2017, Vol. 2, No. 4
Display Method:
Use of Lignin and Hemicelluloses for Facial Synthesis of Gold, Platinum, and Palladium Nanoparticles
2017, 2(4): 149-152.
doi: 10.21967/jbb.v2i4.151
Abstract:
For the first time, we report an environmentally benign process for the preparation of Pt, Au and Pd NPs at ambient atmospheric pressure in aqueous systems, using water-insoluble alkali lignin (AL) and hemicelluloses as reducing/protective agents. Both AL and hemicelluloses showed good performances. The solid AL acted as support for metal NPs. The metal particles reduced by hemicelluloses aggregated to larger particles, and the degree of aggregation increased over time.
2017, 2(4): 153-157.
doi: 10.21967/jbb.v2i4.100
Abstract:
This paper investigated the influence of steam explosion pretreatment with or without acid as the catalyst on the chemical composition and sugar contents of corn stalks. The fiber characteristics of the pretreated corn stalks were analyzed with a scanning electron microscope, a FS-300 automatic fiber analyzer and a fully automatic surface and pore analyzer. The results showed that the steam explosion pretreatment did not change the cellulose content of the corn stalks. However, hemicellulose was degraded and a portion of lignin was solubilized in the steam explosion pretreatment process. When acid was added in the steam explosion process, the fiber surface and cell wall structure of corn stalks were damaged, the specific surface area and pore size increased, and fiber length decreased, all of which were beneficial to subsequent enzymatic hydrolysis with cellulase. However, content of polysaccharides decreased after acid steam explosion pretreatment.
This paper investigated the influence of steam explosion pretreatment with or without acid as the catalyst on the chemical composition and sugar contents of corn stalks. The fiber characteristics of the pretreated corn stalks were analyzed with a scanning electron microscope, a FS-300 automatic fiber analyzer and a fully automatic surface and pore analyzer. The results showed that the steam explosion pretreatment did not change the cellulose content of the corn stalks. However, hemicellulose was degraded and a portion of lignin was solubilized in the steam explosion pretreatment process. When acid was added in the steam explosion process, the fiber surface and cell wall structure of corn stalks were damaged, the specific surface area and pore size increased, and fiber length decreased, all of which were beneficial to subsequent enzymatic hydrolysis with cellulase. However, content of polysaccharides decreased after acid steam explosion pretreatment.
2017, 2(4): 158-162.
doi: 10.21967/jbb.v2i4.107
Abstract:
Hydrothermal pretreatment of poplar wood chips was performed in an acetic acid/sodium acetate buffer medium. To characterize the structural changes of lignin in the pretreatment process, milled wood lignin (MWL) was isolated from both the un-treated and treated poplar wood chips, and analyzed by 1H-NMR, 13C-NMR, 31P-NMR, FT-IR, and GPC-MALLS. Results showed that the lignin in the pretreated wood chips had more phenolic OH groups, less aliphatic OH groups, higher molecular weight, and narrower polydispersity, in comparison with the lignin in the un-treated wood. The acetic acid-sodium acetate buffer pretreatment facilitated the removal of -OCH3 groups and the cleavage of the inter-unit linkages of β-O-4 bond in the lignin. Furthermore, the re-polymerization of lignin in the acetic acid-sodium acetate buffer pretreatment was found to be less than that in autohydrolysis.
Hydrothermal pretreatment of poplar wood chips was performed in an acetic acid/sodium acetate buffer medium. To characterize the structural changes of lignin in the pretreatment process, milled wood lignin (MWL) was isolated from both the un-treated and treated poplar wood chips, and analyzed by 1H-NMR, 13C-NMR, 31P-NMR, FT-IR, and GPC-MALLS. Results showed that the lignin in the pretreated wood chips had more phenolic OH groups, less aliphatic OH groups, higher molecular weight, and narrower polydispersity, in comparison with the lignin in the un-treated wood. The acetic acid-sodium acetate buffer pretreatment facilitated the removal of -OCH3 groups and the cleavage of the inter-unit linkages of β-O-4 bond in the lignin. Furthermore, the re-polymerization of lignin in the acetic acid-sodium acetate buffer pretreatment was found to be less than that in autohydrolysis.
2017, 2(4): 170-174.
doi: 10.21967/jbb.v2i4.84
Abstract:
In this paper a quick method was developed to determine separate furfural and HMF concentrations simultaneously in ethanol-water hydrolysate of reed based on UV spectroscopy. Acid soluble lignin and other interfering substances were first removed by distillation as residue. The distillate was then used for the determination of furfural and HMF by measuring the maximum absorption wavelength and the absorbance at the wavelength. Results showed that the maximum absorption wavelength of the characteristic peak correlated well with the composition of furfural and HMF mixture in an ethanol-water solution, and the absorbance at the maximum absorption wavelength also had an excellent linear relationship with the sum concentration of furfural and HMF in the solution. The separate concentrations of furfural and HMF in a mixture solution could be determined by applying these correlations.
In this paper a quick method was developed to determine separate furfural and HMF concentrations simultaneously in ethanol-water hydrolysate of reed based on UV spectroscopy. Acid soluble lignin and other interfering substances were first removed by distillation as residue. The distillate was then used for the determination of furfural and HMF by measuring the maximum absorption wavelength and the absorbance at the wavelength. Results showed that the maximum absorption wavelength of the characteristic peak correlated well with the composition of furfural and HMF mixture in an ethanol-water solution, and the absorbance at the maximum absorption wavelength also had an excellent linear relationship with the sum concentration of furfural and HMF in the solution. The separate concentrations of furfural and HMF in a mixture solution could be determined by applying these correlations.
2017, 2(4): 175-183.
doi: 10.21967/jbb.v2i4.111
Abstract:
This paper reported the preparation and application of novel chitosan-cellulose composite absorbents for the adsorption of Pb(Ⅱ) and Cr(VI) ions in water. First, oxycellulose or dialdehyde cellulose (DAC) was prepared by sodium periodate oxidation of microcrystalline cellulose (MCC). Second, based on the mechanism of the Mannich reaction, a chitosan/cellulose-based adsorbent (TSFCD) was produced through a cross-linking reaction of thiosemicarbazide (TS) with DAC and chitosan (CS), which was designed specifically for the adsorption of Cr6+ ions from water. Similarly, another chitosan/cellulose-based adsorbent (DBFCM) was also prepared with 2,5-dithiobiurea (DB) as the cross-linking agent for the adsorption of Pb2+ ions in water. The adsorption performance of TSFCD and DBFCM for Cr6+ and Pb2+ ions, respectively, was investigated under various process conditions. Variables included adsorption temperature, time, initial metal ion concentration, pH, and adsorbent dosage. The adsorption kinetics of TSFCD and DBFCM were studied, and isothermal models were developed. Results showed that the adsorption amount increased with the increase of the reaction time, and reached a maximum at about 300 min for the TSFCD/Cr6+ system, and at about 240 min for DBFCM/Pb2+ system. The adsorption performance of TSFCD for Cr6+ and DBFCM for Pb2+ improved at higher temperature, and leveled off at 40℃ and 50℃, respectively. In addition, the removal rate of Cr6+ increased from 49.96% to 70.22% when the TSFCD dosage increased from 0.5 g/L to 3.5 g/L. Similarly, the removal rate of Pb2+ increased from 22.23% to 99.45% with the increase of DBFCM dosage from 0.5g/L to 5.0g/L. The adsorption processes of Pb2+ and Cr6+ were in line with the pseudo-second-order kinetic and the Langmuir isothermal model.
This paper reported the preparation and application of novel chitosan-cellulose composite absorbents for the adsorption of Pb(Ⅱ) and Cr(VI) ions in water. First, oxycellulose or dialdehyde cellulose (DAC) was prepared by sodium periodate oxidation of microcrystalline cellulose (MCC). Second, based on the mechanism of the Mannich reaction, a chitosan/cellulose-based adsorbent (TSFCD) was produced through a cross-linking reaction of thiosemicarbazide (TS) with DAC and chitosan (CS), which was designed specifically for the adsorption of Cr6+ ions from water. Similarly, another chitosan/cellulose-based adsorbent (DBFCM) was also prepared with 2,5-dithiobiurea (DB) as the cross-linking agent for the adsorption of Pb2+ ions in water. The adsorption performance of TSFCD and DBFCM for Cr6+ and Pb2+ ions, respectively, was investigated under various process conditions. Variables included adsorption temperature, time, initial metal ion concentration, pH, and adsorbent dosage. The adsorption kinetics of TSFCD and DBFCM were studied, and isothermal models were developed. Results showed that the adsorption amount increased with the increase of the reaction time, and reached a maximum at about 300 min for the TSFCD/Cr6+ system, and at about 240 min for DBFCM/Pb2+ system. The adsorption performance of TSFCD for Cr6+ and DBFCM for Pb2+ improved at higher temperature, and leveled off at 40℃ and 50℃, respectively. In addition, the removal rate of Cr6+ increased from 49.96% to 70.22% when the TSFCD dosage increased from 0.5 g/L to 3.5 g/L. Similarly, the removal rate of Pb2+ increased from 22.23% to 99.45% with the increase of DBFCM dosage from 0.5g/L to 5.0g/L. The adsorption processes of Pb2+ and Cr6+ were in line with the pseudo-second-order kinetic and the Langmuir isothermal model.
2017, 2(4): 163-169.
doi: 10.21967/jbb.v2i4.156
Abstract:
Enzymatic hydrolysis lignin (EHL) has a variety of active groups, which endow it with excellent properties and broad application prospects. Research work on EHL will promote better utilization of lignin resources and sustainable development of ecological environment. This paper briefly reviewed the research progress on EHL structures, properties, modifications and applications. Future research and development on EHL were also discussed.
Enzymatic hydrolysis lignin (EHL) has a variety of active groups, which endow it with excellent properties and broad application prospects. Research work on EHL will promote better utilization of lignin resources and sustainable development of ecological environment. This paper briefly reviewed the research progress on EHL structures, properties, modifications and applications. Future research and development on EHL were also discussed.
2017, 2(4): 184-185.
doi: 10.21967/jbb.v2i4.162
Abstract:
2017 International Conference on Forest & Paper New Technology and Research (2017 ICFP) was held on September 11-12, 2017, in in Xi'an of China. This conference attracted about 150 attendees from 6 countries, 14 universities, and about 30 pulp/paper-related companies.
2017 International Conference on Forest & Paper New Technology and Research (2017 ICFP) was held on September 11-12, 2017, in in Xi'an of China. This conference attracted about 150 attendees from 6 countries, 14 universities, and about 30 pulp/paper-related companies.
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