Ruthenium Recovery from Acetic Acid Waste Solution by Using PEI-Coated Biomass-Chitosan Composite Fiber

2015 ◽  
Vol 1130 ◽  
pp. 577-580 ◽  
Author(s):  
Jeong Ae Kim ◽  
Myung Hee Song ◽  
Yeoung Sang Yun

Polyethylenimine (PEI)-coated biomass-chitosan composite fiber (PBCF) was fabricated to recover Ru from acetic acid waste solution. The present work aimed to understand the effects of molecular weight of chitosan and drying method on stability and sorption performance of the PBCF. For this, the PBCF was prepared by extruding the mixed solutions of chitosan and Corynebacteriumglutamicum to form the composite fibers which were modified with ionic polymer, PEI. The degree of swelling of PBCFs prepared by hot-air, natural, and freeze drying methods were 1.25, 1.34, and 1.07 %, respectively, indicating that the freeze-drying method was the best. Batch biosorption studies showed that the maximum Ru uptake could be achieved with PBCF prepared with medium molecular weight chitosan, and could reach 34.1 mg/g, which was 7.9 times higher than that of the commercial ion exchange resin, LEWATIT® MonoPlus M 500 (4.3 mg/g). Therefore, PBCF can be considered as an alternative sorbent to synthetic resin for recovery of Ru form industrial acetic acid waste solution.

2013 ◽  
Vol 825 ◽  
pp. 560-563 ◽  
Author(s):  
Sung Wook Won ◽  
In Seob Kwak ◽  
Yeoung Sang Yun

The main purpose of this work is to develop and evaluate the fibrous bacterial biosorbents and to undestand the role of bacterial biomass in functionalizing polyethylenimine (PEI)-coated bacterial biosorbent fiber (PBBF). For this, chitosan fiber (CSF) and chitosan/biomass composite fiber (CSBF) were separately prepared by extruding chitosan solution and chitosan/biomass suspension, respectively. To make PBBF, the CSBF was coated with PEI and then cross-linked by glutaraldehyde. An acetic acid waste solution containing the initial ruthenium concentration of 1822.9 mg/L was used as a model waste solution. Batch sorption studies showed that the maximum Ru uptake of PBBF was 110.5 mg/g, which was 16.5 times higher than that of the commercial ion exchange resin, Lewatit MonoPlus M600. In addition, the thin fiber type of biosorbent showed as fast sorption kinetics as powder form of the raw biomass. Therefore, PBBF was evaluated as a promising biosorbent for recovery of Ru from Ru-containing acetic acid waste solutions. The role of biomass in the fiber was also investigated through sorption experiments and SEM, FTIR and XPS analyses with differently prepared fiber sorbents. In the case that the CSF was made without the biomass, it could not be coated with PEI. Meanwhile, the CSBF could successfully coat with PEI and primary amine groups were significantly increased on the surface of the fiber. Therefore, it can be concluded that the biomass should be essential to make PEI-reinforced chitosan fiber and that the negatively charged carboxyl groups on the biomass give the driving force for binding of cationic polymer PEI.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2644
Author(s):  
Jan Oszmiański ◽  
Sabina Lachowicz ◽  
Paulina Nowicka ◽  
Paweł Rubiński ◽  
Tomasz Cebulak

The present study aimed to evaluate the effect of Jerusalem artichoke processing methods and drying methods (freeze drying, sublimation drying, vacuum drying) on the basic physicochemical parameters, profiles and contents of sugars and polyphenolic compounds, and health-promoting properties (antioxidant activity, inhibition of the activities of α-amylase, α-glucosidase, and pancreatic lipase) of the produced purée. A total of 25 polyphenolic compounds belonging to hydroxycinnamic phenolic acids (LC-PDA-MS-QTof) were detected in Jerusalem artichoke purée. Their average content in the raw material was at 820 mg/100 g dm (UPLC-PDA-FL) and was 2.7 times higher than in the cooked material. The chemical composition and the health-promoting value of the purées were affected by the drying method, with the most beneficial values of the evaluated parameters obtained upon freeze drying. Vacuum drying could offer an alternative to freeze drying, as both methods ensured relatively comparable values of the assessed parameters.


Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1049 ◽  
Author(s):  
Rosalía Rodríguez-Dorado ◽  
Clara López-Iglesias ◽  
Carlos García-González ◽  
Giulia Auriemma ◽  
Rita Aquino ◽  
...  

Processing and shaping of dried gels are of interest in several fields like alginate aerogel beads used as highly porous and nanostructured particles in biomedical applications. The physicochemical properties of the alginate source, the solvent used in the gelation solution and the gel drying method are key parameters influencing the characteristics of the resulting dried gels. In this work, dried gel beads in the form of xerogels, cryogels or aerogels were prepared from alginates of different molecular weights (120 and 180 kDa) and concentrations (1.25, 1.50, 2.0 and 2.25% (w/v)) using different gelation conditions (aqueous and ethanolic CaCl2 solutions) and drying methods (supercritical drying, freeze-drying and oven drying) to obtain particles with a broad range of physicochemical and textural properties. The stability of physicochemical properties of alginate aerogels under storage conditions of 25 °C and 65% relative humidity (ICH-climatic zone II) during 1 and 3 months was studied. Results showed significant effects of the studied processing parameters on the resulting alginate dried gel properties. Stability studies showed small variations in aerogels weight and specific surface area after 3 months of storage, especially, in the case of aerogels produced with medium molecular weight alginate.


Holzforschung ◽  
2002 ◽  
Vol 56 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Thomas Rosenau ◽  
Antje Potthast ◽  
Andreas Hofinger ◽  
Herbert Sixta ◽  
Paul Kosma

Summary Polonowski type degradation reactions are a major reason for the frequently observed instability of solutions of cellulose in N-methylmorpholine-N-oxide monohydrate (NMMO, 1). The degradation is induced by degradation products of cellulose and NMMO generated in situ in the Lyocell system. The presence of both an amine component, such as morpholine or N-methylmorpholine, and an acid component is required for the decomposition process to proceed. The latter might be a low-molecular-weight compound, such as formic acid, acetic acid or gluconic acid, or also a high-molecular-weight acid, such as polyglucuronic acid or ion exchange resin.


2018 ◽  
Vol 12 (02) ◽  
pp. 158 ◽  
Author(s):  
A. Alhanannasir ◽  
Amin Rejo ◽  
Daniel Saputra ◽  
Gatot Priyanto

Pempek is a typical food of Palembang, South Sumatra, Indonesia, mostly processed in the form of wet with a moisture content of 50-60%, so that it only lasts for 3-4 days. In order for pempek to long last, it was processed into instant pempek using the freeze drying method. Pempek had tube form with a size of 3 cm in high and 4 cm in diameter. This study was aimed to see the freeze drying pressure and time to length of cooking, density, and lightness of instant pempek. Stored pempek at temperature of -50° C was carried out freeze drying with a pressure of 0.002 bar, 004 bar, 0.006 bar, and 0.008 bar for 38 hours, 40 hours, 42 hours, and 44 hours with a methodology of Split the Duncan Real Distance Difference Test Plot Design. The result showed that the pressure and time had very significant effect on the length of cooking, density and lightness of pempek. P3 (0.006 bar) pressure treatment affected shorter cooking time of pempek about 10.83 minutes, L2 treatment has 14.17 minutes for cooking times and the P3L2 treatment combination has low density of 0.71 g / cm3 and color brightness (lightness) about 85.38, almost resemble with white color. Making instant pempek with freeze drying method gave better results in ways of shorter and faster cooking time than instant pempek by other drying methods. Keywords: cooking length, freeze drying, instant pempek


2019 ◽  
Vol 70 (2) ◽  
pp. 491-494
Author(s):  
Lacramioara Oprica ◽  
Radu Gheorghe Antohe ◽  
Andreea Verdes ◽  
Marius Nicusor Grigore

The aims of this work was to investigate the effect of thermal drying method (vacuum oven drying), and nonthermal drying method (freeze drying) on the flavonoids content in two red grape varieties (Cabernet Sauvignon and Merlot) from different grape components (seed, skin, and pulp) collected from two experimental fields, Bucium and Copou (North East of Romania). In general, the fresh skin of Cabernet and Merlot varieties has the highest flavonoids content followed by those obtained by oven-drying and freeze-drying process. A similar situation was observed in the other component of grape varieties like pulp and seeds meaning in the way that the flavonoid content in oven-dried samples were higher than that in the freeze-dried samples. In addition, from both varieties, Merlot collected from Bucium presented the highest content compared with Cabernet.


Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 669
Author(s):  
Karolina Östbring ◽  
Ingegerd Sjöholm ◽  
Marilyn Rayner ◽  
Charlotte Erlanson-Albertsson

Thylakoid membranes isolated from spinach have previously been shown to inhibit lipase/co-lipase and prolong satiety in vivo. There is a need to develop thylakoid products that not only have the desired characteristics and functionality after processing, but also are stable and provide equivalent effect on appetite over the promised shelf life. The aim of the present study was therefore to evaluate how the thylakoid powders’ characteristics and functionality were affected by moisture during storage. Thylakoids produced by drum-drying, spray-drying, and freeze-drying were incubated in controlled atmosphere with different relative humidity (10 RH%, 32 RH%, 48 RH% and 61 RH%) for 8 months. The water content in all powders was increased during storage. The water absorption was moisture-dependent, and the powders were considered hygroscopic. Relative humidity showed a definite influence on the rate of chlorophyll degradation and loss of green color in thylakoid powders after storage which correlated with impaired emulsifying capacity. Spray-dried powder had the overall highest chlorophyll content and emulsifying capacity at all RH-levels investigated. Spray drying was therefore considered the most suitable drying method yielding a powder with best-maintained functionality after storage. The results can be applied towards quality control of high-quality functional foods with appetite suppressing abilities.


1989 ◽  
Vol 44 (7-8) ◽  
pp. 705-711 ◽  
Author(s):  
K. L. Conn ◽  
J. P. Tewari

Ultrastructure of the epicuticular wax of four commercially grown Canadian cultivars of canola (Brassica campestris cvs. Tobin and Candle, B. napus cvs. Altex and Westar) was investigated. Freeze-drying and air-drying methods of specimen preparation for scanning electron microscopy were compared. The freeze-drying method resulted in disruption and possible washing away of wax crystals, whereas there was no visible damage with the air-drying method. The freeze-drying method provided evidence for an amorphous layer of wax beneath the wax crystals. Ultrastructure of wax in the four cultivars was generally similar. All cultivars had an evenly distributed layer of wax crystals superimposed on an amorphous layer of wax. Some trends such as density of wax on leaves and siliques appeared to be species-specific, whereas density of wax on stems did not. There appeared to be at least three types of wax crystals present. These included plate-like, filamentous, and rod-like crystals. The rods were present singly or in blocks.


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