may be due to the remaining organic matter. P-25 showed the mixture of both anatase and rutile TiO2. The TiO2 with anatase structure is generally accepted as the most active and efficient photocatalyst compared to rutile and brookite [45]. Therefore, the TiO2 obtained at 600 is expected to be an efficient photocatalyst, which coincides with Lee et al. [4] and ℃ Okour et al. [46]. Here, the 600 was selected as the most efficient temperature taking into ℃ account the energy require to recover the photocatalyst from the sludge. 3.5.2 Thermal analysis (TG/DSC) The thermogram recorded for the settled after TiCl4 coagulation is shown in Fig. 5b. A continuous weight loss distributed between 25-557.39 in the TG plot can be seen. The ℃ thermal treatment of sludge up to 153.77 led mainly to the loss of adsorbed water content ℃ (16.65%) while it resulted in the removal of organic matter (12.67%) between 153.77-493.06 Another weight loss of 0.9919% at 493.06-557.39 may be caused by the release of ℃. ℃ constitution water. The DSC curve of the settled flocs was comparatively smooth and there were no obvious peaks except at 542.72 and 806.99 The transformed temperature of the anatase phase to ℃ ℃. rutile was approximately 550 according to Liao et al. [47]. However, this transformation ℃ occurred at approximately 800 according to results of XRD analysis (Fig. 5a), ℃ corresponding well with the endothermic peak at 806.99 The peak at 542.72 was ℃. ℃ speculated to be the indication of transformation from amorphous structure to apparent anatase phase of TiO2. This is in agreement with the obvious anatase TiO2 at 600 shown ℃ in Fig. 5a. 3.5.3 SEM analysis As mentioned in section 3.5.1, the 600 was selected as the optimum temperature for ℃
may be due to the remaining organic matter. P-25 showed the mixture of both anatase and rutile TiO2. The TiO2 with anatase structure is generally accepted as the most active and efficient photocatalyst compared to rutile and brookite [45]. Therefore, the TiO2 obtained at 600 ℃ is expected to be an efficient photocatalyst, which coincides with Lee et al. [4] and Okour et al. [46]. Here, the 600 ℃ was selected as the most efficient temperature taking into account the energy require to recover the photocatalyst from the sludge. 3.5.2 Thermal analysis (TG/DSC) The thermogram recorded for the settled after TiCl4 coagulation is shown in Fig. 5b. A continuous weight loss distributed between 25-557.39 ℃ in the TG plot can be seen. The thermal treatment of sludge up to 153.77 ℃ led mainly to the loss of adsorbed water content (16.65%) while it resulted in the removal of organic matter (12.67%) between 153.77-493.06 ℃. Another weight loss of 0.9919% at 493.06-557.39 ℃ may be caused by the release of constitution water. The DSC curve of the settled flocs was comparatively smooth and there were no obvious peaks except at 542.72 ℃ and 806.99 ℃. The transformed temperature of the anatase phase to rutile was approximately 550 ℃ according to Liao et al. [47]. However, this transformation occurred at approximately 800 ℃ according to results of XRD analysis (Fig. 5a), corresponding well with the endothermic peak at 806.99 ℃. The peak at 542.72 ℃ was speculated to be the indication of transformation from amorphous structure to apparent anatase phase of TiO2. This is in agreement with the obvious anatase TiO2 at 600 ℃ shown in Fig. 5a. 3.5.3 SEM analysis As mentioned in section 3.5.1, the 600 ℃ was selected as the optimum temperature for
Coagulation%20and%20sludge%20recovery%20using%20titanium%20tetrachloride%20as%20coagulant%20for%20real.docx