Magnetic nanoparticles, ferrites, arsenic removal, water treatment
Issue Date:
2009
Publisher:
Tap chi Khoa hoc
Citation:
15-19
Abstract:
This paper studied the effects of Co, Ni replacement in the Fe1-xCoxFe2O4 and
Fe1-yNiyFe2O4 (x, y = 0, 0.05, 0.1, 0.2, 0.5) nanoparticles, pH, weight of nanoparticles/ml of water
and time of stirring on the arsenic removal ability. The results showed that small amount of 0.25
g/l of Fe3O4 nanoparticles after stirring time of 3 minutes can reduce the arsenic concentration
from 0.1 mg/l to 0.01 mg/l. The removal was also affected by the pH of the water. Absorption of
arsenic by nanoparticles was effective when pH was smaller than 7 and reduced with the increase
of pH. At pH of 13, there was a strong release of arsenic ions from arsenic-absorbed nanoparticles
back to water. The time of stirring was studied from 1 minute to 2 hours, the optimal time was
about few minutes. Co and Ni presence was reported to maintain saturation magnetization stable
under working conditions. For Co replacement, absorption does not change significantly when x $\ge$
0.1 and slightly reduces when x > 0.1. The presence of Ni improved the absorption in most cases.
