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Studies on a non-thermal pulsed corona plasma between two parallel-plate electrodes in water

2012; Institute of Physics; Volume: 45; Issue: 22 Linguagem: Inglês

10.1088/0022-3727/45/22/225203

1361-6463

Myint Myint Sein, Zeba Nasir, Ursula Telgheder, Torsten Schmidt,

Advanced oxidation water treatment

Abstract A non-thermal plasma generated between two parallel-plate electrodes submerged in water was studied in this work. The surface of one of the stainless-steel electrodes (the cathode) was coated with a ceramic layer of Al 2 O 3 . This reactor cell was connected to a water cycle and the discharge was carried out in a closed loop and therefore an equilibrium was established during discharge. The dependence of hydrogen peroxide formation as an indicator for the generation of most important oxidative species OH radicals on the pulse repetition rate, the solution conductivity and the pH of the solution was investigated. The highest yield of H 2 O 2 (3.5 mg L −1 ) was obtained at 20 pps in a NaCl solution with a conductivity of 400 µS cm −1 and pH 7 in 90 min. The maximum energy efficiency of ∼0.1 g kWh −1 H 2 O 2 was obtained. The surface of the coated electrodes, before and after applying of electrical discharges, was analysed by scanning electron microscopy. During the discharge process, the coating was destroyed and the formation of H 2 O 2 decreased to 10% after discharging of nearly 35 h.