scholarly journals Controlled Depolymerization of Cellulose Fibres Isolated from Lignocellulosic Biomass Wastes

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Suh Cem Pang ◽  
Lee Ken Voon ◽  
Suk Fun Chin
Keyword(s):  
Lignocellulosic Biomass ◽  
Acid Catalyst ◽  
Degree Of Polymerization ◽  
Second Order ◽  
Water Soluble ◽  
Cellulose Fibres ◽  
Amberlyst 15 ◽  
Pseudo Second Order ◽  
Chain Lengths ◽  
Optimized Conditions

Various types of lignocellulosic biomass wastes (LBW) had been successfully converted into cello-oligomers with different chain lengths via a controlled depolymerization process. Cellulose fibres isolated from LBW samples were dissolved with room temperature ionic liquid (RTIL) in the presence of an acid catalyst, Amberlyst 15 DRY. The effects of reaction time on the degree of polymerization and yields of water-insoluble cello-oligomers formed were studied. Besides, the yields of water-soluble cello-oligomers such as glucose and xylose were also determined. The depolymerization of cellulose fibres isolated from LBW was observed to follow both second-order and pseudo-second order kinetics under specific conditions. As such, cello-oligomers of controllable chain lengths could be obtained by adjusting the duration of depolymerization process under optimized conditions.

Cellulose nanocrystals by acid vapour: towards more effortless isolation of cellulose nanocrystals

2017 ◽  
Vol 202 ◽  
pp. 315-330 ◽  
Author(s):  
Marcel Lorenz ◽  
Stefan Sattler ◽  
Mehedi Reza ◽  
Alexander Bismarck ◽  
Eero Kontturi
Keyword(s):  
Cellulose Nanocrystals ◽  
Materials Science ◽  
Crystal Surface ◽  
Acid Catalyst ◽  
Strong Acid ◽  
Degree Of Polymerization ◽  
Full Potential ◽  
Cellulose Fibres ◽  
Formidable Challenge ◽  
Pre Treatment

Cellulose nanocrystals (CNCs) are topical in materials science but their full potential is yet to be fulfilled because of bottlenecks in the production: the process consumes huge amounts of water, recycling the strong acid catalyst is difficult, and purification steps are cumbersome, particularly with lengthy dialysis. Production of CNCs with HCl vapour overcomes many of these difficulties but the dispersion of CNCs from the already hydrolysed fibre matrix is a formidable challenge. This study is a fundamental effort to explore very basic means to facilitate CNC dispersion from cotton linter fibres (filter paper), hydrolysed to levelling off degree of polymerization by HCl vapour. The introduction of carboxylic groups on the cellulose crystal surface proved the most efficient method to alleviate dispersion with good yields (ca. 50%) and a provisional possibility to tune the CNC length. By contrast, attempts to directly disperse untreated hydrolysed fibres in various organic solvents and aqueous surfactant solutions were unsuccessful. The results showed that hydrolysis of native cellulose fibres by HCl vapour is indeed a viable method for producing CNCs but it has more potential as a pre-treatment step rather than a full-fledged process on its own.

ADSORPSI ZAT WARNA TEKSTIL REACTIVE RED 141 PADA TANAH LIAT LOKAL ALAMI

Arena Tekstil ◽  
2014 ◽  
Vol 29 (2) ◽  
Author(s):  
Nurulbaiti Listyendah Zahra ◽  
Doni Sugiyana ◽  
Suprihanto Notodarmojo
Keyword(s):  
Second Order ◽  
Pseudo Second Order

Dalam studi ini dipelajari kemampuan adsorpsi tanah liat lokal alami untuk menyisihkan warna pada larutan mengandung zat warna tekstil Reactive Red 141 (RR 141). Tanah liat lokal alami yang diteliti sebagai alternatif adsorben yang murah dalam studi ini berasal dari daerah Arcamanik, Citatah dan Dago (Bandung, Indonesia). Aspek yang dipelajari meliputi pengaruh dosis adsorben, waktu kontak dan konsentrasi awal larutan zat warna. Mekanisme proses adsorpsi dievaluasi menggunakan model isoterm, kinetika dan parameter termodinamika. Hasil penelitian ini menunjukkan bahwa peningkatan efisiensi penyisihan warna dan penurunan kapasitas adsorpsi tanah liat terjadi pada dosis adsorben lebih tinggi dan konsentrasi awal zat warna lebih rendah. Dosis adsorben optimum untuk tanah liat Arcamanik, Dago dan Citatah dicapai pada dosis masing-masing sebesar 10 g/L; 10 g/L; dan 8 g/L, dengan penyisihan zat warna berturut-turut sebesar 65,9%; 65,9%; dan 76,6%. Waktu kesetimbangan adsorpsi RR 141 pada tanah liat Arcamanik dan Citatah dicapai pada 60 menit sedangkan pada tanah liat Dago tercapai pada 120 menit. Kinetika adsorpsi RR 141 pada seluruh tanah liat lokal yang diteliti sesuai dengan model pseudo second order. Data kesetimbangan adsorpsi RR 141 pada tanah liat Arcamanik paling baik digambarkan oleh model isoterm Freundlich sedangkan untuk tanah liat Citatah dan Dago paling baik digambarkan oleh model isoterm Langmuir. Nilai perubahan energi bebas pada tanah liat Arcamanik, Citatah dan Dago masing-masing sebesar -4,794; -7,048 dan -4,234 kJ/mol.

Synthesis and Characterization of Chitosan templated Mesoporous Silica: Efficient use of Mesoporous Silica in the removal of Cu(II) from Aqueous Solutions

2016 ◽  
Vol 4 (2) ◽  
pp. 105-112
Author(s):  
Lalchhing puii ◽  
◽  
Seung-Mok Lee ◽  
Diwakar Tiwari ◽  
◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Aqueous Solutions ◽  
Background Electrolyte ◽  
Second Order ◽  
Order Kinetic ◽  
Sorption Data ◽  
Column Reactor ◽  
Wide Ph Range ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order

A mesoporous silica was synthesized by annealing (3-Aminopropyl) triethoxysilane grafted chitosan at 800˚C. The mesoporous silica was characterized by the XRD (X-ray diffraction) analysis. The BET specific surface area and pore size of silica was found to be 178.42 m2/g and 4.13 nm. The mesoporous silica was then employed for the efficient remediation of aqueous solutions contaminated with Cu(II) under batch and column reactor operations. The mesoporous silica showed extremely high per cent removal of Cu(II) at wide pH range i.e., pH ~2.0 to 7.0. Relatively a fast uptake of Cu(II) was occurred and high percentage removal was obtained at initial concentrations studied from 1.0 to 15.0 mg/L. The equilibrium state sorption data were utilized for the Langmuir and Freundlich adsorption isotherm studies. Moreover, the effect of an increase in background electrolyte concentrations from 0.0001 to 0.1 mol/L NaNO3 was assessed for the uptake of Cu(II) by mesoporous silica. The equilibrium sorption was achieved within 240 min of contact and the kinetic data is best fitted to the pseudo-second-order and fractal like pseudo-second-order kinetic models. In addition, the mesoporous silica was used for dynamic studies under column reactor operations. The breakthrough curve was then used for the non-linear fitting of the Thomas equation and the loading capacity of the column for Cu(II) was estimated.

scholarly journals Optimizing Chitin Depolymerization by Lysozyme to Long-Chain Oligosaccharides

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 320
Author(s):  
Arnaud Masselin ◽  
Antoine Rousseau ◽  
Stéphanie Pradeau ◽  
Laure Fort ◽  
Rodolphe Gueret ◽  
...  
Keyword(s):  
Time Course ◽  
Water Soluble ◽  
Organic Fertilizers ◽  
Symbiotic Associations ◽  
Egg White Lysozyme ◽  
Hen Egg White ◽  
Ecological Transition ◽  
Optimized Conditions ◽  
Hydrolysis Of ◽  
Long Chain

Chitin oligosaccharides (COs) hold high promise as organic fertilizers in the ongoing agro-ecological transition. Short- and long-chain COs can contribute to the establishment of symbiotic associations between plants and microorganisms, facilitating the uptake of soil nutrients by host plants. Long-chain COs trigger plant innate immunity. A fine investigation of these different signaling pathways requires improving the access to high-purity COs. Here, we used the response surface methodology to optimize the production of COs by enzymatic hydrolysis of water-soluble chitin (WSC) with hen egg-white lysozyme. The influence of WSC concentration, its acetylation degree, and the reaction time course were modelled using a Box–Behnken design. Under optimized conditions, water-soluble COs up to the nonasaccharide were formed in 51% yield and purified to homogeneity. This straightforward approach opens new avenues to determine the complex roles of COs in plants.

Preparation and Aplication of Cation Adsorbent by Canada Goldenrod (Solidago canadensis L.)

2011 ◽  
Vol 396-398 ◽  
pp. 75-87
Author(s):  
Zai Fu Yang ◽  
Xiao Jing Yang ◽  
Li Hong Sun ◽  
Lian Lian Xu
Keyword(s):  
Sulfuric Acid ◽  
Cation Exchange ◽  
Agricultural Land ◽  
Reaction Medium ◽  
Volume Ratio ◽  
Second Order ◽  
Experimental Results ◽  
Solidago Canadensis ◽  
Order Kinetic ◽  
Pseudo Second Order

ABSTRACT: Cation adsorbent was prepared from the Solidago Canadensis（which are abandoned agricultural land of alien invasive plants）by Sulfuric acid esterification modified , isoamyl alcohol as reaction medium. Design L934 orthogonal experiment, the Solidago canadensis cation exchange adsorbent, the optimal preparation conditions. Experimental results show that at 15°C, concentrated sulfuric acid and amyl alcohol volume ratio of 5:6 obtained under conditions of Solidago canadensis cation exchange adsorbent for Pb(II) exchange best. The experimental results of Pb(II) adsorption onto the Solidago Canadensis based cation adsorbent showed that the best conditions are: the initial pH 5, the concentration of Pb(II) 300mg/L，the dosage of cation adsorbent 1.2mg/L and adsorption time 3h. The adsorption data were analyzed by using pseudo-first-order and pseudo-second-order kinetic models were found to follow the pseudo-second-order kinetic model.

Studies of Chromium Removal from Tannery Effluents by Dead Streptomyces Rimosus

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Mohamed Nasser Sahmoune ◽  
Krim Louhab ◽  
Aissa Boukhiar
Keyword(s):  
Fractional Power ◽  
Kinetic Studies ◽  
Second Order ◽  
Order Kinetic ◽  
Streptomyces Rimosus ◽  
Tannery Effluents ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ph Range

Dead streptomyces rimosus was found to be an effective biosorbent for the removal of chromium from industrial tanning effluents. A sorption level of 65 mg/g was observed at pH 4.8 while the precipitation effect augmented this value at a higher pH range. Chromium desorption increased with decreasing desorption agents pH (including HCl and H2SO4) to a maximum value of 95% at approximately zero pH. The biosorption data of trivalent chromium by streptomyces rimosus has been used for kinetic studies based on fractional power, Elovich, pseudo-first order and pseudo-second order rate expressions. The time-dependent Cr (III) biosorption data were well-described by a pseudo-second-order kinetic model. The intraparticle diffusion is not the rate-limiting step for the whole reaction. It was found that the biosorption equilibrium data fit well with the Langmuir model.

scholarly journals Kinetic Study of the Bioadsorption of Methylene Blue on the Surface of the Biomass Obtained from the Algae D. antarctica

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jhonatan R. Guarín ◽  
Juan Carlos Moreno-Pirajan ◽  
Liliana Giraldo
Keyword(s):  
Methylene Blue ◽  
Kinetic Study ◽  
Adsorption Capacity ◽  
Scientific Community ◽  
Second Order ◽  
Maximum Adsorption Capacity ◽  
Pseudo Second Order ◽  
Best Fit ◽  
Total Elimination ◽  
Purification Of Water

Currently, there is a great pollution of water by the dyes; due to this, several studies have been carried out to remove these compounds. However, the total elimination of these pollutants from the aquatic effluents has represented a great challenge for the scientific community, for which it is necessary to carry out investigations that allow the purification of water. In this work, we studied the bioadsorption of methylene blue on the surface of the biomass obtained from the algae D. antarctica. This material was characterized by SEM and FTIR. To the data obtained in the biosorption experiments, different models of biosorption and kinetics were applied, finding that the best fit to the obtained data is given by applying the pseudo-second-order models and the Toth model, respectively. It was also determined that the maximum adsorption capacity of MB on the surface of the biomass is 702.9 mg/g, which shows that this material has great properties as a bioadsorbent.

Synthesis of fatty 1,2,4-trioxanes by peracetalisation of β-hydroxy hydroperoxides

Synthesis ◽  
2021 ◽  
Author(s):  
Thomas De Dios Miguel ◽  
Dan Louvel ◽  
Killian Onida ◽  
Adeline Lavoignat ◽  
Stephane Picot ◽  
...  
Keyword(s):  
Sulfonic Acid ◽  
Heterogeneous Catalysts ◽  
Antimalarial Activity ◽  
Acid Catalyst ◽  
Methyl Tert Butyl Ether ◽  
Significant Activity ◽  
Butyl Ether ◽  
Aliphatic Aldehydes ◽  
Toluene Sulfonic Acid ◽  
Optimized Conditions

The peracetalisation of a β-hydroxy hydroperoxide derived from methyl oleate was studied using benzaldehyde as a model substrate to give the corresponding fatty 1,2,4-trioxane. The desired product was obtained as a mixture of regioisomers but only one diastereoisomer of each was formed. The nature of the acid catalyst was studied and both para-toluene sulfonic acid (PTSA) and Amberlyst A35 (A35) were found to be efficient homogeneous and heterogeneous catalysts, respectively. The nature of the solvent was also investigated and ethereal solvents such as 2-methyltetrahydrofuran (2-MeTHF), methyl tert-butyl ether (MTBE) and cyclopentyl methyl ether (CPME) gave the best NMR yield (85%) for the preparation of the fatty trioxane. The optimized conditions were applied to a range of aromatic and aliphatic aldehydes and the corresponding 1,2,4-trioxanes were isolated with 30-91% yields (21 examples). The antimalarial activity of 3 trioxanes was studied against Plasmodium falciparum, however, no significant activity was detected (IC50 > 1600 nM).

A Comparative Sorption Study of Ni (II) form Aqueous Solution Using Silica Gel, Amberlite IR-120 and Sawdust

2019 ◽  
Vol 233 (9) ◽  
pp. 1275-1292 ◽  
Author(s):  
Atta ul Haq ◽  
Muhammad Rasul Jan ◽  
Jasmin Shah ◽  
Maria Sadia ◽  
Muhammad Saeed
Keyword(s):  
Sorption Capacity ◽  
Silica Gel ◽  
Low Cost ◽  
Sorption Process ◽  
Second Order ◽  
Order Kinetic ◽  
Sorption Data ◽  
Desorption Study ◽  
Pseudo Second Order ◽  
Sorption Study

Abstract The presence of heavy metals in water causes serious problems and their treatment before incorporating into the water body is a challenge for researchers. The present study was conducted to compare the sorption study of Ni (II) using silica gel, amberlite IR-120 and sawdust of mulberry wood in batch system under the influence of pH, initial Ni (II) concentration and contact time. It was observed that sorption process was depending upon pH and maximum sorption was achieved at pH 7.0. Kinetic data were well fitted into pseudo-second order kinetic model due to high R2 values and closeness of experimental sorption capacity and calculated sorption capacity of pseudo-second order. Isotherms study showed that Langmuir is one of the most suitable choices to explain sorption data due to high R2 values. The monolayer sorption capacities of silica gel, amberlite IR-120 and sawdust were found to be 33.33, 25.19, and 33.67 mg g−1, respectively. Desorption study revealed that NaCl is one of the most appropriate desorbent. It may be concluded from this study that sawdust is a suitable sorbent due to low cost, abundant availability and recycling of the materials for further study.

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