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AssigneesD.C. Water & Sewer Authority, Hampton Roads Sanitation District
InventorsBernhard Wett, Ahmed Omari, Pusker Regmi, Mark Miller, Charles B. Bott, Sudhir N. Murthy
Estimating the term…
A reactor and control method thereof for nitrogen removal in wastewater treatment achieves a measured control of maintaining high ammonia oxidizing bacteria (AOB) oxidation rates while achieving nitrite oxidizing bacteria (NOB) repression, using various control strategies, including: 1) ammonia and the use of ammonia setpoints, 2) operational DO and the proper use of DO setpoints, 3) bioaugmentation of a lighter flocculant AOB fraction, and 4) proper implementation of transient anoxia within a wide range of reactor configurations and operating conditions.
1) A reactor for biological nitrogen removal from wastewaters comprising a nitrite-shunt which targets repression of the nitrite oxidizing bacteria (NOB) under controlled transient anoxia conditions, the conditions being controlled either along the flow-path or along the process time-line, wherein a dissolved oxygen (DO) profile switches between a lower DO-setpoint of less than 0.1 mg/L and a upper DO-setpoint of greater than 1.0 mg/L, and wherein at least one of an aeration system activation interval or the upper DO setpoint are set such that an on-line measured ammonia concentration is higher than an ammonia setpoint of 1.5 mg NH4—N/L in more than 75% of the transiently aerated reactor volume (in space or time).
14) A method of controlling a reactor for biological nitrogen removal from wastewaters comprising a nitrite-shunt which targets repression of the nitrite oxidizing bacteria (NOB) under controlled transient anoxia conditions, the conditions being controlled either along a flow-path or along a process time-line, wherein a dissolved oxygen (DO) profile switches between a lower DO-setpoint of less than 0.1 mg/L and an upper DO-setpoint of greater than 1.0 mg/L, and wherein at least one of an activation of an aeration system of the reactor or the upper DO setpoint is dependent on an on-line measured ammonia concentration being higher than an ammonia setpoint of 1.5 mg NH4—N/L in more than 75% of transiently aerated reactor volume (in space or time).
Dependencies are inferred from the claim text.