10/23/2015
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NASECA Field Day
Rice Lake
Sept 24 2015
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We study P in lakes, streams, soils, runoff, treatment
systems….
Amazing number of research articles, technical reports etc on
this subject
International Stormwater Best
Management Practices (BMP)
Database
Pollutant Category Summary
Statistical Addendum:
Paul McGinley
College of Natural Resources
ProQuest
Research
Library
1993
Why this interest in phosphorus?
Explore “predevelopment”
Examine “development” (construction / postconstruction)
 Examine “treatment” … how can we
categorize / explore them
2015
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Phosphorus (P) is an element
Essential
Limiting…. P goes up, biology goes up
Objective– provide a framework
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10/23/2015
Phosphorus (P) is an element
 Essential
 Limiting…. P goes up, biology goes up
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Watershed
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Lakes and Streams … it’s the P concentration!
1000 acres
Lake
100 acres
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10/23/2015
50 lb P/year
0.05 lb P/acre-year
20 ppb P
20 ppb P
150 lb P/acre Plant / Organic P
300 lb P/acre Soil P
Bedrock / Aquifer P
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10/23/2015
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150 lb P/acre Plant / Organic P
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Runoff Volume / Pathway Changes
Acquisition & Conveyance of P
300 lb P/acre Soil P
Bedrock / Aquifer P
Adapted from Yanai, R.D., 1992. Phosphorus Budget of a 70-year-old northern hardwood
forest Biogeochemistry 17:1-22
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Runoff Volume / Pathway Changes
Acquisition & Conveyance of P
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Runoff Volume / Pathway Changes
Acquisition & Conveyance of P
Concentration
Mean
1.0 mg/l
mg/l
0.1 mg/l
Dissolved
Total
Phosphorus Phosphorus
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10/23/2015
Assume 10% of the water leaving our 1000
acre watershed has 0.5 mg/l P
 That’s 100 lbs
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 Particulate
▪ Mineral
▪ Organic
Total Phosphorus
 Particulate
▪ Mineral
▪ Organic
+
Total Phosphorus
+
 “Dissolved” or “Soluble”
▪ HPO4, H2PO4
▪ Organic
Phosphorus retention in soils means that
eroded soils contain phosphorus
 Smaller particles often “enriched” in
phosphorus (have a higher P content)
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 “Dissolved” or “Soluble”
▪ HPO4, H2PO4
▪ Organic
P
Total P (mg/kg)
Organic – P - Molecules
P
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10/23/2015
Biological Uptake
 Sedimentation
 Filtration
 Reaction
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Analog in biological wastewater treatment
Part of the predevelopment cycling
Can estimate P uptake / turnover mass/area
Long-term assimilation may require organic
matter accumulation (“accretion”)
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Settling velocity /Phosphorus content / Time
Considerations
 Soluble P
 P Enrichment
 Resuspension
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10/23/2015
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Settling velocity /Phosphorus content / Time
Considerations
 Soluble P
 P Enrichment
Apparent P Content (mg/kg)
Retain P by capturing solids on or within a
filtration matrix
 Considerations
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 Particulate P
 “in-depth” vs “surface”
 Resuspension
 Solids loading
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Phosphorus reacts with solution or surface to
change form (“sorb” or “precipitate”)
Factors Controlling Phosphate Interaction with Iron Oxides
Liping Weng,* Willem H. Van Riemsdijk, and Tjisse Hiemstra
Journal of Environmental Quality, 2012
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Phosphorus reacts with solution or surface to
change form (“sorb” or “precipitate”)
Trapping Phosphorus in Runoff with a Phosphorus Removal Structure
Chad J. Penn,* Joshua M. McGrath, Elliott Rounds, Garey Fox, and Derek
Heeren
Journal of Environmental Quality
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10/23/2015
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Phosphorus reacts with solution or surface to
change form (“sorb” or “precipitate”)
Direct runoff to vegetated pervious areas
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 Phosphorus
▪ Particulate P
The Adsorption Isotherm
▪ Sedimentation
▪ Filtration
Phosphorus
Adsorbed
On
Solid
Milligram P
/Gram Solid
▪ Soluble P
▪ Vegetative uptake
▪ Reactions with solid phase
THE ROLE OF THE RESIDENTIAL SHORELAND LAWN AS A HYDROLOGIC CONNECTION
BETWEEN DOWNSPOUT AND LAKE
By Kaylea M. Foster A Thesis
Phosphorus Concentration in Solution
(Milligram P / Liter Solution)
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Direct runoff to vegetated pervious areas
 Follow the water
Fraction of Runon That
Runs Off
Runoff as Fraction of Runon
1.5
1.3"
¼ - ½ inch/hour
1
0.5"
0.5
0.25"
0.1"
0
0.01
0.1
1
10
Infiltration Rate (in/hr)
Runon Ratio
500 / 5(w) x 40 (L)
The fraction of runon to the secondary buffer that would infiltrate for different storm
sizes and infiltration rates (assumes a 500 ft2 impervious area draining to a five foot
wide channel, forty feet long and one hour storm of depth shown). Dashed lines show
the fitted equation based on soil infiltration rate and storm depth.
.
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10/23/2015
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Increased phosphorus from land increases
surface water phosphorus concentrations
Groundwater phosphorus < 0.05 mg/l
Runoff phosphorus > 0.3 mg/l
Phosphorus can be removed from water
through biological uptake, reaction, filtering,
settling
Hopefully understanding these mechanisms
can help us evaluate treatment alternatives
Paul McGinley
College of Natural Resources
UW-Stevens Point / UW-Extension
 (715) 346-4501
 Paul.mcginley@uwsp.edu
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