What is oxidation ditch sewage treatment method?

The oxidation ditch is a variant of the activated sludge process, and its aeration tank is a closed ditch, so it is different from the traditional activated sludge process in hydraulic flow pattern. It is an end-to-end circulating aeration ditch, in which sewage permeates and is purified. Oxidation ditch process has become the first choice for small and medium-sized urban sewage plants because of its outstanding advantages of economy and simplicity, and it has been applied in aerobic treatment of some livestock and poultry wastewater. The process flow is shown in the following figure:

Generally, the main design parameters in livestock and poultry wastewater treatment are:

Hydraulic retention time: 2-4 hours;

sludge age: generally more than 2 days;

organic load (BOD5): .5 ~ .15kg/[kg (activated sludge)? Day];

volumetric load (BOD5): .2 ~ .4kg/(m3? Day);

activated sludge concentration: 2 ~ 6mg/l;

average velocity in the ditch: .3 ~ .5m/s.