Use ORP to Control Simultaneous Nitrification and Denitrification in Oxidation Ditch Process

Simultaneous nitrification and denitrification(SND) is the main reason to the high nitrogen removal of oxidation ditch process.To achieve SND at high efficiency,redox potential(ORP) was used as a controlling parameter.This paper finds that:1) U_ORP can indicate SND,if U_ORP is between-30 mV to 30 mV,SND progress favorably,but if U_ORP is more than 30 mV,nitrification can be produced enough,denitrification is low,if U_ORP is lower than-30 mV,the result is the reverse to U_ORP more than 30 mV.2) If the U_ORP is between-30 mV to 30 mV,the rate of total inorganic nitrogen is more than 88%,the NO^-3 being removed is about 99% of the total NO₃^- being removed.3) The logarithm of the ratio of NH₄⁺-N to NO₃^- is a linear correlation,R is -0.97.