RESUMO
The development of environmentally friendly adsorbents has become increasingly important for treating waste generated by the growing global industry. In this study, new biosorbents were synthesized from an all-natural chitosan and watermelon pulp for the treatment of congo red textile dye from water. Biosorbents were prepared by lyophilizing chitosan-added watermelon pulp (AC-WPC). The prepared biosorbents were characterized by BET, SEM, Zeta Potential and FT-IR analysews. Accordingly, the BET surface area of AC-WPC was 120.92 m2/g. SEM analysis showed that the structures were porous and the results were consistent with the BET analysis. FT-IR analysis confirmed the chemical structures. The isoelectric points of the biosorbents were determined by zeta potential analysis. The AC-WPC biosorbent demonstrated 86% cell viability with cytotoxicity testing. For this reason, it was determined that the AC-WPC biosorbents produced does not cause any serious damage to the cell. Following this, adsorption study of congo red textile dye in water was carried out with these biosorbents. Langmuir and Freundlich isotherms were studied in adsorption experiments, and it was found that the Freundlich isotherms were compatible. Pseudo first and second kinetic models were also studied and found to be compatible with Pseudo Second Kinetic Model. The highest adsorption capacity was observed at 100 mg/l congo red concentration with 98.02% removal and 490.1 mg/g adsorption capacity using AC-WPC. It is thought that these results will potentially contribute to the literature on the removal of textile dyes or other pollutants using chitosan-added watermelon pulp.
Assuntos
Quitosana , Citrullus , Vermelho Congo , Poluentes Químicos da Água , Vermelho Congo/química , Quitosana/química , Citrullus/química , Adsorção , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier , Humanos , Sobrevivência Celular/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Corantes/química , Corantes/toxicidade , Corantes/isolamento & purificaçãoRESUMO
Magnetic Co0.5Mn0.5Fe2O4 nanoparticles were successfully prepared via the combustion and calcination process, with an average particle diameter of 31.5 nm and a saturation magnetization of 25.25 emu·g-1, they were employed to adsorbe Congo red (CR) from wastewater, the Pseudo-second-order kinetic and Freundlich isotherm were consistent with the adsorption data, indicating that their adsorption was a multilayer chemisorption process, the thermodynamic investigation showed that the adsorption was a favored exothermic process. The ionic strength of Cl- in CR solution had no obvious effect on the adsorption efficiency of Co0.5Mn0.5Fe2O4 nanoparticles, and the maximum adsorbance was 58.3 mg·g-1 at pH 2, decreasing as the pH of the CR solutions increased from 2 to 12. The ion leaching experiment and XRD demonstrated that Co0.5Mn0.5Fe2O4 nanoparticles had excellent stability, and the relative removal rate was 93.85% of the first time after 7 cycles. Cyclic voltammetry and electrochemical impedance spectroscopy demonstrated that CR was adsorbed onto Co0.5Mn0.5Fe2O4 nanoparticles, and the electrical conductivity of Co0.5Mn0.5Fe2O4 nanoparticles decreased after adsorption of CR. Magnetic Co0.5Mn0.5Fe2O4 nanoparticles displayed a promising application in wastewater treatment.
Assuntos
Cobalto , Vermelho Congo , Compostos Férricos , Compostos de Manganês , Termodinâmica , Adsorção , Cinética , Cobalto/química , Compostos Férricos/química , Vermelho Congo/química , Compostos de Manganês/química , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio , Águas Residuárias/química , Purificação da Água/métodos , Nanopartículas/química , Concentração Osmolar , Técnicas Eletroquímicas/métodosRESUMO
Treating dye-containing wastewater poses numerous challenges due to its high chemical complexity and its persistent nature. Thus, the present study aims to synthesize biochar derived from banana peel (BC) and its nanocomposites with copper oxide nanoparticles (CuOx/BC1-x) for the purpose of adsorptive removing Congo red (CR) dye from water. Several analytical methods were utilized to describe the physicochemical features of the CuOx/BC1-x nanocomposites. It was found that the crystallinity of the nanocomposites gradually improved, while the specific surface area and the surface electronegativity were reduced with increasing x value. The effects of x values (0-0.5), interaction time (10-120 min), adsorbent dose (0.01-0.05 g), initial CR concentration (20-200 mg/L), and the solution temperature (20-60 °C) were evaluated on CR removal. The obtained results revealed that the CuO0.5/BC0.5 nanocomposite showed the highest adsorption efficiency with a maximum adsorption capacity of 233.6 mgg-1. Analysis of the equilibrium experimental data revealed that the Langmuir and the pseudo-2nd-order models were the most proper to describe the current adsorption process. Moreover, the thermodynamics studies demonstrated that the adsorption process was spontaneous, endothermic, and random.
Assuntos
Carvão Vegetal , Vermelho Congo , Cobre , Musa , Poluentes Químicos da Água , Purificação da Água , Musa/química , Vermelho Congo/química , Carvão Vegetal/química , Purificação da Água/métodos , Adsorção , Poluentes Químicos da Água/química , Cobre/química , Nanocompostos/química , Corantes/química , Águas Residuárias/química , CinéticaRESUMO
The utilization of electroplating sludge (ES) to derive metal oxide functional materials is a key strategy, as it enables the recycling of valuable elements, mitigates environmental risks, and aligns with green, low-carbon development strategies. Nevertheless, the development of metal oxide composite functional materials with distinctive structures and properties derived from ES continues to present several challenges. Herein, we synthesized CuFe2O4/MgFe2O4 metal oxide composites from ES by one-step hydrothermal method. As-obtained CuFe2O4/MgFe2O4 metal oxide composites (MMOs) have a unique layered structure, richer mesoporous and microporous structures, activity sites. When evaluated as an adsorbent for Congo red (CR), as-synthesized CuFe2O4/MgFe2O4 with layered structure composite exhibited excellent adsorption capacity (1039.1 mg/g) and reusability (85.55% after five cycles), which was superior to most similar adsorbents reported till date. Such improvement is explored to mainly originate from two respects: the physical adsorption facilitated by the abundant pores formed through the stacking and growth of CuFe2O4 and MgFe2O4, and the chemisorption resulting from surface complexation and hydrogen bonding between the MMOs and CR. This strategy to directly transform ES into functional materials shows great promise both in waste management and preparation of robust adsorbents for wastewater treatment.
Assuntos
Vermelho Congo , Galvanoplastia , Esgotos , Vermelho Congo/química , Esgotos/química , Adsorção , Cobre/química , Poluentes Químicos da Água/química , Óxidos/química , Compostos FerrososRESUMO
Herein, we report two different adsorbents from spherical nanocellulose (SNC) in successive steps, for the adsorption of Hg2+ ions and Congo red (CR). Cellulose extracted from pine needles was subsequently converted to SNC through mixed acidic hydrolysis. As-obtained SNC was esterified with methionine at C6 of the anhydroglucose unit to produce SNC-methionine ester (SNC-ME). The amino group of methionine residue in SNC-ME was protonated to SNC-PME with positive surface charge. The SNC-ME and SNC-PME were evaluated as Hg2+ ions and CR adsorbents, respectively. The SNC, SNC-ME, SNC-PME, Hg2+-loaded SNC-ME, and CR-loaded SNC-PME were characterized by FTIR, XRD, XPS, Zeta potential, BET, FESEM, EDS, and surface charge analysis. SNC-ME showed Hg2+ ions removal efficiency of 94.8 ± 1.9 % in 40 min, while SNC-PME showed CR removal efficiency of 96.1 ± 3.8 % in 90 min. The adsorption data of both the adsorbents fitted best into pseudo-second order kinetic and Langmuir isotherm. The maximum adsorption capacity of SNC-ME for Hg2+ ions was 211.5 ± 3.1 mg/g and that of SNC-PME for CR was 281.1 ± 7.1 mg/g. The astounding recyclability of the adsorbents for ten repeat cycles with significant cumulative adsorption capacity of 760.9 ± 12.8 mg/g for Hg2+ ions and 758.8 ± 12.7 mg/g for CR endorses their spectacular potentiality for wastewater treatment.
Assuntos
Celulose , Vermelho Congo , Mercúrio , Metionina , Celulose/química , Adsorção , Mercúrio/química , Mercúrio/isolamento & purificação , Metionina/química , Vermelho Congo/química , Vermelho Congo/isolamento & purificação , Esterificação , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Cinética , Prótons , Purificação da Água/métodos , Íons/química , Nanoestruturas/químicaRESUMO
Efficient capture of dyes from wastewater is of great importance for environmental remediation. Yet constructing adsorbents with satisfactory adsorption efficiency and low cost remains a major challenge. This work reports a simple and scalable method for the fabrication of functionalized porous pullulan hydrogel adsorbent decorated with ATTM@ZIF-8 for the adsorption of congo red (CR) and malachite green (MG). The embedding of ammonium tetrathiomolybdate (ATTM) into the ZIF-8 nanoclusters offered additional adsorption sites and enlarged the pore size of the resulting ATTM@ZIF-8. The homogeneous dispersion of the nanoparticles in the three-dimensional network of polysaccharide gels prevents their agglomeration and thus improves the affinity for dye molecules. The resulting adsorbent AZP-20 at optimized composite ratios exhibits high activity, selectivity, interference resistance, reusability and cytocompatibility in dye adsorption applications, and possesses high removal rate of dye in real water systems. Batch experiments demonstrated that the adsorption rate of AZP-20 for MG and CR was 1645.28 mg g-1 and 680.33 mg g-1, and would be influenced by pH conditions. Adsorption kinetics followed pseudo-second-order model. Adsorption isotherms followed Langmuir model for MG and Freundlich model for CR. The adsorption of dye molecules primarily relied on electrostatic interaction (MG) and π-π stacking interaction (CR). Conclusively, the prepared AZPs adsorbent illuminated good application prospects in the treatment of complex component dye wastewater.
Assuntos
Vermelho Congo , Glucanos , Hidrogéis , Corantes de Rosanilina , Poluentes Químicos da Água , Corantes de Rosanilina/química , Vermelho Congo/química , Vermelho Congo/isolamento & purificação , Hidrogéis/química , Adsorção , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Glucanos/química , Cinética , Purificação da Água/métodos , Concentração de Íons de Hidrogênio , Corantes/química , Águas Residuárias/químicaRESUMO
A novel composite hydrogel prepared from polyacrylamide (PAM), polydopamine-modified montmorillonite (PDA@MMT), graphene and hydroxypropyl cellulose (HPC), loaded with Ag NPs, was prepared for the catalytic degradation of methylene blue (MB) and Congo red (CR) using in situ reduction. HPC significantly enhanced the dispersion of PDA@MMT within the hydrogel, endowing the hydrogel with excellent mechanical properties, with stress and strain of 1773 kPa and 4005 %, and elastic modulus and toughness of 43.4 kPa and 29.54 MJ/m3, respectively. The introduction of graphene (GN) increased the rate of electron transfer during the catalytic process and significantly improved the catalytic efficiency, with catalytic rate constants of 1.360 and 0.803 min-1 for MB and CR at 20 °C, respectively. The hydrogels were endowed with excellent antimicrobial properties due to the introduction of Ag NPs. In the future, this hydrogel is expected to play an important role in environmental pollution control.
Assuntos
Grafite , Hidrogéis , Nanopartículas Metálicas , Azul de Metileno , Prata , Prata/química , Catálise , Grafite/química , Hidrogéis/química , Nanopartículas Metálicas/química , Azul de Metileno/química , Vermelho Congo/química , Polímeros/química , Bentonita/química , Indóis/química , Resinas Acrílicas/químicaRESUMO
Two polyurethane polyaniline nanocomposites have been synthesized using two in situ polymerization routes of dried and wet bases to valorize the polyurethane waste. The physical and chemical properties of polyurethane-based nanocomposites were compared using SEM, XRD, FTIR, and Zeta potential. SEM images showed that the average particle size of the dried-based composite was 56 nm, while the wet-based composite had an average size of 75 nm. The separation efficiency for methylene blue (MB) and Congo red (CR) dyes was evaluated against free polyurethane foam waste. It was evident that pure polyurethane (PPU) achieved only 4.79% and 16.71% removal for MB and CR, respectively. These dye decontamination efficiencies were enhanced after nano polyaniline decoration of polyurethane foam either through dried base polymerization (DPUP) or wet base polymerization (WPUP). WPUP composite records 11.23% and 85.99% for MB and CR removal, respectively, improved to 26.69% and 90.07% removal using DPUP composite for the respective dyes. The adsorption kinetics, isotherms, and thermodynamics were investigated. The experimental results revealed the pseudo-second-order kinetic model as the most accurately described kinetics model for both CR and MB adsorption. The Langmuir model provided the best fit for the data, with maximum adsorption capacities of 110.98 mg/g for CR and 26.86 mg/g for MB, with corresponding R-squared values of 0.9974 and 0.9608, respectively. Regeneration and reusability studies of PPU, WPUP, and DPUP showed effective reusability, with DPUP displaying the highest adsorption capacity. These results aid in creating eco-friendly and cost-efficient adsorbents for dye removal in environmental sanitation.
Assuntos
Compostos de Anilina , Corantes , Nanocompostos , Poliuretanos , Poluentes Químicos da Água , Poliuretanos/química , Compostos de Anilina/química , Corantes/química , Poluentes Químicos da Água/química , Nanocompostos/química , Adsorção , Azul de Metileno/química , Eliminação de Resíduos Líquidos/métodos , Descontaminação/métodos , Cinética , Vermelho Congo/químicaRESUMO
Microalgae-fungal pellets were applied as novel dual-biosorbents for dye removal compared to fungal pellets. Both pellet types effectively removed anionic dyes better than cationic dyes, with the maximum adsorbing efficiency being nearly 100 % at a wide pH range of 3-8. The adsorption isotherms of anionic Congo Red dye and Coomassie brilliant blue R-250 dye using both pellet types and their biosorption kinetics were intensively studied. Noteworthy, the maximum adsorption capacity and affinity of microalgae-fungal pellets were much higher than those of fungal pellets. Both fungal pellets were also applied in the bioremediation of palm oil mill effluent (POME). The repeated treatment of POME by replacing pellets every 12 h enhanced the percent removal of color, phenolic compounds, and COD up to 90.97 ± 0.36 %, 70.71 ± 0.90 % and 56.55 ± 1.98 %, respectively. This study has demonstrated the promising potential for addressing dye removal and bioremediation of colored-industrial effluent in a sustainable and economically viable manner.
Assuntos
Biodegradação Ambiental , Corantes , Resíduos Industriais , Microalgas , Óleo de Palmeira , Óleos de Plantas , Poluentes Químicos da Água , Óleo de Palmeira/química , Corantes/química , Corantes/metabolismo , Óleos de Plantas/química , Óleos de Plantas/metabolismo , Adsorção , Microalgas/metabolismo , Concentração de Íons de Hidrogênio , Fungos/metabolismo , Cinética , Purificação da Água/métodos , Vermelho Congo/química , Águas Residuárias/química , Análise da Demanda Biológica de OxigênioRESUMO
This context summarizes a detail on the fabrication of Acacia senegal Gum Hydrogel (ASGh) within well-engineered microemulsion, and thereafter chemical modification for environmental remediation. In brief, Divinylsulfone was used to crosslink polymeric chains and produce ASGh in Ë50 µm size within the reverse-microemulsion of Natrium-bis-(2-ethylhexyl) sulfosuccinate in gasoline. ASGh were subjected to chemical modification via versatile diethylenetriamine to produce m-[ASGh] for adsorptive removal of methyl orange (MO), eosin Y (EY) and congo red (CR) from waste-water. ASGh and m-[ASGh] were characterized through Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and zeta potential measurements. For instance, FT-IR spectra depicted new bands upon Diethylenetriamine modification. The zeta potential measurements confirm a positively charged surface of m-[ASGh] upon Diethylenetriamine addition. Interestingly, 0.05 g m-[ASGh] demonstrated 91.0, 84.1, and 73.0 % removal efficiency towards MO, EY and CR, respectively in 2 h equilibrium time. Langmuir, Freundlich and modified-Freundlich isotherms were applied to further delineate adsorption data. Modified-Freundlich model depicted comparatively more agreeable fit, and delivered R2 value nearer to unity. Further, 143 mg·g-1, 130 mg·g-1 and, 116 mg·g-1 maximum adsorption capacity (QM) was represented by m-[ASGh] towards MO, EY and CR, respectively in 2 h. Interestingly, real water sample were tested whereby, the QM against MO, EY and CR was 146 mg·g-1, 132 mg·g-1 and, 111 mg·g-1, respectively in 2 h equilibrium time. To conclude, m-[ASGh] could be treated as decolorizing agent in real waste-water polluted through negatively charged organic pollutants, particularly MO.
Assuntos
Goma Arábica , Hidrogéis , Poluentes Químicos da Água , Purificação da Água , Adsorção , Hidrogéis/química , Hidrogéis/síntese química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Goma Arábica/química , Cinética , Purificação da Água/métodos , Resíduos Industriais , Acacia/química , Espectroscopia de Infravermelho com Transformada de Fourier , Águas Residuárias/química , Vermelho Congo/química , Compostos Azo/química , Compostos Azo/isolamento & purificaçãoRESUMO
Amyloid fibril formation is a central biochemical process in pathology and physiology. Over decades, substantial advances were made in elucidating the mechanisms of amyloidogenesis, its links to disease, and the production of functional supramolecular structures. While the term "amyloid" denotes starch-like features of these assemblies, no evidence of amyloidogenic behavior of polysaccharides has been so far reported. Here, we investigate the potential of amylum (starch) not only to self-assemble into hierarchical fibrillar structures but also to exhibit canonical amyloidogenic properties. Ordered amylum structures were formed through a sigmoidal growth process with characteristic amyloid features including typical nanofibril morphology, binding to indicative dyes, inherent luminescence, apple-green birefringence upon Congo red staining, and notable mechanical rigidity. These findings shed light on polysaccharide self-assembly and expand the generic amyloid phenomenon.
Assuntos
Amiloide , Amiloide/química , Amiloide/metabolismo , Amido/química , Vermelho Congo/químicaRESUMO
The widespread use of synthetic dyes has serious implications for both the environment and human health. Therefore, there is an urgent need for the development of novel, high-efficiency adsorbents for these dyes. In this study, a Zirconium-based metal-organic framework (MOF) with controllable morphology was in-situ grown on bacterial nanocellulose (BC) via a solvothermal method. The resulting BC@MOF composite nanofibers have a high specific surface area of 651 m2/g and can be assembled into a self-supported porous membrane (BMMCa) through vacuum filtration with the assistance of calcium ions. The addition of Ca(II) significantly enhanced the mechanical properties of the membrane through dispersion effect and electrostatic interactions, as well as enhancing its adsorption performance through the salting-out effect. The BMMCa membrane, with its hierarchical porous structure and high flux, exhibits high selectivity for Congo red (CR) with an ultra-high adsorption capacity of 3518.6 mg/g. Furthermore, the self-supporting membrane achieved rapid and convenient removal of CR through circulating filtration adsorption. The adsorption mechanism and selectivity were verified through the molecular dynamics simulation calculations by Materials Studio (MS) software. This membrane-based adsorbent, with its ultra-high adsorption capacity, good selectivity, and recycling ability, has great potential for practical wastewater treatment applications.
Assuntos
Celulose , Vermelho Congo , Estruturas Metalorgânicas , Celulose/química , Estruturas Metalorgânicas/química , Vermelho Congo/química , Vermelho Congo/isolamento & purificação , Adsorção , Porosidade , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Nanofibras/química , Membranas Artificiais , Simulação de Dinâmica Molecular , Zircônio/química , BactériasRESUMO
The work was aimed at evaluating the adsorptive properties of waste newspaper (WN) activated carbons chemically produced using sodium salts for methylene blue (MB) and congo red (CR) removal. The activated carbons, designated as AC1, AC2, AC3 and AC4 were prepared through impregnation with NaH2PO4, Na2CO3, NaCl and NaOH, respectively and activation at 500 °C for 1 h. The activated carbons were characterized for surface chemistry, thermal stability, specific area, morphology and composition. The AC1 with a surface area of 917 m2/g exhibits a greater MB capacity of 651 mg/g. Meanwhile, a greater CR capacity was recorded by AC2 at 299 mg/g. The pseudo-second order model fitted well with the kinetic data, while the equilibrium data could be described by Langmuir model. The thermodynamic parameters, i.e.., positive ΔH°, negative ΔG° and positive ΔS° suggest that the adsorption of dyes is endothermic, spontaneous and feasible at high solution temperature. To conclude, WN is a potential cellulose source for producing activated carbon, while NaH2PO4 activation could be employed to convert WN into activated carbon for effective dye wastewater treatment.
Assuntos
Celulose , Carvão Vegetal , Vermelho Congo , Azul de Metileno , Azul de Metileno/química , Celulose/química , Vermelho Congo/química , Adsorção , Carvão Vegetal/química , Cinética , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Papel , Purificação da Água/métodos , Termodinâmica , Sais/química , TemperaturaRESUMO
Adsorptive membranes for the efficient separation of dyes with the same charges are quite desirable. Herein, a novel membrane of lanthanum hydroxide/cellulose hydrogel coated filter paper (LC) was prepared through a facile strategy of dip-coating followed by freeze-shaping. With the aid of cellulose gel, the generated La(OH)3 achieved fine dispersion. In addition, the pore size of LC membrane could be regulated by altering the cellulose concentration or the lanthanum chloride dosage, which was crucial for its water flux. In particular, the obtained membrane possessed a high water flux (128.4 L m-2 h-1) and a high dye rejection (97.2 %) for anionic Congo red (CR) only driven by the gravity, which outperformed many previously reported membranes. More intriguingly, its dye rejection for anionic methyl orange (MO) was only 0.9 %, exhibiting high selectivity for dyes with the same charges. Single-solute adsorption experiments indicated that the CR adsorption on the membrane was best fitted by the pseudo-first-order kinetic model, and it followed the Langmuir monolayer adsorption mechanism.
Assuntos
Celulose , Corantes , Lantânio , Membranas Artificiais , Lantânio/química , Celulose/química , Corantes/química , Corantes/isolamento & purificação , Porosidade , Adsorção , Cinética , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Hidróxidos/química , Vermelho Congo/química , Vermelho Congo/isolamento & purificaçãoRESUMO
Nanocomposites have emerged as promising materials for pollutant removal due to their unique properties. However, conventional synthesis methods often involve toxic solvents or expensive materials. In this study, we present a novel ternary nanocomposite synthesized via a simple, cost-effective vacuum filtration method. The composite consists of calcium phosphate (CaP), biowaste-derived nanocellulose (diameter <50 nm) (NC), and chitosan (CH). The nanocomposite exhibited exceptional pollutant removal capabilities due to the hybrid approach of combining adsorption and size exclusion that widens and accelerates pollutant removal. When tested with synthetic wastewater containing 10 ppm of Ni ions and 10 ppm of Congo red (CR) dye, it achieved impressive removal rates of 98.7% for Ni ions and 100% for CR dye. Moreover, the nanocomposite effectively removed heavy metals such as Cd, Ag, Al, Fe, Hg, Mo, Li, and Se at 100%, and Ba, Be, P, and Zn at 80%, 92%, 87%, and 97%, respectively, from real-world municipal wastewater. Importantly, this green nanocomposite membrane was synthesized without the use of harmful chemicals or complex modifications and operated at a high flux rate of 146 L/m2.h.MPa. Its outstanding performance highlights its potential for sustainable pollutant removal applications.
Assuntos
Fosfatos de Cálcio , Celulose , Quitosana , Nanocompostos , Águas Residuárias , Poluentes Químicos da Água , Nanocompostos/química , Águas Residuárias/química , Quitosana/química , Poluentes Químicos da Água/química , Celulose/química , Fosfatos de Cálcio/química , Adsorção , Metais Pesados/química , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Vermelho Congo/químicaRESUMO
Biomaterials like chitosan, hydroxyapatite have been used in biomedical and pharmaceutical field, due to its valuable biochemical and physiological properties. In current work firstly our group has isolated a polysaccharide chitosan along with hydroxyapatite biomaterial from the same source by varying the process condition via greener approach. We have adapted greener approach for the isolation of chitosan within a short period of time and this is the very first report for the isolation of both chitosan and hydroxyapatite simultaneously from the same waste edible garden snail shells. Both these materials were thoroughly characterized by using UV, FT-IR, SEM techniques. Among synthetic colourants, congo red dye is recognized as carcinogens, which are usually used in the textile manufacturing. Interestingly, one of our biomaterial hydroxyapatite has shown good selectivity towards Congo red dye. The sensitivity range was obtained from 10 to 100 µM within the LOD of 101.52 nM. The developed sensor has been tested for various industrial effluents and shown good agreement with our results. Meanwhile these chitosan and hydroxyapatite have also been used as capping agent for the preparation of stable gold nanoparticles.
Assuntos
Quitosana , Vermelho Congo , Durapatita , Quitosana/química , Vermelho Congo/química , Animais , Durapatita/química , Caramujos/química , Exoesqueleto/química , Química Verde/métodos , Corantes/química , Corantes/isolamento & purificação , Corantes/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Nanopartículas Metálicas/química , Ouro/químicaRESUMO
More sustainable materials have been becoming an important concern of worldwide scientists, and cellulosic materials are one alternative in water decontamination. An efficient strategy to improve removal capacity is functionalizing or incorporating nanomaterials in cellulose-based materials. The new hybrid cDAC/ZnONPs was produced by green synthesis of zinc oxide nanoparticles (ZnONPs), promoting the in situ reduction and immobilization on the cationic dialdehyde cellulose microfibers (cDAC) surface to remove Congo red dye from water. cDAC/ZnONPs was characterized by scanning electron microscopy (SEM-EDS) and infrared spectroscopy (FTIR), which showed efficient nanoparticles reduction. Adsorption efficiency on cationic cellulose surface was investigated by pH, contact time, initial concentration, and dye selectivity tests. The material followed the H isotherm model, which resulted in a maximum adsorption capacity of 1091.16 mg/g. Herein, was developed an efficient and ecologically correct new adsorbent, highly effective in Congo red dye adsorption even at high concentrations, suitable for the remediation of contaminated industrial effluents.
Assuntos
Vermelho Congo , Poluentes Químicos da Água , Purificação da Água , Óxido de Zinco , Óxido de Zinco/química , Vermelho Congo/química , Vermelho Congo/isolamento & purificação , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Purificação da Água/métodos , Química Verde , Concentração de Íons de Hidrogênio , Celulose/química , Celulose/análogos & derivados , Corantes/química , Nanopartículas/química , Cinética , Nanopartículas Metálicas/química , Celulose Oxidada/química , Cátions/químicaRESUMO
Wastewater textile dye treatment is a challenge that requires the development of eco-friendly technology to avoid the alarming problems associated with water scarcity and health-environment. This study investigated the potential of phengite clay as naturally low-cost abundant clay from Tamgroute, Morocco (TMG) that was activated with a 0.1 M NaOH base (TMGB) after calcination at 850 °C for 3 h (TMGC) before its application in the Congo red (CR) anionic dye from the aqueous solution. The effect of various key operational parameters: adsorbent dose, contact time, dye concentration, pH, temperature, and the effect of salts, was studied by a series of adsorption experiments in a batch system, which affected the adsorption performance of TMG, TMGC, and TMGB for CR dye removal. In addition, the properties of adsorption kinetics, isotherms, and thermodynamics were also studied. Experimental results showed that optimal adsorption occurred at an acidic pH. At a CR concentration of 100 mg L-1, equilibrium elimination rates were 68%, 38%, and 92% for TMG, TMGC, and TMGB, respectively. The adsorption process is rapid, follows pseudo-second-order kinetics, and is best described by a Temkin and Langmuir isotherm. The thermodynamic parameters indicated that the adsorption of CR onto TMGB is endothermic and spontaneous. The experimental values of CR adsorption on TMGB are consistent with the predictions of the response surface methodology. These led to a maximum removal rate of 99.97% under the following conditions: pH = 2, TMGB dose of 7 g L-1, and CR concentration of 50 mg L-1. The adsorbent TMGB's relatively low preparation cost of around $2.629 g-1 and its ability to regenerate in more than 6 thermal calcination cycles with a CR removal rate of around 56.98%, stimulate its use for textile effluent treatment on a pilot industrial scale.
Assuntos
Argila , Vermelho Congo , Hidróxido de Sódio , Poluentes Químicos da Água , Vermelho Congo/química , Adsorção , Argila/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/análise , Hidróxido de Sódio/química , Corantes/química , Silicatos de Alumínio/química , Concentração de Íons de Hidrogênio , Eliminação de Resíduos Líquidos/métodos , Eliminação de Resíduos Líquidos/economia , Purificação da Água/métodos , Purificação da Água/economia , Cinética , Águas Residuárias/química , TermodinâmicaRESUMO
Creating new adsorbents is crucial for removing contaminants from water due to increased industrialization, which has worsened water pollution in recent years. In this study, a magnetic biocomposite, Zirconium (Zr)-doped chitosan (CS)-coated iron oxide nanoparticles (Fe3O4-NPs)-peanut husk (PH)-based activated carbon (AC) (Zr-CS/Fe3O4-NPs@PH-AC), was synthesized for efficient removal of alizarin red (AR) and congo red (CR) dyes, alongside antibacterial applications. Characterization via scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis revealed micropores and mesopores development due to chemical activation of PH biomaterial and Fe3O4-NPs addition. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) identified functional groups and structural properties. Vibrating sample magnetometry (VSM) analyzed magnetic properties. Optimal conditions for AR/CR removal were determined, including Zr-CS/Fe3O4-NPs@PH-AC dose, dye dose, contact time, and temperature, achieving maximum removal percentages. Experimentally determined maximum adsorption capacities for AR and CR were 374.3 and 154.1 mg·g-1, respectively. Cytotoxicity studies affirmed the eco-friendly and non-toxic nature of the adsorbent by exhibiting the reduction in the cell viability from 100 % to 88.68 % from the 0 to 200 µg·L-1 respectively. Additionally, the biocomposite exhibited significant antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) due to magnetic NPs. The material in this study shows extreme compatibility for numerous applications.
Assuntos
Antibacterianos , Carvão Vegetal , Quitosana , Vermelho Congo , Águas Residuárias , Poluentes Químicos da Água , Zircônio , Quitosana/química , Zircônio/química , Vermelho Congo/química , Antibacterianos/farmacologia , Antibacterianos/química , Adsorção , Águas Residuárias/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Carvão Vegetal/química , Purificação da Água/métodos , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , AntraquinonasRESUMO
The release of industrial wastewater has adverse effects on both aquatic ecosystems and the environment. Discharging untreated organic dyes into aquatic environments significantly amplifies pollution levels in these ecosystems. Ensuring the appropriate disposal of organic colorants and their derivatives before introducing them into wastewater streams is essential to prevent environmental contamination. This study aimed to develop an eco-friendly and sustainable approach to synthesize a chitosan-functionalized silver (Ag) nanocomposite using Solanum trilobatum for color pollutant mitigation. The synthesized CS-Ag nanocomposite was analyzed using various techniques such as UV-visible, FTIR, TEM, and EDS. TEM analysis revealed that the CS-Ag nanocomposite had a spherical nanostructure, with diameters ranging from 17.4 to 43.9 nm. These nanocomposites were tested under visible light irradiation to analyze their photocatalytic character against Congo red (CR). The nanocomposite exhibited a remarkable dye removal efficiency of over 93.6% within 105 min under irradiation. In the experimental recycling study, the CS-Ag nanocomposites demonstrated remarkable stability and reusability. Furthermore, the CS-Ag nanocomposite exhibited promising inhibition activity against bacterial pathogens. Our research revealed that the synthesized nanocomposite has the potential to act as a highly effective photocatalyst and bactericidal agent in various industrial and clinical applications.