Pseudo Secondorder Kinetics Model
Mostrando 1-10 de 10 artigos, teses e dissertações.
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1. Chitosan and gum arabic nanoparticles for heavy metal adsorption
Abstract Chitosan (CT) is a polysaccharide with the ability to adsorb metals on its surface. In this work, CT-based nanoparticles (NPs) are produced by complex formation with gum arabic (GA) to increase their adsorbent potential for removal of heavy metals in aqueous medium. Adsorption efficiency is evaluated as a function of NP composition and polysaccharid
Polímeros. Publicado em: 10/07/2018
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2. Biosorption of anionic textile dyes from aqueous solution by yeast slurry from brewery
ABSTRACT This study investigated the biosorption of the anionic textile dyes: Reactive Red 239 (RR239), Reactive Black B (RBB) and Direct Blue 85 (DB85) according to pH, biomass dosage, contact time and dye concentration onto waste beer yeast slurry. The kinetics and isotherm of the removal of dyes were also studied. The equilibrium of biosorption reaction w
Braz. arch. biol. technol.. Publicado em: 11/05/2017
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3. Removal of Pb(II) ions and malachite green dye from wastewater by activated carbon produced from lemon peel
In the present study, a high-surface area activated carbon was prepared by chemical activation of lemon peel with H3PO4 as the active agent. Then, the adsorption behavior of Malachite green dye and Pb(II) ions on the produced activated carbon was studied. Batch process was employed for sorption kinetics and equilibrium studies. Experimental data were �
Quím. Nova. Publicado em: 2014-06
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4. Chemical modification of chitosan in the absence of solvent for diclofenac sodium removal: pH and kinetics studies
Chitosan was modified with acetylacetone and ethylenediamine in the absence of solvent. The new biopolymer obtained from the modification was characterized by elemental analysis and NMR 13C and applied in the removal of diclofenac sodium aqueous solution varying the pH and time. Through elemental analysis was possible to verify a decreasing in C/N relation a
Mat. Res.. Publicado em: 15/04/2014
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5. Removal of Phenol from aqueous solutions by Polymeric composites containing Ni and Co particles
Magnetic composites have a wide range of potential technological applications; however the evaluation of this material for extraction of phenolic compounds has not been sufficiently studied. Due to its high toxicity and solubility the removal of phenolic compounds from the aquatic environments has critical importance. In this work polymeric composites were p
Polímeros. Publicado em: 25/10/2013
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6. Estudos de adsorção de tetraciclina em partículas de quitosana
Devido às suas propriedades físico-químicas e biológicas, associadas à abundância e ao baixo custo da matéria-prima, a quitosana tem sido considerada um material de ampla aplicação em diversos campos, tais como em sistemas de liberação de fármacos. Muitas dessas propriedades estão associadas à presença de grupos amino em sua cadeia polimérica
Publicado em: 2009
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7. BORON REMOVAL FROM OIL PRODUCTION WASTEWATER AND EFFLUENTS BY ADSORPTION / REMOÇÃO DE BORO DE ÁGUAS E EFLUENTES DE PETRÓLEO POR ADSORÇÃO
The presence of boron in waters has increased continually and in parallel to the industrial development. And also, the harmful effects to the organisms and living creatures has increased as well, especially on plants, where the gap between the deficiency and the toxicity is very short. In the present work it was investigated the effects of different operatin
Publicado em: 2009
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8. Dissolution kinetics of ulexite prepared under different calcination temperatures
Ulexite is one of the boron minerals used as a raw material in the production of boron compounds. It contains a substantial amount of hydration water. Using calcination methods, the B2O3 grade of ulexite can be increased. In this study, the effect of calcination temperature on dissolution kinetics of ulexite in ammonium chloride solutions was investigated in
Brazilian Journal of Chemical Engineering. Publicado em: 2008-12
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9. Impregnation of chelating agent 3,3-bis-N,N bis-(carboxymethyl)aminomethyl-o-cresolsulfonephthalein in biopolymer chitosan: adsorption equilibrium of Cu(II) in aqueous medium
The aim of this study was to impregnate the chelating agent 3,3-bis-N,N,bis-(carboxymethyl)aminomethyl-o-cresolsulfonephthalein in chitosan and to investigate the adsorption of Cu(II) ions. The chemical modification was confirmed by FTIR spectrometry, thermogravimetric analysis (TGA) and energy dispersive x-ray spectroscopy (EDX). The adsorption studies were
Polímeros. Publicado em: 2006-06
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10. Alternative nonlinear model for estimating second-order rate coefficients for biodegradation.
A modification of the second-order model for biodegradation was derived, applied to an example data set, and shown to be superior for describing the anaerobic biodegradation of p-cresol by an enriched bacterial consortium. The modified model circumvents the no-growth assumption implicit in the use of the second-order rate equation, but still requires the ass