Filtration and Antibacterial Properties of Bacterial Cellulose Membranes for Textile Wastewater Treatment (original) (raw)
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World Journal of Microbiology and Biotechnology, 2006
Acetobacter xylinum (Gluconacetobacter xylinus) is a bacterium that produces extracellular cellulose under static culture conditions. The highly reticulated cellulose matrix along with the entrapped cellulose-forming bacteria is commonly referred to as a pellicle. The processed bacterial cellulose membrane/film was modified into a composite bacterial cellulose membrane (CBCM) for pervaporation separation of aqueous-organic mixtures. The CBCM was prepared by coating with alginate or alginate+polyvinylpyrrolidone and cross-linking with glutaraldehyde. The pervaporation performance was determined using aqueous-organic mixtures such as, 1:1 (v/v) water-ethanol, water-isopropanol and water-acetone. The pervaporation performance of the CBCM was more effective for zeotropic mixtures (water-acetone) in comparison to the investigated azeotropic mixtures (water-ethanol and waterisopropanol). The selectivity of CBCM was found to be 4.8, 8.8, 19.8 for water-ethanol, water-isopropanol and water-acetone mixtures, respectively. The permeation flux for the water-acetone mixture was found to be 235 ml/ m 2 /h. The present investigation demonstrated that the CBCM could be employed to concentrate azeotropic as well as zeotrope forming binary mixtures by preferential pervaporation of water, with low energy requirements in contrast to the established method of distillation. In addition, the effects of feed composition, operating temperature, membrane thickness, and method of CBCM preparation on pervaporation performance have been evaluated. Investigations with the CBCM revealed that 94.5% ethanol, 98% acetone and 98.5% isopropanol concentrations could be attained from the initial 50% aqueous mixtures of these chemicals by way of pervaporation. In the case of the isopropanol-water mixture the resolving property of the membrane was more evident as the concentration arrived at was 98.5%, in contrast to other binary mixtures. The surface characteristics of the CBCM were revealed by scanning electron microscopy. In view of its properties the CBCM can be useful for pervaporation separation of these chemicals at moderate temperatures and pressure. The CBCM could be employed in the downstream processing of heat-labile and flavor-imparting volatile molecules in the field of food biotechnology and fabrication of membrane bioreactors for on-line product purification. Further studies are under progress to use the membrane for the immobilization of food processing enzymes.
Wastewater Treatment Using a Modified Cellulose Acetate Membrane
Cellulose Chemistry and Technology, 2021
The main objective of this work has been to study the performance of membranes developed for treating purified wastewater. Polymeric membranes have been developed from solutions containing cellulose acetate (AC) and polysulfone (PSF), using N,N-dimethylformamide (DMF) as solvent and polyethylene glycol (PEG) as additive. The phase inversion method was chosen as a technique for producing the membrane films. The incorporation of PEG allowed us to study the effect of the additive on the morphological structure, and to predict the performance of the membranes formed. Examining the flux, permeability and selectivity of the membranes allowed studying the efficiency and performance of each membrane. The application results achieved in wastewater treatment at Chenoua/TIPAZA station were very satisfactory and in accordance with the standards required by WHO. The optimal performance, in terms of permeability and selectivity, was obtained for the MC membrane with the composition: PSF/PEG/AC of...
Evaluation of cellulose and carboxymethyl cellulose/poly(vinyl alcohol) membranes
Carbohydrate Polymers, 2013
Cellulose was isolated from rice straw and converted to carboxymethyl cellulose (CMC). Both polymers were crosslinked with poly(vinyl alcholo) (PVA). The physical properties of the resulting membranes were characterized by FT-IR, TGA, DSC and SEM. The cellulose and CMC were first prepared from bleached rice straw pulp. The infrared spectroscopy of the resulting polymer membranes indicated a decrease in the absorbance of the OH group at 3300-3400 cm −1 , which is due to bond formation with either the cellulose or CMC with the PVA. The thermal stability of PVA/cellulose and PVA/CMC membranes was lower than PVA membrane. The surface of the resulting polymer membranes showed smooth surface in case of the PVA/CMC membrane and rough surface in case of the PVA/cellulose membrane. Desalination test, using 0.2% NaCl, showed that pure PVA membranes had no effect while membranes containing either cellulose or CMC as filler were able to decrease the content of the NaCl from the solution by 25% and 15%, respectively. Transport properties, including water and chloroform vapor were studied. The moisture transport was reduced by the presence of both cellulose and CMC. Moreover, the membranes containing cellulose and CMC showed significantly reduced flux compared to the pure PVA. The water sorption, solubility and soaking period at different pH solutions were also studied and showed that the presence of both cellulose and CMC influences the properties.
Water
In membrane-based water purification technology, control of the membrane pore structure is fundamental to defining its performance. The present study investigates the effect of the preparation conditions on the final pore size distribution and on the dye removal efficiency of cellulose acetate membranes. The membranes were fabricated by means of phase inversion (using different speeds of film casting and different thicknesses of the casted solution) and introducing modifications in the preparation conditions, such as the use of a coagulation bath instead of pure water and the addition of a surfactant as a solution additive. Both isotropic and anisotropic membranes could be fabricated, and the membranes’ pore size, porosity, and water permeability were found to be greatly influenced by the fabrication conditions. The removal capacity towards different types of water contaminants was investigated, considering, as model dyes, Azure A and Methyl Orange. Azure A was removed with higher e...
MATEC Web of Conferences
Produced water is a wastewater generated from petroleum industry with high concentration of pollutants such as Total Dissolved Solid, Organic content, and Oil and grease. Membrane technology has been currently applied for produced water treatment due to its efficiency, compact, mild and clean process. The main problem of produced water using membrane is fouling on the membrane surface which causes on low permeate productivity. This paper is majority focused on the improvement of anti-fouling performance through several modifications to increase CA membrane hydrophilicity. The membrane was prepared by formulating the dope solution consists of 18 wt-% CA polymer, acetone, and PEG additive (3 wt-%, 5 wt-%, and 7 wt-%). The membranes are casted using NIPS method and being irradiated under UV light exposure. The SEM images show that parepared membrane has asymmetric structure consist of dense layer, intermediete layer, and finger-like support layer. The filtration test shows that PEG addition increase the membrane hydrophilicity and the permeate flux increases. UV light exposure on the membrane improves the membrane stability and hydrophilicity. The imrpovement of membrane anti-fouling performance is essential to achieve the higher productivity without lowering its pollutants rejection.
Preparation and Characterization of Antibacterial Cellulose/Chitosan Nanofiltration Membranes
Polymers, 2017
Presently, most nanofiltration membranes are prepared with non-biodegradable petrochemical materials. This process is harmful to the ecosystem and consumes a large amount of non-renewable energy. In this study, biodegradable and biocompatible antibacterial cellulose/chitosan nanofiltration membranes (BC/CS-NFMs) were fabricated and characterized for their mechanical strength, antimicrobial activity, salt and dye filtration performance, and polyethylene glycol (PEG) retention using Thermal gravimetric analysis (TGA), Field emission scanning electron microscopy(FE-SEM), Fourier transform infrared spectroscopy(FT-IR), and X-ray diffraction (XRD). The BC/CS-NFMs were obtained by the hydrolysis and carboxymethylation of dense cellulose/chitosan membranes (BC/CSMs). The tensile strength of the BC/CS-NFMs decreased as the chitosan content increased. In addition, the thermal stability and antibacterial ability of the BC/CS-NFMs improved. The pore size is less than 1 nm, and a spongy, layered structure is observed in the cross-sectional FE-SEM images. FT-IR analysis shows that a part of the hydroxyl in cellulose transforms to carboxymethyl during the hydrolysis and carboxymethylation of the BC/CSMs. No obvious changes can be observed in the cellulose and chitosan after the blend membrane formation from the XRD measurements. Based on the experimental results on the permeation and rejection of BC/CS-NFMs, different proportions of cellulose and chitosan nanofiltration membranes almost did not affect the water flux and rejection rate. The BC/CS-NFMs showed better water flux and a higher rejection rate in aqueous dye-salt solutions.
MEMBRANE PROPERTY OPTIMIZATION FOR TREATMENT OF TEXTILE INDUSTRIAL EFFLUENT
Rasayan Journal of Chemistry, 2024
Textile industry wastewater is rich in color, has a low BOD/COD ratio, and contains high levels of salts (TSS and TDS). There is the presence of heavy metals at high concentrations. This has a major environmental impact underlined by chemical oxygen demand (COD) and biochemical oxygen demand (BOD). These issues arise from the presence of dye, pieces of fiber, and other surface treatment agents viz., detergents, salts, and caustic soda. Hence membrane optimization is investigated for treatment and recovery of these components, which would provide both economic and ecological benefits. It was required to provide chemically stable membranes, which would provide efficient separation for these components at effluent conditions of pH, temperature, and other parameters. A major challenge here was a selection of membrane and backing material with sustainability at low pH conditions of textile effluent. Hencepolysulfone (PSF) based membranes with cellulose as backing were optimized and tried for clarification of textile effluent. These membrane properties were further optimized for the recovery of other components. Membrane formation and performance were optimized with the proposition of a two-stage process for clarification and further concentration. Formed membranes showed excellent removal of impurities, validated by ICPMS. The clarified solution can be further treated for concentration enhancement from 7 to 20 %. Such recovered alkaline solution can be recycled or used in further applications. This solution provides an economically attractive and environmentally benign process. Further, it provides the advantages of low energy consumption, high efficiency in separation, and non-thermal processing of sensitive composite products.
IOP Conference Series: Materials Science and Engineering
Bacteria cellulose (BC) derived from Acetobacter xylinum strain possess several advantages such as elevated water holding capacity, high porosity and excellent mechanical strength. BC is useful to replace vegetal plant and applied into various industrial field such as papermaking, packaging and textile. In this study, BC membranes were produced from coconut water based consists of 8.0% sugar, 0.5% ammonium sulphate and 1.0% acetic acid at pH 4.5, followed with the addition of 10.0% inoculum before subjected to static incubation for 7 days. This study evaluated the changes of BC membrane properties using different concentration of sodium hydroxide (NaOH) under room temperature within 24 hours. The morphological, physical, chemical structure and water vapour permeability (WVP) of BC were analysed using FESEM, XRD, FTIR and WVP analysis, respectively. Results show that BC is mainly consist of cellulose with high crystallinity and smaller crystallite sizes. The differences in NaOH concentrations varied the fibrils diameter of cellulose, in accordance to FESEM images. The use of higher concentration of NaOH (≥ 2.0%) gave a smooth cellulose structure with less porosity, thus reducing the WVP properties of BC.
Evaluation of the Potential of Bacterial Cellulose in the Treatment of Oily Waters
Chemical engineering transactions, 2019
Cellulose is the most abundant biopolymer on the planet and has a wide range of applications in different industrial sectors. Environmental preservation policies, on the other hand, promote the development of research to replace vegetable cellulose (VC), due to the fact that its production causes several damages to the environment. In this way, bacterial cellulose (BC) appears as a promising alternative to VC, since it differs from its vegetal similar mainly because it presents fibers of a nanometric character against the micrometric of the vegetable, which gives it excellent mechanical properties like greater purity, higher index of crystallinity, higher water absorption power and higher tensile strength. Thus, the present study was carried out for the development of a filter base on the use of BC membrane for the treatment of oily waters. BC membranes were initially produced in an alternative medium based on corn steep liquor (industrial waste) due to the fact that the standard pr...