MWEA Lagoon Conference February 18, 2014 Holland, Michigan - PowerPoint PPT Presentation

MWEA Lagoon Conference February 18, 2014 Holland, Michigan “Duckweed” Jeff Grames NuSystems, Inc.

Duckweed in Michigan  The Species of Duckweed in Michigan is Lemna Minor  How Duckweed Reproduces  How Fast Does Duckweed Reproduce?

The Plusses and Minuses of Duckweed  Plusses: Nutrient Removal  Minuses: Lower Oxygen Transfer

Photosynthesis and Respiration Algae + CO 2 + Sunlight More Algae + Oxygen + Carbonate • Biomass increases nutrient uptake ( P, N ). • Bacterial respiration decreases organic waste (C) • ReNew allows algae to produce more oxygen. Carbon Dioxide Pollutants Algae Bacteria Oxygen

Lagoon Cell Two Influent Influence of Time of Day on Dissolved Oxygen Levels 20.0 DO Before, mg/l DO After, mg/l 16.0 12.0 DO, mg/l 8.0 4.0 0.0 6:00 12:00 18:00 0:00 6:00 12:00 18:00 Time of Day

Duckweed Control Methods  Manual Removal  Chemical Control

Manual Removal

Chemical Removal

State and Federal Laws Regarding Pesticide Application  Pesticide Use in the United States  Pesticide Applied to the Waters of Michigan  Certified Applicator