Removing phosphorus from drainage water the phosphorus removal structure
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Transcript of Removing phosphorus from drainage water the phosphorus removal structure
Removing Phosphorus from Drainage Water:
The P Removal Structure
C. Penn, J. Payne*, J. Vitale, J. McGrath and D. Haak
Oklahoma State UniversityUniversity of Maryland
Illinois River Watershed Partnership
P transport to surface waters
Occurs primarily via surface flow:
- Particulate P – carried on eroded particles, not immediately bio-available
- Dissolved P – 100% biologically available
Legacy P
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 20100
100
200
300
400
500
600
Trt 1
Trt 2
Trt 3
Trt 4
Trt 5
Coale, F.J. and R. Kratochvil 2011: Unpublished data
Meh
lich-
3 P
hosp
horu
s (m
g kg
-1)
Plant optimum soil test P level
Cessation of fertilizer applications
Managing P Losses
Most traditional BMPs do:- target particulate P
- veg buffers, riparian areas- prevent soil P from increasing
- limit P applications
Managing P losses
Most traditional BMPs do not:- target dissolved P
- difficult to target High P soils will continue to produce
dissolved P for years
Runoff P vs. Soil Test P (Miami, OK)
y = 0.0016x + 0.287
R2 = 0.89
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0 500 1000 1500 2000 2500
Soil Test P (ppm)
Ru
no
ff P
(p
pm
)
P sorbing materials (PSM)
PSM: -any material that chemically removes dissolved P from a solution, reducing soluble P.
Examples include: Al, Fe, Ca and Mg. Many by-products contain P sorbing minerals. Can be used for treatment of soil or manure;
however, P is not removed from system. Better use would be treatment of runoff
Phosphorus Sorption Materials
Acid mine drainage residuals
Steel slag
Drinking water treatment residuals
Fly ash
Waste recycled gypsum
Photo Credit: K.D. Chamberlain
Manufactured PSM
Selection Process for PSMs
Material Availability
Cost & Transportation
Potential contaminants
Alkalinity/acidity
Soluble salts
Total, acid soluble,
and water soluble Na & heavy metalsSorption characteristics
Physical Properties
Particle size distribution
and bulk density
Hydraulicconductivity
P P P P P P P P P
High P water
PSM layer
Drainage layerClean water is released
P P PP P P
P P P
3 Necessary Components
Effective PSM in sufficient quantity P-rich water must flow thru PSM Ability to retain and replace PSM
Advantages of P removal structure
Remove both particulate and dissolved P Ability to remove PSM after saturation Various metals and pesticides are removed
Potential application of PSM
Ag runoff
Urban runoff
Many Types of Structures
Confined Bed
Confined Bed
• Good for large filter
• Ideal for drainage swales that require high peak flow and non restricted drainage
– Achieved through shallow PSM with large surface area
Box Filter
Perforated steel box Vertically positioned
pipe inside box Filled with steel slag Small ditches or
pond overflow Drawback: small
amount of material
Tile Drained Filter
PSM over and under perforated pipes
Dam at end for slow retention time
Can use large amount of material
Low cost
Storm Drainage Filter
DESIGN GUIDANCE
Model development
Developed with lab flow through studies and validated with pilot scale filter
Developed a user friendly empirical model Tested 16 different materials
- add P at constant rate- vary retention time and P concentration- measure P in outflow
Pilot scale filter at OSU
010203040506070
0 100 200 300
P re
mo
ved
(mg
/kg
)
P added (mg/kg)
Aug 2012Nov 2009
Model use
Site hydrology Targeted P removal PSM characterization
Inputs
Outputs
Design parameters
Example of Software
Example Pond Filter Data
0 20 40 60 80 100 120 140 160 180 2000
10
20
30
40
50
60
70
Measured
Predicted
P added (mg kg-1)
Cum
ulat
ive
P r
emov
ed (
mg
kg-
1)
EXAMPLE DESIGN
Poultry Farm in OK
Creek
flowdirection
poultry houses
structure location
Funding Source: USDA-NRCS CIG
Site Conditions
Drainage area: 9 acres Slope: 6% Peak flow rate; 2 yr, 24 hr storm: 1,000 gpm Annual flow volume: 9 acre-ft Typical dissolved P: 1 - 2 mg L-1
Annual dissolved P load: 49 lbs Goal is to remove 45% of annual load
Step by step description found at: www.P-structure.blogspot.com
40 tons treated slag
To date: 67% of dissolved P trapped
0 10 20 30 40 50 60 70 80 90 1000
100
200
300
400
500
600
700
Time (minutes)
Flow
(gal
lons
per
min
ute)
Storm: June 25, 2014
Peak Flow of 687 gpmInflow range 2.25-11.3 mg of P per literRemoved 0.33lb of the 0.58lb P that entered
PSMMass (Mg)
Cumulative year 1 removal
(%)
Lifetime (yrs)
Hydraulic conductivity
(cm s-1)
Area (m2)
PSM depth (cm)
WTR* 7 37 21 0.01 286 2.3
AMDR† 4 50 7 0.009 225 2.2
Fly ash‡
3 (plus 95% sand)
50 3.60.03 (mixed
with 95% sand)
406 13
>6.35 cm slag§
171 21 1.4 1.0 190 50
Treated > 6.35 cm slag**
36 45 3.5 1.0 40 50
Potential design options to meet given P removal and 1,000 gpm flow
Next steps?
Design software is completed Interactive guidance based on user inputs OSU is licensing software NRCS standard (cost-share) will be completed
after software is online Commercialization is key to dissemination
Potential uses
Golf course industry Home-owners association Storm water management Ag industry TMDLs Nutrient credit brokers
Thank you!
Illinois River in Oklahoma
Questions
Why did the chicken cross the stream?
To avoid creating a water quality violation!
Comparison to other BMPs
• In the short term there is no BMP that can appreciably reduce soluble P losses where flow cannot be reduced
– P “mining” with hay crops or corn to reduce soil P levels
• Sharpley et al. (2009): only 4.6 mg/kg decrease per year in Mehlich-3 P with continuous corn
• Not very fast
Comparison to other BMPs• Treatment wetlands
– Require excessive retention time (days), thus requires many acres of space if high flow rates are to be treated
• inefficient
– P is not really removed from the system
ECONOMICS
“IT DEPENDS”
Economics Example: Westville
• Metal & custom fabrication: $2677– ¼” carbon steel
• Slag transportation, sieving, coating: $853• Earth work for pad & berms: $846• Paint, seed, & erosion mat: $613• TOTAL: ~ $5000• Includes profit from private companies
except for metal painting and installation• Annual renewal estimated at $1213
Economics Example: Westville
Year $ P removal (lbs.)
Cumulative P removal cost
($/lb P)
1 4989 22 226.772 1213 22 140.953 1213 22 112.354 1213 22 98.055 1213 22 89.466 1213 22 83.747 1213 22 79.66