Adsorption of a cationic dye by Marula (Sclerocarya birrea) fruit seed shell based biosorbent: Equilibrium and kinetic studies

Abstract

Adsorption of methylene blue from aqueous solution using a low cost Sclerocarya birrea fruit shell powder based biosorbent was investigated in a batch system. Results showed that optimum adsorption capacity was achieved at pH 8 and biosorbent dosage of 0.6 g, with a maximum adsorption capacity of 27.690 mg g -1 . Equilibrium studies showed that experimental data fitted well on the Temkin isotherm (R 2 = 0.9641), as well as the Langmuir isotherm (R 2 = 0.9626). The adsorption process followed the pseudosecond order rate kinetics with R 2 values greater than 0.999. Fourier transform infrared spectroscopy (FTIR) spectrum showed the presence of absorption bands typical of a plant based biomaterial. Given the abundant availability of the S. birrea trees in Southern Africa, the seed fruit shell can be used as a source of low cost biosorbent.

Bleaching of crude marula oil using activated bentonite and activated marula shells: A comparative analysis

“…Peaks at 2853/cm and 2930/cm emerged after adsorption and are attributed to medium C-H stretch vibrations of alkanes. The presence of aliphatic compounds suggests that these compounds contain C-H bonds and are organic compounds and these IR bands are similar to those of other plant materials (Moyo et al, 2015;Edokpayi et al, 2015;Mathew et al, 2017).…”

“…Biosorption has gained more research interests because it is renewable and cheap and marula shells have gained interest in reducing quantity of Pb (II) and Cu (II) Moyo et al (2015), methylene blue in aqueous solution (Mathew et al, 2017;, adsorption of methyl orange and zinc Lotfy et al (2012), removal of parasites Misihairabgwi et al (2014). Marula shells can be acid activated resulting in increase in acidic functional groups.…”