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•Furan compounds have been produced from cellulose and four lignocellulosic wastes.•MW-assisted hydrolysis is assayed for different ILs, catalysts and organic diluents.•Water dosage, ...reaction times and temperatures have been optimized.•Kinetic models confirm optimal time and temp for separate HMF and furfural production.•Ultrasound pretreatment+stirring in the microwave oven drastically enhance yields.
Native cellulose, lignocellulosic materials from Brazil (carnauba palm leaves and macauba pulp and shell) and pine nut shell from Spain have been studied as substrates for the production of HMF and furfural in a conventional microwave oven. In order to promote the dissolution of native cellulose, several ionic liquids, catalysts, organic solvents and water doses have been assessed. The most suitable mixture (5mL of choline chloride/oxalic acid, 2mL of sulfolane, 2mL of water, 0.02g of TiO2 and 0.1g of substrate) has been chosen to conduct kinetic studies at different reaction times (5–60min) and various temperatures (120–200°C) and to evaluate the best conditions for HMF+furfural production according to Seaman’s model. The best production yields of HMF+furfural have been attained for native cellulose, with a yield of 53.24% when an ultrasonic pretreatment was used prior to a microwave treatment with stirring.
A procedure for the determination of Pb isotope ratios by coupling liquid chromatography to a multicollector ICP-MS has been developed. The procedure allows the direct injection of samples after ...dissolution without resorting to time-consuming off-line separation procedures. The separation of Pb from concomitant elements is carried out by anionic exchange as ethylenediamine tetraacetic acid (EDTA) chelates using EDTA and ammonium nitrate as a mobile phase. A flow injection system allows the injection of NIST 981 Pb isotopic standard, before and after the Pb peak from the sample, and the on-line addition of Tl for mass bias correction and bracketing. The procedure was validated by injecting NIST 981 into the chromatographic system and by comparing the results for real samples with the classical off-line separation procedure using Pb spec resins. The optimised procedure was applied to archaeological samples containing different concentrations of Pb. It was observed that the only limitation to the accuracy of the procedure was the concentration of Pb in the samples as no preconcentration is performed. Solid archaeological samples containing at least 500 μg g
−1
of Pb can be studied using the proposed procedure.
On-line coupling of HPLC-MC-ICP-MS allows Pb isotope ratio measurements in archaeological samples without prior off-line Pb separation.
Different g-C
3
N
4
composite systems (coke carbon/g-C
3
N
4
, Bi/Bi
2
WO
6
/g-C
3
N
4
and Bi/Bi
2
MoO
6
/g-C
3
N
4
) have been assessed as photocatalysts for wastewater pollutants removal. The coke ...carbon/g-C
3
N
4
hybrid, produced by thermal treatment at 550 °C of a composite made from melamine cyanurate and coke, only showed activity under UV-light irradiation. On the other hand, inorganic Bi spheres/Bi mixed oxides/g-C
3
N
4
nanohybrids (Bi/Bi
2
WO
6
/g-C
3
N
4
and Bi/Bi
2
MoO
6
/g-C
3
N
4
composites), produced by thermal reduction of Bi
2
WO
6
or Bi
2
MoO
6
by g-C
3
N
4
, exhibited a remarkable red-shift, up to 620 nm, and allowed the visible-light driven degradation of the contaminant, albeit in combination with some adsorption.
The use of nanocarriers (NCs), i.e., nanomaterials capable of encapsulating drugs and releasing them selectively, is an emerging field in agriculture. In this study, the synthesis, characterization, ...and in vitro and in vivo testing of biodegradable NCs loaded with natural bioactive products was investigated for the control of certain phytopathogens responsible for wood degradation. In particular, NCs based on methacrylated lignin and chitosan oligomers, loaded with extracts from Rubia tinctorum, Silybum marianum, Equisetum arvense, and Urtica dioica, were first assayed in vitro against Neofusicoccum parvum, an aggressive fungus that causes cankers and diebacks in numerous woody hosts around the world. The in vitro antimicrobial activity of the most effective treatment was further explored against another fungal pathogen and two bacteria related to trunk diseases: Diplodia seriata, Xylophilus ampelinus, and Pseudomonas syringae pv. syringae, respectively. Subsequently, it was evaluated in field conditions, in which it was applied by endotherapy for the control of grapevine trunk diseases. In the in vitro mycelial growth inhibition tests, the NCs loaded with R. tinctorum resulted in EC90 concentrations of 65.8 and 91.0 μg·mL−1 against N. parvum and D. seriata, respectively. Concerning their antibacterial activity, a minimum inhibitory concentration of 37.5 μg·mL−1 was obtained for this treatment against both phytopathogens. Upon application via endotherapy on 20-year-old grapevines with clear esca and Botryosphaeria decay symptoms, no phytotoxicity effects were observed (according to SPAD and chlorophyll fluorescence measurements) and the sugar content of the grape juice was not affected either. Nonetheless, the treatment led to a noticeable decrease in foliar symptoms as well as a higher yield in the treated arms as compared to the control arms (3177 vs. 1932 g/arm), suggestive of high efficacy. Given the advantages in terms of controlled release and antimicrobial product savings, these biodegradable NCs loaded with natural extracts may deserve further research in large-scale field tests.
Sugarcane bagasse is the major by-product of the sugarcane industry and, due to its abundant availability, it has been extensively studied for lignocellulosic bioconversion in the production of ...bioethanol and other value-added commercial products. In the study presented herein, a combined pretreatment using sulfolane, TiO2 and alkali microwave irradiation (MW-A) was assessed for the dissolution of lignin prior to enzymatic saccharification of holocellulose. Total reducing sugars (TRS) and saccharinic acid yields were investigated. The increase in NaOH concentration up to 5% and in temperature from 120 °C to 140 °C were found to have a positive influence on both yields. While increasing the reaction time from 5 to 60 min only led to an increase in TRS yield <2%, a reaction time of 30 min almost doubled the saccharinic acids production. TRS yields and saccharinic acid production were approximately 5% and 33% higher when the sulfolane-TiO2 reaction medium was used, as compared to MW-A in water, reaching up to 64.8% and 15.24 g/L of saccharinic acids, respectively. The proposed MW-A pretreatment may hold promise for industrial applications, given the good TRS yields obtained, and the associated enzyme and time/energy savings. The use of sulfolane-TiO2 reaction medium is encouraged if saccharinic acids are to be recovered too.
The technology of gas-permeable tubular membranes (GPMs) is promising in reducing ammonia emissions from livestock manure, capturing NH3 in an acidic solution, and obtaining final products suitable ...for valorization as fertilizers, in line with the principles of the circular economy. This study aimed to evaluate the performance of several e-PTFE membrane systems with different configurations for the recovery of NH3 released from pig slurry. Ten different configurations were tested: only a submerged membrane, only a suspended membrane in the same chamber, only a suspended membrane in an annex chamber, a submerged membrane + a suspended membrane in the same chamber, and a submerged membrane + a suspended membrane in an annex chamber, considering in each case the scenarios without and with agitation and aeration of the slurry. In all tests, sulfuric acid (1N H2SO4) was used as the NH3 capture solution, which circulated at a flow rate of 2.1 L·h−1. The results showed that NH3-N removal rates ranged from 36–39% (for systems with a single submerged or suspended membrane without agitation or aeration of the slurry) to 70–72% for submerged + suspended GPM systems with agitation and aeration. In turn, NH3-N recovery rates were found to be between 44–54% (for systems with a single membrane suspended in an annex compartment) and 88–91% (for systems based on a single submerged membrane). However, when choosing a system for farm deployment, it is essential to consider not only the capture and recovery performance of the system, but also the investment and operating costs (ranging from 9.8 to 21.2 €/kg N recovered depending on the selected configuration). The overall assessment suggests that the simplest systems, based on a single membrane, may be the most recommendable.
Green leafy vegetables are essential for a balanced diet, providing vital nutrients for overall well-being. However, concerns arise due to contamination with toxic substances, such as arsenic, posing ...risks to food safety and human health. This study analyzes inorganic (iAs), monomethyl (MMA), and dimethyl arsenic (DMA) in specific leafy vegetables (
Amaranthus tricolor
L.,
Corchorus olitorius
L.,
Cordia myxa
L.,
Hibiscus sabdariffa
L.,
Ipomoea batatas
(L.) Lam.,
Moringa oleifera
Lam., and
Spinacia oleracea
L.) grown in the heavily polluted Ambagarh Chouki region, Chhattisgarh, India. Concentrations of DMA, MMA, and iAs ranged from 0 to 155, 0 to 7, and 131 to 3579 mg·kg
−1
, respectively. The health quotient (HQ) for iAs ranged between 0.37 and 3.78, with an average value of 2.58 ± 1.08.
Graphical abstract
Leafy plants are commonly consumed as vegetables in India due to their high nutrient and vitamin content. This study, conducted in Ambagarh Chowki (India), investigated the accumulation potential of ...52 elements (including Al, As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Ho, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, P, Pb, Pr, Rb, Sb, Sc, Se, Sm, Sn, Sr, Tb, Te, Th, Ti, Tl, Tm, U, V, W, Y, Yb, and Zn) in seven leafy vegetable species, namely Amaranthus tricolor L., Corchorus olitorius L., Cordia myxa L., Hibiscus sabdariffa L., Ipomoea batatas (L.) Lam., Moringa oleifera Lam., and Spinacia oleracea L. Technique: Inductively coupled plasma mass spectrometry (ICP-MS) was employed for analysis. The maximum concentrations of elements such as Al, Ba, Be, Bi, Cd, Co, Cr, Fe, Ga, Ge, Li, Mn, Ni, Pb, Sb, Th, Tl, U, V, W, and REEs were observed in S. oleracea leaves, indicating their highest accumulation potential. In contrast, the maximum concentrations of As were found in H. sabdariffa leaves; Ca and Si in M. oleifera leaves; Mg, Sr, and Mo in A. tricolor leaves; and P, K, Cu, and Zn in C. myxa leaves, respectively. Twenty-one elements (Cr, Cd, Pb, Ni, Co, V, Cu, Zn, Fe, Mn, Th, Sb, Ba, Be, Li, Sr, Tl, U, Se, Sn, and REEs) exceeded permissible limits set by the WHO. The elevated hazard index values indicated significant non-carcinogenic effects. The sources of these elements could be attributed to a combination of geological factors and agricultural practices. This study highlights the need for further investigation into the potential health implications of consuming these vegetables in the aforementioned region.Leafy plants are commonly consumed as vegetables in India due to their high nutrient and vitamin content. This study, conducted in Ambagarh Chowki (India), investigated the accumulation potential of 52 elements (including Al, As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Ho, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, P, Pb, Pr, Rb, Sb, Sc, Se, Sm, Sn, Sr, Tb, Te, Th, Ti, Tl, Tm, U, V, W, Y, Yb, and Zn) in seven leafy vegetable species, namely Amaranthus tricolor L., Corchorus olitorius L., Cordia myxa L., Hibiscus sabdariffa L., Ipomoea batatas (L.) Lam., Moringa oleifera Lam., and Spinacia oleracea L. Technique: Inductively coupled plasma mass spectrometry (ICP-MS) was employed for analysis. The maximum concentrations of elements such as Al, Ba, Be, Bi, Cd, Co, Cr, Fe, Ga, Ge, Li, Mn, Ni, Pb, Sb, Th, Tl, U, V, W, and REEs were observed in S. oleracea leaves, indicating their highest accumulation potential. In contrast, the maximum concentrations of As were found in H. sabdariffa leaves; Ca and Si in M. oleifera leaves; Mg, Sr, and Mo in A. tricolor leaves; and P, K, Cu, and Zn in C. myxa leaves, respectively. Twenty-one elements (Cr, Cd, Pb, Ni, Co, V, Cu, Zn, Fe, Mn, Th, Sb, Ba, Be, Li, Sr, Tl, U, Se, Sn, and REEs) exceeded permissible limits set by the WHO. The elevated hazard index values indicated significant non-carcinogenic effects. The sources of these elements could be attributed to a combination of geological factors and agricultural practices. This study highlights the need for further investigation into the potential health implications of consuming these vegetables in the aforementioned region.
Smilax aspera L. (commonly known as sarsaparilla) is recognized for its composition rich in flavonoids, phenylpropanoids, steroidal saponins, stilbenoids, and tannins, exhibiting anti-inflammatory, ...cytotoxic, and antimicrobial properties. This study investigates the hydromethanolic extracts of its leaves and fruits through vibrational spectroscopy and gas chromatography–mass spectrometry, evaluating their potential as biorationals for safeguarding crops. Analysis of S. aspera leaf and fruit extracts revealed the presence of phytochemicals such as lactones and other furan derivatives. In vitro assessments against three phytopathogens—Erwinia amylovora, Pseudomonas syringae pv. actinidiae, and Xanthomonas campestris pv. campestris—demonstrated strong antibacterial activity, with minimum inhibitory concentration (MIC) values of 1500 μg·mL−1 for both extracts. Biofilm tests indicated that the leaf extract reduced biofilm formation by 78–85%, while the fruit extract led to a reduction of 73–92.5%. At a concentration of 750 µg·mL−1, the extracts caused a decrease in amylovoran synthesis by 41–58%. Additionally, noticeable alterations in membrane permeability were observed at MIC and MIC/2 doses. Subsequent in vivo trials conducted on Pyrus communis L. trees utilizing the combined aerial part extract yielded substantial protection against E. amylovora at a dose of 1500 μg·mL−1, reaching 80% wilting reduction for the leaf extract. The findings presented herein cast S. aspera extracts as a promising natural-based treatment against these bacterial phytopathogens.
Functional nanomaterials find numerous applications in electrochemical biosensors and lab-on-a-chip devices, such as the glucose sensors used by diabetic patients. In this work, polymeric carbon ...nitride (g-C3N4) −which mimicks peroxidases behavior− was used, in combination with 3,3′,5,5′-tetramethylbenzidine (TMB) −a redox indicator−, to detect glucose in a quantitative way. The utilization of two non-noble metal co-catalysts, Fe(III) and Cu(II), embedded in the polymer structure by adsorption (Cu(II)–Fe(III)-g-C3N4), considerably increased the sensitivity towards glucose as compared to that of pristine g-C3N4. TMB and glucose oxidase (GOx) were also adsorbed on the catalyst, resulting in a solid-state composite that changed its color from yellow to green when exposed to a solution containing glucose. The UV–Vis monitoring of the intensity of the band at 675 nm, associated with oxidized TMB, showed that the response of the Cu(II)–Fe(III)-g-C3N4 system was faster than that of the one based on pristine g-C3N4. This behavior was further confirmed by electron spin resonance (ESR) spectroscopy. Moreover, ESR experiments conducted with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) evidenced that the Cu(II)–Fe(III)-g-C3N4 catalyst was able to produce about twice as many radicals as pristine g-C3N4. The proposed composite material may hold promise as a solid substrate for glucose sensing, given that concentration levels in the low ppb range can be detected by UV–Vis diffuse reflectance spectroscopy and concentrations above 100 ppm (μM) can be easily detected by the naked eye.
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•Cu(II)–Fe(III)-g-C3N4 can be used as a HRP-mimicking nanozyme for glucose detection.•Solid-state sensor changes its color from yellow to green when exposed to glucose.•Glucose can be detected in a quantitative way in the 10−3−105 μM range.•Metal co-catalysts considerably increase glucose sensitivity vs. pristine g-C3N4.
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