System and method for removing pollutants from water
AssigneeNorth American Wetland Engineering, Inc.
InventorsScott D. Wallace, Paul E. Lambrecht
Life of this patent
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Abstract
A system and method for removing pollutants from wastewater. The system includes a constructed wetland cell in which the filtered wastewater is flowed generally vertically. The flow of wastewater is unsaturated through the wetland cell to aerate the wastewater. The wastewater may be further aerated by a blower or injector. The treated wastewater from the wetland cell is blended with untreated wastewater, then either recirculated through the wetland cell or conveyed to a disposal system.
Claims35
A constructed system for treating wastewater, comprising:
- an inlet admitting wastewater into the system;
- an outlet conveying treated wastewater from the system;
- a bed medium;
- a wastewater supply configured to deliver the wastewater proximate an upper portion of the bed medium and comprising a first reservoir, a second reservoir, and a pump, the pump conveying wastewater from the second reservoir to the upper portion of the bed medium, the first reservoir in fluid communication with the second reservoir and receiving wastewater from the wastewater return, the first reservoir accommodating the inlet and comprising a mixing device for mixing wastewater from the wastewater return and wastewater from the inlet;
- and
- a wastewater return, at least a portion of the wastewater return disposed proximate a lower portion of the bed medium,
- the wastewater forming a substantially vertical and unsaturated flow from the wastewater supply through at least a portion of the bed medium, the wastewater subsequently conveyed from the bed medium by the wastewater return.
A constructed wetland for treating wastewater, comprising:
- a vertical flow unit comprising a granular bed medium;
- and
- a substantially impermeable anaerobic wastewater container with an inlet and an outlet;
- means for mixing a stream of wastewater from the vertical flow unit with a stream of wastewater from the inlet;
- and
- a pump for conveying the wastewater from the wastewater container to an upper portion of the vertical flow unit.
A system for treating wastewater, comprising:
- a constructed wetland cell comprising a bed medium, a wastewater supply, a wastewater return, and a multiplicity of plants rooted in the bed medium, at least a portion of the wastewater supply disposed proximate an upper portion of the bed medium, at least a portion of the wastewater return disposed proximate a lower portion of the bed medium such that the wastewater is conveyed from the wastewater supply through the bed medium in a substantially vertical, unsaturated flow;
- an air supply system for increasing oxygen concentration in the wastewater before the wastewater is conveyed to the wetland cell;
- a first tank containing a first filter for mixing wastewater from the wetland cell and exogenous wastewater and for denitrifying wastewater in the first tank;
- and
- a second tank configured for receiving wastewater from the first tank, the second tank with a pump for pumping wastewater to the wastewater supply.
A process for treating wastewater in a constructed wastewater treatment system comprising a constructed wetland unit, a wastewater supply system, a wastewater return system, and a substantially impervious container, the constructed wetland unit comprising a substantially impervious tank and a granular bed medium disposed in the wetland unit tank, the container with an outlet, an inlet, and a mixing device, the wastewater supply system delivering wastewater to an upper portion of the bed medium, the wastewater return system delivering wastewater from proximate a lower portion of the bed medium to the container, the process comprising:
- conveying the wastewater through the wastewater supply system from the container to the upper portion of the bed medium;
- trickling the aerated wastewater through a portion of the bed medium in a substantially vertical and unsaturated flow to the lower portion of the bed medium;
- and
- mixing the wastewater from the constructed wetland unit with wastewater entering the impervious container from the inlet.
Dependencies are inferred from the claim text.