The application of intermittent cycle extended aeration systems (ICEAS) in wastewater treatment

Abstract

Many biological methods are currently used to treat wastewaters, such as e.g. aerobic, anaerobic, sequencing batch reactors, biofilters. However, these technologies are limited by low nutrient removal efficiency, high energy and large area requirements. Hereby, the intermittent cycle extended aeration system (ICEAS), or continuous flow sequencing batch reactor (SBR) can be an alternative solution. Therefore, understanding all aspects of this technology – such as reaction mechanisms, nitrogen conversion cycle, and operation conditions – are very necessary. This paper reviews the mechanism and key factors affecting the ICEAS operation conditions to treat many wastewaters. An ICEAS combines many biological processes as aerobic, anoxic, and anaerobic in one tank. ICEAS has some advantages compared with traditional activated sludge such as less space demand, low investment costs, low aeration to save operating costs, and automatic operation. An ICEAS shows its high efficiencies in removing organic compounds (90–97 % of COD removal) and nutrients (97–99 % of TN removal), limiting the accumulation of nitrite and nitrate. The continuous inflow feeding into ICEAS reduces organic loading shock and is beneficial to the growth of microorganisms community. Hope this paper will help to promote further application of ICEAS technology for wastewater treatment around the world.