How to calculate the aeration volume of sewage treatment plant

The oxygen demand of sewage in the aerobic zone of the biological reaction tank should be calculated according to the following formula based on the removal of five-day biochemical oxygen demand, nitrification and nitrogen removal of ammonia nitrogen:

< p> O2 = 0.001aQ(So-Se)-c△XV+b[0.001Q(Nk-Nke)-0.12△XV]

-0.62b[0.001Q(Nt-Nke-Noe) -0.12△XV] (6.8.2)

Where: O2—oxygen demand of sewage (kgO2/d);

Q—inlet flow rate of biological reaction pool (m3 /d);

So—the five-day biochemical oxygen demand concentration of the biological reaction tank inlet water (mg/L);

Se—the five-day biochemical oxygen demand concentration of the biological reaction tank effluent Concentration (mg/L);

△XV - microbial biomass discharged from the biological reaction tank system; (kg/d);

Nk - total Kjeldahl nitrogen in the biological reaction tank inlet water Concentration (mg/L);

Nke—Total Kjeldahl nitrogen concentration in the effluent of the biological reaction tank (mg/L);

Nt—Total nitrogen concentration in the influent of the biological reaction tank (mg /L);

Noe—the concentration of nitrate nitrogen in the effluent of the biological reaction tank (mg/L);

0.12△XV—the nitrogen content in the microorganisms discharged from the biological reaction tank system ( kg/d);

a—oxygen equivalent of carbon, when the carbon-containing material is measured as BOD5, take 1.47;

b—constant, the amount of oxygen required to oxidize each kilogram of ammonia nitrogen ( kgO2/kgN), take 4.57;

c—constant, the oxygen equivalent of bacterial cells, take 1.42.

When removing carbon-containing pollutants, remove five days of biochemical oxygen demand per kilogram The amount can be 0.1.2kgO2.