Organic Soils, i.e. Histosols

Soils: An Introduction (Singer and Munns)

Non-agricultural Use of Soil

Using Soil as a Recycler

Solid Waste

Liquid Waste

Disposal/Treatment Options

http://ga.water.usgs.gov/edu/wuww.html

Soils: An Introduction (Singer and Munns)

Two options:On-site: Septic System

Off-site: Sewage Trt Plants

Waste Water Treatment Plants(WWTP)

Combined OR Separate sewage

from runoffSoils: An Introduction (Singer and Munns)

WWTP Goals:

Clean water (effluent) to return to streams remove excess

nutrients minimize pathogens appropriate

temperature

Sanitary solids disposal landfill incinerate land application

Biosolids = solids after trtmt

Soils: An Introduction (Singer and Munns)

Biosolids Processing

Phosphorus (P): Crop Need vs Water

Quality

Soil:crop production

Goal: Satisfy P need, minimize P loss

Water:eutrophication

greenfacts.org

Balance

www.milorganite.com

N:P ratio in these sources less than plant requires

Effects of Biosolids Treatment

Biosolids concentrated with P disposal=land

application

Do biosolids differ in P availability as compared to manure or fertilizer?

P Removal Method: Lime

solids pumped to this tank

addition of lime raise pH

reduce pathogens precipitate P as Ca-P

(very insoluble)Baraboo, WI

P Removal Method: Fe or Al

add at influent entry Fe

precipitate Fe-P can become soluble

in reducing conditions

Al precipitate Al-P too much Al can

cause toxicity in soil

separate for solidsLodi (Al)Portage (Fe) WI

P Removal Method: Biological

primary influent trt microorganisms “eat”

dissolved P solids removed by

settling for further trtMadison, WI

Biosolids Trtmt Effects

lime (Ca)

Fe or Al

biological

P Removal Method

Experimental Approaches

Field Study with plant real environment

Incubations no plant controlled conditions

Biosolids History Incubation

Soil IDSoil

Series

Field Biosolids History

1A Plano None

1B Plano 15 apps

2A Plano None

2B Plano 2 apps

3BRingwood

13 apps

P Source

Treatment

TP(%)

PWEP†

(%)

Madison

Biological

4.45 11.3

Baraboo

Lime 1.05 0.1

LodiAlum (Al)

3.67 0.3

Portage Iron (Fe) 3.63 1.2

Manure - 0.67 33.8

KH2PO4 - 22.8 100

† PWEP=percent of TP that is water extractable

Soil Classification

Plano Fine-silty, mixed, superactive, mesic Typic Argiudolls

Ringwood Fine-loamy, mixed, superactive, mesic Typic Argiudolls

Both soils are typical of MMSD land-application program

Effects on Bray P1

-10

0

10

20

30

40

50

60

1A=0 apps 1B=15 apps

Soil

Bra

y P

1 ch

ang

e (m

g P

kg-1

)

Lime Al Fe Biological Manure KH2PO4

a

b

bc

b c

d

a

bb

c c

d

KH2PO

4

† bars within a soil followed by the same letter are not statistically different at p=0.05

Plano 1 Plano 2 Ringwood

1A 1B 2A 2B 3B

P Sources(0) (15

apps)(0) (2

apps)(13 apps)

--------------------------PBC (kg P ha-

1)--------------------------

Lime 8.4 10.5 6.6 8.5 8.3

Al 19.9 -104.7 23.8 45.4 -222.9

Fe 9.2 12.6 10.6 17.4 16.7

Biological 7.0 5.8 8.3 8.2 7.2

Manure 7.3 5.2 7.3 7.9 6.2

KH2PO4 4.2 2.7 4.5 3.7 3.7

Effects on PBCPBC = P rate/∆STP

ALL SOILS; r=0.53

-10

-5

0

5

10

15

20

25

30

0 1 2 3 4 5 6

Water Extractable P in Biosolids (g kg-1)

Change in B

P1 (

mg k

g-1)

Predicting STP

Biosolid and manure properties

Soil Extractant

WEP AmOxP TPP to [Fe+Al]

ratio

---------------------------r---------------------------

All Soils (n=100)

ΔWEP 0.58*** 0.36*** 0.22* 0.46***

ΔBP1 0.53** ns -0.39*** 0.52***

ΔM3 0.48** ns -0.37*** 0.40***

*, **, *** indicate statistical significance at p=0.05, 0.01, and 0.001, respectively

-10

10

30

50

70

90

110

-100 -50 0 50 100 150 200

P Rate

= Total P Added - P Removed (kg P ha-1)

Ch

an

ge

in

Bra

y P

1 (

mg

P k

g-1) Biological: PBC=4

Lime: PBC=4

Al: PBC=6

Fe: PBC=8

Arlington Field Experiment

Effects on Bray P1

Conclusions

P source treatment greatly influences P availability: lime and biologically treated biosolids change BP1

similar to a typical dairy manure Fe and Al treated biosolids have significantly

greater PBC P fertilizer has the smallest PBC

Field results follow same trends as Incubations

WEP of biosolids could be used to predict PBC

Implications

Is there a “best” method for P removal?

Does P removal method have implications for the functionality of biosolids for other purposes (besides keeping P from leaving in runoff)?

What do WWTP operates need to take into account when deciding on a P removal process?

How is soil being used as a recycler?

Green Waste

Reduce Reuse Recycle

Background:P Chemistry

Solubility in Soils - pH dependent

Brady and Weil, 1999

Optimum P availability between pH 6-7.

-10

-5

0

5

10

15

20

25

1A=0 apps 1B=15 apps

Soil

WE

P c

han

ge

(mg

P k

g-1)

Lime Al Fe Biological Manure KH2PO4

aaabcbcd

a

bc

de

fd

b c

Effects on WEP

KH2PO4