The Experts below are selected from a list of 5376 Experts worldwide ranked by ideXlab platform
Inês Conceição Roberto - One of the best experts on this subject based on the ideXlab platform.
-
production characterization and application of activated carbon from brewer s Spent Grain lignin
Bioresource Technology, 2010Co-Authors: Solange I Mussatto, Marcela Fernandes, George Jackson De Moraes Rocha, J J M Orfao, J A Teixeira, Inês Conceição RobertoAbstract:Different types of activated carbon were prepared by chemical activation of brewer’s Spent Grain (BSG) lignin using H3PO4 at various acid/lignin ratios (1, 2, or 3 g/g) and carbonization temperatures (300, 450, or 600 C), according to a 2 2 full-factorial design. The resulting materials were characterized with regard to their surface area, pore volume, and pore size distribution, and used for detoxification of BSG hemicellulosic hydrolysate (a mixture of sugars, phenolic compounds, metallic ions, among other compounds). BSG carbons presented BET surface areas between 33 and 692 m 2 /g, and micro- and mesopores with volumes between 0.058 and 0.453 cm 3 /g. The carbons showed high capacity for adsorption of metallic ions, mainly nickel, iron, chromium, and silicon. The concentration of phenolic compounds and color were also reduced by these sorbents. These results suggest that activated carbons with characteristics similar to those commercially found and high adsorption capacity can be produced from BSG lignin.
-
the effect of agitation speed enzyme loading and substrate concentration on enzymatic hydrolysis of cellulose from brewer s Spent Grain
Cellulose, 2008Co-Authors: Solange Inês Mussatto, Giuliano Dragone, Marcela Fernandes, Adriane M F Milagres, Inês Conceição RobertoAbstract:Brewer’s Spent Grain components (cellulose, hemicellulose and lignin) were fractionated in a two-step chemical pretreatment process using dilute sulfuric acid and sodium hydroxide solutions. The cellulose pulp produced was hydrolyzed with a cellulolytic complex, Celluclast 1.5 L, at 45 °C to convert the cellulose into glucose. Several conditions were examined: agitation speed (100, 150 and 200 rpm), enzyme loading (5, 25 and 45 FPU/g substrate), and substrate concentration (2, 5 and 8% w/v), according to a 23 full factorial design aiming to maximize the glucose yield. The obtained results were interpreted by analysis of variance and response surface methodology. The optimal conditions for enzymatic hydrolysis of brewer’s Spent Grain were identified as 100 rpm, 45 FPU/g and 2% w/v substrate. Under these conditions, a glucose yield of 93.1% and a cellulose conversion (into glucose and cellobiose) of 99.4% was achieved. The easiness of glucose release from BSG makes this substrate a raw material with great potential to be used in bioconversion processes.
-
hydrogen peroxide bleaching of cellulose pulps obtained from brewer s Spent Grain
Cellulose, 2008Co-Authors: George Jackson De Moraes Rocha, Solange I Mussatto, Inês Conceição RobertoAbstract:Brewer’s Spent Grain (BSG) was evaluated for bleached pulp production. Two cellulose pulps with different chemical compositions were produced by soda pulping: one from the original raw material and the other from material pretreated by dilute acid. Both of them were bleached by a totally chlorine-free sequence performed in three stages, using 5% hydrogen peroxide in the two initial, and a 0.25 N NaOH solution in the last one. Chemical composition, kappa number, viscosity, brightness and yield of bleached and unbleached pulps were evaluated. The high hemicellulose (28.4% w/w) and extractives (5.8% w/w) contents in original BSG affected the pulping and bleaching processes. However, soda pulping of acid pretreated BSG gave a cellulose-rich pulp (90.4% w/w) with low hemicellulose and extractives contents (7.9% w/w and <3.4% w/w, respectively), which was easily bleached achieving a kappa number of 11.21, viscosity of 3.12 cp, brightness of 71.3%, cellulose content of 95.7% w/w, and residual lignin of 3.4% w/w. Alkaline and oxidative delignification of acid pretreated BSG was found as an attractive approach for producing high-purity, chlorine-free cellulose pulp.
-
lignin recovery from brewer s Spent Grain black liquor
Carbohydrate Polymers, 2007Co-Authors: Solange Inês Mussatto, Marcela Fernandes, Inês Conceição RobertoAbstract:Abstract The present study describes the precipitation of lignin by acidification of a black liquor (pH 12.56 and 12.44 g/l soluble lignin) produced by soda pulping of brewer’s Spent Grain. Sulfuric acid was added to the liquor to decrease the pH, forming a lignin-rich precipitate. Ten pH values (varying from 12.56 to 2.15) were studied. The lignin mass precipitated for each pH condition was determined, and the obtained liquors were evaluated regarding the color and concentration of soluble lignin. Some phenolic acids (vanillic, syringic, p-hydroxybenzoic, ferulic and p-coumaric) were quantified in the liquors to verify their removal profiles as a function of the pH alteration. Significant lignin precipitation was only observed at pH
-
brewer s Spent Grain as raw material for lactic acid production by lactobacillus delbrueckii
Biotechnology Letters, 2007Co-Authors: Solange Inês Mussatto, Giuliano Dragone, Marcela Fernandes, Ismael Maciel De Mancilha, Inês Conceição RobertoAbstract:Chemically pre-treated brewer's Spent Grain was saccharified with cellulase producing a hydrolysate with approx. 50 g glucose l(-1). This hydrolysate was used as a fermentation medium without any nutrient supplementation by Lactobacillus delbrueckii, which produced L-lactic acid (5.4 g l(-1)) at 0.73 g g(-1) glucose consumed (73% efficiency). An inoculum of 1 g dry cells l(-1) gave the best yield of the process, but the pH decrease affected the microorganism capacity to consume glucose and convert it into lactic acid.
Solange Inês Mussatto - One of the best experts on this subject based on the ideXlab platform.
-
the effect of agitation speed enzyme loading and substrate concentration on enzymatic hydrolysis of cellulose from brewer s Spent Grain
Cellulose, 2008Co-Authors: Solange Inês Mussatto, Giuliano Dragone, Marcela Fernandes, Adriane M F Milagres, Inês Conceição RobertoAbstract:Brewer’s Spent Grain components (cellulose, hemicellulose and lignin) were fractionated in a two-step chemical pretreatment process using dilute sulfuric acid and sodium hydroxide solutions. The cellulose pulp produced was hydrolyzed with a cellulolytic complex, Celluclast 1.5 L, at 45 °C to convert the cellulose into glucose. Several conditions were examined: agitation speed (100, 150 and 200 rpm), enzyme loading (5, 25 and 45 FPU/g substrate), and substrate concentration (2, 5 and 8% w/v), according to a 23 full factorial design aiming to maximize the glucose yield. The obtained results were interpreted by analysis of variance and response surface methodology. The optimal conditions for enzymatic hydrolysis of brewer’s Spent Grain were identified as 100 rpm, 45 FPU/g and 2% w/v substrate. Under these conditions, a glucose yield of 93.1% and a cellulose conversion (into glucose and cellobiose) of 99.4% was achieved. The easiness of glucose release from BSG makes this substrate a raw material with great potential to be used in bioconversion processes.
-
lignin recovery from brewer s Spent Grain black liquor
Carbohydrate Polymers, 2007Co-Authors: Solange Inês Mussatto, Marcela Fernandes, Inês Conceição RobertoAbstract:Abstract The present study describes the precipitation of lignin by acidification of a black liquor (pH 12.56 and 12.44 g/l soluble lignin) produced by soda pulping of brewer’s Spent Grain. Sulfuric acid was added to the liquor to decrease the pH, forming a lignin-rich precipitate. Ten pH values (varying from 12.56 to 2.15) were studied. The lignin mass precipitated for each pH condition was determined, and the obtained liquors were evaluated regarding the color and concentration of soluble lignin. Some phenolic acids (vanillic, syringic, p-hydroxybenzoic, ferulic and p-coumaric) were quantified in the liquors to verify their removal profiles as a function of the pH alteration. Significant lignin precipitation was only observed at pH
-
brewer s Spent Grain as raw material for lactic acid production by lactobacillus delbrueckii
Biotechnology Letters, 2007Co-Authors: Solange Inês Mussatto, Giuliano Dragone, Marcela Fernandes, Ismael Maciel De Mancilha, Inês Conceição RobertoAbstract:Chemically pre-treated brewer's Spent Grain was saccharified with cellulase producing a hydrolysate with approx. 50 g glucose l(-1). This hydrolysate was used as a fermentation medium without any nutrient supplementation by Lactobacillus delbrueckii, which produced L-lactic acid (5.4 g l(-1)) at 0.73 g g(-1) glucose consumed (73% efficiency). An inoculum of 1 g dry cells l(-1) gave the best yield of the process, but the pH decrease affected the microorganism capacity to consume glucose and convert it into lactic acid.
-
ferulic and p coumaric acids extraction by alkaline hydrolysis of brewer s Spent Grain
Industrial Crops and Products, 2007Co-Authors: Solange Inês Mussatto, Giuliano Dragone, Inês Conceição RobertoAbstract:Abstract This work deals with the alkaline hydrolysis of brewer's Spent Grain (BSG) for the extraction of ferulic and p-coumaric acids, compounds of considerable interest for applications in the food, health, cosmetic, and pharmaceutical industries. A 23 full factorial design with three replicates at the center point was used to investigate the simultaneous effects of the variables: NaOH concentration (1.0, 1.5 and 2.0%, w/v), temperature (80, 100 and 120 °C), and reaction time (30, 60 and 90 min), on the alkaline hydrolysis. The assays were performed using a solid:liquid ratio of 1:20 (w/w). The Student's t-test revealed a positive influence (p 0.90) to the experimental data to describe the extraction of these acids as a function of the operational variables employed. The best alkaline hydrolysis conditions consisted in using a 2% NaOH concentration, at 120 °C for 90 min. Under these conditions, a liquor containing 145.3 mg/l ferulic acid and 138.8 mg/l p-coumaric acid was obtained. These values corresponded to 9.65 mg ferulic acid and 9.22 mg p-coumaric acid per gram of solubilized lignin.
-
Optimum operating conditions for brewer's Spent Grain soda pulping
Carbohydrate Polymers, 2006Co-Authors: Solange Inês Mussatto, George J M Rocha, Giuliano Dragone, Inês Conceição RobertoAbstract:Abstract The soda pulping of brewer's Spent Grain (BSG) pretreated with dilute-acid was studied. A first-order full-factorial design was used to evaluate the effect of the operational variables: soda concentration (1–2%), temperature (80–120 °C) and pulping time (30–90 min), on the properties of the pulp (cellulose and lignin contents) obtained from BSG. The factorial design permitted to identify the optimum operating conditions for BSG soda pulping. Equations relating the responses (properties of the pulp) to the operational variables were thus proposed, and fitted the experimental results at 99 and 90% confidence levels, for the cellulose and lignin contents, respectively. The best pulping conditions (2% soda concentration, 120 °C, 90 min) led to a pulp containing 72.1% w/w cellulose and low residual lignin content (10.4% w/w).
Liyuan Chai - One of the best experts on this subject based on the ideXlab platform.
-
cadmium ii adsorption on esterified Spent Grain equilibrium modeling and possible mechanisms
Chemical Engineering Journal, 2012Co-Authors: Liyuan Chai, Wenqing QinAbstract:Abstract A novel adsorbent—esterified Spent Grain (ESG) was used to remove Cadmium(II) from aqueous solution. Cd(II) adsorption behavior and mechanisms were investigated in this paper. The sorption process was very fast and the equilibrium was established in 15 min. The maximum Cd(II) adsorption capacity of ESG calculated from Langmuir isotherm was 473.93 mg g−1 that was higher than other adsorbents reported. The sorption kinetics was well described by the pseudo-second order kinetic model. The calculated activation energy (Ea) implied that adsorption of Cd(II) on ESG was a chemical adsorption. The thermodynamic parameters of sorption systems indicated a spontaneous and endothermic process. More importantly, Cd(II) binding mechanisms on ESG were discussed by FT-IR and XPS studies. The results showed that the carbon–oxygen (C O) in carboxyl group of ESG directly attached to the cadmium ion that led to most of the adsorption.
-
synthesis of thiol functionalized Spent Grain as a novel adsorbent for divalent metal ions
Bioresource Technology, 2010Co-Authors: Liyuan Chai, Qingwei Wang, Yun-yan Wang, Yonghua Zhu, Zhiyuan Zhang, Zhihui YangAbstract:Abstract Spent Grain (SG) was functionalized with thioglycollic acid in N,N-dimethylformamide (DMF) medium using sodium bisulfate monohydrate (NaHSO4·H2O) as a catalyst, followed by treatment with sodium sulfide nonahydrate (Na2S·9H2O). Characterization of thiol-functionalized Spent Grain (TFSG) was performed using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. These analytical results revealed the emergence of S–H and C O groups after the chemical modification, indicating that thiol groups were successfully grafted onto TFSG. As compared with SG, TFSG showed significant improvement in terms of metal loading capacity. Typically, adsorption capacity for Zn2+ was increased from 125.76 mg g−1 of SG to 227.37 mg g−1 of TFSG, which was confirmed by X-ray fluorescence (XRF) analysis. This increase may be attributed to both the formation of ester linkage and the grafting of thiol groups onto TFSG. The experimental results indicate that TFSG is a promising adsorbent for removal heavy metals from contaminated water.
-
Fast esterification of Spent Grain for enhanced heavy metal ions adsorption
Bioresource technology, 2010Co-Authors: Liyuan Chai, Qingwei Wang, Zhihui Yang, Huxiang Yan, Yun-yan WangAbstract:This work describes a novel method for fast esterification of Spent Grain to enhance its cationic adsorption capacity. The esterification of Spent Grain with citric acid was achieved by using sodium hypophosphite monohydrate (NaH(2)PO(2).H(2)O) as a catalyst in N,N-dimethylformamide (DMF). Fourier transform infrared (FTIR) spectroscopic analysis revealed the formation of ester groups after esterification, demonstrating that Spent Grain was successfully esterified with citric acid. The adsorption capacity of esterified Spent Grain (ESG) for each metal ion was greatly improved as compared with that of raw Spent Grain (RSG). Typically, Pb(2+) adsorption capacity increased from 125.84mg g(-1) of RSG to 293.30mg g(-1) of ESG. This increase can be attributed to both the formation of ester linkage and the grafting of carboxyl groups on Spent Grain. The results suggest that a fast process for esterification of Spent Grain has been realized and ESG has strong ability to adsorb heavy metal ions.
-
Kinetics and thermodynamics of Pb(II) adsorption onto modified Spent Grain from aqueous solutions
Applied Surface Science, 2009Co-Authors: Liyuan Chai, Zhihui Yang, Qingwei WangAbstract:Abstract Spent Grain, a main by-product of the brewing industry, is available in large quantities, but its main application has been limited to animal feeding. Nevertheless, in this study, Spent Grain modified with 1 M NaCl solution as a novel adsorbent has been used for the adsorption of Pb(II) in aqueous solutions. Isotherms, kinetics and thermodynamics of Pb(II) adsorption onto modified Spent Grain were studied. The equilibrium data were well fitted with Langmuir, Freundlich and Dubinin–Radushkevick (D–R) isotherm models. The kinetics of Pb(II) adsorption followed pseudo-second-order model, using the rate constants of pseudo-second-order model, the activation energy ( E a ) of Pb(II) adsorption was determined as 12.33 kJ mol −1 according to the Arrhenius equation. Various thermodynamic parameters such as Δ G ads , Δ H ads and Δ S ads were also calculated. Thermodynamic results indicate that Pb(II) adsorption onto modified Spent Grain is a spontaneous and endothermic process. Therefore, it can be concluded that modified Spent Grain as a new effective adsorbent has potential for Pb(II) removal from aqueous solutions.
Qingwei Wang - One of the best experts on this subject based on the ideXlab platform.
-
synthesis of thiol functionalized Spent Grain as a novel adsorbent for divalent metal ions
Bioresource Technology, 2010Co-Authors: Liyuan Chai, Qingwei Wang, Yun-yan Wang, Yonghua Zhu, Zhiyuan Zhang, Zhihui YangAbstract:Abstract Spent Grain (SG) was functionalized with thioglycollic acid in N,N-dimethylformamide (DMF) medium using sodium bisulfate monohydrate (NaHSO4·H2O) as a catalyst, followed by treatment with sodium sulfide nonahydrate (Na2S·9H2O). Characterization of thiol-functionalized Spent Grain (TFSG) was performed using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. These analytical results revealed the emergence of S–H and C O groups after the chemical modification, indicating that thiol groups were successfully grafted onto TFSG. As compared with SG, TFSG showed significant improvement in terms of metal loading capacity. Typically, adsorption capacity for Zn2+ was increased from 125.76 mg g−1 of SG to 227.37 mg g−1 of TFSG, which was confirmed by X-ray fluorescence (XRF) analysis. This increase may be attributed to both the formation of ester linkage and the grafting of thiol groups onto TFSG. The experimental results indicate that TFSG is a promising adsorbent for removal heavy metals from contaminated water.
-
Fast esterification of Spent Grain for enhanced heavy metal ions adsorption
Bioresource technology, 2010Co-Authors: Liyuan Chai, Qingwei Wang, Zhihui Yang, Huxiang Yan, Yun-yan WangAbstract:This work describes a novel method for fast esterification of Spent Grain to enhance its cationic adsorption capacity. The esterification of Spent Grain with citric acid was achieved by using sodium hypophosphite monohydrate (NaH(2)PO(2).H(2)O) as a catalyst in N,N-dimethylformamide (DMF). Fourier transform infrared (FTIR) spectroscopic analysis revealed the formation of ester groups after esterification, demonstrating that Spent Grain was successfully esterified with citric acid. The adsorption capacity of esterified Spent Grain (ESG) for each metal ion was greatly improved as compared with that of raw Spent Grain (RSG). Typically, Pb(2+) adsorption capacity increased from 125.84mg g(-1) of RSG to 293.30mg g(-1) of ESG. This increase can be attributed to both the formation of ester linkage and the grafting of carboxyl groups on Spent Grain. The results suggest that a fast process for esterification of Spent Grain has been realized and ESG has strong ability to adsorb heavy metal ions.
-
Kinetics and thermodynamics of Pb(II) adsorption onto modified Spent Grain from aqueous solutions
Applied Surface Science, 2009Co-Authors: Liyuan Chai, Zhihui Yang, Qingwei WangAbstract:Abstract Spent Grain, a main by-product of the brewing industry, is available in large quantities, but its main application has been limited to animal feeding. Nevertheless, in this study, Spent Grain modified with 1 M NaCl solution as a novel adsorbent has been used for the adsorption of Pb(II) in aqueous solutions. Isotherms, kinetics and thermodynamics of Pb(II) adsorption onto modified Spent Grain were studied. The equilibrium data were well fitted with Langmuir, Freundlich and Dubinin–Radushkevick (D–R) isotherm models. The kinetics of Pb(II) adsorption followed pseudo-second-order model, using the rate constants of pseudo-second-order model, the activation energy ( E a ) of Pb(II) adsorption was determined as 12.33 kJ mol −1 according to the Arrhenius equation. Various thermodynamic parameters such as Δ G ads , Δ H ads and Δ S ads were also calculated. Thermodynamic results indicate that Pb(II) adsorption onto modified Spent Grain is a spontaneous and endothermic process. Therefore, it can be concluded that modified Spent Grain as a new effective adsorbent has potential for Pb(II) removal from aqueous solutions.
Zhihui Yang - One of the best experts on this subject based on the ideXlab platform.
-
synthesis of thiol functionalized Spent Grain as a novel adsorbent for divalent metal ions
Bioresource Technology, 2010Co-Authors: Liyuan Chai, Qingwei Wang, Yun-yan Wang, Yonghua Zhu, Zhiyuan Zhang, Zhihui YangAbstract:Abstract Spent Grain (SG) was functionalized with thioglycollic acid in N,N-dimethylformamide (DMF) medium using sodium bisulfate monohydrate (NaHSO4·H2O) as a catalyst, followed by treatment with sodium sulfide nonahydrate (Na2S·9H2O). Characterization of thiol-functionalized Spent Grain (TFSG) was performed using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. These analytical results revealed the emergence of S–H and C O groups after the chemical modification, indicating that thiol groups were successfully grafted onto TFSG. As compared with SG, TFSG showed significant improvement in terms of metal loading capacity. Typically, adsorption capacity for Zn2+ was increased from 125.76 mg g−1 of SG to 227.37 mg g−1 of TFSG, which was confirmed by X-ray fluorescence (XRF) analysis. This increase may be attributed to both the formation of ester linkage and the grafting of thiol groups onto TFSG. The experimental results indicate that TFSG is a promising adsorbent for removal heavy metals from contaminated water.
-
Fast esterification of Spent Grain for enhanced heavy metal ions adsorption
Bioresource technology, 2010Co-Authors: Liyuan Chai, Qingwei Wang, Zhihui Yang, Huxiang Yan, Yun-yan WangAbstract:This work describes a novel method for fast esterification of Spent Grain to enhance its cationic adsorption capacity. The esterification of Spent Grain with citric acid was achieved by using sodium hypophosphite monohydrate (NaH(2)PO(2).H(2)O) as a catalyst in N,N-dimethylformamide (DMF). Fourier transform infrared (FTIR) spectroscopic analysis revealed the formation of ester groups after esterification, demonstrating that Spent Grain was successfully esterified with citric acid. The adsorption capacity of esterified Spent Grain (ESG) for each metal ion was greatly improved as compared with that of raw Spent Grain (RSG). Typically, Pb(2+) adsorption capacity increased from 125.84mg g(-1) of RSG to 293.30mg g(-1) of ESG. This increase can be attributed to both the formation of ester linkage and the grafting of carboxyl groups on Spent Grain. The results suggest that a fast process for esterification of Spent Grain has been realized and ESG has strong ability to adsorb heavy metal ions.
-
Kinetics and thermodynamics of Pb(II) adsorption onto modified Spent Grain from aqueous solutions
Applied Surface Science, 2009Co-Authors: Liyuan Chai, Zhihui Yang, Qingwei WangAbstract:Abstract Spent Grain, a main by-product of the brewing industry, is available in large quantities, but its main application has been limited to animal feeding. Nevertheless, in this study, Spent Grain modified with 1 M NaCl solution as a novel adsorbent has been used for the adsorption of Pb(II) in aqueous solutions. Isotherms, kinetics and thermodynamics of Pb(II) adsorption onto modified Spent Grain were studied. The equilibrium data were well fitted with Langmuir, Freundlich and Dubinin–Radushkevick (D–R) isotherm models. The kinetics of Pb(II) adsorption followed pseudo-second-order model, using the rate constants of pseudo-second-order model, the activation energy ( E a ) of Pb(II) adsorption was determined as 12.33 kJ mol −1 according to the Arrhenius equation. Various thermodynamic parameters such as Δ G ads , Δ H ads and Δ S ads were also calculated. Thermodynamic results indicate that Pb(II) adsorption onto modified Spent Grain is a spontaneous and endothermic process. Therefore, it can be concluded that modified Spent Grain as a new effective adsorbent has potential for Pb(II) removal from aqueous solutions.
