Dynamic process control for partial nitritation in wastewater treatment with autotrophic nitrogen removal

10, A method of treating wastewater comprising:

• providing a biological reactor for receiving wastewater therein;
• using an aerator to intermittently aerate the wastewater in the reactor;
• using a plurality of condition sensors to generate condition signals from which a plurality of wastewater characteristics can be derived including a pH level of the wastewater in the reactor;
• using a controller to compare one of the wastewater characteristics derived from the condition sensors to a prescribed primary threshold stored on the controller;
• and
• using the controller to dispense a controlled dosage of an alkaline control solution into the reactor in response to the wastewater characteristic being below the prescribed primary threshold to effect partial nitritation of the wastewater in the reactor.

The method according to claim 10 further comprising;

• using the condition sensors to measure the pH level, a dissolved oxygen level, an ammonium level, and a temperature of the wastewater in the reactor;
• using the controller to calculate a level of free ammonia based upon the wastewater characteristics derived from the condition sensors;
• and
• using the controller to control the dispensing of the controlled dosage of the alkaline control solution only if a level of free ammonia in the wastewater is below the prescribed primary threshold.

The method according to claim 10 further comprising:

• using the condition sensors to measure the pH level, a dissolved oxygen level, an ammonium level, and a temperature of the wastewater in the reactor;
• using the controller to calculate a ratio of dissolved oxygen to a total ammonium concentration based upon the wastewater characteristics derived from the condition sensors;
• and
• using the controller to control the aerator so as to maintain the ratio of dissolved oxygen to a total ammonium concentration below a prescribed second threshold stored on the controller.

The method according to claim 10 further comprising:

• using a plurality of condition sensors to measure a plurality of wastewater characteristics of the wastewater;
• using the controller to calculate a level of free ammonia based upon the measured characteristics of the wastewater;
• and
• using the controller to generate a notification if the level of free ammonia has not increased over a prescribed time interval.