Preparation And Characterization Of Activated Carbon-based Adsorbent For Advanced Treatment Of Petrochemical Wastewater

Since some special pollutants in petrochemical wastewater cannot be completely removed in the conventional pre-secondary treatment,advanced treatment technology for the petrochemical wastewater is needed to meet emission standards.Adsorption-catalytic oxidation is one of the most effective and low-energy petrochemical wastewater treatment methods.In this paper,pore structure characterization and adsorption performance tests were carried out on activated carbon,mesoporous manganese dioxide and iron-loaded silica.The activated carbon with better adsorption performance is selected as the carrier,and the catalysts with different transition metal oxides and different metal loadings were supported on the activated carbon.Phenol was used as a model compound to simulate petrochemical wastewater.The pore structure,adsorption and catalytic oxidation properties for phenol of the samples synthesized under different preparation conditions were investigated.Taking the chemical oxygen demand?COD?of petrochemical wastewater as the index,the sample with better phenol adsorption and catalytic oxidation performance was applied to the treatment of actual petrochemical wastewater,and the adsorption and catalytic oxidation performance of the sample on the actual petrochemical wastewater were investigated.The experiment is mainly divided into the following three parts:?1?The pore structure of activated carbon,mesoporous manganese dioxide,iron-loaded silica and other materials were characterized and phenol was used as a model compound to test the adsorption performance.Activated carbon was selected as a preferred adsorbent for heat treatment modification,and its surface chemistry,pore structure characterization and adsorption performance test were carried out.The results showed that the surface of activated carbon was alkaline and Langmuir equation and pseudo-second order kinetics model were suitable to describe the absorption process indicating that the adsorption type was chemisorption.?2?The transition metal oxides such as iron,copper and manganese were supported on the activated carbon as catalysts,and the pore structure was characterized by samples prepared with different transition metals and different metal loadings.The adsorption and catalytic oxidation properties of phenols prepared by different calcination temperatures,calcination time and impregnation methods were investigated.The results of TG-MS showed that the sample?FeCuMn311?in which the supported metals were iron,copper and manganese?metal mass fractions of 3%,1%,1%?showed better adsorption and catalytic oxidation performance for phenol.?3?FeCuMn311 was used in the petrochemical wastewater adsorption-catalytic oxidation cycle experiment.The results showed that FeCuMn311 exhibits superior adsorption and catalytic oxidation performance to the petrochemical wastewater,and can be used 10 times in the adsorption-catalytic oxidation cycle.The results of TG-MS showed that the intensity of CO₂ peak was increased by dry catalytic oxidation after ozone treatment,indicating that ozone oxidation can improve the catalytic oxidation effect of supported catalyst activated carbon on adsorbed organic matter.