Open AccessEquilibrium and Kinetics Studies of Hexavalent Chromium Biosorption by Luffa Cylindrica using Optimised 1,5-Diphenylcarbazide Method
Publication year - 2020
Publication title -
journal of environmental treatment techniques
Language(s) - English
Resource type - Journals
ISSN - 2309-1185
DOI - 10.47277/jett/9(1)317
Subject(s) - biosorption , hexavalent chromium , adsorption , chromium , freundlich equation , langmuir , langmuir adsorption model , chemistry , aqueous solution , nuclear chemistry , monolayer , fourier transform infrared spectroscopy , materials science , chemical engineering , organic chemistry , biochemistry , sorption , engineering
The Luffa Cylindrica fibers plant have been used as a new biological adsorbent for removal of hexavalent chromium from artificially contaminated aqueous solutions. The experiments took place in the bath mode. The influence of certain parameters on the adsorption of chromuim on the biosorbent, namely the adsorbent-adsorbate contact time, the pH of the solution and adsorbent dose of hexavalent chromium was determined. The kinetic study has shown that the process of adsorption chromuim on luffa cylindrica is a physical process characterized by its reversibility, by the speed of the establishment of equilibrium. The exploitation of adsorption isotherms using different classical models of Langmuir, Freundlich and Temkin has shown that adsorption can be governed by the Langmuir model. The maximum monolayer biosorption capacity of luffa cylindrica was found to be 5.91 mg of chromium /g of LC. The thermodynamic parameters for the adsorption system were determined at 283, 298 and 313°K. The obtained values showed that the chromium adsorption is a spontaneous and exothermic process. Finally, the Luffa cylindrica has been evaluated by FTIR, SEM and x-ray diffraction in order to determine if the biosorption process modifies its chemical structure.