Abstract: The oxidation ditch process is economic and efficient for wastewater
treatment, but its application is limited in case where land is costly due to
its large land area required. An innovative integrated oxidation ditch with
vertical circle (IODVC) system was developed to treat domestic and industrial
wastewater aiming to save land area. The new system consists of a
single-channel divided into two ditches (the top one and the bottom one by a
plate), a Kesner type brush, and an innovative integral clarifier. Different
from the horizontal circle of the conventional oxidation ditch, the flow of
IODVC system recycles from the top zone to the bottom zone in the vertical
circle as the brush is running, and then the IODVC saved land area required by
about 50% compared with a conventional oxidation ditch with an intrachannel
clarifier. The innovative integral clarifier is effective for separation of
liquid and solids, and is preferably positioned at the opposite end of the
brush in the ditch. It does not affect the hydrodynamic characteristics of the
mixed liquor in the ditch, and the sludge can automatically return to the down
ditch without any pump. In this study, experiments of domestic and dye
wastewater treatment were carried out in bench scale and in full scale,
respectively. Results clearly showed that the IODVC efficiently removed
pollutants in the wastewaters, i.e., the average of COD removals for domestic
and dye wastewater treatment were 95% and 90%, respectively, and that the IODVC
process may provide a cost effective way for full scale dye wastewater
treatment.
