Synergistic effect of pulsed corona discharges and ozonation on decolourization of methylene blue in water

The effect of O2 and O3 bubbling on decolourization of methylene blue by pulsed corona discharges in water was studied. The pulsed corona discharges were produced by charging an 80 pF capacitor with a 40 kV DC source, through a 100 MΩ resistor, and discharging it into a needle-plate type reactor at 60 Hz through a rotating spark gap switch. A 20 ml sample of 13.25 mg l-1 methylene blue in distilled water was decolourized in 120 min. Bubbling O2 at 10 ml min-1 through the discharge region reduced the decolourization time to 25 min. Bubbling O2 containing 1500 µmol O3 l-1 at 10 ml min-1 reduced the decolourization time to 8 min. The O3 was produced by fractionating input energy between a water treatment reactor and a O3 generator, i.e. no additional energy was consumed for O3 production. Under the same experimental conditions methylene blue solution in tap water was decolourized in >210 min by corona discharge in solution, in 30 min by corona discharge with O2 bubbling, and in 11 min by corona discharge with bubbling of O2 containing 1500 µmol O3 l-1.

[1]  Abdul Ghaffar,et al.  Water purification by electrical discharges , 2001 .

[2]  Bing Sun,et al.  Use of a pulsed high-voltage discharge for removal of organic compounds in aqueous solution , 1999 .

[3]  Bing Sun,et al.  Optical study of active species produced by a pulsed streamer corona discharge in water , 1997 .

[4]  W. Glaze.  Drinking-water treatment with ozone. , 1987, Environmental science & technology.

[5]  M. Rea,et al.  Evaluation of pulse voltage generators , 1992, Conference Record of the 1992 IEEE Industry Applications Society Annual Meeting.

[6]  Milan Simek,et al.  Generation of chemically active species by electrical discharges in water , 1999 .

[7]  Shuhai Liu,et al.  Apparent energy yield of a high efficiency pulse generator with respect to SO2 and NOx removal , 1995 .

[8]  W. F. L. M. Hoeben,et al.  RAPID COMMUNICATION: Gas phase corona discharges for oxidation of phenol in an aqueous solution , 1999 .

[9]  S. V. Paasen,et al.  Pulsed power corona discharges for air pollution control , 1998 .

[10]  W. C. Finney,et al.  A Preliminary Study of Pulsed Streamer Corona Discharge for the Degradation of Phenol in Aqueous Solutions , 1993 .

[11]  Yasuo Mori,et al.  EHD study of the corona wind between wire and plate electrodes , 1978 .

[12]  J. S. Clements,et al.  Oxidative Processes Occurring When Pulsed High Voltage Discharges Degrade Phenol in Aqueous Solution , 2000 .

[13]  Won-Tae Shin,et al.  Experiments on electrostatic dispersion of air in water , 1997 .

[14]  W. C. Finney,et al.  Formation of hydroxyl radicals, hydrogen peroxide and aqueous electrons by pulsed streamer corona discharge in aqueous solution , 1995 .

[15]  J. S. Clements,et al.  Preliminary Investigation of Prebreakdown Phenomena and Chemical Reactions Using a Pulsed High-Voltage Discharge in Water , 1987, IEEE Transactions on Industry Applications.

[16]  C. Tsouris,et al.  A Pulseless Corona-Discharge Process for the Oxidation of Organic Compounds in Water , 2000 .

[17]  V. P. Silakov,et al.  Electric discharge in water as a source of UV radiation, ozone and hydrogen peroxide , 2001 .

[18]  Foster Dee Snell,et al.  Encyclopedia of Industrial Chemical Analysis , 1975 .

[19]  W. C. Finney,et al.  Aqueous phase pulsed streamer corona reactor using suspended activated carbon particles for phenol oxidation : Model-data comparison , 1999 .

[20]  D. M. Willberg,et al.  Degradation of 4-Chlorophenol, 3,4-Dichloroaniline, and 2,4,6-Trinitrotoluene in an Electrohydraulic Discharge Reactor , 1996 .