Removal of some new direct sulpho aryl azo dyes from aqueous solutions by adsorption onto different types of carbon

Abstract EN

A new group of direct arylazo dyestuffs that are based on the spiro 2-oxoindole (3,2 ´)-1 ´,3 ´- thiazolone moiety was successfully synthesized by the authors [1].

In view of the current interest in utilizing the sulpho arylazo dyestuffs for dyeing different types of fibers, the present paper describes the possibility of using carbon for their removal, as organic pollutants, from aqueous solutions.

The removal of these dyestuffs from their aqueous solutions was carried out by using different adsorbents such as granular carbon, carbon soot, and powdered activated carbon (PAC) at different temperatures ranging from 25 oC to 60 oC.

The adsorption of these dyes on different types of carbon has been found to obey the adsorption isotherms like Langmuir, Freundlich and Branuer Emmitte and Teller (BET) isotherms.

It was found that PAC has the highest capacity of adsorption .Carbon soot is recommended to be used for the removal of such type of dyes from their aqueous solutions due to the low cost of its production with respect to PAC and to solve the problem of its accumulation, as a polluting solid waste.

Different adsorption parameters were calculated from these models for the interpretation of the adsorption process.

It was found that the removal efficiency for color of dyes was over 90 % in case of carbon soot and PAC at higher temperatures.