| 摘要 |
<p>PURPOSE: Disclosed is a wastewater treatment method and unit, more particularly this invention is related to a combined unit that is integrated with anaerobic contact tank, extended aeration tank operated like aerated lagoon, aeration tank packed with media into one body. CONSTITUTION: This wastewater treatment unit comprises a sealed anaerobic tank (12), a primary anaerobic tank (denitrification tank, 13), a primary extended aeration tank (14), an aeration tank (16), a sludge stabilization tank (18), a settling tank (17) in series. In the anaerobic tank, organics of raw wastewater is preliminarily decomposed by anaerobic microorganisms to be easily stabilized in the following aerobic process. Further, the anaerobic tank is sealed to collect bio-gases generated from anaerobic decomposition of organics by anaerobic microbes, collected gases are used as an external carbon source in the denitrification tank and thereby denitrification is promoted. Also, extended aeration process, operated in the endogenous respiration phase of the growth curve and in the lower F/M ratio compared with conventional aeration process, is adopted to aerobic oxidation so that it can avoid unstable quality of water discharge caused by high organic loading with less sludge/suspended solids generation. For the prevention of pin floc and phosphate re-release from microorganisms cell tissue, periodically excess sludge is wasted.</p> |
