Adsorption Behavior of Organic Dyes in Biopolymers Impregnated with H3PO4: Thermodynamic and Equilibrium Studies

Abstract

A lignocellulose-based waste biopolymer was impregnated with phosphoric acid and used for the removal of two organic dyes, Direct Blue (DB) and Reactive Blue (RB), from aqueous solution. Batch adsorption kinetic studies were carried out at different initial concentrations of the dyes, at different temperatures and various initial pH values (2-10). The equilibrium data obeyed the Langmuir isotherm model with high regression coefficient. The kinetic data were also used to test three different kinetic models. The validity of the kinetic models was analyzed and the pseudo-second-order model may be the best fit to explain the rate-determining step. Adsorption of both dyes follows chemisorption. The effective diffusion coefficient and the activation energy were also calculated at different temperatures to establish the mechanism. Thermodynamic studies suggest that the adsorption of DB and RB is highly endothermic in nature. Mass transfer analysis reveals that the adsorption of DB and RB occurs through a film diffusion mechanism. Based on the Langmuir isotherm equation, the single-stage batch absorber design of the adsorption of DB and RB onto activated carbon was studied.

Investigation of the adsorption kinetics of methylene blue onto cotton wastes

“…This indicates that activated adsorption may occur between the dye molecule and the functional groups of organic components such as cellulose and lignin on CS, CW, and CD. Similar results have also been reported for the adsorption kinetics of acid orange 10 onto organobentonite, 7 for the adsorption kinetics of direct blue and reactive blue onto lingnocellulose-based waste biopolymer, 8 and for the kinetics of MB adsorption onto perlite 12 and banana stalk waste. 25 On the other hand, if the correlation coefficients estimated from the plots of the intraparticle diffusion kinetics are more than 0.90, the regression may be regarded as linear.…”

“…7 Senthilkumaar et al have investigated the adsorption kinetics of direct blue and reactive blue by a lignocellulose-based waste * Correspondence: acemioglu@kilis.edu.tr biopolymer. 8 Hameed and El-Khaiary have studied the adsorption kinetics of methylene blue (MB) using broad bean peels. 9 Yao et al have investigated the adsorption kinetics of MB by Xanthoceras sorbifolia seed coat (XSSC), a bioenergy forest waste.…”

Adsorption of Methylene Blue on A Polymeric Matrix of Poly Lactic Acid/Sodium Alginate/Carbon Nanoparticles (PLA/SA/CNP)

“…This revealed that the adsorbent's large surface area and many adsorption sites contributed to an increase in the percentage dye adsorbed; hence, a little increase in the amount of adsorbent provided a signi cantly greater surface area to absorb huge numbers of MB molecules. In the literature, 24 the same outcome has been described.…”

Adsorption of C.I. Natural Red 4 onto Spongin Skeleton of Marine Demosponge

“…Adsorption is reduced due to the lack of sufficient available open sites to adsorb high initial concentrations of the dye [ 11 , 12 , 13 , 14 , 15 , 16 ]. This situation is caused by the mass transfer driving force, which increases when the initial concentration is increased, resulting in higher adsorption of dyes [ 42 , 43 ]. Various studies have confirmed that adsorption capacity increases as the dye concentration increases [ 44 , 45 ].…”