Nitrate removal in a purge stream using constructed wetlands
AssigneeExxonMobil Research and Engineering Company
InventorsChad Shockley, John Miller, Piyush Shah
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Abstract
The present invention comprises a system and methodology for denitrification using constructed wetlands. The constructed wetlands of the present invention can be effectively applied as a wastewater point source treatment technology to any high total dissolved solids (e.g. sulfites and sulfates), carbon deficient wastewater stream for nitrate control. Pollutants are removed from the stream via a number of processes including plant uptake, volatilization, filtration and biological reduction. The present system and methodology offers an ability to reduce outflow stream nitrate concentrations in a cost-effective manner with minimal capital investment.
Claims18
A method for removing nitrates from an effluent comprising the steps of:
- introducing said effluent into a constructed wetlands system as an influent, permitting said influent to flow through said constructed wetlands system wherein said constructed wetlands system comprises vegetation and microbial cells operating to convert said nitrates into nitrogen gas and other byproducts;
- discharging said influent from said constructed wetlands system in a form containing an amount of nitrates which is less than the amount of nitrates in said influent when introduced into said constructed wetlands system;
- and
- introducing said discharged influent into a wastewater processing operation.
A constructed wetlands system for reducing the amount of nitrates contained within an effluent stream, said constructed wetlands system comprising:
- a plurality of wetlands areas comprising vegetation and microbial cells operating to convert said nitrates into nitrogen gas and other byproducts;
- an inlet permitting said effluent stream to flow into said constructed wetlands system;
- and
- at least one gravel berm, said at least one gravel berm permitting said influent to flow from one said wetlands area to another of said wetlands areas.
A method for processing a nitrate-rich WGS purge which is high in total dissolved solids, said method comprising the steps of:
- processing said WGS purge to settle and remove dissolved solids contained in said purge to produce a first effluent;
- introducing said first effluent into a constructed wetlands to remove nitrates from said first effluent via bacterial action to produce a second effluent;
- and
- introducing said second effluent into a wastewater treatment process.
Dependencies are inferred from the claim text.