Assessment of kinetics, equilibrium and thermodynamics of black krom kjr dye adsorption onto aquatic macrophyte pistia stratiote

Aparecido Nivaldo Modenes1, Fabiano Bisinella Scheufele1, Julio Cesar Barbosa1, Andreia Colombo1, Daniela Estelita Goes Trigueros1, Fernando Rodolfo Espinoza-Quinones1, Camila Larissa Hinterholz1, Alexander Dimitrov Kroumov2

1 Department of Chemical Engineering - Postgraduate Program, West Parana State University, Campus of Toledo, Rua da Faculdade 645, Jardim Santa Maria, 85903-000, Toledo, PR, Brazil
2 Department of Applied Microbiology, Division Microbial Synthesis and Ecology , Institute of Microbiology Stephan Angeloff - Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 26, Sofia 1113, Bulgaria

Abstract


The macrophyte Pistia stratiote was used as biosorbent for the removal of Black Krom KJR (BK-KJR) dye in synthetic aqueous solution. Initially, some tests were performed to verify the best operational conditions such as pH, biosorbent particle size, sorption temperature and stirring speed, which were later used in the kinetic and equilibrium tests. All tests were performed in duplicate. The highest removal rates of the pollutant were achieved at the process conditions of initial pH 2, granulometric mixture of roots, 30 C and stirring speed of 80 rpm. In the kinetic test an equilibrium time of 24 h was found. The kinetic data were adjusted by applying the pseudo-first order, pseudo-second order and Elovich models, and as a result the best fit was found with the pseudo-second order model. In the equilibrium study it was found that, among the tested models, Langmuir model was the one that best fitted the experimental data, with a maximum sorption capacity (qmax) of 84.11 1.64 mg g-1 and affinity constant (b) 0.025 0.001 mg L-1. These results showed high potential of the macrophyte Pistia sp. as an alternative material to remove the BK-KJR dye.

Keywords


biosorption; dye; macrophyte; modeling; Pistia stratiote; thermodynamic parameters

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