Nanosecond Pulsed Non-thermal Plasma Organic Wastewater Treatment And Synergic Enhancement Research

With the development of industrial economy and urbanization and the enhancement of people’s awareness of environmental protection,the cleanliness and safety of water supply has become a hot spot of social concern.However,the current water treatment technology is not ideal for the treatment of refractory organic pollutants,which pose a persistent threat to human health and ecosystems.Cold plasma water treatment technology is a composite advanced oxidation technology with high treatment efficiency and no secondary pollution.It’s a green and emerging water treatment technology that has attracted much attention in the field of refractory organic pollutants.In this paper,a set of dielectric barrier discharge(DBD)reactor and wire-net corona discharge reactor were designed and tested with nanosecond pulse power drive,and the discharge phenomenon was studied and compared.Taking the dye Acid Red 73(AR73)as the target pollutant,the research was carried out from the aspects of reactor discharge phenomenon,solution parameters change,pollutant degradation,energy efficiency,etc.The feasibility and influence mechanism of FeOOH combined with cold plasma technology for water treatment were explored.The main results are as follows:(1)The designed DBD water treatment reactor can generate large-area uniform discharge,avoid electrode ablation and corrosion.The DBD reactor has long-term stable working ability,high active material output,and high pollutant degradation efficiency.The average H2O2 generation energy efficiency in the experiment is up to 2.029 g/kW·h.Degradation rate of AR73 can be up to 96.3%when treating 30mg/L AR73 solution for 40 minutes at 200V power supply voltage and 300Hz discharge frequency.(2)The effects of power supply parameters and solution parameters on the degradation of AR73 were systematically studied.The increase of voltage,higher discharge frequency,lower pollutant concentration and acidic environment were beneficial to improve the degradation rate of AR73.The degradation energy efficiency decreases with the increase of the discharge voltage,and increases first and then decreases with the increase of the discharge frequency.The optimal discharge frequency in the experimental range is 200Hz.Standing after the discharge treatment can make the H2O2 generated by the discharge continue to act,and improve the degradation rate and energy efficiency of AR73.When the degradation rate reaches 95%,the energy efficiency Y can be up to 8.84g/kW·h.Compared with changing the power supply parameters,the energy efficiency can be increased by 72.3%.(3)The main synergistic effects of FeOOH and low-temperature plasma are Fenton-like effect and catalytic O3 effect,which effectively improves the utilization rate of H2O2 and O3 generated by discharge,and enables gas-phase discharge to realize in-situ generation of OH in liquid phase,breaks through the limitation of gas-liquid mass transfer.Treat 30mg/L AR73 solution at pH=2,the TOC removal rate can be up to 51%,increased about 80%compared to discharge treatment,and the energy efficiency G50 reached 31.96g/kW·h,increased by 63.6%compared to discharge treatment,and the destructive ability to refractory structures was enhanced.