoplastics at different concentrations including environmentally realistic ones. The nanoplastic accumulation was related to the exposure time and concentration (ranging from 0.001 to 7 mg kg-1), with a tendency for higher accumulation in females. The depuration kinetics showed the elimination of more than 50 % of the nanoplastics within the first few hours, and levels below the detection limit after 4 days of depuration.

Considerable advances have been made recently to quantify nanoplastics in the environment but complex matrices such as biota remains a challenge. We propose for the first time, a labeling strategy to quantify nanoplastics in complex matrices, without any interferences or extensive sample preparation, using an elemental analyzer coupled with an isotope ratio mass spectrometry (EA-IRMS) and compared to Pyrolysis gas chromatography mass spectrometry (Py-GC/MS), to study the uptake of nanoplastics in aquatic crustacea.13C-labeled nanoplastic model materials were synthetized mimicking naturally aged plastics and ensuring their stability in a wide range of media, from freshwaters to seawater. Aquatic crustaceans (Artemia sp.) were exposed to these nanoplastic model materials at different concentrations, including environmentally realistic ones. The uptake was directly related to the exposure time and concentration, with a tendency of higher accumulation in females. The depuration kinetics indicated a depuration in two steps. Our study demonstrates the potential of 13C-labeling, associated with EA-IRMS detection, and offers a new labeling strategy to quantitatively track nanoplastics in complex matrices, strategy that could be applied to a wide range of experiments and in the same way to other stable isotopes. This approach allows for an increased understanding of the impacts of nanoplastics on marine organisms under realistic exposure conditions, through the development of analytical protocols, with detection limits (LOD) and quantification limits (LOQ) reaching 2 mg.kg⁻¹ and 7 mg.kg⁻¹, respectively, in aquatic crustaceans.

This study investigates the adsorption of surfactants on Algerian reservoir rock from Hassi Messaoud. A new data generation method based on a design of experiments (DOE) approach has been developed to improve the accuracy of adsorption modeling using artificial neural networks (ANNs). Unlike traditional data acquisition methods, this approach enables a methodical and structured exploration of adsorption behavior while reducing the number of required experiments, leading to improved prediction accuracy, optimization, and cost-effectiveness. The modeling is based on three key parameters: surfactant type (SDS and EOR ASP 5100), concentration, and temperature. The dataset required for ANN training was generated from a polynomial model derived from a full factorial design (DOE) established in a previous study. Before training, 32 different ANN configurations were evaluated by varying learning algorithms, adaptation functions, and transfer functions. The best-performing model was a cascade-type network employing the Levenberg–Marquardt learning function, learngdm adaptation, tansig activation function for the hidden layer, and purelin for the output layer, achieving an R2 of 0.99 and an MSE of 6.84028 × 10−9. Compared to DOE-based models, ANN exhibited superior predictive accuracy, with a performance factor (PF/3) of 0.00157 and the same MSE. While DOE showed a slight advantage in relative error (9.10 × 10−5% vs. 1.88 × 10−4% for ANN), ANN proved more effective overall. Three optimization approaches—ANN-GA, DOE-GA, and DOE-DF (desirability function)—were compared, all converging to the same optimal conditions (SDS at 200 ppm and 25 °C). This similarity between the various optimization techniques confirms the strength of genetic algorithms for optimization in the field of EOR and that they can be reliably applied in practical field operations. However, ANN-GA exhibited slightly better convergence, achieving a fitness value of 2.3247.

Due to strong anthropogenic pressures and their location at the interface between continental and oceanic environments, estuarine areas are affected by significant diverse pollution and species that live in these areas are particularly exposed. Microplastic (MPs) pollution is a worldwide issue and causes substantiated trouble in estuaries where sometimes the number of MPs equal or exceed the number of fish larvae which suggest a high risk of contamination of biota especially in benthic organisms and demersal fish. There are growing evidence that, beyond intrinsic toxicity, MPs can transfer chemicals (additives or pollutants). In order to get closer to environmental situations, in this study we tackled an issue that is rarely dealt with, namely the trophic transfer of MPs and chemicals through the food chain between a sediment- and a benthic-feeder. To take into account these specificities, we used an emblematic and common species of the European coastlines, the common sole (Solea solea) and its annelid prey. Sole juveniles were fed with estuarine ragworms (Hediste diversicolor) previously exposed to MPs via enriched MPs sediment. The MPs used were either a mixture of micronized plastics collected from the Seine Estuary (eMPs, two environmental concentrations at 1 or 100 mg/kg of sediment, median size range 52-77 μm) or model MPs of PVC particles (at 1 g/kg of sediment, size range 125-250 μm), either uncontaminated or contaminated with Benzo(a)Pyrene (BaP, 11.5 μg/g MPs) or benzophenone-3 (BP3, 66 ng/g MPs). Several indicators of health status such as survival, growth, behaviour, energy metabolism, and histopathology were studied. Sole individuals fed ragworms exposed to eMPs or PVC MPs displayed a change in behaviour (place preference between black/white background). Seine Estuary eMPs lead to an increase in body colour chroma for the highest concentration and behaviour was modified with an increase in time spent on white bottom and transition number for the highest concentration when distance moved increased only at the lowest concentration. Sole exposed to BaP-PVC-MPs displayed the lowest time spent on white background compared to control and BP3-PVC-MPs group. Soles exposed to BP3-PVC MPs displayed a significant skin colour increase in chroma and a wider combination of value/chroma reflecting more diverse skin colours. Finally, lipid content in muscle and DNA damage were significantly higher in BP3-MPs. Although the exact mechanisms underpinning such changes are largely unknown, these observations are indicative of physiological stress which may have a significant impact on survival by increasing predation risks for fish juveniles, hence the ecosystem health and calls for further trophic transfer experimental research.

Microplastics (MPs), resulting from the degradation of plastic waste, were investigated on eight beaches on the Island of Djerba, located in the Gulf of Gabes in Tunisia. The study included 96 sediment samples collected in the summer of 2021 from four beach zones (dune, upper beach, coastline, and lower tidal line). The MPs were obtained using the NaCl density separation method and quantified through microscopic observation. MPs were classified based on shape, size, and dominant color. In addition, Fourier Transform Infrared Spectroscopy in attenuated total reflectance mode (FTIR-ATR) was used to identify the polymer composition of representative MPs. The results revealed microplastic concentrations ranging from 23 particles/kg at Gallela Beach to 126.67 particles/kg at Yati 2 Beach, with the highest accumulation found in the dune zone (65

Reliable quantification of trace metals in polymers by direct solid-state analysis remains limited by the lack of suitable reference materials. In this study, we introduce a novel method for producing standardized plastic samples specifically designed for the calibration and analysis of trace metals by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Carboxylated polystyrene (PS) nanoparticles, capable of adsorbing metal ions from solution, were synthesized and evaluated. The trace metal adsorption capabilities of these PS nanoparticles were assessed with adsorption isotherms fit well with the Freundlich model. The study focused cobalt (Co2+), copper (Cu2+), and lead (Pb2+) The adsorption constants were found to be 0.15 for Co2+, 0.48 for Cu2+, and 3.63 for Pb2+. The metal-sorbed PS nanoparticles were then processed into disc-shaped plastics via hot-press molding, and LA-ICP-MS analysis confirmed the homogeneous metal distribution both at the surface and in depth, with relative standard deviations (RSD) of less than 5% for all metals analyzed. Calibration curves for Pb2+ (1220-4400 mg kg-1), Cu2+ (210-600 mg kg-1), and Co2+ (67-220 mg kg-1) showed strong linear relationships, with R 2 values of 0.96 for Pb2+, 0.95 for Cu2+, and 0.94 for Co2+. The methodology limits of detection (LOD) were determined to be 113 mg kg-1 for Pb2+, 93 mg kg-1 for Cu2+, and 23 mg kg-1 for Co2+. The developed standards enabled the calibration of analytical instruments and thus improve the reliability of assessments concerning the contamination of environments with metal-laden microplastics.

Révolution sociétale des années 50, la production mondiale de plastique a doublé entre 2000 et 2019, atteignant 460 millions de tonnes et devrait presque tripler d’ici 2050. Notre consommation majeure n’est pas le plastique à haute valeur ajoutée (avionique, médical…), mais celui à usage unique qui afflue dans nos poubelles parfois après quelques secondes d’utilisation. Dans le monde, 16 milliards de tasses à café jetables, 5 000 milliards de sacs plastiques et 36 milliards de pailles sont consommés chaque année, et on estime qu’un million de bouteilles en plastique sont vendues chaque minute… soit quelque 500 milliards par an.

Understanding thermodynamic parameters such as Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) is crucial for characterizing surfactant adsorption mechanisms in chemical enhanced oil recovery (cEOR). This paper synthesizes recent studies on the thermodynamics of surfactant adsorption onto various reservoirs rock types, with a focus on quantitative and qualitative parameters critical to optimizing cEOR processes. Generally, surfactant adsorption is exothermic; for example, adsorption of sodium dodecyl sulfate and cetyltrimethylammonium bromide on sandstone and carbonate rocks yields ΔH° values between − 8 and − 20 kJ mol−1 under typical reservoirs conditions. However, adsorption behaviors are influenced by factors such as surfactant type, rock mineralogy, salinity, and temperature, with occasional endothermic interactions observed in high-temperature reservoirs or with specific non-ionic surfactants. A positive linear correlation between ΔH° and ΔS° is commonly observed, indicating that increases in exothermic enthalpy (more negative ΔH°) are associated with increases in entropy (positive ΔS°), suggesting that adsorption processes that promote greater interfacial disorder are energetically favorable. This review not only consolidates key thermodynamic concepts but also provides a comparative analysis of thermodynamic parameters across different rock-surfactant systems, identifying trends and gaps in the literature. By offering insights into the specific conditions that enhance surfactant performance, this study establishes a thermodynamic framework to guide surfactant selection and optimization in cEOR. These contributions aim to deepen understanding of adsorption behavior and inform more effective, tailored cEOR strategies.

Although it is currently recognized that nanoplastics (NPs) are present in the environment, their ability to carry metals or other contaminants and the processes involved are still poorly investigated. Yet, one of the significant threats of plastic debris is found in these associated species. The lack of relevant data is directly explained by our inability to collect enough nanoplastics from the environment for experimental investigation. The models of environmental NPs that we have recently proposed offer new opportunities to characterize their interactions with metals. We have developed an adsorption model based on lead (Pb2+) adsorption experiments (adsorption isotherm at pH 5.5 for Pb(ii)/NP ratios between 0.5 and 100 mg gC-1 and a pH adsorption edge between pH 2 and 8 for Pb(ii)/NPs at 2.5 and 25 mg gC-1 relative to the studied NPs, ionic strength = 5 mmol L-1 NaNO3) using various NP models to describe surface complexation processes and to predict the sorption capacity of NPs. Model hypotheses have suggested that Pb is adsorbed onto NPs via carboxylic sites mainly as mono-ligand and bi-ligand complexes. The empirical model and linear free energy relationship validated the extrapolated stability constants and binding hypothesis. The adsorption capacities of nanoplastics are highly dependent on their surface oxidation state, shape heterogeneity and aggregation which control their carboxylic site density, distribution and then availability. This metal-NP affinity suggests that NPs could act as vectors of metals relative to their behavior regarding other natural adsorbent phases. Although it is currently recognized that nanoplastics (NPs) are present in the environment, their ability to carry metals or other contaminants and the processes involved are still poorly investigated.

Understanding the interactions between nanoplastics (NP) and biota is essential for risk assessment. However, NP quantification in complex matrices remains a challenge, especially when they are not labeled. Most labeling strategies consists in adding another compound (fluorophore, metal, lanthanide …) to the polymer, which can alter the NP properties and poses a risk of leaching phenomena. In the present study, we synthesized spherical and monodisperse 2H-labeling NP (129 nm) with carboxyl groups at their surface (8.7 nm-2) using surfactant-free polymerization. A pyrolysis coupled with gas chromatography/mass spectrometry method was developed to enable their quantification (limit of detection = 7.4 ng), without extensive sample preparation or significant matrix effects. The 2H-labeled NP were then used to study their toxicity and accumulation in the planktonic crustaceans Daphnia magna (D. magna). Daphnids were exposed for 48 h to the deuterated NP at different concentrations, including environmentally realistic ones (from 0.03 to 36 mg kg-1). Little to no acute toxicity were observed in this range of concentration. During the experiment, adsorption on polycarbonate well walls was observed, suggesting that the NP concentration during exposure experiments with organisms should be monitored to take into account possible loss. The NP accumulation (mainly in the digestive tract) increased with the exposure concentration, tending to a plateau at higher concentrations. The depuration was also investigated and was significantly higher (97 % against 59 % in average) when the daphnids have access to algae, which highlight the need to add food in D. magna depuration studies to study the NP fate in these organisms. The present study demonstrated the advantages of stable isotope-labeled NP to better understand the processes controlling NP accumulation and impacts on aquatic biota.

Microplastics (MPs) are causing global concern due to their role as vectors of environmental contaminants. Evaluating their impact on environmental compartments, particularly in sediment and freshwaters, remains challenging due to difficulties in gathering chemical and morphological data. In fact, the analytical process can vary depending on the matrix considered, the non-homogeneous characteristics of MPs, and the targeted size range. Sample treatment is crucial for sediments and waters, requiring a balance between matrix removal and preservation of the MPs. Consequently, MPs often remain embedded in significant amounts of the original matrices, compromising their characterisation. In this regard, Raman spectroscopy shows promise for their comprehensive molecular analysis. However, overcoming the drawbacks associated with fluorescence from organic matter, feldspar, or clays requires considerable effort. Effective signal acquisition necessitates fine-tuning parameters, including background reduction and signal-to-noise ratio amplification. Moreover, data handling involved in chemical scanning large surfaces at high resolution is a challenging task. To overcome these drawbacks, chemometrics have demonstrated high efficacy in processing and extracting targeted information. The application of chemometrics could be relevant in environmental studies due to the large number of samples, the complexity of signal acquisition, and the dataset volumes managed. As such, this study proposes spectroscopic analytical solutions, augmented by chemical imaging and algorithmic processing, for advanced MPs analysis. A spectroscopic working approach was devised and tested through a real case study conducted in the Choqueyapu River basin (La Paz, Bolivia). This methodology allowed the morphological, molecular and quantitative identification of over 44 particles/L and 91 MPs particles/kg, in water and sediment, respectively, consisting of PE, PET, PP, PS and PMMA. MP abundance varied significantly across studied areas, spanning 2 to 4 orders of magnitude. PET fibres predominated in freshwaters, while Lipari Sector sediments were hotspots for PE and PS fragments.

This study evaluated the anaerobic digestion suitability of bio-waste from different sources by comparing their biochemical methane potential (BMP), biodegradability (BI), and content of contaminants (heavy metals and physical impurities) - an often-overlooked factor but one of particular concern in bio-waste. Predominant heavy metals included Cu and Zn, while recurring physical impurities comprised plastics and organic non-biodegradable matter. Food waste from food processing plants were most suitable, exhibiting low contamination and high biogas conversion (BMP > 549 NmLCH4/gVS and BI > 86 %). Conversely, organic fractions from mechanical biological treatment were highly contaminated, while green waste displayed low biogas conversion (BMP < 368 NmLCH4/gVS and BI < 72 %). Food waste from households and medium/large-sized producers also demonstrated high biogas conversion, but variable contamination levels could compromise their suitability. Assessing contaminants alongside BMP and BI provides a comprehensive approach for selecting suitable bio-waste feedstocks that can be introduced in biogas plants.