Degradation Of Tetracycline Hydrochloride By Dielectric Barrier Discharge Plasma

The prevalence of antibiotics in the environment as detected in recent years has been harming the ecological environment and seriously threatening the life and survival of human being,which causes great concern among the people.With the characteristic of discharge stable,easy to operate and low power consumption,DBD plasma technology can effectively degradation antibiotic in wastewater and provides a new way for antibiotic wastewater treatment.In this paper,tetracycline hydrochloride solution was used as simulated antibiotic wastewater,DBD plasma reactor was used in aqueous tetracycline hydrochloride removal.The effects of parameters,packing and catalyst on the degradation process of tetracycline hydrochloride solution were investigated.The results of using DBD plasma reactor with air bubbling showed that tetracycline hydrochloride can be effectively decomposed by DBD plasma.Under the optimum conditions,degradation efficiency of tetracycline hydrochloride solution(100 mL,100 mg·L^-1)reached 92%when the discharge lasted for 30 min,and the maximum energy efficiency of 14.15 g·（kWh）^-1 was obtained.When the DBD plasma reactor was packed with dielectric materials,the electric field intensity and the average electron energy was enhanced.The result indicated that the introduction of dielectric materials was positive for tetracycline hydrochloride degradation.The degradation of tetracycline hydrochloride reached the highest value of 98.7%in a SiO2-packed reactor after 30 min treatment time with oxygen flow rate of 150 mL/min,input power of 1.3 W,and discharge gap of 2.5 mm.A coaxial DBD reactor was used for plasma-catalytic degradation of tetracycline hydrochloride over a series of Mn/γ-Al₂O₃ catalysts.The combination of plasma and the Mn/γ-Al2O3 catalysts significantly enhanced the degradation efficiency of tetracycline hydrochloride compared to the alone plasma process,with the 10%Mn/γ-Al2O3 catalyst exhibiting the best tetracycline hydrochloride degradation efficiency.The maximum degradation efficiency of 99.3%can be achieved after 5min oxidation and a discharge power of 1.3 W.Among the multiple oxidation processes in the coupled Mn/γ-Al₂O₃ and DBD plasma system,the ozone and hydroxyl played important roles because of their outstanding oxidation ability.