Search Results (130)

Geographical origin authentication of agrifood products is essential for ensuring their quality, preventing fraud, and maintaining consumers’ trust. In this study, we used proton nuclear magnetic resonance (¹H NMR) and excitation–emission matrix (EEM) fluorescence spectroscopy combined with chemometric methods for the geographical origin characterization of olive drupes and leaves from different Tuscany subregions, where olive oil production is relevant. Single-block approaches were implemented for individual datasets, using principal component analysis (PCA) for data visualization and Soft Independent Modeling of Class Analogy (SIMCA) for sample classification. ¹H NMR spectroscopy provided detailed metabolomic profiles, identifying key compounds such as polyphenols and organic acids that contribute to geographical differentiation. EEM fluorescence spectroscopy, in combination with Parallel Factor Analysis (PARAFAC), revealed distinctive fluorescence signatures associated with polyphenolic content. A mid-level data fusion strategy, integrating the common dimensions (ComDim) method, was explored to improve the models’ performance. The results demonstrated that both spectroscopic techniques independently provided valuable insights in terms of geographical characterization, while data fusion further improved the model performances, particularly for olive drupes. Notably, this study represents the first attempt to apply EEM fluorescence for the geographical classification of olive drupes and leaves, highlighting its potential as a complementary tool in geographic origin authentication. The integration of advanced spectroscopic and chemometric methods offers a reliable approach for the differentiation of samples from closely related areas at a subregional level. Full article

Lake eutrophication, often driving harmful algal blooms (HABs) and ecosystem degradation, involves complex biogeochemical shifts within sediments. Changes in the sedimentary dissolved organic matter (DOM) composition during transitions from macrophyte to algal dominance are thought to critically regulate internal phosphorus (P) loading, yet the underlying mechanisms, especially in vulnerable plateau lakes like Qilu Lake, require further elucidation. This study investigated the coupled cycling of carbon (C) and P in response to historical ecosystem succession and anthropogenic activities using a 0–24 cm sediment core from Qilu Lake. We analyzed the total organic carbon (TOC), total phosphorus (TP), sequential P fractions, and DOM fluorescence characteristics (EEM-PARAFAC), integrated with chronological series data. The results revealed an asynchronous vertical distribution of TOC and TP, reflecting the shift from a submerged macrophyte-dominated, oligotrophic state (pre-1980s; high TOC, low TP, stable Ca-P dominance) to an algae-dominated, eutrophic state. The eutrophication period (~1980s–2010s) showed high TP accumulation (Ca-P and NaOH85 °C-P enrichment), despite a relatively low TOC (due to rapid mineralization), while recent surface sediments (post-2010s) exhibited a high TOC, but a lower TP following input controls. Concurrently, the DOM composition shifted from microbial humic-like dominance (C1) in deeper sediments to protein-like dominance (C3) near the surface. This study demonstrates that the ecosystem shift significantly regulates P speciation and mobility by altering sedimentary DOM abundance and chemical characteristics (e.g., protein-like DOM correlating negatively with Ca-P), reinforcing a positive feedback mechanism that sustains internal P loading and potentially exacerbates HABs. DOM molecular characteristics emerged as a key factor controlling the internal P cycle in Qilu Lake, providing critical insights for managing eutrophication in plateau lakes. Full article

Although algae possess a high capacity for carbon sequestration, the recalcitrant multilayered cell wall structure and residual microcystin toxicity associated with Microcystis aeruginosa significantly hinder the efficient recovery of algal biomass resources. This study developed a synergistic ozone-ultrasonication (O₃-US) pretreatment strategy, systematically comparing its cell-disruption efficacy with standalone O₃ or US, using harvested algal biomass from natural aquatic systems dominated by Microcystis aeruginosa. The synergistic effects revealed were: (1) O₃-mediated oxidation of extracellular polymeric substances and cell wall matrices, (2) the release of ultrasound-induced cavitation-enhancing intracellular components, and (3) an improvement in the O₃ mass transfer by hydrodynamic shear forces. Through response surface methodology optimization, the O₃-US process achieved maximal performance at 0.14 gO₃/gTSS, with a 4 W/mL ultrasonic intensity, and a 20 min duration. Remarkably, the released protein was 289.2 mg/gTSS, which was 4.3-fold and 1.9-fold, respectively, more than that released in O₃ pretreatment and US pretreatment, while the polysaccharide was 87.5 mg/gTSS, increased by 2.4-fold and 3.1-fold respectively, compared to O₃ alone and US alone. The released solubilized chemical oxygen demand (SCOD) was 1037.1 mg/gTSS, increased by 43.3% and 216.1%, respectively, relative to O₃ alone and US alone. DNA quantification further validated the synergistic cell disruption caused by O₃-US. Fluorescence excitation-emission matrix (EEM) spectroscopy identified biodegradable aromatic proteins (Regions I-II) and soluble microbial byproducts (Region IV) as dominant organic fractions, demonstrating enhanced bioavailability. The hybrid process reduced energy consumption by 33.3% in ultrasonic intensity and 60% in duration versus US alone, while achieving 94.5% microcystin-LR (MC-LR) degradation, which showed a 96.6% risk reduction compared to ultrasonic treatment. This work establishes an efficient, low-energy, and safe pretreatment technology for algal resource recovery, synergistically enhancing intracellular resource release while mitigating cyanotoxin hazards in algal biomass valorization. Full article

The reliance on acidic working environments presents a significant bottleneck in the development and widespread application of peroxymonosulfate (PMS)-activated high-valent iron-oxo systems and iron-based catalysts. In this study, we present a system of non-homogeneous activation of peroxymonosulfate that is capable of overcoming the acidic environment in heterogeneous to generate continuous non-radicals for the selective degradation of organic pollutants such as sulfamethoxazole. The system takes advantage of amphiprotic hydroxides to create a homogeneous neutral pH microenvironment at the heterogeneous interface of the catalyst. The generation of the neutral pH microenvironment is capable of inducing the formation of high-valent iron-oxo species and a more stable cycling of iron ions in the iron-based material., promoting sustained catalytic activity A series of design quenching experiments, electron paramagnetic resonance (EPR) experiments, and three-dimensional excitation-emission matrix fluorescence spectroscopy (3D-EEM) which were conducted to assess the selectivity of FeCo-LDH/PMS under high salt or natural organic conditions, as well as its effectiveness in treating real wastewater. These findings offer a novel approach to overcoming pH limitations and enhancing the selectivity of target pollutants in advanced oxidation processes (AOPs). Full article

Mariculture wastewater is an intractable wastewater, owing to its high salinity inhibiting microbial metabolism. The biocarrier bacterial–microbial consortium (BBM) and bacterial–microbial consortium (BM) were developed to investigate the mechanism of pollutant degradation and microbial community evolution. The BBM exhibited excellent mariculture wastewater treatment, with the highest removal for TOC (91.78%), NH₄⁺-N (79.33%) and PO₄³⁻-P (61.27%). Biocarriers accelerated anaerobic region formation, with the levels of denitrifying bacteria accumulation improving nitrogen degradation in the BBM. Moreover, the biocarrier enhanced the production of soluble microbial products (SMPs) (11.53 mg/L) and extracellular polymeric substances (EPSs) (370.88 mg/L), which accelerated the formation of bacterial and microalgal flocs in the BBM. The fluorescence excitation–emission matrix (EEM) results demonstrated that the addition of biocarriers successfully decreased the production of aromatic-like components in anoxic and aerobic supernatants. Additionally, the biocarrier shifted the bacterial community constitutions significantly. Biocarriers provided an anoxic microenvironment, which enhanced enrichments of Rhodobacteraceae (66%) and Ruegeria (70%), with a satisfying denitrification in the BBM. This study provided a novel biocarrier addition to the BBM system for actual mariculture wastewater treatment. Full article

When high-performance liquid chromatography (HPLC) is used for the analysis of polycyclic aromatic hydrocarbons (PAHs) in complex samples, further examination of HPLC fractions is recommended to confirm PAH assignments solely based on retention times. Gas chromatography–mass spectrometry (GC-MS) has been particularly relevant in the unambiguous determination of PAHs with remarkably similar retention times. The combination of HPLC and GC requires lengthy analysis times to ensure proper assignments. This article presents an approach for the analysis of co-eluted PAHs with no need for further chromatographic separation. Benzo[a]pyrene (BaP) and dibenzo[a,l]pyrene (DBalP) were directly determined in a co-eluted HPLC fraction via room-temperature fluorescence excitation–emission matrices (RTF-EEMs). RTF-EEMs can be recorded in a matter of seconds with a spectrofluorometer equipped with a multichannel detection system. The spectral overlapping of BaP and DBalP was resolved using parallel factor analysis (PARAFAC). The analytical advantages of this approach were demonstrated with the trace analysis (ng/mL) of these two PAHs in pre-concentrated tobacco extracts. Full article

The accumulation of copper (Cu) and zinc (Zn) from piglet feed, coupled with inadequate compost maturation, hinders the safe land application of pig manure (PM). This study employed self-organizing maps (SOMs) integrated with three-dimensional excitation–emission matrix fluorescence spectroscopy (3D-EEM) and parallel factor analysis (PARAFAC) to evaluate PM compost maturity and Cu/Zn passivation under different biochar (BC) dosages (0%, 8%, 10%, and 12%). The results revealed that SOM clustering effectively distinguished composting phases and organic matter transformation trends, while network analysis identified key microbial modules (M5, M6) linked to Cu/Zn passivation. Moreover, 12% BC accelerated compost maturation, maximizing humic content (C1: anthropogenic; C4: terrestrial) by increasing Luteimonas abundance (241.98%) and reducing Terrisporobacter (92%). It also achieved the highest Cu (36.36%) and Zn (32.34%) passivation. Although 10% BC promoted C4 synthesis but inhibited C1 formation, it ultimately reached a similar maturity level to 12% BC. Additionally, 10% BC demonstrated comparable Cu (34.85%) and Zn (27.89%) passivation, making it a more cost-effective alternative. These findings highlight SOM as a robust tool for compost evaluation, optimizing BC application and improving composting efficiency. Full article

Malaria, an infectious disease caused by parasites of the genus Plasmodium—including the most lethal species, Plasmodium falciparum—alters the physicochemical properties of host red blood cells, including their intrinsic autofluorescence after infecting them. This exploratory study aims to investigate the possibility of using autofluorescence as a method for detecting infection in red blood cells. The autofluorescence spectra of uninfected and in vitro infected red blood cells with Plasmodium falciparum were monitored and compared across an excitation wavelength range of 255 to 630 nm. Principal Component Analysis revealed that only two wavelengths (315 and 320 nm), previously undocumented, were able to accurately differentiate infected from uninfected red blood cells, showing an increase in autofluorescence in the ultraviolet and blue regions. This phenomenon is hypothetically associated with the presence of natural fluorophores such as tryptophan, FAD, NADH, porphyrins, and lipopigments. To classify the samples, Linear Discriminant Analysis (LDA) was employed, and Wilks’ Lambda test confirmed that the discriminant function was significant, enabling correct classification of samples in more than 91% of cases. Overall, our results support the potential use of autofluorescence as an effective approach for detecting malaria parasite infection in red blood cells, with the possibility of implementation in portable devices for rapid field diagnostics. Full article

A series of flexible polyacrylonitrile/TiO₂ (PAN/P25) multi-porous nanotubular membranes were successfully constructed by facile electrospinning combined with an ethylene glycol solvothermal induce strategy. The effects of P25 dosage and solvothermal time on the morphology of samples were systematically investigated, which were characterized in terms of surface morphology, microstructure, specific surface area, thermal analysis, wettability, photoelectrochemical and fluorescence spectra. Rhodamine B (RhB) and Escherichia coli (E. coli) were employed as simulated pollutants to evaluate photocatalytic degradation and antibacterial properties of the PAN/P25-3 multi-porous nanotubular membrane. The PAN/P25-3 membrane exhibited the highest photocatalytic degradation efficiency, with 96.1% degradation of RhB within 120 min under a xenon lamp light source and a photocatalytic inactivation rate of 95.8% for E. coli under 365 nm monochromatic light irradiation. The photocatalytic degradation mechanism of the PAN/P25-3 multi-porous nanotubular membrane for RhB was deduced from the results of 3D-EEM fluorescence and scavenger experiments of reactive species. Additionally, the cyclic photodegradation experiments demonstrated that the PAN/P25-3 membrane maintained excellent stability and photocatalytic performance after multiple degradation cycles, confirming its potential for sustainable wastewater treatment applications. Full article

With the growing demand for high-quality discharge, reverse osmosis (RO) technology has been widely applied in landfill leachate treatment; however, the problem of reverse osmosis concentrates (ROCs) has worsened. In this work, a Ti₄O₇-nanotube reactive electrochemical membrane (Ti₄O₇-NT-REM) was employed to treat ROCs from landfill leachate treatment. The effects of current density, flow rate and pH on COD removal were evaluated, and the appropriate conditions were a current density of 20 mA cm⁻², a flow rate of 10 mL s⁻¹ and a pH of 7. Under these conditions, COD, TOC, NH₄⁺-N and NO₃⁻-N were removed by 82%, 68%, 100% and 73%, respectively. In addition, the 3D-EEM fluorescence spectra and GC–MS results revealed that the organics significantly decreased after 120 min of treatment, and aliphatic compounds were the major organic compounds. The stable performance of the REM was illustrated by cyclic treatment (20 cycles) with the assistance of cathodic polarization. In addition, a long service lifetime of 267.3 h and a low energy consumption of 7.6 kWh·kg COD⁻¹ were obtained by related testing and evaluation. The excellent and stable performance confirmed that the Ti₄O₇-NT-REM has broad application prospects in the treatment of ROCs. Full article

Water quality is crucial for the ecological health of rivers. However, assessing environmental stressors in large river basins has been challenging due to limited biodiversity monitoring tools. Combining environmental DNA and water quality monitoring presents new possibilities for evaluating the impact of dissolved organic matter (DOM) on fish diversity. Case studies from the Jinshui River, Futou Lake, and Gan River in the Jinshui River Basin demonstrated that eDNA biomonitoring reached 84.62% OTU asymptote (176 OTUs) and 91.06% species asymptote (49 species). The Gan River had 1.21 and 1.26 times more fish OTUs than Futou Lake and the Jinshui River, with 20 overlapping species among the areas. We identified typical excitation-emission matrix (EEM) components of DOM and three PARAFAC fluorescent components: C1 (microbial humic-like), C2 (terrestrial humic-like), and C3 (tryptophan-like). Sequence diversity was positively correlated with EC, TDS, pH, NH₃-N, DO, COD_Mn, biological index (BIX), and freshness index (β/α). Taxonomic diversity positively correlated with spectral slope ratio (S_R) and C3. Functional diversity positively correlated with S_R but negatively correlated with humification index (HIX). The combined eDNA and DOM monitoring approach shows promise for future assessments of fish biodiversity in river basin environments. Full article

Bone meal has been used as economic and effective additive for heavy metals (HMs) pollution remediation due to the distinct components and structures that enable their favorable properties, such as its low cost, high adsorption capacity, acid-base adjustability, and ion-exchange capability. However, no attempt has been made to establish whether cow bone could promote the passivation of HMs and the removal of metal resistance genes (MRGs) and antibiotics resistance genes (ARGs) during the composting process. Two sizes of cow bone (meal (T2) and granule (T3)) were added to investigate their effects on humification, HMs passivation and the abundance of ARGs and MRGs during swine manure composting. Excitation-emission matrix (EEM)-parallel factor analysis showed that the percentage of maximum fluorescence intensity of humic-like substances were higher in T2 (91.82%) than in T3 (88.46%), implying that T2 could promote the humification process compared to T3. In comparison with control (T1), the addition of T2 and T3 could promote the change of exchangeable Cu and reducible Cu into oxidizable Cu, thus reducing the mobility factors (MF) of Cu in T2 and T3 treatments by 10.48% and 6.98%, respectively. In addition, T2 and T3 could increase exchangeable Zn into reducible Zn and oxidizable Zn, thereby reducing the MF of Zn in T2 and T3 treatments by 18.80% and 2.0%, respectively. Quantitative Real-time PCR (qPCR) analysis revealed that the total abundances of MRGs were decreased by 100% in T2 and T3 treatments, and T2 decreased the total relative abundance of ARGs. Furthermore, the relative abundance of ARGs and MRGs had significantly correlated with intI1 and bio-available of Cu and Zn, which was triggered by selective pressure of HMs and horizontal gene transfer. The present study suggested that cow bone meal as additives can be a feasible approach to promote the passivation of HMs and enhance the removal of MGRs and ARGs by decreasing horizontal gene transfer and selective pressure by bioavailable HMs. Full article

This study investigated the degradation competition and pathways of electrochemical co-degradation of two emerging environmental contaminants, polar acetaminophen (AP) and (moderately) non-polar bisphenol A (BPA), on a boron-doped diamond (BDD) electrode in aqueous solutions. The results showed that both compounds mainly relied on hydroxyl radicals (•OH) to trigger indirect oxidation for their electrochemical degradation, although AP also underwent direct oxidation during electrolysis. The effect of increasing current density on the increases in degradation performance was almost the same for AP and BPA. However, BPA exhibited a better performance in mono-degradation than AP, while the opposite tendency was observed for their co-degradation. Their degradation efficiencies were better in 1 M Na₂SO₄ solution than in a real water matrix. Both UV-vis and excitation–emission matrix (EEM) fluorescence analyses demonstrated that all the aromatic rings of AP and BPA were opened after 30 min of electrolysis at 0.5 A cm⁻² in 1 M Na₂SO₄ solution. Regardless of the small difference in intermediate species, the pathways of electrochemical AP+BPA co-degradation were similar to those of their mono-degradation combination. A double exponential decay model is proposed to simulate the formation and degradation rate constants of benzoquinone (an intermediate). Full article

At a time when the botanical origin of honey is being increasingly falsified, there is a need to find a quick, cheap and simple method of identifying its origin. Therefore, the aim of our work was to show that fluorescence spectrometry, together with statistical analysis, can be such a method. In total, 108 representative samples with 10 different botanic origins (9 unifloral and 1 multifloral), obtained in 2020–2022 from local apiaries, were analyzed. The fluorescence spectra of those samples were determined using a F-7000 Hitachi fluorescence spectrophotometer, Tokyo, Japan. It is shown that each honey variety produces a unique emission spectrum, which allows for the determination of its botanical origin. Taking into account the difficulties in analyzing these spectra, it was found that the most information regarding botanical differences and their identification is provided by synchronous cross-sections of these spectra obtained at Δλ = 100 nm. In addition, this analysis was supported by discriminant and canonical analysis, which allowed for the creation of mathematical models, allowing for the correct classification of each type of honey (except dandelion) with an accuracy of over 80%. The application of the method is universal (in accordance with the methodology described in this paper), but its use requires the creation of fluorescence spectral matrices (EEG) characteristic of a given geographical and botanical origin. Full article

Biochar is a carbon-rich product obtained by pyrolyzing biomass under oxygen-limited conditions and has a wide range of potential for environmental applications. In particular, dissolved organic matter (DOM) released from biochar has an important impact on the fate of pollutants. The study aimed to systematically assess how varying pyrolysis temperatures and biomass feedstocks influence the characteristics of biochar-derived DOM. DOM samples were comprehensively characterized utilizing UV-vis spectroscopy and excitation–emission matrix (EEM) fluorescence spectroscopy, coupled with parallel factor (PARAFAC) analysis. The study discovered that pyrolysis temperature significantly affects DOM characteristics more than feedstock type. An increase in pyrolysis temperature correlated with a notable decrease in dissolved organic carbon content, aromaticity, and fluorescence intensity, alongside a marked increase in pH and hydrophilicity. PARAFAC analysis identified three distinct DOM components: two humic-like substances (C1 and C2) and one protein-like substance (C3). The proportion of protein-like substances increased with higher pyrolysis temperatures, while the humic-like substances’ proportion declined. The compositional shifts in DOM with pyrolysis temperature may significantly influence its environmental behavior and functionality. Further research is necessary to explore the long-term environmental impact and potential applications of biochar-derived DOM. Full article