Removal of biological nitrogen from contaminated water, esp. from sludge treatment - by flowing water through nitrification bed reactor into which oxygen is introduced followed by entry into denitrification chamber

摘要

In a procedure for separately eliminating biological nitrogen from contaminated water, the water flows downwards in a nitrification process through a reaction bed reactor into which oxygen is introduced at various levels. The water leaving the base of this reactor enters a denitrification chamber, from which it flows to an outlet point or is recycled to the nitrification process. Also claimed is an appts. for carrying out the procedure, consisting of a reactor (2) with a water inlet (6) at the top (3), a gas outlet (7) with a sepn. device (8), oxygen inlets (9), and a lower water outlet (10) connected to a denitrification chamber (11) with a water outlet (12). Oxygen is introduced in the form of oxygen-enriched air or technically pure oxygen. Denitrification is carried out using suspended or immobilised denitrification agents. A synthetic carbon cpd. or a natural product such as primary sludge, waste water, etc., acts as source of carbon for the denitrification agents. The evolved gas is removed from the top of the nitrification reactor. The gas outlet pipe (7) is provided with one or more pumps (15). The reactor outlet (10) is connected by a return line (16) and a pump (17) to the water inlet pipe (18). A pump (20) is provided in the denitrification chamber inlet pipe (19). The fresh water outlet (21) from the denitrification chamber (11) is connected to a vessel (23) which is linked by a recirculation pipe (24) and pump (25) back to the denitrification chamber, and by an outlet pipe (26) to the water outlet (12). This outlet pipe (26) is connected to the recirculation pipe (16). Two three-way valves (27,28) are provided in the recirculation pipe (16), one connected to the denitrification chamber inlet pipe (19) and one to a pipe (30) connected via a further three-way valve (29) to the water outlet pipe (26). USE/ADVANTAGE - Used esp. for treating water recovered from sludge handling processes. Nitrogen in the form of ammonium is reliably and economically removed from the water without prodn. of residual materials which must be disposed of separately.