Wastewater treatment system and method
View Patent ↗The invention is directed to a wastewater treatment system having an anoxic biological treatment zone, an aerobic biological treatment zone and a separator. The concentration of oxygen in streams within the system is strategically managed for improved removal of nutrient from the wastewater. A source of biodegradable carbon may be introduced to reduce the concentration of oxygen within the system. An effective treatment time under anoxic or aerobic conditions may further be varied.
1. A wastewater treatment system, comprising:
a first biological treatment zone;
a second biological treatment zone fluidly connected to the first biological treatment zone;
a membrane module comprising a filter membrane fluidly connected to the second biological treatment zone;
a recycle system fluidly connecting the membrane module to the first biological treatment zone;
a source of biodegradable carbon fluidly connected to the recycle system;
a sensor disposed to monitor a characteristic of a liquid exiting the second biological treatment zone; and
a controller configured to allow introduction of the biodegradable carbon based on a signal from the sensor;
wherein the controller is further configured to generate a first control signal that establishes a first liquid circuit from an outlet of the membrane module to an inlet of the second biological treatment zone, and further configured to generate a second control signal that establishes a second liquid circuit from an outlet of the second biological treatment zone to an inlet of the first biological treatment zone.
2. The system of claim 1 , wherein the first biological treatment zone is an anoxic zone.
3. The system of claim 2 , wherein the second biological treatment zone is an aerobic zone.
4. The system of claim 3 , further comprising a third biological treatment zone fluidly connected to a source of the wastewater and to the first biological treatment zone.
5. The system of claim 4 , wherein the third biological treatment zone is an anaerobic zone.
6. The system of claim 4 , wherein an outlet of the second biological treatment zone is fluidly connected to an inlet of the third biological treatment zone.
7. The system of claim 1 , wherein an outlet of the membrane module is fluidly connected to an inlet of the second biological treatment zone.
8. The system of claim 7 , wherein an outlet of the second biological treatment zone is fluidly connected to an inlet of the first biological treatment zone.
9. The system of claim 1 , wherein the sensor comprises an ORP sensor.