Biosorption of an anionic dye by peanut shell modified with gemini surfactants: A study on the stability of the modification and the removal efficiency

MURGUÍA, M.C. AND FERNANDEZ, M.E.

JOURNAL OF MOLECULAR LIQUIDS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2020

0167-7322

In this study, novel biosorbents were obtained from peanut shells modified with gemini-type surfactants. Peanut shells, an agro-industrial residue,were successfully modified to enhance their naturally lowbiosorption capacity towards anionic contaminants. An anionic dye (tartrazine) was employed to test their performance. Three gemini were synthesized from N,N-dimethylamines with different chain length and 1,3-dichloro-2-propanol as a linker. They were purified and characterized and their surfactant properties were determined. The successful modification of the peanut shells was confirmed through a retention study based on a two-phase titration method. Thismethod has not been reported before for modified biosorbents and should be considered to prevent risky lixiviation. Retention was found to be high (98.0–99.7%) and to be chain length-dependent. Biosorption followed the pseudo-second order kinetic model and equilibrium isotherms of the gemini-modified biosorbents were best fitted by the Langmuir model. Their maximumbiosorption capacities (0.126–0.141mmol g−1) proved to be more than threefold higher than that of the unmodified peanut shells. The retention capacity of the gemini was also tested after biosorption studies.