Removal of some 4-pyrazolone dyes from aqueous solutions by adsorption onto different types of carbon

A novel group of 4-pyrazolone based dyestuffs, considered as a group of tartrazine dye analogous, was synthesized by the authors [1]. In view of the current interest in utilizing the arylazo-4-pyrazolone dyestuffs for dyeing different types of fibers, this article 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 materials as granular carbon, carbon soot, and powdered activated carbon (PAC) at different temperatures ranging from room temperature (25°C) to 60°C. Kinetics and mass transfer studies were studied by applying different models such as Lagergren, Weber-Morris, Langmuir, Freundlich and Burnaur Emmette and Teller (BET). Different kinetic parameters ( K ad , K p , a, b, R L , n, K, A, X m ) were calculated from these models. The thermodynamic parameters (∆ H, ∆ S and ∆ G) were calculated for the interpretation of the adsorption process.