Abstract
Denitrification rate (KDN) of suspended activated sludge in the high rate nitrogen removal process using immobilized nitrifiers was investigated in relation to BOD-SS loading and temperature. A demonstration plant and two pilot plants were operated with BOD-SS loading from 0.83 to 14.5mg-BOD5/g-SS/h and temperature from 12 to 27°C. KDN (mg-N/g-SS/h) was almost proportional to the amount of accumulated organic matter (A) multiplied by its metabolism rate constant (κ). KDN changed little with the seasonal change of temperature, as the A value increased with the decreasing temperature, though decreased the κ value. It was found the proportional increase of the A value to BOD-SS loading resulted in the proportional increase of KDN.
