Degradation Of Refractory Organic Compounds In Water By Anodic Contact Glow Discharge Activated Periodate

Periodate（PI）is a new type of oxidant,which can efficiently degrade organic matter through activation,and the development of a new and efficient activation method for periodate is a research hotspot in the field of water treatment.In this thesis,Anodic contact glow discharge electrolysis（ACGDE）was the first time to be used for periodate activation,and the anodic contact glow discharge combined with Ti O₂ activation of periodate was also studied for the treatment of refractory organic compounds in water.The main research contents are as follows:（1）The oxidative degradation of 3-chlorophenol（3-CP）in water was achieved by anodic contact glow discharge activation periodate.The results show that the anode contact glow discharge plasma can efficiently activate PI and improve its oxidative degradation ability.The periodate（1.5m M）could be activated by anodic contact glow discharge plasma to remove 100%of 3-CP（56mg/L）within 2.0min,and the energy utilization and degradation efficiency in this work was higher than that of other activated methods.According to the results of quenching experiments,the main active substance for removing 3-CP was·OH.（2）The nitrogen dye methyl orange（MO）in water was successfully oxidized by anodic contact glow discharge（ACGDE）activation of periodate.Under the condition of p H 3 and periodate（6.0m M）addition,the methyl orange solution（25mg/L）could be decolorized completely in 6mins.After 9 mins of reaction,the COD removal rate was 90.4%,respectively.According to the results of quenching experiment,the main active substances for removing MO were O₂^·-and ¹O₂.（3）Anode contact glow discharge combined with Ti O₂was used to activate periodate for degradation of azo dye methyl orange（MO）.Under the condition of p H3,0.1g/L Ti O₂ and periodate（3 m M）addition,the methyl orange solution（25mg/L）could be decolorized completely in 6mins.Compared with the activation of periodate by anode contact glow discharge,there is a strong synergistic effect in ACGDE/PI/Ti O₂,which has a greater removal effect on MO,and the presence of periodate will lead to a decrease in the adsorption capacity of MO on the Ti O₂ surface.The degradation of MO could be enhanced by Cl^-addition,while SO₄^2-,NO₃^-,and CO₃^2-strongly inhibited the degradation of MO.The free radical quenching experiment showed that O₂^·-,¹O₂ and·OH were produced in the ACGDE/PI/Ti O₂ system,and O₂^·-and ¹O₂ were the main active species in the reaction system.