In the present work, the role of chemical compounds of one abundant vegetable waste, exhausted co... more In the present work, the role of chemical compounds of one abundant vegetable waste, exhausted coffee, on Cr(VI), Cu(II), and Ni(II) sorption has been investigated. For this purpose, exhausted coffee was subjected to sequential extractions by using dichloromethane (DCM), ethanol (EtOH), water, and NaOH 1 %. The raw and treated biomass resulting from the extractions were used for metal ions sorption. Sorption results were discussed taking into consideration polarity and functional groups of raw and treated biomass. In general, the successive removal of extractives led to an insignificant increase in the studied metal ions sorption after DCM, EtOH, and water. The sorption results using free-extractive materials showed that metal sorption can be effectively achieved without this non-structural fraction of the sorbent. Alkaline hydrolysis destroyed in part the structural compounds of the sorbent resulting in an insignificant decrease of chromium removal while a significant increase of copper and nickel sorption was observed. The determination of elemental ratios of exhausted coffee and all treated biomass evidenced the involvement of oxygen functional groups in copper and nickel sorption. FTIR analysis confirmed the involvement of lignin moieties in the chromium sorption by exhausted coffee. As a final remark, this study shows that the sequential extraction opens new expectations to the total valorisation of lignocellulosic-based biomasses. The extractives can be removed and used as a biosource of valuable compounds, and the resulting waste can be used as a sorbent for metal ions keeping the same capacity for metal sorption as the non-extracted biomass.
In this work, the efficiency of a polyelectrolyte complex (PEC) to retain different cellulose mic... more In this work, the efficiency of a polyelectrolyte complex (PEC) to retain different cellulose micro/nanofibers (CMNFs) during paper formation and to improve the physical properties of recycled unbleached fiber paper was analyzed. CMNFs were obtained from a commercial bleached eucalyptus pulp (BEP) using a PFI refiner followed by a chemical treatment with oxalic acid at two different concentrations. Finally, the pulp was fibrillated using a high-pressure homogenizer at three different intensities. The PEC was formed by addition of the xylan (Xyl) solution on chitosan (CH) solution with a Xyl/CH mass ratio of 80/20. The required dosages of PEC solution to neutralize the charges of different nanocellulose fractions were determined by ζ-potential measurements, and the CMNF retentions on recycled unbleached fibers were evaluated in a Britt Dynamic Drainage Jar. The results showed that the maximum retention was obtained when the neutral PEC-CMNF system was added to pulp. Besides, a significant decrease on °SR was observed when PEC and PEC-CMNF systems were added to the untreated pulp, limiting the negative effects of nanocellulose addition on pulp drainability. The incorporation of PEC-CMNF systems to the handsheets increased the tensile index (up to 28%), Mullen index (up to 40%) and internal bonding (up to 255%). Finally, the compressive strength of the handsheets, namely SCT and CMT, increased up to 30 and 70%, respectively. These simultaneous improvement on drainability and mechanical properties makes the proposed PEC-CMNF system a promising solution for the production of packaging paper.
Abstract Diffusivity of a component in a binary mixture is affected by the presence of a second c... more Abstract Diffusivity of a component in a binary mixture is affected by the presence of a second component. The knowledge of the influence on each other component diffusivity is very useful for the prediction of sorption kinetics of binary mixtures. In this work kinetic studies of Cr(VI) and Cu(II) binary mixtures sorption onto exhausted coffee encapsulated in calcium alginate beads were carried out in both bench and pilot scale experiments. The spectroscopic analysis evidenced the complexity of the process since different mechanisms such as adsorption, redox reaction and ion exchange are involved. Experimental data were fitted to the Linear Adsorption Model (LAM). An empirical quadratic model was developed to estimate LAM parameters ( D e ) and α = C f /(C i − C f ) as a function of the initial concentration of metals in the mixture. The empirical model developed enables to estimate the LAM parameters ( D e and α ) of metal ions binary mixtures provided that the initial concentration of the metal ions is included in the range of concentrations studied. The estimated parameters introduced in LAM equation allow simulating the corresponding binary mixtures sorption kinetics. This study constitutes a fast and easy approach to the modelling of sorption kinetics of complex systems in which different processes take place simultaneously.
While water is indispensable for life, around 785 million people do not have access to basic drin... more While water is indispensable for life, around 785 million people do not have access to basic drinking water. Heavy metals present high toxicity at low concentrations, are non-biodegradable and easy to accumulate in living organisms such as human body, causing serious diseases or even death. Copper is usually found at high concentrations in wastewater due to its extensive use in several industrial applications, and effective copper removal systems must be developed. The present work aims at developing effective TEMPO-oxidized cellulose nanofibers (CNFs) based systems able to adsorb Cu(II) in adsorption columns. CNFs were partially modified with alkyl ketene dimer (AKD) to avoid regelation Keywords Cu(II) adsorption Á Wastewater remediation Á Nanocellulose Á Alginate Á Breakthrough curves Á Adsorption kinetics
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
A solid waste material containing Fe(III) and other metal (hydr)oxides produced in a metal surfac... more A solid waste material containing Fe(III) and other metal (hydr)oxides produced in a metal surface treatment industry has been investigated for As(V) removal. In order to facilitate sorbent application, 2% of raw material has been entrapped in calcium alginate gel matrix (2% O-CA). An accurate characterization of the sorption on gel beads was undertaken, considering thermodynamic and kinetic aspects. All experiments were carried out at pH 8, since the maximum As(V) sorption was reached between pH 6 and 9. About isotherms, the best fit was obtained considering the Langmuir model and a capacity of 1.9 mg/g was achieved. The kinetic profiles evidenced that a quantitative sorption was obtained within 10 h. The 2% O-CA beads were also tested for continuous As(V) removal in a fixed bed column. Experiments were performed at constant flow rate, and varying the inlet As(V) concentration. With a view to design an automatic system for As(V) analysis in the outlet flow, the suitability of applying Anodic Stripping Voltammetry was evaluated: the method resulted appropriated to follow the As(V) content in the outlet solutions of columns with metal inlet concentration <1 mg/L. These results suggested that 2% O-CA beads could be a promising sorbent candidate for As(V) removal.
This study was conducted on the reduction reaction of the azo dye Reactive Black 5 by means of th... more This study was conducted on the reduction reaction of the azo dye Reactive Black 5 by means of the Mn 85 Al 15 particles prepared by melt-spinning and ball-milling processes. The morphology, the surface elementary composition and the phase structure of the powders were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. The degradation efficiency of the ball milled powder was measured by using an ultraviolet-visible absorption spectrophotometer and the collected powder was analyzed by means of Fourier transform infrared spectroscopy technique to characterize the functional groups in the extract. The degradation of Reactive Black 5 and the analysis of the aromatic by-products were investigated by high performance liquid chromatography coupled with tandem mass spectrometry. The ball-milled powder shows higher degradation efficiency and the Reactive Black 5 solution was completely decolorized after 30 min. The degradation kinetics and the formation by-products depend on the pH and temperature of the solution. The analyses of the extracted product confirmed the cleavage of the (-N]N-) bonds. Our findings are expected to pave the way for a new opportunity with regard to the functional applications of nanostructured metallic particles.
Cellulose nanofibers (CNFs) are becoming a topic of great interest due to their wide range of pot... more Cellulose nanofibers (CNFs) are becoming a topic of great interest due to their wide range of potential applications. The huge presence of carboxylic groups in TEMPO-oxidized CNFs indicate that this material could interact with cationic species in aqueous solution, such as metal ions. Nevertheless, the contact between nanofibers and water solutions requires a 3D structure to entrap and retain the nanofibers. In this sense, two different 3D structures were synthetized: CNF-calcium alginate beads and CNF-aerogels. After the synthesis and characterization Electronic supplementary material The online version of this article (
The present work aims at glimpsing the rate-determinant process parameters of TEMPO-mediated oxid... more The present work aims at glimpsing the rate-determinant process parameters of TEMPO-mediated oxidation of bleached kraft cellulose for developing kinetic models and real-time monitoring tools. This may contribute to the scaling up of this reaction, frequently used as precursor of the production of cellulose nanofibers. For this, the effect of temperature, TEMPO and NaBr contents, and surface area of the fibers was assessed by means of a total experimental batch of 18 combinations, monitoring the carboxyl content (CC) of the samples and the NaOH consumption during oxidation. The obtained data was used to calculate the kinetic constant as a function of the conditions, as well as correlating the CC with the NaOH consumption, obtaining a strong linear correlation between these parameters. It was found that similar correlations could be used regardless process conditions, except for the case of TEMPO, which was found to protect the fibers from depolymerization and, thus, having different...
More than half of spinal cord injury (SCI) patients develop central neuropathic pain (CNP), which... more More than half of spinal cord injury (SCI) patients develop central neuropathic pain (CNP), which is largely refractory to current treatments. Considering the preclinical evidence showing that polyphenolic compounds may exert antinociceptive effects, the present work aimed to study preventive effects on SCI-induced CNP development by repeated administration of two vegetal polyphenolic extracts: grape stalk extract (GSE) and coffee extract (CE). Thermal hyperalgesia and mechanical allodynia were evaluated at 7, 14 and 21 days postinjury. Then, gliosis, ERK phosphorylation and the expression of CCL2 and CX3CL1 chemokines and their receptors, CCR2 and CX3CR1, were analyzed in the spinal cord. Gliosis and CX3CL1/CX3CR1 expression were also analyzed in the anterior cingulate cortex (ACC) and periaqueductal gray matter (PAG) since they are supraspinal structures involved in pain perception and modulation. GSE and CE treatments modulated pain behaviors accompanied by reduced gliosis in the...
Abstract Recently, the use of magnetic sorbents has gained a spread attention due to their eco-fr... more Abstract Recently, the use of magnetic sorbents has gained a spread attention due to their eco-friendly characteristic, ease of separation and low cost. Herein, a novel biocomposite sorbent magnetic pine cone gel beads (MPCB) was synthetized and investigated for the single and the simultaneous removal of Cu(II) and Cr(VI) from aqueous solution. Pine cones waste materials were first magnetized with Fe3O4 nanoparticles then were encapsulated in calcium gel beads. The physicochemical properties of the prepared MPCB were characterized via scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction and Fourier transform infrared spectrometry (FTIR) analysis. The influences of pH, contact time and initial concentration of metal ions on the sorption process were examined. The adsorption mechanism was investigated; it mainly involved complexation/chelation with surface functional groups, electrostatic interaction and ion exchange. A physical model was adopted to attribute new physico-chemical interpretations of the adsorption mechanism. The kinetic results showed good correlation with pseudo second-order model and the equilibrium data were fitted well to the Langmuir isotherm model with maximum adsorption capacity of 68.64 and 212.22 mg g-1 for Cu(II) and Cr(VI) respectively. In the multi-components system, both competitive and synergistic effects were observed. An antagonism effect was exerted by Cu(II) ions on Cr(VI) sorption while Cu(II) adsorption was not affected and even slightly enhanced by the presence of Cr(V) ions. The competitive sorption behavior of metal ions was analyzed by the modified competitive Langmuir model which provides good fit for the Cu experimental data. This study proves that the MPCB hold great promise for using as effective sorbent for potentially toxic metals remediation.
Espresso extraction is generally carried out at a fixed temperature within the range 85-95°C. In ... more Espresso extraction is generally carried out at a fixed temperature within the range 85-95°C. In this work the extraction of the espressos was made in a new generation coffee machine that enables temperature profiling of the brewing water. The effect of using gradient of temperature to brew espressos on physicochemical and sensorial characteristics of the beverage has been investigated. Three different extraction temperature profiles were tested: updrawn gradient (88-93°C), downdrawn gradient (93-88°C) and fixed temperature (90°C). The coffee species investigated were Robusta, Arabica natural and Washed Arabica. Results proved that the use of gradient temperature for brewing espressos allows increasing or decreasing the extraction of some chemical compounds from coffee grounds. Moreover an appropriate gradient of temperature can highlight or hide some sensorial attributes. In conclusion, the possibility of programming gradient of temperature in the coffee machines recently introduce...
Journal of Chemical Engineering & Process Technology, 2013
Activated carbon is prepared with chemical activation of olive stones, by using H 3 PO 4. Batch a... more Activated carbon is prepared with chemical activation of olive stones, by using H 3 PO 4. Batch adsorption of phenol from aqueous solution was investigated. The adsorptive properties were studied in terms of pH, equilibrium time, initial concentration (C 0 : 25-300 mg/L) and particle sizes (0.125-1.6mm) effects. The experimental kinetic data fitted well the pseudo second order model and the equilibrium isotherm data the Langmuir model. The results indicate that chemical olive stones activated carbon is suitable to be used as an adsorbent material for adsorption of phenol from aqueous solution.
In this work the ability of some vegetable wastes from industrial processes such as cork and yohi... more In this work the ability of some vegetable wastes from industrial processes such as cork and yohimbe bark, grape stalks and olive pits, to remove metal ions from aqueous solutions has been investigated. The influence of pH, sodium chloride and metal concentration on Ni(II) and Cu(II) uptake was studied. Metal uptake showed in all the cases a pH-dependent profile. Maximum sorption was found at an initial pH around 5.0–6.0. In some cases an increase of sodium chloride concentration induced a decrease in metal removal. Adsorption isotherms at the optimum pH were expressed by the noncompetitive Langmuir adsorption model. When comparing the four materials, yohimbe bark waste was found to be the most efficient adsorbent for both metals studied.
It was recently shown that coffee polyphenolic extract exerts preventive effects on central neuro... more It was recently shown that coffee polyphenolic extract exerts preventive effects on central neuropathic pain development, but it is unknown whether its beneficial effects are associated with only one of its major polyphenolic compounds or if the whole extract is needed to exert such effects. The main objective of this study was to determine whether the separate administration of major polyphenols from coffee extract exerts preventive effects on the development of central neuropathic pain in mice compared with the effects of the whole coffee extract. Thus, spinal-cord-injured female ICR-CD1 mice were daily treated with either coffee extract or its major polyphenolic compounds during the first week, and reflexive and nonreflexive pain responses were evaluated within the acute phase of spinal cord injury. In addition, the injury-induced gliosis and dorsal horn sprouting were evaluated with immunohistochemistry. The results showed that the coffee extract prevented spinal cord injury-ind...
In the present work, the role of chemical compounds of one abundant vegetable waste, exhausted co... more In the present work, the role of chemical compounds of one abundant vegetable waste, exhausted coffee, on Cr(VI), Cu(II), and Ni(II) sorption has been investigated. For this purpose, exhausted coffee was subjected to sequential extractions by using dichloromethane (DCM), ethanol (EtOH), water, and NaOH 1 %. The raw and treated biomass resulting from the extractions were used for metal ions sorption. Sorption results were discussed taking into consideration polarity and functional groups of raw and treated biomass. In general, the successive removal of extractives led to an insignificant increase in the studied metal ions sorption after DCM, EtOH, and water. The sorption results using free-extractive materials showed that metal sorption can be effectively achieved without this non-structural fraction of the sorbent. Alkaline hydrolysis destroyed in part the structural compounds of the sorbent resulting in an insignificant decrease of chromium removal while a significant increase of copper and nickel sorption was observed. The determination of elemental ratios of exhausted coffee and all treated biomass evidenced the involvement of oxygen functional groups in copper and nickel sorption. FTIR analysis confirmed the involvement of lignin moieties in the chromium sorption by exhausted coffee. As a final remark, this study shows that the sequential extraction opens new expectations to the total valorisation of lignocellulosic-based biomasses. The extractives can be removed and used as a biosource of valuable compounds, and the resulting waste can be used as a sorbent for metal ions keeping the same capacity for metal sorption as the non-extracted biomass.
In this work, the efficiency of a polyelectrolyte complex (PEC) to retain different cellulose mic... more In this work, the efficiency of a polyelectrolyte complex (PEC) to retain different cellulose micro/nanofibers (CMNFs) during paper formation and to improve the physical properties of recycled unbleached fiber paper was analyzed. CMNFs were obtained from a commercial bleached eucalyptus pulp (BEP) using a PFI refiner followed by a chemical treatment with oxalic acid at two different concentrations. Finally, the pulp was fibrillated using a high-pressure homogenizer at three different intensities. The PEC was formed by addition of the xylan (Xyl) solution on chitosan (CH) solution with a Xyl/CH mass ratio of 80/20. The required dosages of PEC solution to neutralize the charges of different nanocellulose fractions were determined by ζ-potential measurements, and the CMNF retentions on recycled unbleached fibers were evaluated in a Britt Dynamic Drainage Jar. The results showed that the maximum retention was obtained when the neutral PEC-CMNF system was added to pulp. Besides, a significant decrease on °SR was observed when PEC and PEC-CMNF systems were added to the untreated pulp, limiting the negative effects of nanocellulose addition on pulp drainability. The incorporation of PEC-CMNF systems to the handsheets increased the tensile index (up to 28%), Mullen index (up to 40%) and internal bonding (up to 255%). Finally, the compressive strength of the handsheets, namely SCT and CMT, increased up to 30 and 70%, respectively. These simultaneous improvement on drainability and mechanical properties makes the proposed PEC-CMNF system a promising solution for the production of packaging paper.
Abstract Diffusivity of a component in a binary mixture is affected by the presence of a second c... more Abstract Diffusivity of a component in a binary mixture is affected by the presence of a second component. The knowledge of the influence on each other component diffusivity is very useful for the prediction of sorption kinetics of binary mixtures. In this work kinetic studies of Cr(VI) and Cu(II) binary mixtures sorption onto exhausted coffee encapsulated in calcium alginate beads were carried out in both bench and pilot scale experiments. The spectroscopic analysis evidenced the complexity of the process since different mechanisms such as adsorption, redox reaction and ion exchange are involved. Experimental data were fitted to the Linear Adsorption Model (LAM). An empirical quadratic model was developed to estimate LAM parameters ( D e ) and α = C f /(C i − C f ) as a function of the initial concentration of metals in the mixture. The empirical model developed enables to estimate the LAM parameters ( D e and α ) of metal ions binary mixtures provided that the initial concentration of the metal ions is included in the range of concentrations studied. The estimated parameters introduced in LAM equation allow simulating the corresponding binary mixtures sorption kinetics. This study constitutes a fast and easy approach to the modelling of sorption kinetics of complex systems in which different processes take place simultaneously.
While water is indispensable for life, around 785 million people do not have access to basic drin... more While water is indispensable for life, around 785 million people do not have access to basic drinking water. Heavy metals present high toxicity at low concentrations, are non-biodegradable and easy to accumulate in living organisms such as human body, causing serious diseases or even death. Copper is usually found at high concentrations in wastewater due to its extensive use in several industrial applications, and effective copper removal systems must be developed. The present work aims at developing effective TEMPO-oxidized cellulose nanofibers (CNFs) based systems able to adsorb Cu(II) in adsorption columns. CNFs were partially modified with alkyl ketene dimer (AKD) to avoid regelation Keywords Cu(II) adsorption Á Wastewater remediation Á Nanocellulose Á Alginate Á Breakthrough curves Á Adsorption kinetics
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
A solid waste material containing Fe(III) and other metal (hydr)oxides produced in a metal surfac... more A solid waste material containing Fe(III) and other metal (hydr)oxides produced in a metal surface treatment industry has been investigated for As(V) removal. In order to facilitate sorbent application, 2% of raw material has been entrapped in calcium alginate gel matrix (2% O-CA). An accurate characterization of the sorption on gel beads was undertaken, considering thermodynamic and kinetic aspects. All experiments were carried out at pH 8, since the maximum As(V) sorption was reached between pH 6 and 9. About isotherms, the best fit was obtained considering the Langmuir model and a capacity of 1.9 mg/g was achieved. The kinetic profiles evidenced that a quantitative sorption was obtained within 10 h. The 2% O-CA beads were also tested for continuous As(V) removal in a fixed bed column. Experiments were performed at constant flow rate, and varying the inlet As(V) concentration. With a view to design an automatic system for As(V) analysis in the outlet flow, the suitability of applying Anodic Stripping Voltammetry was evaluated: the method resulted appropriated to follow the As(V) content in the outlet solutions of columns with metal inlet concentration <1 mg/L. These results suggested that 2% O-CA beads could be a promising sorbent candidate for As(V) removal.
This study was conducted on the reduction reaction of the azo dye Reactive Black 5 by means of th... more This study was conducted on the reduction reaction of the azo dye Reactive Black 5 by means of the Mn 85 Al 15 particles prepared by melt-spinning and ball-milling processes. The morphology, the surface elementary composition and the phase structure of the powders were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. The degradation efficiency of the ball milled powder was measured by using an ultraviolet-visible absorption spectrophotometer and the collected powder was analyzed by means of Fourier transform infrared spectroscopy technique to characterize the functional groups in the extract. The degradation of Reactive Black 5 and the analysis of the aromatic by-products were investigated by high performance liquid chromatography coupled with tandem mass spectrometry. The ball-milled powder shows higher degradation efficiency and the Reactive Black 5 solution was completely decolorized after 30 min. The degradation kinetics and the formation by-products depend on the pH and temperature of the solution. The analyses of the extracted product confirmed the cleavage of the (-N]N-) bonds. Our findings are expected to pave the way for a new opportunity with regard to the functional applications of nanostructured metallic particles.
Cellulose nanofibers (CNFs) are becoming a topic of great interest due to their wide range of pot... more Cellulose nanofibers (CNFs) are becoming a topic of great interest due to their wide range of potential applications. The huge presence of carboxylic groups in TEMPO-oxidized CNFs indicate that this material could interact with cationic species in aqueous solution, such as metal ions. Nevertheless, the contact between nanofibers and water solutions requires a 3D structure to entrap and retain the nanofibers. In this sense, two different 3D structures were synthetized: CNF-calcium alginate beads and CNF-aerogels. After the synthesis and characterization Electronic supplementary material The online version of this article (
The present work aims at glimpsing the rate-determinant process parameters of TEMPO-mediated oxid... more The present work aims at glimpsing the rate-determinant process parameters of TEMPO-mediated oxidation of bleached kraft cellulose for developing kinetic models and real-time monitoring tools. This may contribute to the scaling up of this reaction, frequently used as precursor of the production of cellulose nanofibers. For this, the effect of temperature, TEMPO and NaBr contents, and surface area of the fibers was assessed by means of a total experimental batch of 18 combinations, monitoring the carboxyl content (CC) of the samples and the NaOH consumption during oxidation. The obtained data was used to calculate the kinetic constant as a function of the conditions, as well as correlating the CC with the NaOH consumption, obtaining a strong linear correlation between these parameters. It was found that similar correlations could be used regardless process conditions, except for the case of TEMPO, which was found to protect the fibers from depolymerization and, thus, having different...
More than half of spinal cord injury (SCI) patients develop central neuropathic pain (CNP), which... more More than half of spinal cord injury (SCI) patients develop central neuropathic pain (CNP), which is largely refractory to current treatments. Considering the preclinical evidence showing that polyphenolic compounds may exert antinociceptive effects, the present work aimed to study preventive effects on SCI-induced CNP development by repeated administration of two vegetal polyphenolic extracts: grape stalk extract (GSE) and coffee extract (CE). Thermal hyperalgesia and mechanical allodynia were evaluated at 7, 14 and 21 days postinjury. Then, gliosis, ERK phosphorylation and the expression of CCL2 and CX3CL1 chemokines and their receptors, CCR2 and CX3CR1, were analyzed in the spinal cord. Gliosis and CX3CL1/CX3CR1 expression were also analyzed in the anterior cingulate cortex (ACC) and periaqueductal gray matter (PAG) since they are supraspinal structures involved in pain perception and modulation. GSE and CE treatments modulated pain behaviors accompanied by reduced gliosis in the...
Abstract Recently, the use of magnetic sorbents has gained a spread attention due to their eco-fr... more Abstract Recently, the use of magnetic sorbents has gained a spread attention due to their eco-friendly characteristic, ease of separation and low cost. Herein, a novel biocomposite sorbent magnetic pine cone gel beads (MPCB) was synthetized and investigated for the single and the simultaneous removal of Cu(II) and Cr(VI) from aqueous solution. Pine cones waste materials were first magnetized with Fe3O4 nanoparticles then were encapsulated in calcium gel beads. The physicochemical properties of the prepared MPCB were characterized via scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction and Fourier transform infrared spectrometry (FTIR) analysis. The influences of pH, contact time and initial concentration of metal ions on the sorption process were examined. The adsorption mechanism was investigated; it mainly involved complexation/chelation with surface functional groups, electrostatic interaction and ion exchange. A physical model was adopted to attribute new physico-chemical interpretations of the adsorption mechanism. The kinetic results showed good correlation with pseudo second-order model and the equilibrium data were fitted well to the Langmuir isotherm model with maximum adsorption capacity of 68.64 and 212.22 mg g-1 for Cu(II) and Cr(VI) respectively. In the multi-components system, both competitive and synergistic effects were observed. An antagonism effect was exerted by Cu(II) ions on Cr(VI) sorption while Cu(II) adsorption was not affected and even slightly enhanced by the presence of Cr(V) ions. The competitive sorption behavior of metal ions was analyzed by the modified competitive Langmuir model which provides good fit for the Cu experimental data. This study proves that the MPCB hold great promise for using as effective sorbent for potentially toxic metals remediation.
Espresso extraction is generally carried out at a fixed temperature within the range 85-95°C. In ... more Espresso extraction is generally carried out at a fixed temperature within the range 85-95°C. In this work the extraction of the espressos was made in a new generation coffee machine that enables temperature profiling of the brewing water. The effect of using gradient of temperature to brew espressos on physicochemical and sensorial characteristics of the beverage has been investigated. Three different extraction temperature profiles were tested: updrawn gradient (88-93°C), downdrawn gradient (93-88°C) and fixed temperature (90°C). The coffee species investigated were Robusta, Arabica natural and Washed Arabica. Results proved that the use of gradient temperature for brewing espressos allows increasing or decreasing the extraction of some chemical compounds from coffee grounds. Moreover an appropriate gradient of temperature can highlight or hide some sensorial attributes. In conclusion, the possibility of programming gradient of temperature in the coffee machines recently introduce...
Journal of Chemical Engineering & Process Technology, 2013
Activated carbon is prepared with chemical activation of olive stones, by using H 3 PO 4. Batch a... more Activated carbon is prepared with chemical activation of olive stones, by using H 3 PO 4. Batch adsorption of phenol from aqueous solution was investigated. The adsorptive properties were studied in terms of pH, equilibrium time, initial concentration (C 0 : 25-300 mg/L) and particle sizes (0.125-1.6mm) effects. The experimental kinetic data fitted well the pseudo second order model and the equilibrium isotherm data the Langmuir model. The results indicate that chemical olive stones activated carbon is suitable to be used as an adsorbent material for adsorption of phenol from aqueous solution.
In this work the ability of some vegetable wastes from industrial processes such as cork and yohi... more In this work the ability of some vegetable wastes from industrial processes such as cork and yohimbe bark, grape stalks and olive pits, to remove metal ions from aqueous solutions has been investigated. The influence of pH, sodium chloride and metal concentration on Ni(II) and Cu(II) uptake was studied. Metal uptake showed in all the cases a pH-dependent profile. Maximum sorption was found at an initial pH around 5.0–6.0. In some cases an increase of sodium chloride concentration induced a decrease in metal removal. Adsorption isotherms at the optimum pH were expressed by the noncompetitive Langmuir adsorption model. When comparing the four materials, yohimbe bark waste was found to be the most efficient adsorbent for both metals studied.
It was recently shown that coffee polyphenolic extract exerts preventive effects on central neuro... more It was recently shown that coffee polyphenolic extract exerts preventive effects on central neuropathic pain development, but it is unknown whether its beneficial effects are associated with only one of its major polyphenolic compounds or if the whole extract is needed to exert such effects. The main objective of this study was to determine whether the separate administration of major polyphenols from coffee extract exerts preventive effects on the development of central neuropathic pain in mice compared with the effects of the whole coffee extract. Thus, spinal-cord-injured female ICR-CD1 mice were daily treated with either coffee extract or its major polyphenolic compounds during the first week, and reflexive and nonreflexive pain responses were evaluated within the acute phase of spinal cord injury. In addition, the injury-induced gliosis and dorsal horn sprouting were evaluated with immunohistochemistry. The results showed that the coffee extract prevented spinal cord injury-ind...
Uploads
Papers by Nuria Fiol