Sodium Chlorite Treatment Research Articles

Revealing spatial distribution and accessibility of cell wall polymers in bamboo through chemical imaging and mild chemical treatments

Understanding the distribution and accessibility of polymers within plant cell walls is crucial for addressing biomass recalcitrance in lignocellulosic materials. In this work, Imaging Fourier Transform Infrared (FTIR) and Raman spectroscopy, coupled with targeted chemical treatments, were employed to investigate cell wall polymer distribution in two bamboo species at both tissue and cell wall levels. Tissue-level Imaging FTIR revealed significant disparities in the distribution and chemical activity of cell wall polymers between the fibrous sheath and fibrous strand. At the cell wall level, Imaging Raman spectroscopy delineated a distinct difference between the secondary wall and intercellular layer, with the latter containing higher levels of lignin, hydroxycinnamic acid (HCA), and xylan, and lower cellulose. Mild acidified sodium chlorite treatment led to partial removal of lignin, HCA, and xylan from the intercellular layer, albeit to a lesser extent than alkaline treatment, indicating susceptibility of these polymers to chemical treatment. In contrast, lignin in the secondary wall exhibited limited reactivity to acidified sodium chlorite but was slightly removed by alkaline treatment, suggesting stable chemical properties with slight alkaline intolerance. These findings provide valuable insights into the inherent design mechanism of plant cells and their efficient utilization.

Fine extraction of cellulose from corn straw and the application for eco-friendly packaging films enhanced with polyvinyl alcohol

Biomass materials substituting for petroleum-based polymers occupy an important position in achieving sustainable development. Cellulose, a typical biomass material, stands out as the primary choice for producing eco-friendly packaging materials. However, it is still a challenge to efficiently utilize cellulose from waste biomass materials in practice. Herein, cellulose-based films were prepared by pretreating waste corn straw, separating straw husk, straw pith and straw leaf, and extracting cellulose through alkali and sodium chlorite treatment to improve its mechanical properties using the cross-linked polyvinyl alcohol (PVA) method in this work. The prepared composite films were characterized by Fourier transform infrared spectrometer (FTIR), X-ray diffraction instrument (XRD), Scanning electron microscopy (SEM), Thermogravimetric (TG) and mechanical properties. The results indicated that corn straw husk exhibited the highest cellulose content of 31.67 wt%, and obtained husk cellulose had the highest crystallinity of 52.5 %. Compared to corn straw, the crystallinity of husk cellulose, pith cellulose and leaf cellulose increased by 19.5 %, 16.4 % and 44.1 %, respectively. Husk cellulose/PVA composite films were the most thermally stable, with a maximum weight loss temperature of 346.8 °C. In addition, the husk cellulose/PVA composite film had the best tensile strength of 37 MPa. Meanwhile, the composite films had good UV shielding, low water vapor transmission rate and biodegradability. Therefore, this work provides a fine utilization route of waste corn straw, and as-prepared cellulose based films have potential application in eco-friendly packaging materials.

Totally chlorine-free peracetic acid pulping for nanocellulose isolation from hemp and poplar

Nanocellulose is a promising and sustainable feedstock for developing advanced and functional materials. However, the characteristics of nanocellulose, such as crystallinity, surface energy, and aspect ratio, can vary depending on biomass source and pretreatment methods, leading to variable performance of the nanocellu-lose-based materials. In this study, cellulose nanocrystals (CNCs) were isolated from hemp and poplar using totally chlorine free (TCF) peracetic acid and sodium chlorite delignification and bleaching pretreatments to probe the influences of biomass source and treatment methods on the isolation and characteristics of CNCs. Our results showed that hemp and poplar were almost completely delignified by peracetic acid treatment, whereas sodium chlorite treatment left 5%–6% lignin in the pulp. The yields of CNCs from raw hemp and poplar biomass ranged from 9.8% to 21.9% and 10.9% to 28.3%, respectively, depending on the treatment methods. The dimensions of CNCs from TCF-treated biomass generally maintained a larger width and aspect ratio than those from sodium chlorite-treated biomass. The poplar-derived CNCs exhibited slightly higher crystallinity of 53%–58% than hemp-derived CNCs of 49%–54%. The zeta potential of the CNCs, ranging from -20.1 mV to -31.1 mV, ensured a well-dispersed aqueous solution. The surface energy (dispersive energy of 40–80 mJ/m2 and specific energy of 2–10 mJ/m2), water interaction, and thermal stability of the CNCs were comparable, regardless of the biomass source and pretreatment methods. Our finding suggests that the TCF technique with peracetic acid treatment is a promising delignification and bleaching approach to obtain cellulose-rich pulps from herbaceous and hardwood biomass for nanocellulose isolation.

Characterization of nanocellulose isolated from bamboo fibers

Nanocellulose is a prominent reinforcing material for the production of advanced nanocomposites owing to its high specific strength, low cost, good thermal and mechanical properties and biodegradability. The current study aims to extract nanocellulose from bamboo fiber by chemical treatment and mechanical grinding. The nanocellulose was extracted by acetic acid and sodium chlorite treatment followed by a mechanical grinding process. Particle size analysis of extracted nanocellulose was performed by dynamic light scattering (DLS). The average size of nanocellulose was observed approximately 25.40 nm. FTIR characterization was performed to observe the change in structural properties of the fibers after each treatment. In addition, optical and morphological analyses were also investigated by UV–Vis spectrometer and FESEM, respectively. The nanocellulose extracted from bamboo fibers can be used as reinforcement for the fabrication of bionanocomposites for several applications such as food packaging, automobile, construction, and electrical Industries.

Changes in Chemical and Thermal Properties of Bamboo after Delignification Treatment

Bamboo delignification is a common method for studying its functional value-added applications. In this study, bamboo samples were delignified by treatment with sodium chlorite. The effects of this treatment on the bamboo’s microstructure, surface chemical composition, and pyrolysis behaviour were evaluated. Field-emission scanning electron microscopy (FE-SEM), Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) were conducted to evaluate these parameters. The FTIR results demonstrated that the lignin peak decreased or disappeared, and some hemicellulose peaks decreased, indicating that sodium chlorite treatment effectively removed lignin and partly decomposed hemicellulose, although cellulose was less affected. The XPS results showed that, after treatment, the oxygen-to-carbon atomic ratio of delignified bamboo increased from 0.34 to 0.45, indicating a lack of lignin. XRD revealed increased crystallinity in delignified bamboo. Further pyrolysis analysis of treated and untreated bamboo showed that, although the pyrolysis stage of the delignified bamboo did not change, the maximum thermal degradation rate (Rmax) and its corresponding temperature (from 353.78 to 315.62 °C) decreased significantly, indicating that the pyrolysis intensity of the bamboo was weakened after delignification. Overall, this study showed that delignified bamboo develops loose surfaces, increased pores, and noticeable fibres, indicating that alkali-treated bamboo has promising application potential due to its novel and specific functionalities.

Fractionating process of lignocellulosic biomass for the enzymatic production of short chain cello-oligosaccharides

This study performed a prior delignification with sodium chlorite treatment on sugarcane straw and coffee husk waste, followed by alkaline treatment strategies; aiming at the increase cellulose recovery efficiency and the decrease of chemical consumption process. This study also explored an effective approach in the use of the cellulose recovery fraction for the enzymatic production of short chain cello-oligosaccharides, using optimal mixture of commercial enzymes (cellulases with esterase), that have never been studied or reported in any other work with this approach. The hydrothermal alkaline treatment using KOH concentration 4.5% w/v, displayed similar effects to treatment with moderate temperature conditions (35 °C) with high a KOH concentration (24% w/v). The cellulose extraction efficiency was significant, around 92%, and achieved delignification close to 91%. Efficient enzyme mixtures that achieved maximum cello-oligosaccharide yields of around 63.56 mg. gsubstrate and low glucose concentrations were developed. This suggests a probably cost reductions and simplification in the purification step, for future application in the different industrial fields.

Investigation of Egyptian Chorisia spp. fiber as a natural sorbent for oil spill cleanup

Egyptian hollow fiber has been explored as natural feasible cellulosic materials that acquired great lumen and hydrophobic characteristics, which empower it to show high oil sorption capacity. The effect of solvent and sodium chlorite treatments and oil type on the sorption characteristics of Egyptian Chorisia spp. hollow fibers have been investigated. The outcomes demonstrate that with the exception of non-polar solvent, ether, Chorisia hollow fiber treated with other solvents show reduction of oil sorption capacity. NaClO2-treated fiber appears the highest and selective absorption of oil from oil/water mixtures and stayed stable after ten sorption/desorption cycles of reutilization with only 15% of sorption limit decrease. Besides, in view of SEM, NaClO2-treated fiber was retained its overall tubular and lumen structures after desorption of oils. These achievements will be reflected in the challenges for purification of other sources of water if there should arise an occurrence of water lack in Egypt.

Preparation of Biopolymer Composite Using Cedar‐Derived Cellulose Nanofibers

Steam treatment followed by milling treatment, an environmentally friendly method, was used and evaluated as a pretreatment of cedar for the preparation of cellulose nanofiber (CNF). The treated cedar was extracted with water followed by acetone and then received sodium chlorite (NaClO2) treatment, and separated into volatile component, water soluble component, acetone soluble component, NaClO2 soluble component, and NaClO2 insoluble component (a raw material of CNF preparation). The effects of steam pressures on the properties of treated cedar were examined from experimental data for the amounts of extracted components and the degree of polymerization. The properties of CNF obtained from cedar that was steam-treated at a steam pressure of 15 atm for a steaming time of 5 min and then milling-treated for 10 s were almost the same as those of commercial CNF (BiNFi-s). The reinforcing effect of CNF obtained in this treament condition was clarified, and the specific tensile strength and the specific Young’s modulus of PLA/CNF composite were 58.1 MPa/g/cm3 and 7.56 GPa/g/cm3 that corresponded to 1.6 and 3.1 times higher than those of PLA only, i.e. 33.0 MPa/g/cm3 and 2.44 GPa/g/cm3, respectively.

Synthesis of Microcrystalline Cellulose from Carpenter Waste and Its Characterizations

ABSTRACT Carpenter waste has been used as a raw material for synthesizing microcrystalline cellulose through various chemical pre-treatment process sequences. Carpenter waste treated with 10% (w/v) sodium hydroxide followed by various concentration of sodium chlorite (0.5%, 0.7%, and 1.0%) treatment has resulted in substantial loss in weight. The synthesized microcrystalline cellulose has been characterized by different instrumental analysis. FT-IR data showed the successful removal of hemicellulose and lignin from the carpenter waste after various chemical treatments. Wide-angle X-ray diffraction analysis is done to measure the crystallinity index and crystal size of the synthesized microcrystalline cellulose. The microcrystalline cellulose produced under different concentrations of sodium chlorite exhibits crystallinity index in the range of 67.56 to 68.85 and calculated average crystal size within the range of 6.47–6.60 nm. The calculated average particle size of microcrystalline cellulose ranges from 96.42 to 437.83 nm depending on the treatment conditions. Higher concentration of sodium chlorite treatment has led to lowering the particle size. Scanning Electron Microscopic image of microcrystalline cellulose shows curled and soft-flat shaped with rough pits and fibrillated network structure. Field Emission Scanning Electron Microscopic analysis reveals the cylindrical rod-shaped morphology and porous structure of the synthesized microcrystalline cellulose from carpenter waste.

Synthesis and Characterization of Microcrystalline Cellulose from Rice Husk

Rice husk was used as a raw material for synthesizing microcrystalline cellulose (MCC) through mechanical and chemical pre-treatment process. Sodium hydroxide treatment (10%) followed by varying concentration of sodium chlorite (0.5%, 0.7%, 1%) treatment has resulted in substantial weight loss. The synthesized MCC was characterized through different instrumental analyses. ATR-IR spectroscopic analysis showed the successful removal of hemicellulose and lignin. Crystallinity index and crystal size were measured through powder XRD technique and was found to be 64.74% and 6.86 nm, respectively. SEM images indicated the average particle size, shape and porosity of MCC. Higher concentration of sodium chlorite treatment has led to minimum particle size, which is confirmed via DLS technique. The onset of thermal degradation of MCC from rice husk was around 340 °C.

Isolation of Cellulose from Wheat Straw Using Alkaline Hydrogen Peroxide and Acidified Sodium Chlorite Treatments: Comparison of Yield and Properties

Environmental concerns due to excessive use of synthetic or petroleum-based materials have encouraged scientists to develop novel, sustainable, and multifunctional material using abundant lignocellulosic biomass. In this work, a study was conducted on the isolation of cellulose from wheat straw using two different methods: acidified sodium chlorite and alkaline hydrogen peroxide. A comparative study was carried out based on the yield and properties of extracted cellulose. The final product (after treatments) was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) for the identification of properties. Both the treatments isolated pure white color cellulose. However, the yield of cellulose isolated through acidified sodium chlorite treatment (81.4%) was higher than alkaline hydrogen peroxide treatment (79%). Moreover, no huge difference was observed in the crystallinity and thermal properties of extracted cellulose.

Isolation and characterization of cellulose nanocrystals from jackfruit peel

In the present work, sustainable nanomaterials, cellulose, and spherical cellulose nanocrystals (SCNCs) were isolated from the non-edible parts of jackfruit (Artocarpus heterophyllus). Of the three different methods tested, sodium chlorite treatment produced the highest yield of cellulose, 20.08 ± 0.05% w/w (dry weight). Peaks observed in CP/MAS 13C NMR spectrum and FTIR frequencies revealed the presence of α-cellulose and absence of other biomass fractions like hemicellulose and lignin. XRD analysis showed a high crystallinity of 83.42%. An appearance of a sharp endothermal peak at 323 °C in DSC and decomposition patterns between 310–420 °C of TGA confirms the presence of cellulose. Further, Sulphuric acid hydrolysis was employed to produce SCNCs and examined by TEM for the morphology and by HPLC for the presence of glucose.

Impact of chemical treatment on the physiochemical and mechanical properties of kenaf fibers

In order to improve the impact of kenaf fibers on crack resistance, durability and mechanical properties in concrete applications, kenaf fibers were treated by different inorganic chemicals (sodium hydroxide NaOH, potassium permanganate KMnO4, potassium dichromate K2Cr2O7, hydrogen peroxide H2O2, and sodium chlorite NaClO2). The characteristics of raw and chemically treated kenaf fibers were investigated through chemical composition analysis, moisture sorption test, scanning electron microscopy test, Fourier transform infrared spectroscopy test, thermogravimetric test, X-ray diffraction test, and single fiber tensile test. Compared to raw kenaf fibers, the hydrogen peroxide treatment increased the cellulose content in the fibers by about 40%; while their crystallinity increased by 26.8%. Correspondingly, the tensile strength of the fibers increased by 18.9%. The alkaline, potassium permanganate, and potassium dichromate treatments showed only a slight increase in these properties; whereas the increases were moderate with sodium chlorite treatment.

Development of two-step pretreatment of Chinese fir sawdust using dilute sulfuric acid followed by sodium chlorite for bioethanol production

Chinese fir sawdust (CFS) is an abundant potential feedstock for bio-ethanol production. However, as a sawdust from this softwood, its high recalcitrance to enzymatic hydrolysis limits its successful application. Herein, a novel two-step pretreatment with dilute sulfuric acid pretreatment followed by sodium chlorite delignification was developed to enhance enzymatic digestibility of CFS. After dilute sulfuric acid pretreatment removed a larger amount of hemicellulose, a simple sodium chlorite treatment demonstrated a remarkable delignification. Under this optimal condition, this pretreatment can yield cellulose-rich (76.8%) pretreated solids and make it possible to achieve high enzymatic hydrolysis yielding cellulose close to 100% by 48 h. Moreover, a high glucose titer of 138.8 g/L and an ethanol titer of 64.6 g/L were obtained by batch-fed enzymatic hydrolysis and subsequent fermentation, which are the highest so far reported for softwood biomass. These results suggest that this pretreatment can significantly improve the enzymatic hydrolysis and bioethanol production of CFS by removing hemicellulose and lignin.

Neutral pH sodium chlorite decreases recovery of Campylobacter in neutralizing buffered peptone water from simulated broiler carcass rinses

ABSTRACTThe goal of this study was to evaluate factors causing low recovery of Campylobacter during regulatory sampling following acidified sodium chlorite (ASC) treatment of broiler carcasses and subsequent carry‐over into neutralizing buffered peptone water (nBPW) rinses. Solution alkalinity was shown to positively correlate with the presence of un‐reduced chlorite anion in the recovery broth, implying that low recovery of Campylobacter from rinses may be due to residual chlorite, an oxidizing agent. To demonstrate the susceptibility of Campylobacter to residual chlorite, three strains were inoculated into pH = 7.5 nBPW with or without addition of sodium chlorite and stored for 24 hr at 4 °C prior to culturing. Microbial counts from the solutions indicated that residual chlorite can decrease recovery by up to 4 log CFU/mL relative to controls. Acceptable recovery of Campylobacter from nBPW rinses containing residual chlorite may require development of a suitable neutralizing agent in the nBPW recovery medium.Practical applicationsRecovery of viable Campylobacter spp. from broiler carcasses following antimicrobial treatment with acidified sodium chlorite may potentially be compromised when using nBPW as the recovery medium. At neutral or slightly alkaline pH, residual sodium chlorite, an oxidizing species, is not reduced by thiosulfate present in nBPW, and demonstrates antimicrobial effects on Campylobacter. Development of a suitable alternative to thiosulfate as a reducing agent in the recovery medium may be required in to provide optimal conditions for recovery of Campylobacter.

Agave tequilana Bagasse as Source of Cellulose Nanocrystals via Organosolv Treatment

Cellulose nanocrystals (CNCs) were isolated from Agave tequilana residues derived from ethanol production. Hemicelluloses and lignin extraction from agave bagasse was carried out via organosolv (ethanol/acetic) digestion followed by conventional sulfuric acid hydrolysis. The ethanol/acetic acid treatment resulted in cellulose yields of approximately 67% after lignin and ash removal. Compared to soda and sodium chlorite treatments with organosolv, the time and chemical load needed for delignification were remarkably reduced. The morphology of the cellulose fiber obtained in the three treatments was between 0.55 and 0.62 mm, with which CNC was obtained in the order of 83 to 195 nm in length. It is noteworthy that the longest cellulose fibers and nanocrystals were obtained from organosolv cellulose. The organosolv treatment led to a high purity cellulose, derived CNCs with a minimum energy consumption and mild chemical usage, and also considered the use of material streams associated with distillation processes. Thus, a viable alternative is suggested for the production of high quality CNC from widely available residual biomass that otherwise poses environmental and health-related risks.

Evaluation of gaseous chlorine dioxide for the inactivation of Tulane virus on blueberries

To determine the effectiveness of gaseous chlorine dioxide (gClO2) against a human norovirus surrogate on produce, gClO2 was generated and applied to Tulane virus-coated blueberries in a 240 ml-treatment chamber. gClO2 was produced by an acidifying sodium chlorite solution. Initial assessments indicated that blueberries treated with gClO2 generated from ≤1 mg acidified sodium chlorite in the small chamber appeared unaffected while gClO2 generated from ≥10 mg of acidified sodium chlorite solution altered the appearance and quality of the blueberries. Treatments of inoculated blueberries with gClO2 generated from 0.1 mg sodium chlorite reduced the virus populations by >1 log after exposure for 30 to 330 min. For the 1 mg sodium chlorite treatments, the virus populations were reduced by >2.2 log after 15 min exposure and to non-detectable levels (>3.3 logs reductions) after 180 min exposure. Measured concentrations of gClO2 peaked in the treatment chamber at 0.9 μg/l after 10 min for 0.1 mg treatments and 600 μg/l after around 20 min for 1 mg treatment. Overall results indicate that gClO2 could be a feasible waterless intervention for blueberries and other produce.

Cellulose Fiber Isolation and Characterization from Sweet Blue Lupin Hull and Canola Straw

In this study, cellulose fibers were removed from crop by-products using a combination of sodium hydroxide treatment followed by acidified sodium chlorite treatment. The objective was to obtain high recovery of cellulose by optimizing treatment conditions with sodium hydroxide (5–20%, 25–75 °C and 2–10 h) followed by acidified sodium chlorite (1.7%, 75 °C for 2–6 h) to remove maximum lignin and hemicellulose, as well as to investigate the effect of lignin content of the starting materials on the treatment efficiency. Samples were characterized for their chemical composition, crystallinity, thermal behavior and morphology to evaluate the effects of treatments on the fibers’ structure. The optimum sodium hydroxide treatment conditions for maximum cellulose recovery was at 15% NaOH concentration, 99 °C and 6 h. Subsequent acidified sodium chlorite treatment at 75 °C was found to be effective in removing both hemicellulose and lignin, resulting in higher recovery of cellulose in lupin hull (~ 95%) and canola straw (~ 93%). The resultant cellulose fibers of both crop by-products had increased crystallinity without changing cellulose I structure (~ 68–73%). Improved thermal stabilities were observed with increased onset of degradation temperatures up to 307–318 °C. Morphological investigations validated the effectiveness of treatments, revealing disrupted cell wall matrix and increased surface area due to the removal of non-cellulosics. The results suggest that the optimized combination of sodium hydroxide and acidified sodium chlorite treatments could be effectively used for the isolation of cellulose fibers from sweet blue lupin hull and canola straw, which find a great number of uses in a wide range of industrial applications.

Extraction and structural characterization of cellulose from milkweed floss

ABSTRACTThe aim of this study was to investigate the utilization of milkweed fruit floss residues as a source for the isolation of cellulose. Cellulose was extracted by acidified sodium chlorite and sodium hydroxide treatments. Characterization of the pristine milkweed floss and extracted cellulose was performed by chemical composition analysis, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The extracted cellulose had mainly α-cellulose as the other components hemicellulose and lignin were significantly removed during cellulose extraction process. The FTIR spectra also indicated that the chemical treatments extensively removed hemicellulose and lignin from the pristine milkweed floss. SEM technique was used to investigate the surface morphology of the pristine milkweed floss and extracted cellulose. The intensity of the crystalline peak in the X-ray diffractograms of the extracted cellulose was higher than that of pristine milkweed. Further, the XRD results indicated a structural transformation of cellulose I (pristine milkweed) to cellulose II (extracted cellulose) because of the chemical treatments. The extracted cellulose, which is a high biomass, had better thermal stability than the pristine milkweed floss owing to removal of non-cellulosic components.

Fabrication of zinc oxide-embedded kapok (Ceiba pentandra) paper

Zinc oxide-embedded kapok (Ceiba pentandra) papers with antimicrobial property were fabricated. Fabrication of papers from kapok fibers was done using chloroform and sodium chlorite treatments. Meanwhile, embedding of zinc oxide particles on the fabricated kapok papers was done using an in situ method. The said method involved soaking the paper in zinc acetate and sodium hydroxide solutions. The method also involved heat treatment of the sample to fasten the formation of zinc oxide particles. X-ray diffraction (XRD) measurement shows the presence of synthesized ZnO particles on the cellulose fibers while scanning electron microscopy (SEM) revealed the flake-like morphology of the embedded ZnO particles. Agar diffusion test shows that the samples have higher antimicrobial effect against Staphylococcus aureus than Escherichia coli.