Keywords: tertiary treatment, industrial effluents, electrolytic cells, electro-oxidation, electro-coagulation, wastewater treatment, groundwater recharge, water reuse, aquifer recharge, agriculture, irrigation, flotation unit, Crete, Greece, discolouration, disinfection, suspended solids
A pilot scale electrolytic unit for tertiary treatment of industrial effluents
Over the past few years, academic research has focused on the development of new treatment technologies for municipal and industrial wastewater that will be suitable for reuse. In this study, an electrolytic pilot scale unit has been manufactured for the tertiary treatment of biologically processed wastewater aiming at its reuse for groundwater recharge or for agricultural purposes. The integrated pilot unit consists of two compartments, the electrolytic cell (reactor) and the unit of flotation and precipitation of the coagulated colloid particles. The anode of the cell is a DSA type electrode with iridium and platinum oxide mixture deposited on a titanium substrate; Stainless Steel 316 is used for the cathode. The adjacent container unit has collectors (scrapers) for the flocculated and precipitated particles. The unit has been operating at the Wastewater Treatment Plant (WWTP) of the Herakleion Industrial Park (Crete, Greece). The first results obtained from the operation of the unit for the tertiary treatment of industrial wastewater are very encouraging. Complete discolouration and disinfection of the wastewater as well as essentially the complete removal of suspended solids. The Chemical Oxygen Demand (COD) of the tertiary treated effluent is negligible and within the guidelines for agricultural water reuse or aquifer recharge.