Biochar from co-pyrolysis of biological sludge and sawdust in comparison with the conventional filling media of vertical-flow constructed wetlands for the treatment of domestic-textile wastewater.

A biochar from co-pyrolysis of a mixture of sawdust and biological sludge (70/30, w/w), providing a high environmental compatibility in terms of water leachable polycyclic aromatic hydrocarbons and inorganic elements, together with a remarkable surface area (389 m2/g), was integrated into laboratory-scale vertical-flow constructed wetlands (VF-CWs), planted with Phragmites australis and unplanted. Biochar-filled VF-CWs have been tested for 8 months for the refining of effluents from the tertiary clariflocculation stage of a wastewater treatment plant operating in a mixed domestic-industrial textile context, in comparison with systems filled with gravel. VF-CW influents and effluents were monitored for chemical oxygen demand (COD), nitrogen and phosphorus cycles, and absorbance values at 254 and 420 nm, the latter as rapid and reliable screening parameters of the removal of organic micropollutants containing aromatic moieties and/or chromophores. Biochar-based systems provided a statistically significant improvement in COD (Δ = 22%) and ammonia (Δ = 35%) removal, as well as in the reduction of UV-Vis absorbance values (Δ = 32-34% and Δ = 28% for 254 and 420 nm, respectively), compared to gravel-filled microcosms. The higher removal of organic was mainly attributed to the well-known adsorption properties of biochars, while for nitrogen the biological mechanisms seem to play a predominant role.

Innovative thermally assisted on-line solid phase extraction-reversed phase liquid chromatography applied to targeted nutrimetabolomics in human biofluids.

In this study, the use of thermal desorption in on-line solid phase extraction coupled with reversed phase liquid chromatography (on-line SPE-LC) was for the first time proposed and demonstrated for the desorption of analytes strongly retained by multiple interaction polymeric sorbents. In detail, this analytical strategy was applied to the on-line SPE-LC targeted analysis of a model set of 34 human gut metabolites characterized by heterogeneous physicochemical properties (i.e., octanol-water partition coefficient in the range -0.3 - 3.4). The novel thermally assisted on-line SPE approach was investigated in comparison to conventional room temperature desorption strategies based on the use of (i) an optimized elution gradient or (ii) organic desorption followed by post-cartridge dilution. The thermally assisted desorption strategy has been shown to be better performing and suitable for the development of a reliable and sensitive method for the analysis of the model group of analytes in urine and serum. In more detail, under the optimized experimental conditions, the proposed method provided negligible matrix effects in both biofluids for almost all target analytes. Moreover, method quantification limits were in the ranges 0.026-7.2 µg L-1 and 0.033-23 µg L-1 for urine and serum, respectively, i.e., comparable to or lower than those reported in methods previously published.

Combining Feature-Based Molecular Networking and Contextual Mass Spectral Libraries to Decipher Nutrimetabolomics Profiles.

Untargeted metabolomics approaches deal with complex data hindering structural information for the comprehensive analysis of unknown metabolite features. We investigated the metabolite discovery capacity and the possible extension of the annotation coverage of the Feature-Based Molecular Networking (FBMN) approach by adding two novel nutritionally-relevant (contextual) mass spectral libraries to the existing public ones, as compared to widely-used open-source annotation protocols. Two contextual mass spectral libraries in positive and negative ionization mode of ~300 reference molecules relevant for plant-based nutrikinetic studies were created and made publicly available through the GNPS platform. The postprandial urinary metabolome analysis within the intervention of Vaccinium supplements was selected as a case study. Following the FBMN approach in combination with the added contextual mass spectral libraries, 67 berry-related and human endogenous metabolites were annotated, achieving a structural annotation coverage comparable to or higher than existing non-commercial annotation workflows. To further exploit the quantitative data obtained within the FBMN environment, the postprandial behavior of the annotated metabolites was analyzed with Pearson product-moment correlation. This simple chemometric tool linked several molecular families with phase II and phase I metabolism. The proposed approach is a powerful strategy to employ in longitudinal studies since it reduces the unknown chemical space by boosting the annotation power to characterize biochemically relevant metabolites in human biofluids.

Development of a comprehensive two-dimensional liquid chromatographic mass spectrometric method for the non-targeted identification of poly- and perfluoroalkyl substances in aqueous film-forming foams.

In this research, we developed an online comprehensive two-dimensional liquid chromatographic (LC × LC) method hyphenated with high-resolution mass spectrometry (HRMS) for the non-targeted identification of poly- and perfluorinated compounds (PFASs) in fire-fighting aqueous-film forming foams (AFFFs). The method exploited the combination of mixed-mode weak anion exchange-reversed phase with a octadecyl stationary phase, separating PFASs according to ionic classes and chain length. To develop and optimize the LC × LC method we used a reference training set of twenty-four anionic PFASs, representing the main classes of compounds occurring in AFFFs and covering a wide range of physicochemical properties. In particular, we investigated different modulation approaches to reduce injection band broadening and breakthrough in the second dimension separation. Active solvent and stationary phase assisted modulations were compared, with the best results obtained with the last approach. In the optimal conditions, the predicted peak capacity corrected for undersampling was higher than three-hundred in a separation space of about 60 min. Subsequently, the developed method was applied to the non-targeted analysis of two AFFF samples for the identification of homologous series of PFASs, in which it was possible to identify up to thirty-nine potential compounds of interest utilizing Kendrick mass defect analysis. Even within the samples, the features considered potential PFAS by mass defect analysis elute in the chromatographic regions discriminating for the ionic group and/or the chain length, thus confirming the applicability of the method presented for the analysis of AFFF mixtures and, to a further extent, of environmental matrices affected by the AFFF.

Quality by Design in optimizing the extraction of (poly)phenolic compounds from Vaccinium myrtillus berries.

Quality by Design was adopted for developing an effective extraction procedure of (poly)phenolic compounds from bilberry (Vaccinium myrtillus L.) fruits, using a pooled sample of berries from different regions of Ukraine. Mechanical solvent extraction, microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE) were investigated by screening matrices. Extraction time (Time, from 5 to 15 min), organic solvent type (OS type, methanol, ethanol and acetone), organic solvent percentage (OS%, from 50% to 90%), sample/extractant ratio (S/E ratio, from 0.025 to 0.1 g mL-1), and, only for MAE, extraction temperature (T, from 30 to 60°C), were selected as critical method parameters (CMPs). The spectrophotometric assays total soluble polyphenols (TSP), total monomeric anthocyanins (TMA), and radical scavenging activity (evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), the 2,2'-azino-di-(3-ethylbenzthiazoline sulfonic acid), and the ferric reducing antioxidant power methods) were chosen as critical method attributes (CMAs). The screening procedure allowed for selecting UAE and methanol, while the other CMPs underwent further optimization through Response Surface Methodology. Target values for TSP, TMA and DPPH were selected and the method operable design region (MODR) was defined by means of Monte-Carlo simulations. The optimized conditions, with the corresponding MODR intervals in bracket, were the following: (i) Time, 17 min (15-23 min); OS%, 56% (44-59%); S/E ratio, 0.030 (0.022-0.034) g mL-1. Under these experimental conditions, CMAs values of the pooled sample were the following (n = 3): TSP=4433±176 mg (+)-catechin eq/100 g dry weight (d.w.); TMA=3575±194 mg cyanidin-3-glucoside eq/100 g d.w.; DPPH=273±5 µg DPPH inhib./mg d.w. The optimized extraction method was tested for matrix effect (ME%) in the UHPLC-MS/MS analysis of 15 anthocyanins and 20 non-anthocyanins individual (poly)phenols commonly found in bilberries, as well as for luteolin, sinapic acid, and pelargonidin-3-glucoside, absent in this fruit and therefore added to the extracts as surrogate standards for evaluating apparent recovery (AR%). |ME%| was in any case ≤ 23% and AR% of the surrogate standards in the range 91-95%, confirming the very good performances of the optimized extraction method.

Electrochemical sensors based on sewage sludge-derived biochar for the analysis of anthocyanins in berry fruits.

The reutilization of waste and the reduction of the general environmental impact of every production are fundamental goals that must be achieved in the framework of a circular economy. Recycled carbon-rich materials may represent a promising alternative to other less-sustainable carbonaceous materials used in the production of electrochemical sensing platforms. Herein, we propose an innovative carbon paste electrode (CPE) composed of biochar derived from biological sludge obtained from municipal and industrial wastewater treatment plants. The physicochemical properties of the biochar after a chemical treatment with an acidic solution obtained from industrial by-products were investigated. The electrode surface characterization was carried out by analyzing common redox probes and multiple phenols bearing varying numbers of -OH and -OCH3 groups in their structure. Furthermore, the CPE was also tested on the evaluation of the phenolic fingerprints of Vaccinium myrtillus, Vaccinium uliginosum subsp. gaultherioides, and Fragaria × ananassa. Standard anthocyanin mixtures and extracts of the aforementioned fruits were analyzed to provide a phenolic characterization of real samples. The obtained results show that the sewage sludge-derived biochar can be a promising material for the development of electroanalytical sensors.

Comparison of chemometric strategies for potential exposure marker discovery and false-positive reduction in untargeted metabolomics: application to the serum analysis by LC-HRMS after intake of Vaccinium fruit supplements.

Untargeted liquid chromatographic-high-resolution mass spectrometric (LC-HRMS) metabolomics for potential exposure marker (PEM) discovery in nutrikinetic studies generates complex outputs. The correct selection of statistically significant PEMs is a crucial analytical step for understanding nutrition-health interactions. Hence, in this paper, different chemometric selection workflows for PEM discovery, using multivariate or univariate parametric or non-parametric data analyses, were comparatively tested and evaluated. The PEM selection protocols were applied to a small-sample-size untargeted LC-HRMS study of a longitudinal set of serum samples from 20 volunteers after a single intake of (poly)phenolic-rich Vaccinium myrtillus and Vaccinium corymbosum supplements. The non-parametric Games-Howell test identified a restricted group of significant features, thus minimizing the risk of false-positive retention. Among the forty-seven PEMs exhibiting a statistically significant postprandial kinetics, twelve were successfully annotated as purine pathway metabolites, benzoic and benzodiol metabolites, indole alkaloids, and organic and fatty acids, and five (i.e. octahydro-methyl-ß-carboline-dicarboxylic acid, tetrahydro-methyl-ß-carboline-dicarboxylic acid, citric acid, caprylic acid, and azelaic acid) were associated to Vaccinium berry consumption for the first time. The analysis of the area under the curve of the longitudinal dataset highlighted thirteen statistically significant PEMs discriminating the two interventions, including four intra-intervention relevant metabolites (i.e. abscisic acid glucuronide, catechol sulphate, methyl-catechol sulphate, and α-hydroxy-hippuric acid). Principal component analysis and sample classification through linear discriminant analysis performed on PEM maximum intensity confirmed the discriminating role of these PEMs.

Colorimetric selective quantification of anthocyanins with catechol/pyrogallol moiety in edible plants upon zinc complexation.

Here is examined the colour development from common anthocyanins (i.e., cyanidin, delphinidin, malvidin, and pelargonidin glycosides) and from anthocyanins-rich extracts (i.e., bilberries, strawberries, and raspberries), using zinc-anthocyanin complexes as molecular probe. We have observed the absorbance increase in the blue region in presence of large excess of zinc ion at acidic pH for cyanidin and delphinidin derivatives, likely due to quinoidal base stabilization from catechol and pyrogallol moiety. The assay condition were studied and applied to natural extracts containing these compounds. The same behaviour was observed for bilberry and, to a minor extent, for raspberry extracts, due to the larger cyanidin/delphinidin contents in the former than in the latter. Anthocyanin standard UV-Vis analysis in buffer has shown a very good linear correlation for cyanidin and delphinidin (R2 = 0.995 and 0.997, respectively), good precision (CV% = 7.4% and 5.3% respectively), high sensitivity (Cyε600nm = 8300 M-1 cm-1, LOD = 0.264 ± 0.005 mg L-1, LOQ = 0.478 ± 0.007 mg L-1, and Dpε600nm = 15,900 M-1 cm-1, LOD = 0.143 ± 0.002 mg L-1, LOQ = 0.478 ± 0.007 mg L-1). The effectiveness of this colorimetric method for the selective quantification of catechol/pyrogallol-based anthocyanins has been demonstrated in the aforementioned complex real matrices and compared to LC-MS/MS analysis and pH-differential method, offering a valuable tool to characterize plant and food extracts particularly rich in zinc-coordinating anthocyanins.

Biochars intended for water filtration: A comparative study with activated carbons of their physicochemical properties and removal efficiency towards neutral and anionic organic pollutants.

Seven biochars (BCs) obtained from pyrolysis or gasification of different vegetal feedstocks were thoroughly characterized in comparison with three commercial activated carbons (ACs) routinely used in drinking water treatment plants. BCs and ACs characterization included the determinations of ash, iodine and methylene blue adsorption indexes, and the release of metals and polycyclic aromatic hydrocarbons, which were performed according to international standards applied for adsorption media to be used in drinking waters. Total specific surface area, micropore and mesopore specific surface area, pH of the point of zero charge, and the release of polychlorinated biphenyls were also determined in all chars. Principal component analysis and cluster analysis were performed in order to summarize the complex set of information deriving from the aforementioned characterizations, highlighting the BC most similar (BC6 from high temperature gasification of woody biomass) and most different (BC7 from low-temperature pyrolysis of corn cob) from ACs. These BCs were studied for their adsorption in ultrapure water towards diiodoacetic acid (an emergent disinfection by-product), benzene, and 1.2-dichlorobenzene, in comparison with ACs, and results obtained were fitted by linearized Freundlich equation. Overall, BC6 showed higher sorption performances compared to BC7, even though both BCs were less performing sorbents than ACs. However, the sorption properties of BCs were maintained also in real water samples collected from drinking water treatment plants.

Characterization Techniques as Supporting Tools for the Interpretation of Biochar Adsorption Efficiency in Water Treatment: A Critical Review.

Over the past decade, biochar (BC) has received significant attention in many environmental applications, including water purification, since it is available as a low-cost by-product of the energetic valorisation of biomass. Biochar has many intrinsic characteristics, including its porous structure, which is similar to that of activated carbon (AC), which is the most widely used sorbent in water treatment. The physicochemical and performance characteristics of BCs are usually non-homogenously investigated, with several studies only evaluating limited parameters, depending on the individual perspective of the author. Within this review, we have taken an innovative approach to critically survey the methodologies that are generally used to characterize BCs and ACs to propose a comprehensive and ready-to-use database of protocols. Discussion about the parameters of chars that are usually correlated with adsorption performance in water purification is proposed, and we will also consider the physicochemical properties of pollutants (i.e., Kow). Uniquely, an adsorption efficiency index BC/AC is presented and discussed, which is accompanied by an economic perspective. According to our survey, non-homogeneous characterization approaches limit the understanding of the correlations between the pollutants to be removed and the physicochemical features of BCs. Moreover, the investigations of BC as an adsorption medium necessitate dedicated parallel studies to compare BC characteristics and performances with those of ACs.

Behaviour of physicochemical and microbiological characteristics of vertical flow constructed wetland substrate after treating a mixture of urban and olive mill wastewaters.

The aim of the current work is to evaluate the effect of a mixture of olive mill wastewater (OMWW) and urban wastewater (UW) on constructed wetland (CW) substrate physicochemical parameters, and to study the abundance and behaviour of microbial community at different depths. In this regard, substrate samples were investigated at three depth levels (0-10 cm, 10-20 cm and 20-30 cm) inside a pilot scale CW treating the mixture. In order to compare the obtained results with the conventional case, a control (CW pilot plant treating only UW) was implemented. Result shows that an increase in electrical conductivity (from 0.134 to 0.222 mS/cm in 0-10 cm and from 0.131 to 0.283 mS/cm in 10-20 cm), total dissolved salts (from 65.45 to 108.67 mg/kg in 0-10cm and from 64.33 to 135.3 mg/kg in 10-20 cm), total organic carbon (from 0.86 to 6.84%), total nitrogen (from 0.1 mg/kg to 0.45, 0.43 and 0.41 mg/kg, in 0-10 cm, 10-20 cm and 20-30 cm respectively) and C/N ratio take place in the substrate after the treatment of the mixture. As for the microbiological parameters, treating the mixture in a CW results in an increase in the yeast and fungi which may optimize the biodegradation of compounds such as polyphenols that are non-easily degraded.

Analytical quality by design in the development of a solvent-modified micellar electrokinetic chromatography method for the determination of sitagliptin and its related compounds.

A solvent-modified micellar electrokinetic chromatography method was developed following the Quality by Design approach for the simultaneous determination of sitagliptin (SIT), an oral antihyperglycemic drug, and its main impurities derived from the synthesis process. The separation system was identified in the scouting phase and was made by sodium dodecyl sulphate (SDS) micelles with the addition of n-butanol and methanol. The knowledge space was investigated through an asymmetric screening matrix, taking into consideration eight critical method parameters (CMPs) involving the composition of the background electrolyte in terms of buffer concentration and pH, the concentration of surfactants and organic modifiers, and voltage. The critical method attributes (CMAs) were identified as analysis time and the distance between the tail of the electroosmotic flow system peak and the front edge of impurity I1 (sitagliptin triazole hydrochloride). A Box-Behnken Design was used in response surface methodology for calculating the quadratic models relating the CMPs to the CMAs. From the models it was possible to compute the method operable design region (MODR) through Monte-Carlo simulations. The MODR was identified in the probability maps as the multidimensional zone where the risk of failure to achieve the desired values for the CMAs was lower than 10 %. The experimental conditions corresponding to the working point, with the MODR interval, were the following: background electrolyte, 14 (10-18) mM borate buffer pH 9.20, 100 mM SDS, 13.6 (11.1-16.0) %v/v n-butanol, 6.7 (4.5-8.8) %v/v methanol; voltage and temperature were set to 28 kV and 22 °C, respectively. The developed CE method was validated in accordance with International Council for Harmonisation guidelines and was applied to the analysis of SIT tablets. The routine analysis for the quality control of the pharmaceutical product could be conducted in about 11 min.

Liquid Chromatographic Quadrupole Time-of-Flight Mass Spectrometric Untargeted Profiling of (Poly)phenolic Compounds in Rubus idaeus L. and Rubus occidentalis L. Fruits and Their Comparative Evaluation.

This study provided a detailed profiling of the antioxidant and bioactive compounds occurring in three varieties of Rubus idaeus L. fruits ("Fall Gold", "Glen Ample" and "Tulameen") compared to Rubus occidentalis L. black raspberry ("Jewel" cultivar), adopting a comprehensive untargeted metabolomics approach developed with UHPLC analysis coupled with quadrupole/time-of-flight high resolution mass spectrometry, using the SWATH® acquisition protocol. The feature selection and annotation workflow, applied to the analysis of raspberry extracts in both polarities, allowed identifying 68 bioactive compounds mainly belonging to the classes of (poly)phenolic compounds. Interestingly, some of these identifications (e.g., ferulic acid glycosides and the ellagitannin-like nobotanin/malabathrin) represent the first report in raspberry fruits. Principal component analysis made possible highlighting the features more related to the expression of a genotype effect within the R. idaeus species or between the two raspberry species herein investigated. Overall, flavanols were the most discriminating features for the Fall Gold variety, whereas ellagitannins and flavonol glycosides represent more distinctive metabolic traits in Glen Ample and Tulameen fruits. Moreover, R. occidentalis Jewel variety was strongly characterized by the occurrence of anthocyanins, such as cyanidin, pelargonidin and delphinidin glycosides.

Amino groups modified SBA-15 for dispersive-solid phase extraction in the analysis of micropollutants by QuEchERS approach.

In the analysis of contaminants in food products, sample preparation is performed by proper adsorbents, whose choice is crucial to eliminate matrix interference. In this work we modified SBA-15 adsorbents by functionalization with (3-aminopropyl)-triethoxysilane (SBA-15-APTES) and N-[3-(trimethoxysilyl)propyl]aniline (SBA-15-AN) aiming to use them for the first time in the clean-up step of a QuEChERS (quick, easy, cheap, effective, rugged and safe) extraction of micropollutants from strawberry, a sugar rich fruit. After physico-chemical characterization by nitrogen adsorption, infrared spectroscopy and thermogravimetric analysis, the adsorption capabilities of SBA-15 sorbents and possible interaction mechanisms were studied at different pH (2.1-8.5) for glucose, sucrose and fructose at concentrations characteristic of those found in strawberries. The performance of the two SBA-15 sorbents was compared with that of commercial PSA (primary secondary amine), usually proposed in QuEChERS protocols. Both SBA-15 materials exhibit up to 30% higher adsorption than PSA, suggesting their possible QuEChERS application. Synthesized SBA-15 adsorbents were hence used as innovative dispersive sorbents in the QuEChERS extractions of 13 PAHs and 14 PCBs from strawberry. For PCBs, SBA-15-AN provides better matrix removal than PSA and comparable extraction recoveries around 90%. For PAHs, the use of SBA-15-AN has the advantage of lower relative standard deviation (7%) than PSA (19%).

Productivity and nutritional and nutraceutical value of strawberry fruits (Fragaria x ananassa Duch.) cultivated under irrigation with treated wastewaters.

BACKGROUND: Agriculture represents a productive sector typically characterized by a high water demand, whereas freshwater (FW) availability is a problem of increasing concern in the world and FW resources are becoming insufficient for sustaining agricultural irrigation. The reuse of treated wastewaters (TWWs) for crop irrigation could be an efficient tool for reducing water shortage. Hence, the present study evaluated the food quality of Fragaria x ananassa (cultivar Camarosa) fruits irrigated with four types of treated wastewaters (TWWs). Strawberries were analysed for yield, sucrose, fructose, glucose, total soluble polyphenols (TSP), total monomeric anthocyanins (TMA), and antiradical and antioxidant capacity. In addition, a targeted quantification of the most representative phenolic compounds of strawberry was performed. RESULTS: TWWs complied the Italian ministerial decree 185/2003 for wastewater reuse, with very few exceptions, mainly represented by chloride concentrations (258-643 mg L-1 versus a legal threshold of 250 mg L-1 ). The reuse of TWWs reduced fruit yield (10-26%) compared to irrigation with tap water as a control. Irrigation with TWWs gave also rise to the decrease of total sugars (14-26%), TSP (2-10%) and TMA (29-49%). Individual phenolic acids, flavonols and flavanols were quite stable in response to the irrigation with TWWs, whereas anthocyanidins decreased significantly. CONCLUSION: Although TWWs negatively affected fruit quality, the nutritional and nutraceutical parameters determined in the present study were in line with data previously reported for strawberries purchased in the market or cultivated in research orchards, thus suggesting that the use of TWWs does not prevent the fruit marketability. © 2020 Society of Chemical Industry.

Vaccinium myrtillus L. extract and its native polyphenol-recombined mixture have anti-proliferative and pro-apoptotic effects on human prostate cancer cell lines.

Vaccinium myrtillus berry extract (VME) and a recombined standard mixture (RSM) of its main native phenolic compounds were investigated for cell growth inhibition and pro-apoptotic activity on hormone-dependent (LNCaP) and hormone-independent (PC3 and DU-145) prostate cancer (PCa) cell lines. Normal prostate epithelial cells (PrEC) were also studied in comparison. VME hindered anchorage-dependent PCa cell proliferation in a dose-dependent manner, that is, at 1/800 (v/v) dilution for LNCaP and PC3, and 1/100 (v/v) dilution for DU-145 (corresponding to 14.15 and 113.2 µg cyanidin-3-O-glucoside equivalents per ml of culture medium), respectively. VME had a growth inhibitory effect towards PrEC at the same dilution of DU-145 cells although the IC50 values indicated that PrEC are more resistant than PCa cell lines. VME also reduced the anchorage-independent growth of PCa cells. The study of the apoptotic profile (i.e., non-apoptotic, early apoptotic, late apoptotic and necrotic cells) evidenced that the apoptotic rate (early+late) was statistically higher in all three cell lines exposed to VME compared to control. Anchorage-dependent and anchorage-independent growth inhibition of RSM was very similar to that displayed by VME. Moreover, RSM exerted its growth inhibitory effect also under hypoxia, the latter representing a biological condition known to sustain PCa proliferation and aggressiveness.

Green and cost-effective synthesis of copper nanoparticles by extracts of non-edible and waste plant materials from Vaccinium species: Characterization and antimicrobial activity.

The aim of this work was the green synthesis of copper nanoparticles (Cu-NPs) using aqueous extracts of (i) bilberry (Vaccinium myrtillus L.) waste residues from the production of fruit juices and (ii) non-edible "false bilberry" fruits (Vaccinium uliginosum L. subsp. gaultherioides). Different cupric salts (CuCl2, Cu(CH3COO)2 and Cu(NO3)2) were used for the synthesis. The formation of stable nanoparticles (CuNPs) was assessed by transmission electron microscopy and the oxidation state of copper in these aggregates was followed by X-ray photoelectron spectroscopy. The polyphenol composition of the extracts was characterized, before and after the synthesis, using spectrophotometric methods (i.e. total soluble polyphenols and total monomeric anthocyanins) and high-performance liquid chromatography coupled with tandem mass spectrometry (i.e. individual anthocyanins). Polyphenol concentration in the extracts was found to decrease after the synthesis, indicating their active participation to the processes, which led to the formation of Cu-NPs. The antimicrobial activity of Cu-NPs, berry extracts, and cupric ion solutions were analysed by broth microdilution and time-kill assays, on prokaryotic and eukaryotic models. The antimicrobial activity of Cu-NPs, especially those derived from bilberry waste residues, appeared to be higher for both Gram-negative and Gram-positive bacteria, and for fungi, compared to the ones of its single components (cupric salts and berry extracts). Therefore, Cu-NPs from the green synthesis here proposed can be considered as a cost-effective sanitization tool with a wide spectrum of action.

Closing the loop in a constructed wetland for the improvement of metal removal: the use of Phragmites australis biomass harvested from the system as biosorbent.

Among the numerous clean-up techniques for water treatment, sorption methods are widely used for the removal of trace metals. Phragmites australis is a macrophyte commonly used in constructed wetlands for water purification, and in the last decades, its use as biosorbent has attracted increasing attention. In view of a circularly economy approach, this study investigated improvement of trace metal removal by recycling the biomass of P. australis colonizing a constructed wetland, which operates as post-treatment of effluent wastewater from an activated sludge plant serving the textile industrial district of Prato (Italy). After the annual mowing of the reed plants, the biomass was dried and blended to derive a sustainable and eco-friendly biosorbent and its sorption capacity for Fe, Cu, and Zn was investigated comparing the batch system with the easier-to-handle column technique. The possibility of regeneration and reuse of the biosorbent was also evaluated. The biomaterial showed an interesting sorption capacity for Cu, Fe, and Zn, both in batch and in column experiments, especially for Fe ions. The immobilization of the biosorbent in column filters induced some improvement in the removal efficiency, and, in addition, this operation mode has the advantage of being much more suitable for practical applications than the batch process.

Improving the efficiency of wastewater treatment plants: Bio-removal of heavy-metals and pharmaceuticals by Azolla filiculoides and Lemna minuta.

In this study, we investigated the removal of Fe(III), Cr(VI), Al(III), diclofenac, and levofloxacin from treated wastewater in the presence of the free-floating plants Azolla filiculoides and Lemna minuta, to understand whether these species can be effectively used in a surface flow constructed wetland as wastewater refining treatment. Fe and Al were selected owing to their wide use as coagulant agents in wastewater treatment plants for promoting clariflocculation processes, whilst Cr was chosen due to its common use in industry. Diclofenac and levofloxacin, two molecules belonging to the most widely used pharmaceutical classes in the world, were studied as representative anti-inflammatory drugs and antibiotics, respectively. The study was performed at laboratory scale, exposing the plants separately to each individual contaminant at the concentrations of 5 mg L-1 for the metals (i.e. 2.5-5 times higher than the European limits concerning discharge into surface water), and 1 µg L-1 for the pharmaceuticals (concentration levels commonly found in wastewater). Depending on the plant species and contaminant tested, the range of different effects observed included low toxicity (i.e. Cr, Fe and diclofenac in L. minuta) and even a stimulatory effect on plant growth (i.e. for A. filiculoides with Al and for L. minuta with Al and levofloxacin). Moreover, both species proved to be very effective in the removal of Fe, Al and levofloxacin, with A. filiculoides showing the best performance (removal efficiency of 92%, 96%, and 60%, respectively), whereas for Cr and diclofenac the removal was always less than 10%. The higher removal capacity of A. filiculoides compared to L. minuta can be attributed to its superior tolerance of the contaminants, probably in turn related to the presence of nitrogen-fixing microorganism in its fronds.

Optimization and validation of a method based on QuEChERS extraction and liquid chromatographic-tandem mass spectrometric analysis for the determination of perfluoroalkyl acids in strawberry and olive fruits, as model crops with different matrix characteristics.

A QuEChERS method was optimized and validated for the LC-MS/MS analysis of perfluoro-n-pentanoic acid (PFPeA), perfluoro-1-butanesulfonic acid (PFBuS), perfluoro-n-hexanoic acid (PFHxA), perfluoro-n-heptanoic acid (PFHpA), perfluoro-1-hexanesulfonic acid (PFHxS), perfluoro-n-octanoic acid (PFOA), perfluoro-n-nonanoic acid (PFNA), perfluoro-1-octanesulfonic acid (PFOS) and perfluoro-n-decanoic acid (PFDA) in freeze-dried strawberry and olive, as model fruits characterized by very different chemical compositions. The method was evaluated for apparent recovery, intra-day and inter-day precision, matrix effect and recovery. The method optimized for strawberry provided for most compounds absolute values of matrix effect (|ME%|) ≤ 11%, except for PFHxA, which showed a signal suppression of 22%. The extraction efficiency was tested at the spike levels 500-5000 pg/g d.w. for PFPeA, PFBuS, and PFHxA, and 100-1000 pg/g d.w. for the other target analytes, evidencing as a whole recoveries in the range of 65-89%. For olive fruits, due to their high fat content, an ultrasound-assisted extraction was necessary to obtain an efficient sample disgregation so as to increase the extraction yield and its precision. Moreover, a d-SPE clean-up with GCB allowed to achieve |ME%| ≤ 8% (except for PFBuS, which showed a signal enhancement of 19%) and recoveries calculated at the aforementioned spike levels were in the range 75-97%. The two methods provided very good linearity (R2 ≥ 0.9984) from 10,000 pg/g down to compound specific quantification limits, which were included in the ranges of 2.9-393 pg/g and 2.6-127 pg/g for strawberry and olive fruit, respectively. The methods were applied to the analysis of PFAAs in strawberry and olive fruits commercially available in two Italian supermarkets, as well as obtained under irrigation with various treated wastewaters (TWWs), evidencing in both cases a higher PFAAs occurrence in olives than in strawberry. However, PFAAs concentrations determined in the investigated fruit matrixes were quite low, being their sum 1.9 ng/g d.w. in the worst case (i.e. olive fruits grown under irrigation with TWWs).