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 the solution respectively, m is the amount of nZVI/BC (g/L).
The figure showing that the Methyl Red concentration increases the unit removal capacity also increases. As the concentration of dye dosages increase the removal efficiency decrease. Max. URC is decolorized at the 200 mg/l dye concentration i.e. 1000 mg/g is totally degraded. Fig4.2. Removal efficiency (RE) and Unit Removal Capacity (URC) at different concentrations of Methyl …show more content…
200 mg/L and nZVI conc. (0.20 g/L) and initial pH of the conical flask was measured. The pH of the dye solutions were adjusted with dilute HCl (0.1N) or KOH (0.1N) solution by using a pHmeter with pH of solutions being 2,4, 6,8, 10,12 .The adsorption of MR dye on nZVI was studied in a pH range of 2–12. Methyl red is slightly acidic pH ranges from 4.5- 6.5. Fig. 4.3 shows the obtained results. The figure indicates that, for MR, the adsorption is strong in acidic medium. As the pH increase, the adsorption capacity for nZVI decreases. For MR, the adsorption is high in acidic medium and increases with the increase in solution pH. This result may be due to change in surface charge of both the dyes molecules and functional groups of adsorbent. More absorption capacity is well worked on 4 & 6 pH. As the pH is increases, however, the overall surface charge on the cells will become positive, which will promote reaction with Methyl Red as an anionic dye through electrostatic forces of attraction. At pH 2 ,the removal capacity is low due the structure of methyl red and iron particles. It has greater tendency to attract them and corroision starts