How to Evaluate and Manage Non-Biosolids

Residuals

Greg EvanyloCrop & Soil Environmental Sciences

Virginia Tech; gevanylo@vt.edu

Management Strategy Benefit Scale

Source reduction and water conservation

10 – Maximum benefit to processor and environment

Recovery for human uses 7

Recovery for animal uses 4

Recovery for soil conditioners and fertilizers

2

Disposal in landfill, and impoundment or incineration

0 – No benefit ↓ increasing cost

Disposal in hazardous waste management facility

Residuals Utilization and Disposal Hierarchy

Property Use

Solids Determine wet application method and rate

TKN, NH4-N, Org N Calculate plant available N (PAN)

Volatile solids, OM Determine carbon content, value as soil amendment

FOG, BOD, COD Determine potential odor, O2 depletion, soil quality effects, direct plant effects

C:N Estimate N mineralization for PAN

P, K, S, Ca, Mg, micros Calculate nutrient supply, potential antagonistic effects (e.g. Ca:Mg-induced grass tetany)

By-product Properties Necessary to Evaluate Land Application Benefits and Drawbacks

Property Use

Heavy metals, B, Mo, Na, Cl, Al, Fe

Prevent toxicity to plants and animals, food chain concerns, and soil quality loss; P-binding

Synthetic organic compounds

Prevent toxicity to plants and animals, food chain concerns, and water quality impairment

Electrical conductivity (EC), soluble salts, Na absorption ratio (SAR)

Prevent phytotoxicity and soil structure destruction

pH, CaCO3 equivalency (CCE)

Determine liming potential, micronutrient availability

Microbial density Estimate pathogen risk

By-product Properties Necessary to Evaluate Land Application Benefits and Drawbacks

Water treatment residuals (WTR) Food processing residuals (FPR)

◦ Plant –based◦ Animal-based

Incinerator ash

Residual By-products to be Evaluated

Flocculated suspended sediment and organic matter from water treatment facilities

Generated with additions of Al2(SO4)3 (alum), Al polymer, FeCl3 and/or lime

Consists largely of soil mineral, amorphous Al and Fe oxides, and organic matter

Low nutrient value and high P-binding medium

Value as a pathogen-free, low heavy metal-containing topsoil substitute and environmental P sorbent

Water Treatment Residuals

Hagerstown WTRVariable Conc (%) Lbs per dry ton

Total AvailableSolids 26.1

TKN 0.45 9.0 ≤2

NH4-N 0.01 0.2 0.2

Org-N 0.44 8.8 1-2

P 0.12 2.4 ? (P2O5)

K 0.19 3.8 4.6 (K2O)

Al 7.47 149

Fe 2.91 58

Sorption comparisons◦100-600 mg P/kg soil◦ 15,000-30,000 mg P/kg WTR

Higher P binding by fresh (amorphous) than aged (crystalline) WTR

Phosphorus saturation index (PSI = [Pox]/[Alox + Feox]) can be used to calculate WTR application rates for reducing P in drainage from low P-sorbing soils.

Limitations◦ High EC (15-30 dS/m) in Fe-rich WTR◦ Highly soluble C can reduce WTR P binding

Use of WTR to bind P

Incidental organic by-product generated by processing agricultural commodities◦Feed and spent brewery grain◦Fruit and vegetable◦Meat and milk

Key compositional factors◦N and P◦Dissolved and suspended solids◦Fats, oils and grease (FOG)◦Low pollutant concentrations

Food Processing Residuals (FPR)

Pickling Liquid Effluent (Vlasic)Property Conc Lbs/10,000 gals (0.37 acre-

in)Total Available

Solids (%)

1.55 1294

TKN (%) 2.58 33.4 28 (est)

NH4-N (%)

2.00 25.9 25.9

Org-N (%)

0.58 7.5 2.3 (@30% min)

P (%) 1.29 16.7 38 (P2O5)

K (%) 0.96 12.4 15 (K2O)

VS=50%, C=29%, C:N=11.3

Pickling Liquid Effluent (Vlasic)

Property

Concentration

Total lbs/10,000 gals

pH 7.50

S (%) 1.61 21

Ca (%) 1.88 24

Mg (%) 0.25 3

Na (%) 8.63 112

SAR = Na/[(Ca + Mg)/2]0.5 = 19.4

Sea Watch Liquid

Property Conc Lbs per dry tonTotal Available

Solids 25.1TKN (%) 8.68 173.6 93 (est)NH4-N(%) 0.58 11.6 11.6

Org N (%) 8.10 162 81 (@50% min)

P (%) 1.32 26.4 60 (P2O5)

K (%) 1.35 27.0 37 (K2O)

VS=71%, C=41%, C:N=4.7

Sea Watch LiquidProperty Concentration

100% 50% (diluted w/ water)

pH 5.38 5.00Ca (%) 0.44 0.49Mg (%) 0.28 0.27Cl (%) 10.7Na (%) 7.78 6.79SAR 1.92 ?

EC (dS/m) 34.5Specific ion toxicity limits:Cl=0.01%, Na=0.007%

Sensient FlavorsProperty Conc Lbs per dt

Total AvailableSolids (%) 10.5TKN (%) 5.66 113.2 79 (est)NH4-N (%) 2.79 55.8 55.8

Org-N (%) 2.87 57.4 23.0 (@ 40% min)

P (%) 2.10 42.0 96 (P2O5)

K (%) 1.02 20.4 25 (K2O)VS=55%, C=32%, C:N=5.6

Sensient Flavors

Property

Concentration

Total lbs/10,000 gals

Density (lbs/gal)

8.76 87,600

Ca (%) 2.11 185

Mg (%) 0.30 26

Na (%) 7.70 675SAR = Na/[(Ca + Mg)/2]0.5 = 42

Interpretation of Soil EC ReadingsSaturated paste

2:1 water:soil

Rating Crops affected

-----mmhos/cm-----

<1.0 <0.40 Salinity effects negligible

Possibly beans

1.1-2.0 0.40-0.80 Very slightly saline

Clovers, carrots, bell pepper, lettuce

2.1-4.0 0.81-1.20 Moderately saline

Broccoli, potato

4.1-8.0 1.21-1.60 Saline Cotton, alfalfa, grains, bermudagrass

8.1-16 1.61-3.20 Strongly saline Only salt tolerant grasses, herbaceous plants, trees and certain shrubs will grow

>16 >3.20 Very strongly saline

Potential for Soil Permeability Limitations from Irrigation

SAR Use restriction for varying EC (mmhos/cm)

None Slight/moderate Severe

0-3 >0.7 0.7-0.2 <0.2

3-6 >1.2 1.2-0.3 <0.3

6-12 >1.9 1.9-0.5 <0.5

12-20 >2.9 2.9-1.3 <1.3

20-40 >5.0 5.0-2.9 <2.9

Poultry DAF Sludge (Allens Hurlock)

Property Conc Lbs per dry tonTotal Available (est)

Solids (%) 7.92TKN (%) 4.63 92.6 32NH4-N (%) 0.62 12.4 12

Org N (%) 4.01 80.2 20 (@25% min)

P (%) 0.56 11.2 26 (P2O5)

K (%) 0.03 0.6 1 (K2O)VS=96%, C=55%, C:N=12.0

Poultry Tank Cleanings (Allens Hurlock)

Property Conc Lbs per dry tonTotal Available (est)

Solids (%) 21.5TKN (%) 1.27 25.4 Net negative N

availability (immobilization)

NH4-N (%) 0.14 2.8

Org N (%) 1.13 22.6

P (%) 0.14 11.2 26 (P2O5)

VS=98%, C=57%, C:N=44.9

Poultry Processing Residuals (Perdue Pilkenrood)

Property Conc Lbs per dry tonTotal Available (est)

Solids (%) 4.38TKN (%) 2.97 59.4 15

NH4-N (%) 0.37 7.4 7.4

Org-N (%) 2.60 52.0 7.8 (@15% min)

P (%) 1.24 22.8 54 (P2O5)

K (%) 0.05 1.0 1 (K2O)

VS=90%, FOG=41%, C=52%, C:N=17.6

Particularly high in meat and poultry processing sludges

Can clog soil and leaf pores Surface application w/o incorporation can

result in odor problems Recommend limiting the FOG application

rate to 1.5% of soil weight (~30,000 lbs/acre) annually

Managing FOG

By-product BOD TSS FOG

----------------g/Mg----------------

Fruit 4.8-25 1- 6

Vegetables 1.7-70.9 3- 64

Grains for oil

Processing 9-1017 5- 116

Production 136-1607 68- 411

Poultry 705-1540 275- 2800 175-1735

Beef/pork 820-4900 520- 4500 140-5000

Fish & shellfish 500-3000 160-18000 115-1600

Wastewater Characteristics of FPRs

Sludge Incinerator Ash

Property Conc Property Conc

Solids (%) 44 pH 7.9SiO2 (%) 40.4 K2O (%) 1.88

Al2O3 (%) 17.3 As (ppm) <10.6

Fe2O3 (%) 10.4 MnO (ppm)

4900

P2O5 (%) 7.31 Cd (ppm) 47

CaO (%) 6.95 Cr (ppm) 455Soil Screening Levels (SSLs):As=0.4, Cd=78, Cr=235, Mn=3600

Brandt, R.C. and K.S. Martin. 1996. The food processing residual management manual. Natural Resource, Agriculture and Engineering Service (NRAES). Ithaca, NY. NRAES-92.

J.F. Power and W.A. Dick (Editors). 2000. Land application of agricultural, industrial, and municipal by-products. SSSA Book Series No. 6. Soil Science Society of America, Inc. Madison, WI.

References for Evaluating and Managing Non-biosolids Residuals