Influence factors for treating coking wastewater by ultrasonic wave

The treatment of coking wastewater was researched by ultrasonic wave. The influences of irradiation time,ultrasonic power,initial pH value of coking wastewater,initial concentrations of chemical oxygen demand (CODCr) and ammonium ( NH+4-N),and dissolved gas on the removal of CODCr and NH+4-N were investigated systematically. The ultrasonic treatments of coking wastewater combined with oxidants were comparatively analyzed. The results show that the ultrasonic treatment combined with H2O2 or Fenton reagent had a synergetic effect,and then the removal rates of CODCr and NH+4-N greatly increase. The order of removal rate is the following:ultrasonic treatment+Fentonultrasonic treatment+H2O2Fentonultrasonic treatmentH2O2. According to the analysis results of GC-MS,the removal process of CODCr and NH+4-N was preliminary studied. It is found that the proportions of non-biodegradation organisms,such as naphthalene,anthracene and quinoline,obviously decreased in treated coking wastewater.