2.4.3. Effect of shaking method and particle size on heavy metal
ion removal by MOSB
To test the effect of particle size, the MO seed powder was
sieved and the fraction with mesh size 500–1000, 250–500 and
250–106 m were selected for use in the sorption tests and from
here onwards the size ranges are discussed as 500, 250 and 106 m,
respectively. For eachofthedifferentparticle sizes, 0.5 g ofthepowder
wasmixed with100 mL of a 10 mg L−1 synthetic samplemixture
of the metals studied. To extract the metal ions from synthetic
solutions, two shakers were used, namely, an orbiter shaker and
ultrasonic sonicator. The shaking was performed at room temperature
(22 ± 1 ◦C)for 1 h using orbiter shaker at 500 oscillations min−1
and sonication for 45 min using an ultrasonic sonicator. Samples
frombothmethods of extraction were thencentrifugedat 4000 rpm
for 10 min. The supernatant solutions were further filtered under
ultra-filtration, with a 0.45 m glass fiber filter paper. The free metals
in the filtrate were then analyzed using FAAS.