Flotation Technology Floating Wetlands & Storm Water Ponds

Transcription

1 Flotation Technology Floating Wetlands & Storm Water Ponds A Floating Wetland in full bloom. September, 2012 Maryland Aquatic Nurseries

2 Promising results Idea Rafted plants for pollution control of stormwater runoff and effluent treatment systems Theory ~ Roots of rafted plants are in direct contact with the nutrients in water and have greater uptake potential than soil-based plants

3 The Synergy System Combine Floating Wetland s with aeration to improve oxygenation and nutrient uptake by plants and Control algal stimulants - FE and P

4 Easton Club East Farm Pond Before Blue-Green Algae Bloom - Toxic Pond

5 Farm Pond - After Aeration and Floating Wetlands Installed I m really enjoying the movement of the rafts in the breeze. All of the rafts are looking good.

6 Everyone at the Grounds Committee meeting was so happy about all the progress on the pond project. Once the Cattails and Phragmites are out of the sales ponds, the local model boat club wants to start using the ponds for meets. Other people want to fish. Sales Pond - Before

7 Sales Pond - After The ponds are exquisite. I highly recommend that our neighbors get out and take a look. The water lilies are blooming and we have several species of frogs in addition to other avian friends.

8 Janet s Way - Before We are finally making progress with the community, and residents are starting to think of the ponds as "community" ponds, and not just for the benefit of homeowners who live next to them. Yea! This is a wonderful change in attitude and I m extremely happy to see it.

9 Janet s Way After Janet's Way pond is just stunning, if I do say so myself. I've decided to add my own little park right on the edge of my property so I can look out at the rafts in all their glory.

10 It s a combination of things

11

12 nutrient reduction

13 and of course, beautification.

14 Factors Affecting Nutrient Uptake grams/m2/day Nitrogen Phosphorous Pan. Typ. Hib. Spar. Aer. No Aer Pan. Typ. Hib. Spar. Aer. No Aer. (1) Swine Lagoon (2) Fish Effluent (3) Storm Water (1) Swine Lagoon (2) Fish Effluent (3) Storm Water Reference: (1) Robert Hubbard USDA (2) Andrew Lazur UMCES (3) Richard Schuck MAN Factors: Plant Variety Nutrient Level Circulation/Aeration

15 MIPS Project Nutrient Uptake Rafted Plants vs. Soil Based Mimulus Mimulus Saururus Saururus rafted potted rafted potted Mean N uptake (g) * * Mean P uptake (g) 0.633* * % and 456% greater uptake of N and P respectively for rafted Saururus plants compared to soil based 296% and 182% greater N and P uptake observed in rafted Mimulus compared to potted

16 Northeast SARE Grant Evaluating floating wetlands in integrated aquaculture systems Initial planting of 2 hibiscus Root mass of Hibiscus after 75 days Hibiscus after 30 days in channel

17 Plant Channels after 60 days

18 SARE Nutrient Remediation Summary Hibiscus Spartina Biomass production dry wt. (kg) Biomass production/m2 dry wt. (kg) * g Nitrogen uptake/m g Nitrogen uptake/m2/day ** g Phosphorus uptake/m g Phosphorus uptake/m2/day The six plant channels removed 15.4% and 8.75% of N and P respectively *~ 25% greater biomass than in constructed marsh (Craft, et al., 1999) ** ~ twice uptake in natural marshes

19 NRAC Nutrient Uptake Study

20 Stormwater Pond Evaluation

21 CBT Stormwater Pond Study Nutrient uptake in FW s

22 Pond Species Nitrogen/ft2 (g) Phosphorus/ft2 (g) Farm Hibiscus ± ± ± ± Decodon ± ± ± ± Justicia ± ± ± ± Iris ± ± ± ± Lyons Hibiscus ± ± ± ± Decodon ± ± ± ± Justicia ± ± ± ± Iris ± ± ± ± Dutchmans Hibiscus ± ± ± ± Decodon ± ± ± ± Justicia ± dormant ± dormant Iris ± ± ± ± 0.003

23 Denitrification in Floating Wetlands Jeff Cornwell, HPL/UMCES In late fall 2011, the root/soil mass from floats was placed in incubation chambers. Sediment cores from the same location were also collected for similar incubation We measured, under flooded conditions, a timecourse change in nitrate, ammonium, oxygen and N2-N, the later from changes in the N2:Ar ratio

24 Negative rates indicate uptake by the substrate nitrate fluxes are directed into the soil Nitrate uptakes are high because of high because of high nitrate concentrations in the ponds Nitrate is the substrate for denitrification, and uptake can support denitrification The large ammonium efflux from FW 1 is more than matched by the nitrate uptake

25 We added 150 mol L-1 nitrate (2.25 mg L-1) to see if nitrate concentration limited microbial denitrification Ambient nitrate concentrations in the ponds were 4.5 and 0.75 mg L-1 NO3-N Oxygen uptake rates were higher in the FW s than in the soil Denitrification rates were high in all Pond 1 cores (both sediment and FW s) and high in the floats in Pond 2 If pond 1 was 2 meters deep, it would take 125 days for sediment dentrification to remove all the nitrate. If we add in 100% FW coverage, it would be about half. For pond 2, sediment plus complete FW coverage could remove all the nitrate in ~ 15 days.

26 Floating Wetlands and Stormwater BMP s FW s serve as a good environment for a variety of aquatic plants Decadon, Justicia, and Hibiscus have shown greatest uptake Plant nutrient uptake increases as ambient concentrations increase Plants provide habitat for wildlife FW s can provide aesthetic enhancement Vegetative growth cut be removed at season end to reduce nutrient mineralization over winter In the fall, the floating wetlands had high rates of denitrification, roughly similar to what is found in bottom sediments Nitrate removal would be the sum of FW denitrification + sediment denitrification + plant assimilation. FW s have the potential to remove nitrogen not only as plant biomass, but also through microbial denitrification. management increases growth Early plant management important plant vigor and predation

27 Special thanks to: Larry and Bertie Galpin, Briar Creek Pond Photos The residents of Easton Club East Encouraging Comments Research and Data: USDA ~ Robert Hubbard UMCES, HPL ~ Andrew Lazur, Angie Hengst, Erin Markin, Jeff Cornwell, Court Stevenson, Lorie Staver, Sarah Marnell MAN ~ Richard Schuck, Kelly Billing UM Extension ~ Don Webster Northeast Regional Aquaculture Center