COD removal and decolorization efficacy of ozonation process in spiral high pressure super mixing reactor for treatment of alcohol distilleries wastewater

Alcohol distillery wastewater is a highly polluted wastewater which its treatment poses a special problem. In this work, the efficiency of ozonation process exploited in a spiral high pressure super mixing reactor was studied for COD removal and decolorization of alcohol distilleries wastewater. The results was also compared with a conventional reactor.

The present laboratory-scale research was done on real effluent from anaerobic wastewater treatment unit of alcohol wastewater. Experiments were conducted in a pressurized spiral super mixing reactor equipped with static mixers and also in a control conventional reactor with the same volume. The process performance criteria, such as COD, BOD and color, were determined according to standards methods for water and wastewater examination.

The pressurized spiral super mixing reactor showed high efficiency in removing pollutants and reducing ozone consumption as compared to conventional reactor. Typically, during 30 min, and pH =5.3, the COD removal efficiency in the pressurized spiral super mixing reactor was 4.8 times higher than that of conventional reactor. According to the results, the efficacy of ozonation process increased by changing the pH from acidic to alkaline. Generally, the respective highest removal efficiency of COD and color was obtained at pH=11 and pH=5.3 in both reactors at their maximum retention time. Also the biodegradability of wastewater (BOD/COD) was enhanced in both reactors following ozonation process.

The pressurized spiral super mixing reactor performance in reducing ozone consumption highlights the potential applicability of this reactor for wastewater treatment of alcohol industry. The reactor can be used as pre-treatment or post treatment processes for the appropriate treatment of industrial wastewater.