Hamid Kazemi Hakki; Pouya Shekari; Ahmad Najafidoust; Nosrat Dezhvan; Masoume Seddighi Rad
Abstract
Nowadays, not only the lack of water sources but also water pollution by industrial wastewater has become a major challenge. One of the pollutants of water resources, which threatens water resources, is phenol that enters the environment through wastewater from various industries such as petrochemicals, ...
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Nowadays, not only the lack of water sources but also water pollution by industrial wastewater has become a major challenge. One of the pollutants of water resources, which threatens water resources, is phenol that enters the environment through wastewater from various industries such as petrochemicals, refineries, pharmaceuticals, etc. This compound, due to its toxicity, high stability and solubility in water caused many problems and it is very important to remove it from industrial wastewater. Therefore, the main purpose of this study is to remove phenol from wastewater by using catalytic oxidation. Fe-ZSM-5 catalyst was synthesized by precipitation method and its characteristics were determined by XRD, FTIR, SEM and BET analyses. The results of XRD analysis showed that the iron ions are in the MFI structure and the catalyst has a good crystallinity phase, so that it retains its MFI structure. BET analysis showed the specific surface area of the synthesized catalyst is 293g/m2. The catalytic activity of Fe-ZSM-5 was investigated in degradation of phenol and the results showed that the mentioned catalyst had the highest removal percentage (85.82%) in 90 min at pH = 4.25 and T= 70 °C. The effect of various parameters such as ultraviolet radiation, initial pollutant concentration, catalyst loading and H2O2 concentration on the catalytic activity were also investigated.
Masoud Samandari; Afshin Tagva Manesh; Seyed Ali Hosseini; Sakineh Mansouri
Abstract
The catalytic wet peroxide oxidation (CWPO) of phenol from wastewater using Mg-Al LDH and calcined LDH at 500 ºC was investigated. The LDH was synthesized by co-precipitation and characterized by XRD, FTIR, SEM, EDS and BET. XRD result showed that during calcination of LDH at 500 ºC, LDH decomposed ...
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The catalytic wet peroxide oxidation (CWPO) of phenol from wastewater using Mg-Al LDH and calcined LDH at 500 ºC was investigated. The LDH was synthesized by co-precipitation and characterized by XRD, FTIR, SEM, EDS and BET. XRD result showed that during calcination of LDH at 500 ºC, LDH decomposed to the mixed oxide. The SEM images approved Mg-Al LDH comprised of flakes and the calcined LDH comprised of spherical nanoparticles. BET results indicated the specific surface area of 100.2 and 86.3 m2.g-1 for pure LDH and calcined LDH, respectively. The process was optimized by one factor at a time method and considering four process factors i.e. reaction temperature, peroxide dosage, initial phenol concentration, and reaction time. The optimum conditions resulted at initial phenol concentration of 100 ppm, reaction temperature of 60 ºC, with peroxide volume of 3 mL and time on stream of 45 min over calcined LDH with maximum 85% removal of phenol. On the pure LDH, the maximum phenol removal (79%) resulted at peroxide volume of 2.5 mL at 55 min. The study concluded that the calcined Mg-Al LDH due to synergistic effect of MgO and Mg-Al mixed oxide showed higher catalytic activity despite a relatively low surface area.