4.5. Investigation of the effect of methylene blue dye solution
concentration
To investigate the effect of methylene blue solution concentration on
the removal from dye wastewater, at first, solutions of different
concentrations (10, 30, 50 ppm) were prepared. 100 ml sample was taken
from each sample and 0.1gr of nanocomposite
(NiFe2O4@SiO2) @HKUST-1)
(30%) was added in the presence of oxygenated water and again under
ultrasound for better mixing. after 10 minutes, samples were collected
and centrifuged, and the amount and removal efficiency were calculated
using a spectrophotometer.
Fig (17): Diagram of the effect of dissolved concentration on the
degradation of methylene blue dye.
It can be seen in Fig 17 that the removal efficiency in methylene blue
aqueous solution at 10 ppm concentration had the highest removal
efficiency. So that after 60 minutes about 95% removal was done.
However, for methylene blue dye solution with concentration (30 and 50
ppm), the removal efficiency reached (62.4% and 59.03%). This
indicates that the removal efficiency decreased with increasing
concentration of methylene blue dye solution. The reason for this
decrease is that as the concentration of the dye solution increases, the
dye molecules in the solution increase and given the constant
concentration of the nanocomposite metal-organic framework synthesized
in these solutions, the active sites and specific surface area of the
nanocomposites are completely saturated and filled. As a result, the
lower the concentration of the dye solution, the less the dye molecule
in the solution so pore volumes and surface areas will be filled in a
longer time and their removal efficiency will be higher.