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How to Evaluate and Manage Non- Biosolids Residuals. Greg Evanylo Crop & Soil Environmental Sciences Virginia Tech; gevanylo@vt.edu. Residuals Utilization and Disposal Hierarchy. By-product Properties Necessary to Evaluate Land Application Benefits and Drawbacks.
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How to Evaluate and Manage Non-Biosolids Residuals Greg Evanylo Crop & Soil Environmental Sciences Virginia Tech; gevanylo@vt.edu
By-product Properties Necessary to Evaluate Land Application Benefits and Drawbacks
By-product Properties Necessary to Evaluate Land Application Benefits and Drawbacks
Residual By-products to be Evaluated • Water treatment residuals (WTR) • Food processing residuals (FPR) • Plant –based • Animal-based • Incinerator ash
Water Treatment Residuals • 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
Use of WTR to bind P • 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 saturationindex (PSI = [Pox]/[Alox + Feox]) can be used to calculate WTR application rates forreducing P in drainage from lowP-sorbing soils. • Limitations • High EC (15-30 dS/m) in Fe-rich WTR • Highly soluble C can reduce WTR P binding
Food Processing Residuals (FPR) • 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
Pickling Liquid Effluent (Vlasic) VS=50%, C=29%, C:N=11.3
Pickling Liquid Effluent (Vlasic) SAR = Na/[(Ca + Mg)/2]0.5 = 19.4
Sea Watch Liquid VS=71%, C=41%, C:N=4.7
Sea Watch Liquid Specific ion toxicity limits: Cl=0.01%, Na=0.007%
Sensient Flavors VS=55%, C=32%, C:N=5.6
Sensient Flavors SAR = Na/[(Ca + Mg)/2]0.5 = 42
Poultry DAF Sludge (Allens Hurlock) VS=96%, C=55%, C:N=12.0
Poultry Tank Cleanings (Allens Hurlock) VS=98%, C=57%, C:N=44.9
Poultry Processing Residuals (Perdue Pilkenrood) VS=90%, FOG=41%, C=52%, C:N=17.6
Managing FOG • 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
Sludge Incinerator Ash Soil Screening Levels (SSLs): As=0.4, Cd=78, Cr=235, Mn=3600
References for Evaluating and Managing Non-biosolids Residuals • 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.