Improvement of water quality using dielectric barrier discharge plasma

The improvement of water quality using by atmospheric plasma produced from a dielectric barrier discharge (DBD) was studied. An experiment was set-up with a 4 mm diameter pipe, which contains 2 electrodes and has an air flow with the rate of 15 liters per minute. Surface water, domestic wastewater and DI water were treated with the DBD plasma for some period of time. Electricity was supplied at 3.5 kV with the frequency of 5.5 kHz. Some key parameters of water quality includes the level of chemical oxygen demand (COD), total suspended solid (TSS), color, and odor are measured before and after. The result showed that strong acid with pH below 2 was observed after 60 minutes plasma treatment for the DI water, while the surface water and wastewater needs about 120 minutes to pH below 2 even though the pH value are about the same at the beginning. Moreover, It was formed that the COD, TSS microorganism was noticeably decreased, therefore the increasing of transparency level. This result confirms that atmospheric DBD plasma generated acidity in water as reduce amount of organic and suspended solid in water.