Biologically Treated Pom Case Study

3.3.2. Biologically treated POME
From Fig. 9a and b, it is clear that there is no need of using high loading of C, N, S triple doped TiO2, TiO2-ZnO as maximum photoactivity can be achieved at 2 g/L. Even if high photocatalyst concentration is used, the degradation efficiency will be lowered. This result is in concord with the results of ........(2002) that the photodegradation of.....was relatively high at photocatalyst loading of ......and that high photocatalyst loading(RH > 10.6%, T = 318 K) hindered the photodegradation of .
Also, the influence of COD concentration on the COD removal of biologically treated POME was investigated and shown in Fig.9c. As observed, the COD removal was reduced with an increasing COD concentration. The highest
11a-c show the photodegradation curves of biologically treated POME using a fresh and regenerated.................photocatalyst. The regeneration tests can be operated at the optimum conditions (COD concentration 300 mg/L and catalyst concentration 2 g/L) for 5 cycles.
.Fig.11a show the adsorption capacity of fresh and regenerated photocatalyst versus time. For cycle 5, Fig.11a show that around ....% of the virgin capacity of the C,N, S triple doped-TiO2-ZnO was regenerated and increasing the regeneration time did not increase the regeneration capacity. Therefore, 3 h regeneration was used in each cycle. For cycle 4, the virgin capacity was slightly higher than that of Set 5. This result is consistent with the result of Fig. 11a. Fig.11a shows a plot of COD/COD0 ratio as a function of irradiation time for each
C,N,S triple doped-TiO2-ZnO nanocomposites as visible-active photocatalysts were successfully synthesized and characterized and evaluated by activity tests for the degradation of Direct red 16 and biologically treated POME. The particle size of C,N,S triple doped-TiO2-ZnO as estimated from scherer XRD equation was ..... nm TiO2 nanoparticles that contain 1.5 wt % methionine as a doping agent and 1:3 weight ratio (ZnO: TiO2) exhibit high photocatalytic capability comparable to the other modified sample under visible light which pure TiO2 photoactivity is negligible. The effect of pollutant concentration, catalyst concentration and irradiation time on photocatalyst performance was also optimized based on RSM. The synthesized photocatalytic nanocomposite materials degraded Direct red 16 and biologically treated POME to a good extent. The effect of initial concentrations on photodegradation of both of the selected pollutant was significant. Also, the direct red 16 removal decreased with decreasing irradiation time and with increasing pH. The highest photodegradation efficiency was achieved at 1 g/L and 2 g/L of photocatalyst concentration for Direct re 16 and biologically treated POME, respectively. Finally, the photocatalytic regeneration of the prepared photocatalyst was