scholarly journals Effect of Unbleached Rice Straw Cellulose Nanofibers on the Properties of Polysulfone Membranes

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 938 ◽  
Author(s):  
Mohammad Hassan ◽  
Ragab E. Abou Zeid ◽  
Wafaa S. Abou-Elseoud ◽  
Enas Hassan ◽  
Linn Berglund ◽  
...  

In addition to their lower cost and more environmentally friendly nature, cellulose nanofibers isolated from unbleached pulps offer different surface properties and functionality than those isolated from bleached pulps. At the same time, nanofibers isolated from unbleached pulps keep interesting properties such as hydrophilicity and mechanical strength, close to those isolated from bleached pulps. In the current work, rice straw nanofibers (RSNF) isolated from unbleached neutral sulfite pulp (lignin content 14%) were used with polysulfone (PSF) polymer to make membrane via phase inversion. The effect of RSNF on microstructure, porosity, hydrophilicity, mechanical properties, water flux, and fouling of PSF membranes was studied. In addition, the prepared membranes were tested to remove lime nanoparticles, an example of medium-size nanoparticles. The results showed that using RSNF at loadings from 0.5 to 2 wt.% can significantly increase hydrophilicity, porosity, water flux, and antifouling properties of PSF. RSNF also brought about an increase in rejection of lime nanoparticles (up to 98% rejection) from their aqueous suspension, and at the same time, with increasing flux across the membranes. Tensile strength of the membranes improved by ~29% with addition of RSNF and the maximum improvement was obtained on using 0.5% of RSNF, while Young’s modulus improved by ~40% at the same RSNF loading. As compared to previous published results on using cellulose nanofibers isolated from bleached pulps, the obtained results in the current work showed potential application of nanofibers isolated from unbleached pulps for improving important properties of PSF membranes, such as hydrophilicity, water flux, rejection, and antifouling properties.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohammad L. Hassan ◽  
Wafaa S. Abou-Elseoud ◽  
Amaal H. Abd Elkader ◽  
Enas A. Hassan

Abstract Cellulose nanofibers isolated from unbleached pulp are characterized by different surface properties due to presence of lignin at their surface, in addition to lower cost than isolated from bleached pulp. In the current work, the effect of cellulose nanofibers isolated from unbleached neutral sulfite and bleached soda rice straw pulps (so called UBCNF and BCNF) on improving paper sheet properties of unbleached and bleached rice straw pulp (so called UBP and BP) was studied. The effect on mechanical properties (tensile strength, burst strength, and tearing resistance) and physical properties (porosity and water vapor permeability) was studied. Scanning electron microscopy (SEM) was used to assist in explaining the obtained results. The result showed that using BCNF and BP resulted in better improvement in mechanical properties and also more effective in reducing porosity of paper sheets than in case of using UBCNF and UBP. These results indicated stronger bonding between nanofibers and pulps’ fibers in case of using BCNF and BP (surfaces rich in cellulose hydroxyl groups) than in case of UBCNF and UBP (surfaces rich in lignin). Water vapor permeability of paper sheets made from unbleached or bleached pulps did not significantly affect by the addition the nanofibers.


2018 ◽  
Vol 77 (1) ◽  
pp. 15-32 ◽  
Author(s):  
Dyna Theng ◽  
Gerard Arbat ◽  
Marc Delgado-Aguilar ◽  
Bunthan Ngo ◽  
Laurent Labonne ◽  
...  

Author(s):  
А.В. Вураско ◽  
Е.И. Симонова ◽  
А.Р. Минакова ◽  
Д.Д. Манойлович

Получение доступных сорбентов на основе природных материалов, для визуального колористического определения содержания ионов металлов в загрязненных природных и сточных водах является актуальным направлением исследований. Сорбенты на основе технической целлюлозы удовлетворяют этим требованиям. В работе для получения технической целлюлозы предложено использовать биомассу соломы риса. Для удаления из соломы риса минерального компонента при проведении окислительно-органосольвентной варки используют стадию щелочной обработки, которая приводит к деструкции полисахаридов, снижая выход технической целлюлозы. В связи с этим целью работы является изучение закономерностей проведения щелочной обработки соломы риса для максимального сохранения высокого выхода технической целлюлозы, извлечения минеральной части и возможности применения данной целлюлозы в качестве колористического сорбента. С учетом предварительных исследований найдены оптимальные значения технологических факторов, обеспечивающих высокий выход волокнистого материала из соломы риса при минимальном содержании в нем минеральных компонентов. Последующая органосольвентная варка позволяет получить техническую целлюлозу с выходом – 48,8% от абсолютно сухого сырья (а.с.с), зольностью 0,05% от а.с.с., содержанием лигнина 2,5% от а.с.с., удовлетворительными прочностными характеристиками, высокими сорбционными свойствами, необходимой белизной и рН водной вытяжки. Выявлено, что техническая целлюлоза из соломы риса содержит металлы, накопленные биомассой за вегетативный период. Щелочная обработка и окислительно-органосольвентная делигнификация в большинстве случаев приводят к снижению концентрации металлов в технической целлюлозе. Исключение составляют алюминий, железо и свинец, содержание которых в технической целлюлозе увеличивается. Таким образом, целлюлоза, полученная в оптимальных условиях щелочной обработки и последующей окислительно-органосольвентной варки из соломы риса, с учетом содержащихся в ней металлов, пригодна для использования в качестве сорбента для визуального колористического определения содержания ионов металлов в загрязненных природных и сточных водах. Receive available sorbents based on natural materials for visual color determination of the content of metal ions in contaminated natural and waste waters is a topical area of research. Sorbents on the basis of technical cellulose satisfy these requirements. In the process of obtaining technical cellulose is proposed to use biomass straw rice. Removal of straw rice mineral component when carrying out the oxidation-organosolvent use the cooking stage alkali treatment, which leads to degradation of polysaccharides, reducing the output of technical cellulose. In this regard, the aim of this work is to study the regularities of the alkaline treatment of rice straw for maximum preservation of the high output technical cellulose, extracting the mineral and the possibility of using the cellulose as the colour of the sorbent. Taking into account the preliminary studies, optimal conditions of technological factors were found ensuring a high yield of fibrous material from rice straw with a minimum content of mineral components in it. Subsequent organosolvent pulping yields technical pulp with a yield of 48.8% bone dry raw material (BDRM), an mineral ash content of 0.05% of BDRM, a lignin content of 2.5% of BDRM, satisfactory strength properties, high sorption properties, the necessary whiteness and pH of aqueous extract. It is revealed that the technical cellulose from straw of rice contains metals accumulated biomass during the vegetation period. Alkaline treatment and oxidative-organosolvent the delignification in most cases leads to a decrease of metal concentrations in pulp technical. With the exception of aluminum, iron and lead, the content of which is technical cellulose increases. Thus, cellulose obtained in optimum conditions of alkaline treatment and subsequent oxidation-organosolvent pulping of straw of rice, taking into account the contained metals suitable for use as a sorbent for visual color determination of the content of metal ions in polluted natural and sewage waters.


2021 ◽  
Author(s):  
Md. Mostafizur Rahman ◽  
Nur-Al-Sarah Rafsan ◽  
Jannatun Nayeem ◽  
Mohammad Moniruzzaman ◽  
M. Sarwar Jahan

Abstract Rice straw was fractionated with nitric acid in order to avoid the cooking liquor recovery in pulp production from agricultural residue (rice straw). The rice straw treated with 11.03% nitric acid at 90 ℃ for 3hr yields 53.09% pulp. The nitric acid treated rice straw pulp had high amount of lignin and minerals. However, further treatment of nitric acid pulp with low potassium hydroxide reduced the lignin and ash sufficiently as well as the pulp yield. Pulp yield reduced from 53.09 to 34.27%. The papermaking properties of the nitric acid followed by KOH treated pulp showed better quality than the nitric acid pulp. Nitric acid liquor was used several times. Pulp yield decreased in every step of reusing of the nitric acid spent liquor although residual lignin content increased. The final effluent liquor was rich with potassium, nitrogen and biomass that can be used as soil nutrient for cultivation.


Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2138 ◽  
Author(s):  
José Carlos Alcántara ◽  
Israel González ◽  
M. Mercè Pareta ◽  
Fabiola Vilaseca

Agricultural residues are major potential resources for biomass and for material production. In this work, rice straw residues were used to isolate cellulose nanofibers of different degree of oxidation. Firstly, bleached rice fibers were produced from the rice straw residues following chemical extraction and bleaching processes. Oxidation of rice fibers mediated by radical 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) at pH 10 was then applied to extract rice cellulose nanofibers, with diameters of 3–11 nm from morphological analysis. The strengthening capacity of rice nanofibers was tested by casting nanocomposite films with poly(vinyl alcohol) polymer. The same formulations with eucalyptus nanofibers were produced as comparison. Their thermal and mechanical performance was evaluated using thermogravimetry, differential scanning calorimetry, dynamic mechanical analysis and tensile testing. The glass transition of nanocomposites was shifted to higher temperatures with respect to the pure polymer by the addition of rice cellulose nanofibers. Rice nanofibers also acted as a nucleating agent for the polymer matrix. More flexible eucalyptus nanofibers did not show these two phenomena on the matrix. Instead, both types of nanofibers gave similar stiffening (as Young’s modulus) to the matrix reinforced up to 5 wt.%. The ultimate tensile strength of nanocomposite films revealed significant enhancing capacity for rice nanofibers, although this effect was somehow higher for eucalyptus nanofibers.


2021 ◽  
Vol 254 ◽  
pp. 117441
Author(s):  
Tianzhong Yuan ◽  
Jinsong Zeng ◽  
Bin Wang ◽  
Zheng Cheng ◽  
Kefu Chen

2018 ◽  
Vol 156 ◽  
pp. 01010 ◽  
Author(s):  
Siti Maftukhah ◽  
Abdullah Abdullah

Rice straw is one of very abundant waste of agricultural and has not utilized maximally. This waste contain cellulose and potential in the manufacture of cellulase enzymes. Research on the production of cellulase enzyme from lignocellulose has been done a lot of enzyme activity is still low. This research using cellulose is 71.95% and conducted with 6 stages. First, the preparation of raw material. Second, the decrease of lignin content with alkali pretreatment. Third, the breeding of fungi Aspergillus niger ITBCC L74 . Fourth, incubation in the inoculum. Fifth, the production of cellulase enzyme by solid fermentation method. Finally, the analysis includes protein content, enzyme activity, enzyme characterization and kinetics of enzymatic reactions. The highest enzyme activity of this study is 3.12 U/ml and protein content is 0.34 mg/ml with fermentation time is 4 day and water content is 75%. In enzyme characterization obtained optimum pH and temperature are 4 and 60°C, respectively. And obtained paramatic kinetic are Vmax and Km for 40, 50, 60 and 70°C temperature are Vmax: 6.42; 4.7; 5.82 and 4.46 U/ml and Km : 1.32; 0.38; 0.32; and 0.12%, respectively.


2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Kengo Sasaki ◽  
Mami Okamoto ◽  
Tomokazu Shirai ◽  
Yota Tsuge ◽  
Hiroshi Teramura ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Safoora Mirmohamadsadeghi ◽  
Keikhosro Karimi ◽  
Akram Zamani ◽  
Hamid Amiri ◽  
Ilona Sárvári Horváth

Organosolv pretreatment was used to improve solid-state anaerobic digestion (SSAD) for methane production from three different lignocellulosic substrates (hardwood elm, softwood pine, and agricultural waste rice straw). Pretreatments were conducted at 150 and 180°C for 30 and 60 min using 75% ethanol solution as an organic solvent with addition of sulfuric acid as a catalyst. The statistical analyses showed that pretreatment temperature was the significant factor affecting methane production. Optimum temperature was 180°C for elmwood while it was 150°C for both pinewood and rice straw. Maximum methane production was 152.7, 93.7, and 71.4 liter per kg carbohydrates (CH), which showed up to 32, 73, and 84% enhancement for rice straw, elmwood, and pinewood, respectively, compared to those from the untreated substrates. An inverse relationship between the total methane yield and the lignin content of the substrates was observed. Kinetic analysis of the methane production showed that the process followed a first-order model for all untreated and pretreated lignocelluloses.


2021 ◽  
Author(s):  
Osmond Datsomor ◽  
Zhao Gou-qi ◽  
Lin Miao

Abstract The objective of this study was to investigate the axenic culture of Pleurotus ostreatus, Phanerochaete chrysosporium, and the coculture (P. chrysosporium and P. ostreatus) for their potential to break down lignin and to enhance the rumen fermentability of rice straw. Rice straw was fermented by two lignin-degrading fungi, namely, P. ostreatus, P. chrysosporium, and coculture (P. ostreatus and P. chrysosporium) under solid-state fermentation (SSF). The coculture exhibited a mutual intermingling plus inhibition interaction. Coculture treated straw had a lower lignin content (5.26%) compared to P. chrysosporium axenic treated straw (6.18%), although P. ostreatus axenic treated straw was the lowest (3.27%). The polysaccharide content of coculture treated straw was higher than P. chrysosporium axenic treated straw, although smaller than P. ostreatus. P. ostreatus and coculture suitably delignified rice straw without adversely affecting cellulose. Treatment of rice straw with coculture improved in vitro dry matter digestibility (68.08%), total volatile fatty acids (35.27%), and total gas (57.4 ml/200 mg) compared to P. chrysosporium (45.09%, 32.24%, 44.39 ml/200 mg) but was second to P. ostreatus (75.34%, 38.31%, 65.60 ml/200 mg). The coculture via synergistic interaction has the potential to decompose lignin and improve the nutritive value of rice straw than P. chrysosporium.


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