چكيده به لاتين
Abstract
Phenol and its derivatives are widely used as raw materials in many chemical, petrochemical and pharmaceutical industries. Phenol is also found in sewage from various industries, including wood preservatives, pesticides, textiles, paper and paint. The red color of phenol or Phenol Sulphon Phthalene is a type of tri-a-methyl methane that is widely used in various industries. This color is very toxic because of the presence of phenolic ring and its entry into the environment has adverse effects. In recent years, the advanced oxidation process for water treatment has been considered. These processes are capable of completely destroying organic pollutants during physical processes such as absorption and flocculation. In these processes, hydroxyl radicals are commonly used. Of course, this method is known as a costly method. Today, the use of oxidants such as proxy monosulfate and persulfate has expanded to this end. Homogeneous and heterogeneous catalysts are the best materials for the removal of organic pollutants. The heavy metals in the structure of these catalysts convert the oxidant into a radical form, and then convert organic contaminants into harmless materials. In this research, homogeneous and heterogeneous porous catalysts such as Fe3O4, Co3O4, Mn3O4 ،CoFe2O4, RuO2/Fe3O4@nSiO2@mSiO2, Co3O4/Fe3O4@nSiO2@mSiO2, RuO2/Al2O3, Co3O4/Al2O3 and Co3O4 /SBA-15 have been studied because of very good properties for removing phenol contaminants. The properties of this catalysts were characterized by SEM-EDS, XRD, TEM (transmission electron microscopy) and Nitrogen adsorption-desorption. Performance of phenol oxidation was dramatically influenced by operating parameters, such as catalyst dosage, oxidant and phenol concentration and reaction temperature. The mesoporous Fe3O4 catalyst was synthesized by Co-precipitation method, the mesoporous Co3O4, Mn3O4 ،CoFe2O4, Al2O3 and SBA-15 catalysts were synthesized by hydrothermal method and heterogeneous catalysts such as RuO2/Fe3O4@nSiO2@mSiO2, Co3O4/Fe3O4@nSiO2@mSiO2, RuO2/Al2O3, Co3O4/Al2O3 and Co3O4 /SBA-15 were synthesized by impregnation method. At an optimum concentration (50 ppm), the Fe3O4 bulk catalyst is not capable of producing radical sulfate due to its low oxidation-reduction potential and therefore does not function effectively in the phenol removal reaction.
The 0.4 g of Co3O4 and Mn3O4 as bulk catalysts in the presence of 2 g of the oxone are capable of removing 100% of the phenol at ambient temperature from the reaction medium for 40 and 30 minutes, respectively. While 0.4 g of CoFe2O4 catalyst in the presence of 2 g of the oxone are capable of removing 83% of the phenol from the reaction medium for 110 minute. The 0.2 g of RuO2/Fe3O4@nSiO2@mSiO2, Co3O4/Fe3O4@nSiO2@mSiO2, RuO2/Al2O3, Co3O4/Al2O3 and Co3O4 /SBA-15 as supported catalysts in the presence of 1 g of the oxone are capable of removing 100% of the phenol at ambient temperature from the reaction medium for 40 , 40, 60, 50 and 30 minutes, respectively.
Keywords: Advanced oxidation processes (AOPs), Peroxymonosulfate (PMS), Mesoporous metal oxide catalyst, Phenol degradation
