Enhanced nitrogen removal from nitrate-rich mature leachate via partial denitrification (PD)-anammox under real-time control.

It is difficult to achieve high standard effluent through conventional nitrification-denitrification process treating mature leachate and the advanced treatment is usually required. This study proposed an economical process for enhancing nitrogen removal from nitrate-rich leachate which combined partial-denitrification and anammox (PD/A) in a SBR. Under the concentration of influent ammonia and nitrate of 47.5 mg/L and 93.7 mg/L on average, TN removal efficiency of 84.8% was obtained with the effluent TN less than 20 mg/L. It was found that enhanced nitrogen removal of mature landfill leachate through PD-anammox was estimated to save 40% organic carbon addition and reduce the cost of sludge treatment in this study. Moreover, the ORP and pH could potentially be used as control parameters to maintain the stability of combined process.