Development of the First Russian Anammox-Based Technology for Nitrogen Removal from Wastewater

Abstract

A pilot single-stage setup with the reactor volume of 20 m 3 was constructed for ammonium removal from the filtrate of thermophilically digested sludge. The setup was operated at temperatures of 20-37°C, dissolved oxygen concentrations of 0.1-0.7 mg/L, pH of 5.7-8.5, hydraulic retention time of 12-36 h, and filtrate output of up to 30 m 3 /day. The efficiency of nitrogen removal was 75-90%, nitrogen load was 0.9-1.1 kg N/(m 3 Áday), and the specific volumetric nitrogen removal capacity of the reactor reached 0.8-1.0 kg N/(m 3 Áday). The sludge retained activity at low pH (5.7) and enhanced nitrite concentration (up to 250 mg/L). A correlation was established between conductivity reduction of the treated liquid and nitrogen removal efficiency, and the formula for calculation of ammonium concentration using the conductivity was proposed.