Study On The Catalytic Performance Of Copper-loaded Silica Microspheres In Phenol Oxidation

The discharge of wastewater containing phenol and its derivatives has caused serious pollution to water resources.This type of waste water is usually highly toxic and seriously endangers to human health and environmental safety.Catalytic wet hydrogen peroxide oxidation（CWPO）,as an effective phenol-containing wastewater treatment technology,has been widely studied due to its high efficiency,weak p H sensitivity,and non-selectivity.Silica particles have been widely used in various fields such as liquid chromatography column packing and catalyst preparation,due to their low price,controllable morphology,high specific surface area,and high porosity.In combination with the above introduction,this thesis uses laboratory-made Si O₂seeds as a catalyst carrier and supports Cu（Ⅱ）as the active center.The phenol in the aqueous solution was degraded by CWPO to simulate the treatment of phenol-containing wastewater to explore the catalytic performance of the prepared catalyst in the reaction of phenol degradation.In this thesis,firstly,the St（?）ber method was used to prepare silica particles using ethanol as the solvent,tetraethylorthosilicate（TEOS）as the silicon source,and ammonia（NH₃·H₂O）as the catalyst.Under the condition of a certain Cu Cl₂ concentration,the Si O₂-Cu²⁺catalyst was formed through electrostatic adsorption between silica particles and Cu²⁺.The Si O₂-Cu²⁺particles were calcined in a high-temperature resistance furnace to prepare a Si O₂-Cu O catalyst with Cu O structure.Dynamic light scattering（DLS）,scanning electron microscope（SEM）,X-ray diffraction（XRD）and other test methods were employed to determine the structure,morphology,particle size distribution and Zeta potential of the obtained Si O₂ seeds,Si O₂-Cu²⁺catalyst and Si O₂-Cu O catalyst.Characterized by UV-vis,it was calculated that the adsorption capacity of Si O₂seeds for Cu²⁺is 96.76 mg/g.After that,this experiment used the prepared Si O₂-Cu²⁺and Si O₂-Cu O particles as the catalyst,and hydrogen peroxide as the oxidant.Under different reaction conditions（reaction temperature,reaction time,initial p H,oxidant concentration,and catalyst concentration）,CWPO was investigated with degradation treatment of phenol with a concentration of 1 g/L in the water phase.The experimental data showed that the self-made Si O₂-Cu²⁺catalyst and Si O₂-Cu O catalyst in this experiment can achieve about 100%phenol conversion rate within 3 h and 4 h,respectively,at a reaction temperature of 70℃,a certain oxidant and catalyst concentration.The COD removal rate of phenol and its oxidation products showed obvious experimental condition dependence.Under suitable reaction conditions,using Si O₂-Cu²⁺catalyst and Si O₂-Cu O catalyst,the COD removal rate of the sample was different in the reaction for 12 h and 20 h reached 90.27%,89.09%.During the experiment with hydrogen peroxide as the oxidant,the degradation reaction showed weak sensitivity to the initial p H value of 4～9.Based on the above experimental results,it can be concluded that the Si O₂-Cu²⁺catalyst and Si O₂-Cu O catalyst made by our laboratory showed good catalytic activity in the degradation of phenol CWPO.