ABSTRACT
The deleterious impact of osmotic stress, induced by water deficit in arid and semi-arid regions, poses a formidable challenge to cotton production. To protect cotton farming in dry areas, it's crucial to create strong plans to increase soil water and reduce stress on plants. The carboxymethyl cellulose (CMC), gibberellic acid (GA3) and biochar (BC) are individually found effective in mitigating osmotic stress. However, combine effect of CMC and GA3 with biochar on drought mitigation is still not studied in depth. The present study was carried out using a combination of GA3 and CMC with BC as amendments on cotton plants subjected to osmotic stress levels of 70 (70 OS) and 40 (40 OS). There were five treatment groups, namely: control (0% CMC-BC and 0% GA3-BC), 0.4%CMC-BC, 0.4%GA3-BC, 0.8%CMC-BC, and 0.8%GA3-BC. Each treatment was replicated five times with a completely randomized design (CRD). The results revealed that 0.8 GA3-BC led to increase in cotton shoot fresh weight (99.95%), shoot dry weight (95.70%), root fresh weight (73.13%), and root dry weight (95.74%) compared to the control group under osmotic stress. There was a significant enhancement in cotton chlorophyll a (23.77%), chlorophyll b (70.44%), and total chlorophyll (35.44%), the photosynthetic rate (90.77%), transpiration rate (174.44%), and internal CO2 concentration (57.99%) compared to the control group under the 40 OS stress. Thus 0.8GA3-BC can be potential amendment for reducing osmotic stress in cotton cultivation, enhancing agricultural resilience and productivity.
Subject(s)
Carboxymethylcellulose Sodium , Charcoal , Gibberellins , Gossypium , Chlorophyll A , Osmotic Pressure , WaterABSTRACT
Drought stress poses a significant challenge to maize production, leading to substantial harm to crop growth and yield due to the induction of oxidative stress. Deashed biochar (DAB) in combination with carboxymethyl cellulose (CMC) presents an effective approach for addressing this problem. DAB improves soil structure by increasing porosity and water retention and enhancing plant nutrient utilization efficiency. The CMC provides advantages to plants by enhancing soil water retention, improving soil structure, and increasing moisture availability to the plant roots. The present study was conducted to investigate the effects of DAB and CMC amendments on maize under field capacity (70 FC) and drought stress. Six different treatments were implemented in this study, namely 0 DAB + 0CMC, 25 CMC, 0.5 DAB, 0.5 DAB + 25 CMC, 1 DAB, and 1 DAB + 25 CMC, each with six replications, and they were arranged according to a completely randomized design. Results showed that 1 DAB + 25 CMC caused significant enhancement in maize shoot fresh weight (24.53%), shoot dry weight (38.47%), shoot length (32.23%), root fresh weight (19.03%), root dry weight (87.50%) and root length (69.80%) over control under drought stress. A substantial increase in maize chlorophyll a (40.26%), chlorophyll b (26.92%), total chlorophyll (30.56%), photosynthetic rate (21.35%), transpiration rate (32.61%), and stomatal conductance (91.57%) under drought stress showed the efficiency of 1 DAB + 25 CMC treatment compared to the control. The enhancement in N, P, and K concentrations in both the root and shoot validated the effectiveness of the performance of the 1 DAB + 25 CMC treatment when compared to the control group under drought stress. In conclusion, it is recommended that the application of 1 DAB + 25 CMC serves as a beneficial amendment for alleviating drought stress in maize.
Subject(s)
Charcoal , Zea mays , Carboxymethylcellulose Sodium/pharmacology , Chlorophyll A , Droughts , Soil/chemistry , WaterABSTRACT
Healing of complex wounds requires dressings that must, at least, not hinder and should ideally promote the activity of key healing cells, in particular fibroblasts. This in vitro study assessed the effects of three wound-dressings (a pure Ca2+ alginate: Algostéril®, a Ca2+ alginate + carboxymethylcellulose: Biatain alginate® and a polyacrylate impregnated with lipido-colloid matrix: UrgoClean®) on dermal fibroblast activity. The results showed the pure calcium alginate to be non-cytotoxic, whereas the other wound-dressings showed moderate to strong cytotoxicity. The two alginates stimulated fibroblast migration and proliferation, whereas the polyacrylate altered migration and had no effect on proliferation. The pure Ca2+ alginate significantly increased the TGF-ß-induced fibroblast activation, which is essential to healing. This activation was confirmed by a significant increase in Vascular endothelial growth factor (VEGF) secretion and a higher collagen production. The other dressings reduced these fibroblast activities. The pure Ca2+ alginate was also able to counteract the inhibitory effect of NK cell supernatants on fibroblast migration. These in vitro results demonstrate that tested wound-dressings are not equivalent for fibroblast activation. Only Algostéril was found to promote all the fibroblast activities tested, which could contribute to its healing efficacy demonstrated in the clinic.
Subject(s)
Alginates , Cell Movement , Cell Proliferation , Fibroblasts , Vascular Endothelial Growth Factor A , Wound Healing , Fibroblasts/drug effects , Wound Healing/drug effects , Humans , Alginates/pharmacology , Cell Movement/drug effects , Cell Proliferation/drug effects , Vascular Endothelial Growth Factor A/metabolism , Collagen/metabolism , Bandages , Transforming Growth Factor beta/metabolism , Carboxymethylcellulose Sodium , Cells, Cultured , Killer Cells, Natural/drug effects , Acrylic Resins , Hexuronic Acids , Glucuronic Acid , SkinABSTRACT
Microbial biological control agents are believed to be a potential alternative to classical fertilizers to increase the sustainability of agriculture. In this work, the formulation of Trichoderma afroharzianum T22 (T22) spores with carboxymethyl cellulose (CMC) and Pluronic F-127 (PF-127) solutions was investigated. Rheological and microscopical analysis were performed on T22-based systems at three different CMC/PF-127 concentrations, showing that polymer aggregates tend to surround T22 spores, without viscosity, and the viscoelastic properties of the formulations were affected. Contact angle measurements showed the ability of PF-127 to increase the wettability of the systems, and the effect of the formulations on the viability of the spores was evaluated. The viability of the spores was higher over 21 days in all the formulations, compared to the control in water, at 4 and 25 °C. Finally, the effectiveness of the formulations on sweet basil was estimated by greenhouse tests. The results revealed a beneficial effect of the CMC/PF-127 mixture, but none on the formulation with T22. The data show the potential of CMC/PF-127 mixtures for the future design of microorganism-based formulations.
Subject(s)
Carboxymethylcellulose Sodium , Poloxamer , Trichoderma , Poloxamer/chemistry , Trichoderma/chemistry , Carboxymethylcellulose Sodium/chemistry , Agriculture , Spores, Fungal/chemistryABSTRACT
Viscoelastic behaviors of aqueous systems of commercially available sodium carboxymethyl cellulose (NaCMC) samples with the degrees of substitution (DS) of approximately 0.68 and 1.3, and the weight-average molar masses (Mw) higher than 200 kg mol-1 dissolved in pure water and aqueous sodium chloride solutions were investigated over a wide concentration (c) range of NaCMC samples. The dependencies of the specific viscosity (ηsp), the average relaxation time (τw), and the reciprocal of the steady-state compliance (Je-1) on c were discussed. The relationships ηsp â c3, τw â c2, and Je-1 â c, characteristic of the rod particle suspensions, were clearly observed in a range lower than the c where the critical gel behavior was observed. Thus, a new concept based on the rheology of rod particle suspensions was employed to interpret the viscoelastic behaviors obtained in the c range. In this context, NaCMC polymer molecules are assumed to behave as extended rod particles with length (L) and diameter (d), including effective electrostatic repulsive distances, due to the dissociation of Na+ in aqueous systems. Thus, the number density of polymer molecules is given to be ν = c/Mw, and viscoelastic parameters such as ηsp, τw, and Je-1 are calculated using the theoretical model for rod particle suspensions proposed by Doi and Edwards. This concept reasonably described not only the viscoelastic data obtained in this study but also those from other groups using NaCMC samples with different DS and Mw values.
Subject(s)
Carboxymethylcellulose Sodium , Rheology , Water , Carboxymethylcellulose Sodium/chemistry , Viscosity , Water/chemistry , ElasticityABSTRACT
Polyelectrolyte-based ionic-junction fibers newly serve as signal transmission and translation media between electronic devices and biological systems, facilitating ion transport within organic matrices. In this work, we fabricated gel filaments of carboxymethyl cellulose (CMC) chelated with Cu(II) ions through wet-spinning, using a saturated coagulant of CuSO4. Interestingly, the as-spun fibers exhibited dramatic 3D porous frameworks that varied with the temperature and precursor concentration. At 20 °C, the Cu(II) chelation networks favored the formation of well-organized cellular chambers or corrugated channels, displaying dense stacking patterns. However, critical transitions from cellular chambers to corrugated channels occurred at precursor dope concentrations of approximately 2 and 7 wt %, with the porous structure diminishing beyond 8 wt %. We have proposed schematic diagrams to mimic the 3D pore structure, dense porous stacking, and formation mechanism, according to electronic micrographs. Our investigations revealed that the distinct ion-junction channels or chambers are under the control of axial drawing extension as well as the outside-inside penetration of Cu(II) ions into the dope and inside-outside diffusion of water into coagulants. Therefore, controlling the metal chelation-water diffusion process at specific temperatures and concentrations will offer valuable insights for tailoring ionic-junction soft filaments with gradient hierarchically porous structures and shape memory properties.
Subject(s)
Carboxymethylcellulose Sodium , Copper Sulfate , Carboxymethylcellulose Sodium/chemistry , Porosity , Copper Sulfate/chemistry , Copper/chemistryABSTRACT
Interface engineering is essential for cellulosic fiber-reinforced polymer composites to achieve high strength and toughness. In this study, carboxymethyl cellulose (CMC) functionalized with hydrophobic quaternary ammonium ions (QAs) were utilized to modify the interface between holocellulose fibers (HF) and acrylic resin. The wet HF/CMC papers were prepared by vacuum filtration, akin to papermaking, followed by cationic ion exchange with different hydrophobic QAs. Subsequently, the modified papers were dried, impregnated with an acrylic resin monomer, and cured to produce transparent composite films. The effect of the hydrophobic QA moieties on the structure and optical and mechanical properties of the HF/CMC/acrylic resin composites were investigated. The composite film with cetyltrimethylammonium (CTA)-functionalized CMC showed high optical transmittance (87%) with low haze (43%), while the composite film with phenyltrimethylammonium (PTMA)-functionalized CMC demonstrated high Young's modulus of 7.6 GPa and high tensile strength of 180 MPa. These properties are higher than those of the composites prepared through covalent interfacial modification strategies. The results highlighted the crucial role of hydrophobic functionalized CMCs in facilitating homogeneous resin impregnation in the HF fiber network, producing a composite with enhanced interfacial adhesion strength, increased optical transparency, and mechanical strength. This facile use of hydrophobic CMCs as interfacial compatibilizers provides an energy-efficient route for preparing transparent, thin, and flexible composite films favorable in optoelectronic applications.
Subject(s)
Acrylic Resins , Carboxymethylcellulose Sodium , Hydrophobic and Hydrophilic Interactions , Tensile Strength , Carboxymethylcellulose Sodium/chemistry , Acrylic Resins/chemistry , Quaternary Ammonium Compounds/chemistry , Cellulose/chemistry , Elastic ModulusABSTRACT
Mechanical stimuli such as strain, force, and pressure are pervasive within and beyond the human body. Mechanoresponsive hydrogels have been engineered to undergo changes in their physicochemical or mechanical properties in response to such stimuli. Relevant responses can include strain-stiffening, self-healing, strain-dependent stress relaxation, and shear rate-dependent viscosity. These features are a direct result of dynamic bonds or noncovalent/physical interactions within such hydrogels. The contributions of various types of bonds and intermolecular interactions to these behaviors are important to more fully understand the resulting materials and engineer their mechanoresponsive features. Here, strain-stiffening in carboxymethylcellulose hydrogels cross-linked with pendant dynamic-covalent boronate esters using tannic acid is studied and modulated as a function of polymer concentration, temperature, and effective cross-link density. Furthermore, these materials are found to exhibit self-healing and strain-memory, as well as strain-dependent stress relaxation and shear rate-dependent changes in gel viscosity. These features are attributed to the dynamic nature of the boronate ester cross-links, interchain hydrogen bonding and bundling, or a combination of these two intermolecular interactions. This work provides insight into the interplay of such interactions in the context of mechanoresponsive behaviors, particularly informing the design of hydrogels with tunable strain-stiffening. The multiresponsive and tunable nature of this hydrogel system therefore presents a promising platform for a variety of applications.
Subject(s)
Hydrogels , Hydrogels/chemistry , Viscosity , Stress, Mechanical , Carboxymethylcellulose Sodium/chemistry , Cellulose/chemistry , Tannins/chemistry , Hydrogen BondingABSTRACT
Many crucial components inside electronic devices are made from non-renewable, non-biodegradable, and potentially toxic materials, leading to environmental damage. Finding alternative green dielectric materials is mandatory to align with global sustainable goals. Carboxymethyl cellulose (CMC) is a bio-polymer derived from cellulose and has outstanding properties. Herein, citric acid, dextrin, and CMC based hydrogels are prepared, which are biocompatible and biodegradable and exhibit rubber-like mechanical properties, with Young modulus values of 0.89 MPa. Hence, thin film CMC-based hydrogel is explored as a suitable green high-k dielectric candidate for operation at low voltages, demonstrating a high dielectric constant of up to 78. These fabricated transistors reveal stable high capacitance (2090 nF cm-2) for ≈±3 V operation. Using a polyelectrolyte-type approach and poly-(2-vinyl anthracene) (PVAn) surface modification, this study demonstrates a thin dielectric layer (d ≈30 nm) with a small voltage threshold (Vth ≈-0.8 V), moderate transconductance (gm ≈65 nS), and high ON-OFF ratio (≈105). Furthermore, the dielectric layer exhibits stable performance under bias stress of ± 3.5 V and 100 cycles of switching tests. The modified CMC-based hydrogel demonstrates desirable performance as a green dielectric for low-voltage operation, further highlighting its biocompatibility.
Subject(s)
Carboxymethylcellulose Sodium , Dextrins , Hydrogels , Dextrins/chemistry , Carboxymethylcellulose Sodium/chemistry , Hydrogels/chemistry , Hydrogels/chemical synthesis , Biocompatible Materials/chemistry , Green Chemistry TechnologyABSTRACT
This study aimed to evaluate effective treatment strategies for laboratory waste with an initial pH of 1.0, containing Cr6+, Mn2+, Co2+, Fe3+, Ni2+, Cu2+, Zn2+, Sr2+, Hg2+, and Pb2+ ions, focusing on flocculation, precipitation, and adsorption techniques. The study utilized microparticles derived from Moringa oleifera seed husks (MS), cryogels of carboxymethyl cellulose (CMC), and hybrid cryogels combining CMC and MS (CMC-MS25 and CMC-MS50) as adsorbents. The optimal strategy involved raising the pH to 7 using NH4OH, leading to the partial precipitation of metal ions. The remaining supernatant was then passed through columns packed with the aforementioned adsorbents. Utilizing CMC-MS25 and CMC-MS50 adsorbents resulted in the simultaneous removal of over 90% of the targeted metal ions. The adsorption of Cu2+ ions onto the adsorbents was facilitated by electrostatic interactions between Cu2+ ions and carboxylate groups, as well as Cu-OH chelation, as confirmed by X-ray photoelectron spectroscopy. Under optimized conditions, the fixed-bed column adsorption capacity was determined as 88.2 mg g-1. The CMC-MS25 adsorbents proved reusable at least 5 times, with the recovered Cu2+ ions potentially suitable for other processes. The scalability and feasibility of producing these novel adsorbents suggest a promising, cost-effective solution for treating complex matrices and recovering high-value metals, as copper.
Subject(s)
Carboxymethylcellulose Sodium , Moringa oleifera , Seeds , Carboxymethylcellulose Sodium/chemistry , Moringa oleifera/chemistry , Seeds/chemistry , Adsorption , Water Pollutants, Chemical/chemistry , Metals, Heavy/chemistry , Metals/chemistryABSTRACT
Schwertmannite (SCH) is a promising material for adsorbing inorganic arsenic (As). We synthesized SCH nanoparticles (nano-SCH) via a modified chemical oxidation method and investigated the application of nano-SCH for the remediation of As-contaminated soils. The production of nano-SCH was successfully prepared using the persulfate oxidation method with carboxymethyl cellulose stabilization. The spherical structure of the nano-SCH particles had an average hydrodynamic diameter of 296 nm with high specific surface areas (108.9 m2/g). Compared with SCH synthesized via the H2O2 oxidation method, the percentage of Fe3+ precipitation in nano-SCH synthesis increased from 63.2% to 84.1%. The inorganic As adsorption capacity of nano-SCH improved by 2.27 times at solution pH = 6. After remediation of heavily As-contaminated soils by using 5% nano-SCH, the leachability of inorganic As rapidly decreased to 0.01% in 30 d. Correspondingly, the immobilization efficiencies of inorganic As in soil reached >99.9%. The inorganic As fractions in treated soil shifted from specifically and nonspecifically bound forms to amorphous and crystalline hydrous oxide-bound fractions. After treatment with 5% nano-SCH for 60 d, soil pH slightly decreased from 5.47 to 4.94; by contrast, soil organic matter content increased by 20.9%. Simultaneously, dehydrogenase concentration in soil decreased by 22.4%-34.7% during the remediation process. These changes in soil properties and As immobilization jointly decreased microbial activity and initiated the re-establishment of bacterial communities in the soil. In summary, this study presents a novel and high-productivity technology for nano-SCH synthesis and confirms the high As immobilization effectiveness of nano-SCH in the remediation of As-contaminated soils.
Subject(s)
Arsenic , Environmental Restoration and Remediation , Iron Compounds , Soil Pollutants , Arsenic/analysis , Carboxymethylcellulose Sodium , Hydrogen Peroxide , Soil/chemistry , Soil Pollutants/analysisABSTRACT
The green synthesis of metal oxide nanoparticles (NPs) has garnered considerable attention from researchers due to its utilization of eco-friendly solvents during synthesis and cost-effective approaches. This study focuses on the synthesis of titanium oxide (TiO2) and dopamine (DA) carboxymethyl cellulose (CMC)-doped TiO2 (DA/CMC/TiO2) NP using Psidium guajava leaf extract, while also investigating the structural, optical, and morphological and biocidal potential of the prepared NPs. Significantly larger zones of inhibition were observed for DA/CMC/TiO2 NPs compared to TiO2 against various pathogens. Moreover, the MTT assay was carried out to evaluate the anticancer activity of the prepared samples against MG-63 cells, and the results revealed that DA/CMC/TiO2 NPs exhibited significantly higher level of anticancer activity compared to TiO2. The experimental results demonstrated that DA/CMC/TiO2 NPs exhibited enhanced anticancer activity in a dose-dependent manner when compared to TiO2 NPs.
Subject(s)
Anti-Infective Agents , Metal Nanoparticles , Psidium , Carboxymethylcellulose Sodium/pharmacology , Dopamine , Plant Extracts/pharmacology , Plant Extracts/chemistry , Metal Nanoparticles/chemistryABSTRACT
Advancements in polymer science and nanotechnology hold significant potential for addressing the increasing demands of food security, by enhancing the shelf life, barrier properties, and nutritional quality of harvested fruits and vegetables. In this context, biopolymer-based delivery systems present themselves as a promising strategy for encapsulating bioactive compounds, improving their absorption, stability, and functionality. This study provides an exploration of the synthesis, characterization, and postharvest protection applications of nanocarriers formed through the complexation of chitosan oligomers, carboxymethylcellulose, and alginate in a 2:2:1 molar ratio. This complexation process was facilitated by methacrylic anhydride and sodium tripolyphosphate as cross-linking agents. Characterization techniques employed include transmission electron microscopy, energy-dispersive X-ray spectroscopy, infrared spectroscopy, thermal analysis, and X-ray powder diffraction. The resulting hollow nanospheres, characterized by a monodisperse distribution and a mean diameter of 114 nm, exhibited efficient encapsulation of carvacrol, with a loading capacity of approximately 20%. Their suitability for phytopathogen control was assessed in vitro against three phytopathogens-Botrytis cinerea, Penicillium expansum, and Colletotrichum coccodes-revealing minimum inhibitory concentrations ranging from 23.3 to 31.3 µg·mL-1. This indicates a higher activity compared to non-encapsulated conventional fungicides. In ex situ tests for tomato (cv. 'Daniela') protection, higher doses (50-100 µg·mL-1, depending on the pathogen) were necessary to achieve high protection. Nevertheless, these doses remained practical for real-world applicability. The advantages of safety, coupled with the potential for a multi-target mode of action, further enhance the appeal of these nanocarriers.
Subject(s)
Chitosan , Cymenes , Solanum lycopersicum , Carboxymethylcellulose Sodium , AlginatesABSTRACT
The presented study was focused on the simple, eco-friendly synthesis of composite hydrogels of crosslinked carboxymethyl cellulose (CMC)/alginate (SA) with encapsulated g-C3N4 nanoparticles. The structural, textural, morphological, optical, and mechanical properties were determined using different methods. The encapsulation of g-C3N4 into CMC/SA copolymer resulted in the formation of composite hydrogels with a coherent structure, enhanced porosity, excellent photostability, and good adhesion. The ability of composite hydrogels to eliminate structurally different dyes with the same or opposite charge properties (cationic Methylene Blue and anionic Orange G and Remazol Brilliant Blue R) in both single- and binary-dye systems was examined through adsorption and photocatalytic reactions. The interactions between the dyes and g-C3N4 and the negatively charged CMC/SA copolymers had a notable influence on both the adsorption capacity and photodegradation efficiency of the prepared composites. Scavenger studies and leaching tests were conducted to gain insights into the primary reactive species and to assess the stability and long-term performance of the g-C3N4/CMC/SA beads. The commendable photocatalytic activity and excellent recyclability, coupled with the elimination of costly catalyst separation requirements, render the g-C3N4/CMC/SA composite hydrogels cost-effective and environmentally friendly materials, and strongly support their selection for tackling environmental pollution issues.
Subject(s)
Alginates , Carboxymethylcellulose Sodium , Coloring Agents , Hydrogels , Water Pollutants, Chemical , Carboxymethylcellulose Sodium/chemistry , Hydrogels/chemistry , Alginates/chemistry , Coloring Agents/chemistry , Catalysis , Water Pollutants, Chemical/chemistry , Methylene Blue/chemistry , Azo Compounds/chemistry , Nitriles/chemistry , Nitrogen Compounds/chemistry , Photolysis , Adsorption , Green Chemistry Technology/methods , Anthraquinones , GraphiteABSTRACT
Nanoscale zerovalent iron (Fe0)-based materials have been demonstrated to be a effective method for the U(VI) removal. However, limited research has been conducted on the long-term immobilization efficiency and mechanism of Fe0-based materials for U(VI), which are essential for achieving safe handling and disposal of U(VI) on a large scale. In this study, the prepared carboxymethyl cellulose (CMC) and sulfurization dual stabilized Fe0 (CMC-Fe0/FeS) exhibited excellent long-term immobilization performances for U(VI) under both anoxic and oxic conditions, with the immobilization efficiencies were respectively reached over 98.0 % and 94.8 % after 180 days of aging. Most importantly, different from the immobilization mechanisms of the fresh CMC-Fe0/FeS for U(VI) (the adsorption effect of -COOH and -OH groups, coordination effect with sulfur species, as well as reduction effect of Fe0), the re-mobilized U(VI) were finally re-immobilized by the formed FeOOH and Fe3O4 on the aged CMC-Fe0/FeS. Under anoxic conditions, more Fe3O4 was produced, which may be the main reason for the long-term immobilization U(VI). Under oxic conditions, the production of Fe3O4 and FeOOH were relatively high, which both played significant roles in re-immobilizing U(VI) through surface complexation, reduction and incorporation effects.
Subject(s)
Uranium , Carboxymethylcellulose Sodium , Iron , AdsorptionABSTRACT
Due to traumatic injuries, including those from surgical procedures, adhesions occur in over 50% of cases, necessitating exclusive surgical intervention for treatment. However, preventive measures can be implemented during abdominal organ surgeries. These measures involve creating a barrier around internal organs to forestall adhesion formation in the postoperative phase. Yet, the effectiveness of the artificial barrier relies on considerations of its biocompatibility and the avoidance of adverse effects on the body. This study explores the biocompatibility aspects, encompassing hemocompatibility, cytotoxicity, and antibacterial and antioxidant activities, as well as the adhesion of blood serum proteins and macrophages to the surface of new composite film materials. The materials, derived from the sodium salt of carboxymethylcellulose modified by glycoluril and allantoin, were investigated. The research reveals that film materials with a heterocyclic fragment exhibit biocompatibility comparable to commercially used samples in surgery. Notably, film samples developed with glycoluril outperform the effects of commercial samples in certain aspects.
Subject(s)
Hyaluronic Acid , Urea , Humans , Tissue Adhesions/prevention & control , Carboxymethylcellulose SodiumABSTRACT
The progressive decline of the coal industry necessitates the development of effective treatment solutions for acid mine drainage (AMD), which is characterized by high acidity and elevated concentrations of heavy metals. This study proposes an innovative approach leveraging sulfate-reducing bacteria (SRB) acclimated to contaminated anaerobic environments. The research focused on elucidating the physiological characteristics and optimal growth conditions of SRB, particularly in relation to the pH level and temperature. The experimental findings reveal that the SRB exhibited a sulfate removal rate of 88.86% at an optimal temperature of 30 °C. Additionally, SRB gel particles were formulated using sodium alginate (SA) and carboxymethyl cellulose (CMC), and their performance was assessed under specific conditions (pH = 6, C/S = 1.5, T = 30 °C, CMC = 4.5%, BSNa = 0.4 mol/L, and cross-linking time = 9 h). Under these conditions, the SRB gel particles demonstrated an enhanced sulfate removal efficiency of 91.6%. Thermal analysis via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) provided further insights into the stability and properties of the SRB gel spheres. The findings underscore the potential of SRB-based bioremediation as a sustainable and efficient method for AMD treatment, offering a novel and environmentally friendly solution to mitigating the adverse effects of environmental contamination.
Subject(s)
Biodegradation, Environmental , Mining , Hydrogen-Ion Concentration , Alginates/chemistry , Sulfates/chemistry , Bacteria/metabolism , Temperature , Gels/chemistry , Carboxymethylcellulose Sodium/chemistry , Metals, Heavy/chemistry , Metals, Heavy/isolation & purification , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/isolation & purificationABSTRACT
In the current study, a novel methylene blue (MB)-based colorimetric method for a quick, inexpensive, and facile approach for the determination of fouling intensity of reverse osmosis (RO) membrane has been reported. This technique is based on the interaction of MB with the organic foulants and shows the corresponding change in the colour intensity depending on the severity of fouling. The organic foulants, such as albumin, sodium alginate, and carboxymethyl cellulose (CMC), were chosen as model foulants, and the membranes were subjected to foul under extreme fouling conditions. The fouled membranes underwent an MB treatment followed by image-processing analyses. The severity of surface fouling of membranes was evaluated in terms of fouling intensity and correlated with the corresponding decline of permeate flux. The maximum fouling intensity of the albumin, sodium alginate, and CMC sodium were found to be 8.83, 23.38, and 9.19%, respectively, for the definite concentration of foulants. The physico-chemical interactions of the given foulants and MB were confirmed by changes in zeta potentials and increased sizes of the foulant by the dynamic light scattering technique. The surface fouling over the membrane surface was confirmed by the characterization of membranes.
Subject(s)
Colorimetry , Methylene Blue , Albumins , Alginates , Carboxymethylcellulose Sodium , OsmosisABSTRACT
Geosynthetic clay liners (GCLs) are mostly used as flow barriers in landfills and waste containments due to their low hydraulic conductivity to prevent the leachate from reaching the environment. The self-healing and swell-shrink properties of soft clays (expansive soils) such as bentonite enable them as promising materials for the GCL core layers. However, it is important to modify their physico-chemical properties in order to overcome the functional limitations of GCL under different hydraulic conditions. In the present study, locally available black cotton soil (BCS) is introduced in the presence of an anionic polymer named carboxymethyl cellulose (CMC) as an alternative to bentonite to enhance the hydraulic properties of GCL under different compositions. The modified GCL is prepared by stitching the liner with an optimum percentage of CMC along with various percentages of BCS mixed with bentonite. Hydraulic conductivity tests were performed on the modified GCL using the flexi-wall permeameter. The results suggest that the lowest hydraulic conductivity of 4.58 × 10-10 m/s is obtained when 25% of BCS is blended with bentonite and an optimum 8% CMC and further addition of BCS results in the reduction of the hydraulic conductivity.
Subject(s)
Bentonite , Refuse Disposal , Bentonite/chemistry , Clay , Soil , Methylcellulose , Refuse Disposal/methods , Carboxymethylcellulose SodiumABSTRACT
This study explores nitrate reduction in aqueous solutions using carboxymethyl cellulose loaded with zero-valent iron nanoparticles (Fe0-CMC). The structures of this nano-composite were characterized using various techniques. Based on the characterization results, the specific surface area of Fe0-CMC measured by the Brunauer-Emmett-Teller analysis were 39.6 m2/g. In addition, Scanning Electron Microscopy images displayed that spherical nano zero-valent iron particles (nZVI) with an average particle diameter of 80 nm are surrounded by carboxymethyl cellulose and no noticeable aggregates were detected. Batch experiments assessed Fe0-CMC's effectiveness in nitrate removal under diverse conditions including different adsorbent dosages (Cs, 2-10 mg/L), contact time (t, 10-1440 min), initial pH (pHi, 2-10), temperature (T, 10-55 °C), and initial concentration of nitrate (C0, 10-500 mg/L). Results indicated decreased removal with higher initial pHi and C0, while increased Cs and T enhanced removal. The study of nitrate removal mechanism by Fe0-CMC revealed that the redox reaction between immobilized nZVI on the CMC surface and nitrate ions was responsible for nitrate removal, and the main product of this reaction was ammonium, which was subsequently completely removed by the synthesized nanocomposite. In addition, a stable deviation quantum particle swarm optimization algorithm (SD-QPSO) and a least square error method were employed to train the ANFIS parameters. To demonstrate model performance, a quadratic polynomial function was proposed to display the performance of the SD-QPSO algorithm in which the constant parameters were optimized through the SD-QPSO algorithm. Sensitivity analysis was conducted on the proposed quadratic polynomial function by adding a constant deviation and removing each input using two different strategies. According to the sensitivity analysis, the predicted removal efficiency was most sensitive to changes in pHi, followed by Cs, T, C0, and t. The obtained results underscore the potential of the ANFIS model (R2 = 0.99803, RMSE = 0.9888), and polynomial function (R2 = 0.998256, RMSE = 1.7532) as accurate and efficient alternatives to time-consuming laboratory measurements for assessing nitrate removal efficiency. These models can offer rapid insights and predictions regarding the impact of various factors on the process, saving both time and resources.