0.20 g of adsorbent was added to 20 mL of 50 mg/L dye solution and Vortex at 150 rpm for various time intervals at 5, 10, 15, 30, 60, minutes. The above steps were repeated using dye concentrations of 100, 150 and 200 mg/L dye solutions. Adsorbent dosage is an important parameter because it determines the capacity of adsorbent for a given initial concentration of dye molecules. Then their % absorbance’s were calculated by spectrophotometer (λmax=410) and thus amount adsorbed were calculated. Data obtained from the experiments with 0.20 adsorbent concentrations are presented in Fig. 4.1.1 Initial conc. of methyl red dye 25 & 50 mg/l are 100 absorbed within 60 min. The removal efficiency of 75 mg/l conc.is 80% within 60 min.100 & 200 mg/l dye conc. is not absorbed efficiently. It showed that increasing dyes conc. resulted in a sharply decrease in the adsorption yield.
Fig 4. 1. Methyl Red removal with 0.2 g/L Fe Nanoparticle at different contact time
4.1.2 Unit Removal Capacity (URC) at different concentrations of Methyl Red
Unit removal capacity is the amount of dye removed per unit weight of iron dosage.The decolorization efficiency (η%) of MO and the unit removal capacity (mg/g) were calculated using the following URC= C0-Ce/m
Where C0 and Ce are the initial and equilibrium MO concentrations (mg/L) in…