Biological treatment of high ammonium content urban landfill leachate using an anaerobic-aerobic process

摘要

Biological system consisting of an up-flow anaerobic sludge blanket (UASB) and anoxic-oxic (A/O) reactor was applied to treat high ammonium content urban landfill leachate. Inhibitory effect of free ammonia (FA) and free nitrous acid (FNA) on nitrifying bacteria activity was used to achieve nitrogen removal via nitrite pathway in the A/O. Results demonstrated that removed efficiencies of COD, total nitrogen (TN) and (NH_4)~+-N were 95.3%, 84.6 % and 99.2%, respectively. Stable nitrite pathway with above 90% nitrite accumulation was successfully achieved in the A/O reactor by synergetic inhibition of FA and FNA on the activity of nitrite oxidizing bacteria (NOB). Moreover, Fluorescence in situ hybridization (FISH) analysis showed that AOB was dominant microorganism.