Bioreactors for the Reduction of Nutrient Transport

Why Bioreactors ?  Proven technology  Requires no modification of current practices  No land taken out of production  No decrease in drainage effectiveness  Very low maintenance  Estimated life - 15 to 20 years  Cost effective

Capacity Control Structure 5’ Soil Backfill Woodchips Trench bottom 1’ Below tile invert 20’ section of tile Length dependent on treatment area Diversion Structure Second Generation Bioreactors

Capacity control structure Up to soil surface Side View Trench bottom 1’ below tile invert 5’ section of non-perforated tile Length dependent on treatment area Diversion structure Top View 5’ Soil backfill 10’ Wide

Third Generation Bioreactors

Solid pipe Perforated pipe Plastic Liner

Managed Drainage 28 acres 100 ft Spacing Free Drainage 31 acres 100 ft Spacing W Managed Drainage With Bioreactor 34 acres 100 ft Spacing

Site Contributing area (acres) Loading Density (acre/ 100sq. ft.) Load Reduction (%) Decatur West Decatur East DeLand East Bioreactor Efficacy

Sizing a system for a 60% removal from 40 acres ?

100*40/3 = 1333 sq. ft.

Current Work

Unintended Consequences?

Sampling Bioreactors Inlet Samples Outlet Samples

Dissolved MeHg in Bioreactor Inlets -Eight non-detects -Six samples contained detectable MeHg - Maximum: 0.16 ng/L - Maximum: 0.16 ng/L - Average:0.09 ng/L - Average:0.09 ng/L

Dissolved MeHg in Bioreactor Outlets

Capacity control structure Up to soil surface Side View Trench bottom 1’ below tile invert 5’ section of non-perforated tile Length dependent on treatment area Diversion structure Top View 5’ Soil backfill 10’ Wide Trench bottom at tile invert

What about Phosphorus? P Removal?

Four 6” PVC Bioreactor Cells 20 ft Woodchips 5 ft Iron Filings Two Cells with Filings Upstream Two Cells with Woodchips Upstream Temperature Sensors Gas Extraction Ports

Phosphorus Removal Chamber Solid pipe Solid 6” pipe Perforated pipe Plastic Liner