Microbiological cycling ofmethane and Nitrogen in a wastewater treatment plant in The Netherlands

The efficient removal of nitrogen from wastewater is of key importance to prevent deoxygenation and eutrophication of the receiving water bodies. Traditionally, nitrogenous compounds have been removed by a combination of nitrification and denitrification. More recently, the anaerobic ammonium oxidation (anammox) process has been applied in wastewater treatment plants. In addition to nitrogen, the concentration of dissolved methane can also be high in these systems. Methane is a potent greenhouse gas and emission to the atmosphere has to be minimized in order to reduce global warming.