A novel type ozonizer for wastewater treatment

Electrochemical Ozone Production as an Environmentally Friendly Technology for Water Treatment

“…Ozone is an unstable gas and, therefore, its generation should be carried out in situ [5]. The main commercially available technology for ozone generation is based on the corona process [5,29,32], which comprises the application of a silent electric discharge in a cooled/dried gaseous phase containing oxygen (O2 or air) [32,39,40]. The fundamental processes leading to ozone generation during the silent electric discharge are depicted in the scheme presented in Fig.…”

“…The efficiency for the oxygen ozone conversion process (O2 + O9 O3) taking place during silent electric discharge (corona process) depends on several factors [32,39,40]: (i) oxygen source (O 2 or air); (ii) gas temperature and (iii) presence of impurities in the gaseous phase. The efficiency presented by most of the commercially available corona devices, using air as the O2 source, is l 0.4 -2.0 wt% and requires an "apparent" energy demand (where costs concerning gas refrigeration and heat exchange are not considered) of l 14 -28 Wh/g [5,4,32].…”

“…Considering that nitrogen is not an inert gas inside the corona device, this experimental approach using air presents the environmental inconvenience of releasing strong pollutants such as NOx compounds and HNO 3 into the atmosphere [32,39,40].…”

Advanced purification of petroleum refinery wastewater by catalytic vacuum distillation

“…Up to now, although many technologies and processes have been conventionally attempted for treatment of refinery wastewater, including biological treatment [5,6], wet oxidation [7], ozone treatment [8] and chemical coagulation [9,10]. However, in the biological processes, some aromatic petroleum hydrocarbons show high stability to biological degradation [6].…”

Degradation of diuron in aqueous solution by dielectric barrier discharge

“…But the UV light and many reactive species produced in the discharge region cannot be utilized by this conventional ozonation because of the short lifetimes of some reactive species [10,4]. Recently, several attempts were carried out to apply gas corona discharge (GCD) to producing reactive species for water purification [3,[11][12][13]. The difference between GCD and DBD is that in DBD at least one electrode should be covered with dielectric, which limits the current flow to the system and distributes the discharge almost uniformly over the entire electrode area.…”