Organic Soils, i'e' Histosols

1
Organic Soils, i.e. Histosols
Soils An Introduction (Singer and Munns)
2
Non-agricultural Use of Soil

• Using Soil as a Recycler

3
Solid Waste
4
Liquid Waste
5
Disposal/Treatment Options
Two options On-site Septic System Off-site
Sewage Trt Plants
Soils An Introduction (Singer and Munns)
http//ga.water.usgs.gov/edu/wuww.html
6
Waste Water Treatment Plants(WWTP)

• Combined OR
• Separate sewage from runoff

Soils An Introduction (Singer and Munns)
7
WWTP Goals

• Clean water (effluent) to return to streams
• remove excess nutrients
• minimize pathogens
• appropriate temperature
• Sanitary solids disposal
• landfill
• incinerate
• land application

8
Biosolids solids after trtmt
Soils An Introduction (Singer and Munns)
9
Biosolids Processing
10
Phosphorus (P) Crop Need vs Water Quality
greenfacts.org
Soil crop production
Water eutrophication
Goal Satisfy P need, minimize P loss
11
Balance
www.milorganite.com
NP ratio in these sources less than plant
requires
12
Effects of Biosolids Treatment

• Biosolids
• concentrated with P
• disposalland application
• Do biosolids differ in P availability as compared
  to manure or fertilizer?

13
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
14
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 solids

Lodi (Al) Portage (Fe) WI
15
P Removal Method Biological

• primary influent trt
• microorganisms eat dissolved P
• solids removed by settling for further trt

Madison, WI
16
Biosolids Trtmt Effects
lime (Ca)
Fe or Al
biological
P Removal Method
17
Experimental Approaches

• Field Study
• with plant
• real environment

• Incubations
• no plant
• controlled conditions

18
Biosolids History Incubation
PWEPpercent of TP that is water extractable
19
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

20
Effects on Bray P1
KH2PO4
bars within a soil followed by the same letter
are not statistically different at p0.05
21
Effects on PBC
PBC P rate/?STP
22
Predicting STP
, , indicate statistical significance at
p0.05, 0.01, and 0.001, respectively
23
Effects on Bray P1
Arlington Field Experiment
24
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

25
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?

26
Green Waste

• Reduce Reuse Recycle

27
BackgroundP Chemistry

• Solubility in Soils - pH dependent

Optimum P availability between pH 6-7.
Brady and Weil, 1999
28
Effects on WEP
KH2PO4