Investigation of adsorption of the dyestuff astrazon red violet 3rn (basic violet 16) on montmorillonite clay

Abstract

-In this study, color removal by absorption from synthetically prepared wastewater was investigated using montmorillonite clay by adsorption. As dyestuff Astrazon Red Violet 3RN (Basic Violet 16) was used. Experimental parameters selected were pH, temperature, agitation speed, initial dyestuff concentration, adsorbent dosage and ionic strength. It was established that adsorption rate increased with increasing pH, temperature, dye concentration and agitation speed, but decreased with increased ionic strength and adsorbent dosage. Adsorption equilibrium data obtained by a series of experiments carried out in a water bath were employed with common isotherm equations such as Langmuir, Freundlich, Temkin, Elovich and Dubinin-Radushkevich. It was found that the Langmuir equation appears to fit the equilibrium data better than the other models. Furthermore, the fit of the kinetic data to common kinetic models such as the pseudofirst-order, second-order, Elovich and intraparticle diffusion models was tested to elucidate the adsorption mechanism. Kinetic data conformed to the pseudo-second-order model, indicating chemisorptions. In addition, the thermodynamic parameters activation energy, Ea, enthalpy ΔH*, entropy, ΔS*, and free energy change, ΔG*, were calculated. The values of the calculated parameters indicated that physical adsorption of ARV on the clay was dominant and that the adsorption process was endothermic.

Removal of Anionic Dye by Natural Algerian Montmorillonite

“…The increase in methyl orange adsorption with the increase in adsorbent mass is attributed to increase in surface area of micro pores and the increase in availability of vacant adsorption sites. Similar results have been reported for the adsorption of methyl orange on Algerian MMT [18][19][20].…”

Avaliação Da Adsorção E Estudo Eletroquímico De Células Solares Produzidas Com Tio2 E Corante Extraído Do Hibiscus

“…Os modelos de adsorção são ferramentas úteis para o estudo de mecanismos de coordenação de moléculas em determinadas superfícies, fornecendo uma visão mais detalhada do equilíbrio requerido para que a interface TiO 2 /Corante se complete, levando consequentemente a uma melhor caracterização dos sistemas estudados. 19 Isotermas, como de Langmuir, Freundlich, Temkin e Elovich são modelos que se aplicáveis, cada qual com suas determinadas características, fornecem constantes e a capacidade máxima de adsorção fazendo com que seja possível um estudo mais detalhado do caso. 20 Na Tabela 2 são apresentados os modelos de isotermas de adsorção aplicados, com suas respectivas equações.…”

“…20 Na Tabela 2 são apresentados os modelos de isotermas de adsorção aplicados, com suas respectivas equações. 19,20 As medidas de absorção/adsorção foram realizadas em um espectrofotômetro UV-Vis-320G, Gehaka, em 540 nm, a 25 ºC, com fins de se determinar a capacidade máxima de adsorção do corante na superfície do semicondutor e a região de absorção do corante no espectro eletromagnético. Os valores encontrados, foram utilizados para os cálculos das concentrações finais das soluções e da quantidade do fotossensibilizante adsorvida no TiO 2 .…”

Adsorption of acid dye onto activated Algerian clay

“…The result is shown in Table 3. Several studies found that the kinetics of adsorption of dyes on clay supports obey to the pseudo-second-order [15][16][17][18]. …”