Search results

Search:
in the keywords: sorption isotherms

Sort By:

Limit search:

Sorption Equilibrium of Azo Dyes Direct Orange 26 and Reactive Blue 81 onto a Cheap Plant Sorbent/Równowaga Sorpcji Barwników Azowych Direct Orange 26 I Reactive Blue 81 Na Tanim Sorbencie Roślinnym

100%

Tomczak E., Tosik P.

issue 3

435-445

Azo dye-plant sorbent system was investigated in the paper. Direct Orange 26 and Reactive Blue 81 azo dyes were sourced from Boruta-Zachem Kolor Sp. z o.o. Mechanically and chemically modified rye straw was used as a “low-cost” biosorbent. During experiments, dye concentration changes in the solution and sorbent in time were measured at constant temperature until equilibrium was reached. Sorption equilibrium was described by 2-parameter (Freundlich, Langmuir) and 3-parameter (Redlich-Peterson and Radke-Prausnitz) equations widely used in adsorption studies. Characteristic coefficients of equations were determined and the proposed approximations of the results of experimental studies were evaluated statistically. Higher sorption capacity was obtained for Direct Orange 26 than for Reactive Blue 81.

W pracy prowadzono badania dla układu barwnik azowy - sorbent roślinny. Barwniki azowe Direct Orange 26 i Reactive Blue 81 pochodziły z Zakładu Boruta - Zachem Kolor Sp. z o.o. Jako biosorbenta użyto modyfikowanej fizycznie i chemicznie słomy żytniej, materiału taniego i łatwo dostępnego. Wykonano eksperymenty, kontrolując w czasie zmiany stężenia barwników w roztworze i sorbencie. Eksperymenty prowadzono w stałej temperaturze do ustalenia równowagi procesu. Opisu równowagi sorpcyjnej dokonano za pomocą równań dwu- i trójparametrowych szeroko stosowanych w adsorpcji. Wyznaczono charakterystyczne współczynniki równań i dokonano oceny statystycznej proponowanych aproksymacji wyników badań eksperymentalnych. Większą pojemność sorpcyjną uzyskano dla Direct Orange 26 niż dla Reactive Blue 81.

Adsorption of anionic dyes onto natural, thermally and chemically modified smectite clays

100%

Kyzioł-Komosińska J., Rosik-Dulewska C., Pająk M., Krzyżewska I., Dzieniszewska A.

Polish Journal of Chemical Technology

2014

vol. 16

issue 4

33-40

The aim of this study was to determine the adsorption capacity of the smectite clays (from the overburden of the lignite deposit in Belchatow) for two anionic dyes, i.e. Reactive Blue 81 (RB-81) and Direct Blue 74 (DB-74). Additionally, the influence of the thermal and chemical (acid and alkali) clay modifications on the amount of bonded dyes was investigated. The adsorption capacity of the clay (natural and modified) was different for studied dyes and depended on the initial concentration and modification type. All the modified clays adsorbed the dyes at pH>pHPZC as the negatively charged surfaces of their particles (in accordance with the formula: AOH ↔ AO- + H+) prevented the formation of electrostatic bonds between the anionic dyes and the clay surface. The dyes were mainly bound with the hydrogen bonds forming between the donor groups in the dyes and the acceptor groups (-SiO and -Al2OH) in the clays. The coefficients in the adsorption isotherms were estimated with the linear and non-linear regression. The linear regression method was found that the Freundlich and Dubinin-Radushkevich isotherms described the dye sorption much better than the Langmuir model. On the other hand, all three models described well the experimental data in the non-linear regression method. Furthermore, the 1/n value (<1) obtained from the Freundlich equation for all the dye-sorbent systems indicated the favorable sorption.

Refine search results

1 Ecological Chemistry and Engineering S

1 Polish Journal of Chemical Technology

2 2014

1 Dzieniszewska A.

1 Krzyżewska I.

1 Kyzioł-Komosińska J.

1 Pająk M.

1 Rosik-Dulewska C.

1 Tomczak E.

1 Tosik P.

Search results

Sorption Equilibrium of Azo Dyes Direct Orange 26 and Reactive Blue 81 onto a Cheap Plant Sorbent/Równowaga Sorpcji Barwników Azowych Direct Orange 26 I Reactive Blue 81 Na Tanim Sorbencie Roślinnym

Adsorption of anionic dyes onto natural, thermally and chemically modified smectite clays