Design And Application Of Wastewater Treatment Reactor Based On High Voltage Pulse Power Supply

In recent decades,with the rapid development of Chinese society and the continuous improvement of people’s living standards,environmental problems have become increasingly important.A large number of industrial and domestic wastewater are directly dumped into the environment without treatment which result in a lot of water pollution accidents.Ozone has been used in the field of wastewater treatment since the last century because of its strong oxidation.The power supply of ozone generator has developed from power frequency high voltage power supply to high frequency high voltage power supply.Although the heating and efficiency have been improved,there are still some problems in practical application,such as high heating capacity and low efficiency of ozone preparation.The pulsed power supply can produce a steep rise,accelerating electrons rather than ions as much as possible which increase the efficiency of non-equilibrium plasma generation.The voltage waveform generated by the single discharge of the pulse power supply is the same,and the discharge phenomenon produced is also highly similar,so the production of ozone can be controlled by adjusting the repetition frequency of the pulse power supply.In this paper,dielectric barrier discharge is used to prepare ozone,and the selected dielectric barrier discharge structure is line-cylinder type.In the design process of ozone generator,the oxidation resistance of ozone generator materials and the influence of different gas sources on ozone production are studied.The equivalent capacitance of the line-cylinder ozone generator is small,which can produce voltage with steeper rising edge,and its electric field distribution is very uneven,so it is easier to discharge and produce plasma.In this paper,through COMSOL simulation analysis and experimental demonstration,the most matching structure parameters with the pulse power supply are finally determined.In order to improve the efficiency of wastewater treatment,the effect of pH value on COD(chemical oxygen demand)removal by ozone was studied in this paper.By comparing the COD removal efficiency of ozone / hydrogen peroxide,ozone / metal oxide and ozone / activated carbon,it is found that the ozone / activated carbon process has the best effect.After 75 minutes of treatment,the COD removal rate of 500 ml coking wastewater with initial COD of 3250mg/L can reach 83.9%.