2.2. Preparation and characterization of MOSB
Dry MO seeds were obtained from a local supplier in Gaborone
and stored at room temperature prior to use. The seeds were
deshelled by hand and the kernels were washed with copious
amounts of doubly distilled water to remove any adhering dirt
before drying them in the oven at 65 ◦C for 24 h. The seed kernels
were ground to powder using mortar and pestle and the
oil extracted by mixing the seeds powder (75–80 g) in 40–60 ◦C
petroleum ether (200 mL) for 30 min on an orbital shaker (Stuart
Scientific). The powder was then obtained by suction filtration and
dried in at room temperature in open air on a bench. The powder
was further dried for 24 h and ground to finer powder using mortar
and pestle. Powder was sieved through mesh sieves to obtain a
homogeneous biomass. No other chemicals or physical treatments
were used prior to biosorption experiments.
The MOSB was also characterized by Fourier Transform Infrared
(FTIR) spectroscopy (PerkinElmer System2000) as described in Section
2.3.