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1.
Environ Sci Pollut Res Int ; 31(1): 1158-1176, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38038911

RESUMO

This study aimed to assess the dynamic simulation models provided by Aspen adsorption (ASPAD) and artificial neural network (ANN) in understanding the adsorption behavior of atenolol (ATN) on gasified Glyricidia sepium woodchips activated carbon (GGSWAC) within fixed bed columns for wastewater treatment. The findings demonstrated that increasing the bed height from 1 to 3 cm extended breakthrough and exhaustion times while enhancing adsorption capacity. Conversely, higher initial ATN concentrations resulted in shorter breakthrough and exhaustion times but increased adsorption capacity. Elevated influent flow rates reduced breakthrough and exhaustion times while maintaining constant adsorption capacity. The ASPAD software demonstrated competence in accurately modeling the crucial exhaustion points. However, there is room for enhancement in forecasting breakthrough times, as it exhibited deviations ranging from 6.52 to 239.53% when compared to the actual experimental data. ANN models in both MATLAB and Python demonstrated precise predictive abilities, with the Python model (R2 = 0.985) outperforming the MATLAB model (R2 = 0.9691). The Python ANN also exhibited superior fitting performance with lower MSE and MAE. The most influential factor was the initial ATN concentration (28.96%), followed by bed height (26.39%), influent flow rate (22.43%), and total effluent time (22.22%). The findings of this study offer an extensive comprehension of breakthrough patterns and enable accurate forecasts of column performance.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Atenolol , Carvão Vegetal , Redes Neurais de Computação , Purificação da Água/métodos
2.
Chemosphere ; 307(Pt 4): 136054, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36007742

RESUMO

In this work, engineered biochar decorated layered double hydroxides and cellulose nanocrystals (B-CuFe-CNC) biocomposites were synthesized by the facile ultrasonicated-co-precipitation technique. The biocomposite was investigated for purification of Eriochrome Black T (EBT) dye from water. The characterization results showed that the presence of CNC in biochar-layered double hydroxides resulted in a two-dimensional rod-like structure with excellent crystallinity, improved surface functionalities, and provides an attractive platform for the enhanced adsorption of azo anionic dye molecules. The adsorption system was appropriately demonstrated by the BBD-RSM (R2 > 0.994). The biocomposite exhibited higher EBT adsorption in the acidic pH range (2-5) due to strong electrostatic and chemical interactions. The kinetic and isotherm results were well demonstrated by pseudo-second order, Freundlich, and Redlich Peterson models. The maximum adsorption capacity of biocomposite was 876.2 mg/g achieved within 45 min. The spectroscopic analyses imply that the high removal of EBT by biocomposite is mainly governed by electrostatic attraction, hydrogen bonding, and chemical/metal complexation mechanisms. The biocomposite maintained high EBT removal after six successive adsorption cycles and excellent dye adsorption in the different water matrices. The results suggest that tailoring biochar properties with layered double hydroxide and CNC is a promising way for the enhanced removal of dye contaminants from wastewater.


Assuntos
Nanopartículas , Poluentes Químicos da Água , Adsorção , Compostos Azo , Celulose , Carvão Vegetal , Hidróxidos/química , Cinética , Águas Residuárias/química , Água/análise , Poluentes Químicos da Água/análise
3.
Artigo em Inglês | MEDLINE | ID: mdl-35314938

RESUMO

The presence of emerging contaminants (ECs) originating from pharmaceutical waste in water, wastewater, and marine ecosystems at various geographical locations has been clearly publicised. This review paper presents an overview of current monitoring data on the occurrences and distributions of ECs in coastal ecosystem, tap water, surface water, ground water, treated sewage effluents, and other sources. Technological advancements for EC removal are also presented, which include physical, chemical, biological, and hybrid treatments. Adsorption remains the most effective method to remove ECs from water bodies. Various types of adsorbents, such as activated carbons, biochars, nanoadsorbents (carbon nanotubes and graphene), ordered mesoporous carbons, molecular imprinting polymers, clays, zeolites, and metal-organic frameworks have been extensively used for removing ECs from water sources and wastewater. Extensive findings on adsorptive performances, process efficiency, reusability properties, and other related information are thoroughly discussed in this mini review.

4.
Environ Res ; 209: 112861, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35143802

RESUMO

In this research work, a novel hybrid composite consisting of biochar (B), layered double hydroxide (CuFe) and chitosan (CS) (B-CuFe-CS) was produced using an ultrasonication-assisted co-precipitation method. The resultant composite was employed for adsorptive removal of Eriochrome black T (EBT) from water. Physicochemical characterization indicated that the B-CuFe-CS containing 10 wt % CS exhibited a heterogeneous structure with better crystallographic and textural characteristics. The B-CuFe-CS with abundant surface functionalities (-CO, -C-O, -OH, -NO3, and MMO), facilitates faster and enhanced removal of the EBT. The kinetic results showed better fitting to the pseudo-second order model, and equilibrium was achieved within 30 min. Equilibrium data was well explained by Langmuir and Redlich Peterson isotherm models (R2 > 0.98), indicating the EBT removal onto B-CuFe-CS followed monolayer adsorption. The maximum adsorption capacity was 806.4 mg/g, which was higher than pristine B-CuFe (476.19 mg/g) and many other adsorbents. The spectroscopic analysis (FTIR and XPS) and experimental results suggested that EBT adsorption is mainly governed by electrostatic, chemical and anion-exchange interactions. It is evident from these results that coupling B-CuFe composite with bio-filler (chitosan) resulted in an efficient bio-adsorbent to effectively purify dye-contaminated water streams.


Assuntos
Quitosana , Poluentes Químicos da Água , Adsorção , Compostos Azo , Carvão Vegetal , Quitosana/química , Concentração de Íons de Hidrogênio , Hidróxidos/química , Cinética , Água , Poluentes Químicos da Água/análise
5.
3 Biotech ; 9(8): 314, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31406636

RESUMO

Initially, a new moderate halophilic strain was locally isolated from seawater. The partial 16S rRNA sequence analysis positioned the organism in Marinobacter genus and was named 'Marinobacter litoralis SW-45'. This study further demonstrates successful utilization of the halophilic M. litoralis SW-45 lipase (MLL) for butyl ester synthesis from crude palm fruit oil (CPO) and kernel oil (CPKO) in heptane and solvent-free system, respectively, using hydroesterification. Hydrolysis and esterification of enzymatic [Thermomyces lanuginosus lipase (TLL)] hydrolysis of CPO and CPKO to free fatty acids (FFA) followed by MLL-catalytic esterification of the concentrated FFAs with butanol (acyl acceptor) to synthesize butyl esters were performed. A one-factor-at-a-time technique (OFAT) was used to study the influence of physicochemical factors on the esterification reaction. Under optimal esterification conditions of 40 and 45 °C, 150 and 230 rpm, 50% (v/v) biocatalyst concentration, 1:1 and 5:1 butanol:FFA, 9% and 15% (w/v) NaCl, 60 and 15 min reaction time for CPO- and CPKO-derived FFA esterification system, maximum ester conversion of 62.2% and 69.1%, respectively, was attained. Gas chromatography (GC) analysis confirmed the products formed as butyl esters. These results showed halophilic lipase has promising potential to be used for biosynthesis of butyl esters in oleochemical industry.

6.
Int J Biol Macromol ; 133: 1288-1298, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31055112

RESUMO

A report on the de novo Whole Genome Sequence (WGS) of Marinobacter litoralis SW-45, a moderately salt-tolerant bacterium isolated from the seawater in Malaysia is presented. The strain has a genome size of 3.45 Mb and is capable of producing halophilic lipase, protease and esterase enzymes. Computational prediction of non-coding RNA (ncRNA) genes in M. litoralis SW-45 was performed using standalone software known as the non-coding RNA characterization (nocoRNAc). In addition, a phylogenetic tree showing the evolutionary relationship between the strain and other members of the genus Marinobacter was constructed using 16SrRNA sequence information. A total of 385 ncRNA transcripts, 1124 terminator region, and 2350 Stress Induced Duplex Destabilization sites were predicted. The current WGS shotgun project has provided the relevant genetic information that may be useful for the strain's improvement studies. This manuscript gives the first description of M. litoralis with a complete genome.


Assuntos
Marinobacter/genética , RNA não Traduzido/genética , Sequenciamento Completo do Genoma , Evolução Molecular , Filogenia , RNA Ribossômico 16S/genética
7.
Environ Sci Pollut Res Int ; 25(31): 31508-31519, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30203351

RESUMO

The adsorption behavior of basic, methylene blue (MB), and reactive, remazol brilliant violet 5R (RBV), dyes from aqueous solution onto Intsia bijuga sawdust-based activated carbon (IBSAC) was executed via batch and column studies. The produced activated carbon was characterized through Brunauer-Emmett-Teller (BET) surface area and pore structural analysis, proximate and ultimate, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). Batch studies were performed to investigate the effects of contact time, initial concentration, and solution pH. The equilibrium data for both MB and RBV adsorption better fits Langmuir model with maximum adsorption capacity of 434.78 and 212.77 mg/g, respectively. Kinetic studies for both MB and RBV dyes showed that the adsorption process followed a pseudo-second-order and intraparticle diffusion kinetic models. For column mode, the breakthrough curves were plotted by varying the flow rate, bed height, and initial concentration and the breakthrough data were best correlated with the Yoon-Nelson model compared to Thomas and Adams-Bohart model. The adsorption activity of IBSAC shows good stability even after four consecutive cycles.


Assuntos
Carvão Vegetal/química , Corantes/isolamento & purificação , Fabaceae/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Dióxido de Carbono/química , Corantes/química , Difusão , Cinética , Azul de Metileno/química , Azul de Metileno/isolamento & purificação , Microscopia Eletrônica de Varredura , Micro-Ondas , Naftalenossulfonatos/química , Naftalenossulfonatos/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Madeira/química
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