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2.
Int J Biol Macromol ; : 132329, 2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38744362

RESUMO

The present work develops an effective bioadsorbent of cross-linked chitosan-genipin/SiO2 adsorbent (CHI-GNP/SiO2). The developed CHI-GNP/SiO2 was employed for the removal of organic dye (reactive orange 16, RO16) from simulated wastewater. The optimization of the fundamental adsorption variables (CHI-GNP/SiO2 dose, time, and pH) via the Box-Behnken design (BBD) was attained for achieving maximal adsorption capacity and high removal efficiency. The good agreement between the Freundlich isotherms and empirical data of RO16 adsorption by CHI-GNP/SiO2 indicates that the adsorption process follows a multilayer adsorption mechanism. The reasonable agreement between the pseudo-second-order model and the kinetic data of RO16 adsorption by CHI-GNP/SiO2 was obtained. The maximum RO16 adsorption capacity (qmax) of CHI-GNP/SiO2 was identified to be 57.1 mg/g. The adsorption capacity of CHI-GNP/SiO2 is attributed to its unique surface properties, including its highly porous structure and the presence of functional groups such as amino and hydroxyl groups. According to the results of this investigation, CHI-GNP/SiO2 has the potential to be an adsorbent for the removal of acidic dyes from wastewater.

3.
Int J Phytoremediation ; : 1-12, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38711172

RESUMO

Herein, this work targets to employ the blended fruit wastes including rambutan (Nephelium lappaceum) peel and durian (Durio zibethinus) seed as a promising precursor to produce activated carbon (RPDSAC). The generation of RPDSAC was accomplished through a rapid and practical procedure (microwave-ZnCl2 activation). To evaluate the adsorptive capabilities of RPDSAC, its efficacy in eliminating methylene blue (MB), a simulated cationic dye, was measured. The Box-Behnken design (BBD) was utilized to optimize the crucial adsorption parameters, namely A: RPDSAC dose (0.02-01 g/100 mL), B: pH (4-10), and C: time (2-6 min). The BBD design determined that the highest level of MB removal (79.4%) was achieved with the condition dosage of RPDSAC at 0.1 g/100 mL, contact time (6 min), and pH (10). The adsorption isotherm data is consistent with the Freundlich concept, and the pseudo-second-order versions adequately describe the kinetic data. The monolayer adsorption capacity (qmax) of RPDSAC reached 120.4 mg/g at 25 °C. Various adsorption mechanisms are involved in the adsorption of MB dye onto the surface of RPDSAC, including π-π stacking, H-bonding, pore filling, and electrostatic forces. This study exhibits the potential of the RPDSAC as an adsorbent for removal of toxic cationic dye (MB) from contaminated wastewater.

4.
Ann Med Surg (Lond) ; 86(4): 1836-1842, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38576953

RESUMO

Introduction and importance: Right middle lobe syndrome (MLS) is a rare lung disorder primarily affecting children with a history of asthma or atopy. It encompasses a range of pathological and clinical conditions, from recurrent collapses of the middle lobe to bronchiectasis. In this study, the authors present a case series featuring four individuals with MLS associated with asthma, aiming to deepen our understanding of this uncommon condition. Case presentation: Four paediatric patients with right MLS exhibited symptoms of persistent cough, dyspnoea, and recurrent asthma exacerbations. Radiographic evaluations confirmed features consistent with right MLS, and bronchoscopy revealed mucus plugs and oedematous airways obstructing the right middle lobe bronchus. Treatment with bronchodilators, antibiotics, and corticosteroids led to symptom improvement and resolution of atelectasis. Clinical discussion: MLS is a rare condition characterized by chronic collapse of the right middle lobe and bronchiectasis. It is challenging to diagnose MLS, but computed tomography (CT) scans provide detailed lung images for confirmation. Treatment focuses on addressing the underlying cause, such as infections or mucus obstruction. Lobectomy may be considered in severe cases. This case series emphasizes the need for further research on MLS, as its rarity and characteristics remain unclear. Conclusion: These cases exhibited obstructive MLS with and without asthma. Accurate diagnosis is challenging, requiring imaging techniques. MLS has clinical implications, particularly in asthma patients. Future studies should focus on understanding the aetiology of non-obstructive MLS.

5.
Artigo em Inglês | MEDLINE | ID: mdl-38648399

RESUMO

INTRODUCTION: Cellular-based autograft (CBA) is being used in posterolateral lumbar arthrodesis as a fusion supplementation alternative. OBJECTIVE: To assess radiographic fusion in patients undergoing posterolateral lumbar fusion with unilateral Trinity CBA compared with contralateral local bone autograft as an internal control. METHODS: A single surgeon's practice database was interrogated for consecutive patients undergoing primary posterolateral lumbar fusion with Trinity from 2018 to 2021. Patients had Trinity applied unilaterally, with local bone autograft applied contralaterally. Fusion was assessed postoperatively by using CT after 9 months. Demographics and patient-reported outcome measures were collected preoperatively and up to 12 months postoperatively. RESULTS: Thirty-nine patients were included. There were 81 attempted fusion levels. Overall fusion rate, defined as bony bridging on at least one side of a given level for all levels fused, was 85.2% of patients. No statistically significant difference was observed in fusion rates between CBA versus local bone (79.0% versus 76.54% of levels attempted, respectively, P = 0.3527). Oswestry Disability Index improved by 3 months (P = 0.0152) and was maintained. Two patients required revision for symptomatic nonunion. CONCLUSIONS: Similar radiographic fusion rates were achieved with Trinity and local bone. Trinity is a viable alternative to local bone in posterolateral lumbar fusion.


Assuntos
Transplante Ósseo , Vértebras Lombares , Fusão Vertebral , Humanos , Fusão Vertebral/métodos , Masculino , Feminino , Vértebras Lombares/cirurgia , Pessoa de Meia-Idade , Transplante Ósseo/métodos , Idoso , Aloenxertos , Resultado do Tratamento , Estudos Retrospectivos , Transplante Autólogo , Autoenxertos , Medidas de Resultados Relatados pelo Paciente
6.
Sarcoidosis Vasc Diffuse Lung Dis ; 41(1): e2024007, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38567561

RESUMO

While sarcoidosis is typically a multisystem disease, it can, in some instances, exclusively affect the vertebrae, leading to back pain. Additionally, sarcoidosis may manifest with inflammation of the sacroiliac joints, not meeting the criteria for spondyloarthritis, yet contributing to back pain. In this report, we present a case involving a previously healthy 55-year-old woman who sought medical attention due to chronic back pain. She was subsequently diagnosed with spinal sarcoidosis, based on MRI, PET scan, and biopsy results. Furthermore, treatment with prednisolone monotherapy demonstrated substantial improvement in her symptoms.

9.
Burns ; 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38492981

RESUMO

BACKGROUND: Major burn injury, despite advancements in care and prevention, can have a profound impact on long-term morbidity, affecting quality of life and socioeconomic standing. We aim to explore factors predicting recovery of independence, the expected rate and time in majorly burned patients, and the measures of progress used. METHOD: A systematic search of four databases (MEDLINE, EMBASE, COCHRANE, CINAHL) was conducted for studies reporting outcomes pertaining to physical ability indicative of independent function in adult (>15 y) cohorts who had suffered a major burn (>20% TBSA) up to 30 years after treatment in a developed specialised burn service. Data extracted included factors affecting rate of and time to achievement of function in five independence domains, as well as the outcome measures used. RESULTS: 21 eligible studies were included comprising 1298 major burns survivors with a combined mean age of 39.6 y and a mean TBSA of 25.8%. The most significant recurring factors impacting recovery of independent function were older age, female gender, burn severity, prolonged ICU and hospital admission, preceding mental health conditions, and post-acute psychological issues. Exercise-based rehabilitation conferred benefits on major burn patients even over 2 years following injury. Discharge to independent living from hospital occurred in 27% to 97% of patients, while reported return to work rates varied from 52% to 80%. Burns Specific Health Scale-Brief, Functional Independence Measure, and Physical Composite Score (SF-36) were the most widely used outcome scoring systems. CONCLUSION: Major burn survivors have protracted recovery with potential for persistent chronic impairments, remaining consistently below baseline levels of function. Non-modifiable factors such as age and gender, and disease characteristics such as burn size with associated physical, physiological and psychosocial sequelae are contributory. Further research is required to explore achievement of specific milestones of major burn and polytrauma critical care patients, while early targeted rehabilitation addressing physical, psychological, and vocational needs has promising potential benefit.

10.
Int J Phytoremediation ; : 1-11, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38456236

RESUMO

In this study, a hydrothermal approach was employed to graft chitosan (Chit)/algae (ALG) with salicylaldehyde (SA), resulting in the synthesis of a biocomposite named salicylaldehyde-based chitosan Schiff base/algae (Chit-SA/ALG). The main objective of this biocomposite was to effectively remove methyl violet (MV), an organic dye, from aqueous solutions. The adsorption performance of Chit-SA/ALG toward MV was investigated in detail, considering the effects of three factors: (A) Chit-SA/ALG dose (ranging from 0.02 to 0.1 g/100 mL), (B) pH (ranging from 4 to 10), and (C) time (ranging from 10 to 120 min). The Box-Behnken design (BBD) was utilized for experimental design and analysis. The experimental results exhibited a good fit with both the pseudo-second-order kinetic model and the Freundlich isotherm, suggesting their suitability for describing the MV adsorption process on Chit-SA/ALG. The maximum adsorption capacity of Chit-SA/ALG, as calculated by the Langmuir model, was found to be 115.6 mg/g. The remarkable adsorption of MV onto Chit-SA/ALG can be primarily attributed to the electrostatic forces between Chit-SA/ALG and MV as well as the involvement of various interactions such as n-π, π-π, and H-bond interactions. This research demonstrates that Chit-SA/ALG exhibits promising potential as a highly efficient adsorbent for the removal of organic dyes from water systems.


The novelty of this work comes from introducing a new bio-organic based composite adsorbent of chitosan (Chit) biopolymer and algae (ALG) biomass. Moreover, the functionality and chemical stability of Chit­ALG composite was further developed by grafting process with salicylaldehyde (SA) using hydrothermal process. The incorporation of ALG biomass into polymeric matrix of Chit and grafting process with SA makes Chit a unique hybrid adsorbent toward cationic dye (methyl violet dye).

11.
Int J Biol Macromol ; 263(Pt 2): 129989, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38354916

RESUMO

In this study, the synthesis and experimental theoretical evaluation of a new chitosan/alginate/hydrozyapatite nanocomposite doped with Mn2 and Fe2O3 for Cr removal was reported. The physicochemical properties of the obtained materials were analyzed using the following methods: SEM-EDX, XRD, FTIR, XPS, pH drift measurements, and thermal analysis. The adsorption properties were estimated based on equilibrium and adsorption kinetics measurements. The Langmuir, Freundlich and Temkin isotherms were applied to analyze the equilibrium data. The thermodynamic analysis of adsorption isotherms was performed. A number of equations and kinetic models were used to describe the adsorption rate data, including pseudo-first (PFOE) and pseudo-second (PSOE) order kinetic equations. The obtained test results show that the synthesized biomaterial, compared to pure chitosan, is characterized by greater resistance to high temperatures. Moreover, this biomaterial had excellent adsorption properties. For the adsorption of Cr (VI), the equilibrium state was reached after 120 min, and the sorption capacity was 455.9 mg/g. In addition, DFT calculations and NCI analyses were performed to get more light on the adsorption mechanism of Cr (VI) on the prepared biocomposite.


Assuntos
Quitosana , Nanocompostos , Poluentes Químicos da Água , Purificação da Água , Óxidos , Águas Residuárias , Quitosana/química , Cromo/química , Adsorção , Alginatos/química , Compostos Férricos/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Cinética , Materiais Biocompatíveis , Nanocompostos/química , Concentração de Íons de Hidrogênio
12.
Int J Biol Macromol ; 263(Pt 1): 130304, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38382796

RESUMO

This present work targets the production of an eco-friendly adsorbent (hereinafter KA/CEL) from kaolin clay functionalized with cellulose extract obtained from peanut shells. The adsorbents were used for decolorization of two different types of organic dyes (cationic: methylene blue, MB; anionic: Congo red, CR) from an aqueous environment. Several analytical methods, including Brunauer-Emmett-Teller (surface properties), Fourier Transforms infrared (functionality), scanning electron microscope, Energy dispersive X-Ray (morphology), and pHpzc test (surface charge), were used to attain the physicochemical characteristics of KA/CEL. The Box-Behnken Design (BBD) was applied to determine the crucial factors affecting adsorption performance. These included cellulose loading at 25 %, an adsorbent dose of 0.06 g, solution pH set at 10 for MB and 7 for CR, a temperature of 45 °C, and contact times of 12.5 min for MB and 20 min for CR dye. The adsorption data exhibited better agreement with the pseudo-second-order kinetic and Freundlich models. The Langmuir model estimated the monolayer capacity to be 291.5 mg/g for MB and 130.7 mg/g for CR at a temperature of 45 °C. This study's pivotal finding underscores the promising potential of KA/CEL as an effective adsorbent for treating wastewater contaminated with organic dyes.


Assuntos
Vermelho Congo , Poluentes Químicos da Água , Corantes/química , Argila , Caulim , Arachis , Azul de Metileno , Celulose , Adsorção , Cinética , Concentração de Íons de Hidrogênio
13.
Ecotoxicol Environ Saf ; 272: 116073, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38335580

RESUMO

Plastic mulching and organic amendments are prevalent agricultural practices worldwide. Plastic mulching has long been suspected as a significant source of DEHP contamination in terrestrial ecosystems. However, effects of DEHP contamination on greenhouse gas emissions and microbial biomass carbon (MBC) remain unclear. Here, a microcosm experiment was set up to assess the impact of DEHP exposure on MBC and carbon dioxide (CO2) emission in two different soils (acidic and alkaline) with the inclusion of alfalfa straw. The treatment includes: (i) control with no amendment (T1); (ii) alfalfa straw addition (20 g kg-1) (T2); (iii) DEHP (10 mg kg-1) + alfalfa straw (T3); and (iv) DEHP (100 mg kg-1) + alfalfa straw (T4). Against the background of alfalfa inclusion, DEHP exposure led to a potential reduction in cumulative CO2 emissions by 16.35 % and 6.91 % in alkaline soil and 12.27 % and 13.65 % in acidic soil for T3 and T4, respectively. The addition of DEHP triggered CO2 emissions and manifested a detrimental negative priming effect in both soil types. In both soils, average CO2 emission fluxes were highest for the T2 treatment. The MBC fluctuated at around 80 mg kg-1 for the control group, alfalfa straw alone (T2) treatment considerably enhanced MBC contents, whereas DEHP contamination in T3 and T4 treatments suppressed the stimulatory effect of alfalfa on MBC in both alkaline and acidic soils. Furthermore, a positive relationship was observed between soil CO2 emissions and MBC in both soils. Overall, these findings highlight the toxic impact of DEHP on MBC and its role in mitigating CO2 emissions in diverse soils. DEHP exposure counters the CO2 emissions induced by alfalfa straw. In addition, the inhibitory effect of DEHP on CO2 fluxes in alkaline soil is less pronounced than in acidic soil. Therefore, further cutting-edge research is crucial since DEHP contamination poses serious ecological threats to agroecosystems.


Assuntos
Dietilexilftalato , Ácidos Ftálicos , Solo , Dióxido de Carbono/análise , Dietilexilftalato/toxicidade , Medicago sativa , Biomassa , Ecossistema , Microbiologia do Solo , Agricultura
14.
Int J Biol Macromol ; 259(Pt 1): 129147, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38181921

RESUMO

A composite of chitosan biopolymer with microalgae and commercial carbon-doped titanium dioxide (kronos) was modified by grafting an aromatic aldehyde (salicylaldehyde) in a hydrothermal process for the removal of brilliant green (BG) dye. The resulting Schiff's base Chitosan-Microalgae-TiO2 kronos/Salicylaldehyde (CsMaTk/S) material was characterised using various analytical methods (conclusive of physical properties using BET surface analysis method, elemental analysis, FTIR, SEM-EDX, XRD, XPS and point of zero charge). Box Behnken Design was utilised for the optimisation of the three input variables, i.e., adsorbent dose, pH of the media and contact time. The optimum conditions appointed by the optimisation process were further affirmed by the desirability test and employed in the equilibrium studies in batch mode and the results exhibited a better fit towards the pseudo-second-order kinetic model as well as Freundlich and Langmuir isotherm models, with a maximum adsorption capacity of 957.0 mg/g. Furthermore, the reusability study displayed the adsorptive performance of CsMaTk/S remains effective throughout five adsorption cycles. The possible interactions between the dye molecules and the surface of the adsorbent were derived based on the analyses performed and the electrostatic attractions, H-bonding, Yoshida-H bonding, π-π and n-π interactions are concluded to be the responsible forces in this adsorption process.


Assuntos
Quitosana , Microalgas , Compostos de Amônio Quaternário , Poluentes Químicos da Água , Adsorção , Carbono , Quitosana/química , Concentração de Íons de Hidrogênio , Aldeídos , Cinética , Poluentes Químicos da Água/química
15.
Int J Phytoremediation ; 26(4): 459-471, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37583281

RESUMO

This work aims to apply the use of food-grade algae (FGA) composited with chitosan-benzaldehyde Schiff base biopolymer (CHA-BD) as a new adsorbent (CHA-BA/FGA) for methyl violet 2B (MV 2B) dye removal from aqueous solutions. The effect of three processing variables, including CHA-BA/FGA dosage (0.02-0.1 g/100 mL), pH solution (4-10), and contact duration (10-120 min) on the removal of MV 2B was investigated using the Box-Behnken design (BBD) model. Kinetic and equilibrium dye adsorption profiles reveal that the uptake of MV 2B dye by CHA-BA/FGA is described by the pseudo-second kinetics and the Langmuir models. The thermodynamics of the adsorption process (ΔG°, ΔH°, and ΔS°) reveal spontaneous and favorable adsorption parameters of MV 2B dye onto the CHA-BA/FGA biocomposite at ambient conditions. The CHA-BA/FGA exhibited the maximum ability to absorb MV 2B of 126.51 mg/g (operating conditions: CHA-BA/FGA dose = 0.09 g/100 mL, solution pH = 8.68, and temperature = 25 °C). Various interactions, including H-bonding, electrostatic forces, π-π stacking, and n-π stacking provide an account of the hypothesized mechanism of MV 2B adsorption onto the surface of CHA-BA/FGA. This research reveals that CHA-BA/FGA with its unique biocomposite structure and favorable adsorption properties can be used to remove harmful cationic dyes from wastewater.


The first novel aspect of this research work comes from the utilization of food-grade algae which contains various types of negative functional groups hydroxyl, carboxyl, and phosphate to modify a cationic biopolymer (Chitosan) to improve its adsorptive property toward removal of a cationic dye such as methyl violet 2B. The second novel aspect of this research work is to use the hydrothermal process to assist the grafting of an aromatic ring of benzaldehyde into the polymer matrix of the chitosan-food grade algae composite via a Schiff base linkage to improve its chemical stability and functionality.


Assuntos
Quitosana , Corantes de Rosanilina , Poluentes Químicos da Água , Corantes/química , Quitosana/química , Violeta Genciana/química , Bases de Schiff/química , Benzaldeídos , Concentração de Íons de Hidrogênio , Biodegradação Ambiental , Termodinâmica , Adsorção , Cinética , Poluentes Químicos da Água/química
16.
Int J Biol Macromol ; 256(Pt 1): 128267, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37992917

RESUMO

In this study, chitosan/nano SiO2 (CTS/NS) was chemically modified with bisphenol A diglycidyl ether (BADGE) cross-linker-assisted hydrothermal process to create an effective adsorbent, CTS-BADGE/NS, for the removal of reactive orange 16 (RO16) dye from aquatic systems. Box-Behnken design (BBD) was used to optimize the adsorption process by varying the adsorbent dose (0.02-0.1 g/100 mL), pH (4-10), and time (20-360 min). The adsorption isotherm results indicated that the Langmuir model fits the experimental data well, suggesting that the adsorption process involves a monolayer formation of RO16 on the surface of CTS-BADGE/NS. The kinetic modeling of RO16 adsorption by CTS-BADGE/NS demonstrated that the pseudo-first-order model fits the adsorption data. CTS-BADGE/NS achieved an adsorption capacity of 97.8 mg/g for RO16 dye at optimum desirability functions of dosage 0.099 g/100 mL, solution pH of 4.44, and temperature of 25 °C. Overall, the π-π electron donor-acceptor system significantly improved the adsorption performance of the CTS-BADGE/NS. The results of the regeneration investigation demonstrate that the CTS-BADGE/NS exhibits effective adsorption of RO16, even after undergoing five consecutive cycles. The results of this study suggest that the developed CTS-BADGE/NS composite can be a promising adsorbent for water purification applications.


Assuntos
Compostos Azo , Compostos Benzidrílicos , Quitosana , Poluentes Químicos da Água , Adsorção , Compostos de Epóxi , Dióxido de Silício , Cinética , Concentração de Íons de Hidrogênio
17.
Int J Biol Macromol ; 255: 128075, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37977465

RESUMO

Herein, a quadruple biomagnetic nanocomposite of cross-linked chitosan-ethylene glycol diglycidyl ether/organo-nanoclay (MCH-EGDE/ORNC) was designed for the uptake of remazol brilliant blue R (RBBR) dye from aqueous environment. The adsorption process was systematically improved via the Box-Behnken design (BBD) to determine the influence of key uptake parameters, including MCH-EGDE/ORNC dosage, pH, and time, on the RBBR removal. The highest RBBR removal of 87.5 % was achieved at the following conditions: MCH-EGDE/ORNC dosage: 0.1 g/100 mL; pH: 4.0; contact time: 25 min. The findings of the kinetics and equilibrium studies revealed an excellent fit to the pseudo-second order and the Freundlich models, respectively. The adsorption capacity of the MCH-EGDE/ORNC for RBBR was found to be 168.4 mg/g, showcasing its remarkable adsorption capability. The present work highlights the potential of MCH-EGDE/ORNC biomaterial as an advanced adsorbent and lays the foundation for future applications in water purification and environmental remediation.


Assuntos
Quitosana , Nanocompostos , Compostos Azo , Concentração de Íons de Hidrogênio
18.
Lupus ; 33(1): 3-4, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38064438

RESUMO

This article is a celebration of the 40th anniversary of APS, a disease that appears to affect one in 2000 people. The quality of life of patients affected has improved significantly as a result of early diagnosis and effective treatment.


Assuntos
Síndrome Antifosfolipídica , Lúpus Eritematoso Sistêmico , Humanos , Aniversários e Eventos Especiais , Qualidade de Vida , Síndrome Antifosfolipídica/diagnóstico , Inibidor de Coagulação do Lúpus , Anticorpos Anticardiolipina
19.
Int J Phytoremediation ; 26(4): 579-593, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37740456

RESUMO

In this study, bamboo waste (BW) was subjected to pyrolysis-assisted ZnCl2 activation to produce mesoporous activated carbon (BW-AC), which was then evaluated for its ability to remove cationic dyes, specifically methylene blue (MB) and crystal violet (CV), from aqueous environments. The properties of BW-AC were characterized using various techniques, including potentiometric-based point of zero charge (pHpzc), scanning electron microscopy with energy dispersive X-rays (SEM-EDX), X-ray diffraction (XRD), gas adsorption with Brunauer-Emmett-Teller (BET) analysis, infrared (IR) spectroscopy. To optimize the adsorption characteristics (BW-AC dosage, pH, and contact time) of PBW, a Box-Behnken design (BBD) was employed. The BW-AC dose of 0.05 g, solution pH of 10, and time of 8 min are identified as optimal operational conditions for achieving maximum CV (89.8%) and MB (96.3%) adsorption according to the BBD model. The dye removal kinetics for CV and MB are described by the pseudo-second-order model. The dye adsorption isotherms revealed that adsorption of CV and MB onto BW-AC follow the Freundlich model. The maximum dye adsorption capacities (qmax) of BW-AC for CV (530 mg/g) and MB (520 mg/g) are favorable, along with the thermodynamics of the adsorption process, which is characterized as endothermic and spontaneous. The adsorption mechanism of CV and MB dyes by BW-AC was attributed to multiple contributions: hydrogen bonding, electrostatic forces, π-π attraction, and pore filling. The findings of this study highlight the potential of BW-AC as an effective adsorbent in wastewater treatment applications, contributing to the overall goal of mitigating the environmental impact of cationic dyes and ensuring the quality of water resources.


The novelty of this research work comes from the conversion of the bamboo waste (BW) into mesoporous activated carbon (BW-AC) via pyrolysis-assisted ZnCl2 activation for the removal of cationic dyes such as methylene blue (MB) and crystal violet (CV) from aqueous media. The effectiveness of the obtained activated carbon was tested toward removal of two structurally different cationic dyes (CV and MB), where a statistical optimization employing a response surface methodology with Box-Behnken design was applied to optimize dye removal. In addition to determination of the working parameters for dye removal, the adsorption kinetics and thermodynamic parameters for the adsorption process were determined to provide molecular-level insight.


Assuntos
Corantes , Poluentes Químicos da Água , Corantes/química , Azul de Metileno/análise , Carvão Vegetal/química , Violeta Genciana/química , Poluentes Químicos da Água/química , Biodegradação Ambiental , Adsorção , Termodinâmica , Cinética , Concentração de Íons de Hidrogênio
20.
Int J Phytoremediation ; 26(5): 699-709, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37740478

RESUMO

A major worldwide challenge that presents significant economic, environmental, and social concerns is the rising generation of food waste. The current work used chicken bones (CB) and rice (R) food waste as alternate precursors for the production of activated carbon (CBRAC) by microwave radiation-assisted ZnCl2 activation. The adsorption characteristics of CBRAC were investigated in depth by removing an organic dye (crystal violet, CV) from an aquatic environment. To establish ideal conditions from the significant adsorption factors (A: CBRAC dosage (0.02-0.12 g/100 mL); B: pH (4-10); and C: duration (30-420), a numerical desirability function of Box-Behnken design (BBD) was utilized. The highest CV decolorization by CBRAC was reported to be 90.06% when the following conditions were met: dose = 0.118 g/100 mL, pH = 9.0, and time = 408 min. Adsorption kinetics revealed that the pseudo-first order (PFO) model best matches the data, whereas the Langmuir model was characterized by equilibrium adsorption, where the adsorption capacity of CBRAC for CV dye was calculated to be 57.9 mg/g. CV adsorption is accomplished by several processes, including electrostatic forces, pore diffusion, π-π stacking, and H-bonding. This study demonstrates the use of CB and R as biomass precursors for the efficient creation of CBRAC and their use in wastewater treatment, resulting in a greener environment.


The novelty of this research work relates to converting food wastes (mixture of chicken bones and rice waste) into activated carbon via microwave assisted ZnCl2 activation. Moreover, the produced activated carbon was successfully applied as a potential adsorbent for removal of a toxic cationic dye; namely, crystal violet (CV) from aqueous environment.


Assuntos
Oryza , Eliminação de Resíduos , Poluentes Químicos da Água , Animais , Perda e Desperdício de Alimentos , Violeta Genciana/química , Carvão Vegetal/química , Micro-Ondas , Galinhas , Alimentos , Biodegradação Ambiental , Adsorção , Cinética , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio
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