COMPOSTING 101 to 450 Paul Walker Illinois State University - Normal

Transcription

1 COMPOSTING 101 to 450 Paul Walker Illinois State University - Normal

2 COMPOST DEVELOPMENT COMPOST QUALITY ON-SIGHT QUALITY DETERMINATION POLLUTANT REMOVAL EROSION / SEDIMENT CONTROL

3 COMPOST PROCESS FLOW CHART Analyze Markets Feedstocks Determine Recipes Prepare Materials sort, grind, chip, shred Active Composting Amendments Bulking Agents Low Tech High Tech Curing Screening Compost Quality Assessment overs Product Refinement Additives Storage Bagging Blending

4 OM M.O. Compost + C0 2 + H 2 O + N0 3 + SO 4 + heat

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6 RECIPE FORMULATION C:N 25:1 to 30:1 Particle size small but not fine Moisture 40 65%, 50% COMPLEX RECIPE VS. SIMPLE MIXTURE

7 STAGES OF COMPOSTING Mesophilic Stage 50 F 113 F Thermophilic Stage 122 F 160 F

8 PHASES OF AEROBIC COMPOSTING Mesophilic active phase: moderate temps., lasts for a few hrs. to a few days Thermophilic active phase: high temps., lasts from a few days to several weeks Mesophilic curing and maturation phase: moderate to ambient temps., lasts 1-6 months or longer.

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10 WINDROW TEMPERATURE DYNAMICS C Time (days)

11 Temperature SIMPLIFIED TEMPERATURE CHANGES IN AN AEROBIC COMPOST PILE O C Active Phase A = mesophilic B = thermophilic C = mesophilic D = maturation Curing Phase 10 A B C D Time

12 TEMPERATURE Optimal temperatures result in faster breakdown of organic materials OPTIMAL temperature are in the upper range of mesophilic and lower range of thermophilic microorganism (~45 C to 55 C) Pathogen reduction (55 C to 65 C) Excessively high temperatures (> 65 C) inhibit microbial activity Moisture moderates wide swings in temperature

13 CONDITIONS REQUIRED TO INACTIVATE WEED SEEDS AND PATHOGENS 150 peak 130 peak 120 peak 2 Days 4-6 Days 5-6 Days

14 COMPOSTING BMP s aerobic, aerobic, aerobic monitor temperature monitor moisture monitor O 2 or CO 2

15 THREE IMPORTANT FACTORS FOR MAKING GOOD COMPOST PRODUCTS Chemical makeup of raw ingredients Physical size and shape ->porosity of pile Population of organisms involved in the composting process

16 CARBON COMPOUNDS Carbohydrates Hemicellulose Fats, oils Cellulose Chitin Lignin

17 NITROGEN Amino Acids Proteins Sources: Green plant tissue Animal wastes

18 VARIABLES IN THE MIX Particle size well graded Bulk density Moisture 45-65% Carbon:Nitrogen 25-30:1 ph A good recipe mixes feedstocks in ratios that meet these targets!

19 PARTICLE SIZE AND POROSITY Particle size regulates microbial access to food source, water and oxygen Smaller particles have more surface area than large particles; easy access HOWEVER, fine particles produce small pores; restricted air flow can lead to anaerobic conditions Wood chips create porosity, but carbon is not easily available to microbes

20 Oxygen Content Atmospheric O 2 concentration: 20.9% Composting is an aerobic process, so we need O 2 O 2 levels in compost air should not go < ~6% Optimal O 2 concentration for composting: 10-16% O 2 >16% to minimize odors As pile heats up, more O 2 will be consumed

21 PILE SIZE AND SHAPE Pile size will affect O 2 content and temperature Small piles maintain higher internal O 2 concentrations than large piles BUT it will not retain heat if the pile is too small Large piles retain higher temperatures than small piles BUT aeration is insufficient when too large

22 MOISTURE CONTENT Optimal range 46% - 65% Low moisture hinders composting process because microbes need water dry pile will become cool, composting is slowed down Moisture content > 65% means pore spaces filled with water rather than air insufficient O 2 anaerobic conditions results in hot pile to cools down odors due to anaerobic digestion

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24 WINDROW TURNING FREQUENCY First 3-5 Days Next 3-4 Weeks Week 5 to End Turn Daily Turn 1-3 Times/Week Turn Once/Week (max.)

25 METHODS OF AEROBIC COMPOSTING In-Vessel Static Pile Windrow

26 FRESH COMPOST Partially Decomposed Not Stable

27 MATURE COMPOST Partially Stabilized May Arrest Plant Growth Suitable Organic Soil Conditioner

28 CURED COMPOST Highly Stabilized Excellent Soil Conditioner

29 COMPOST ANALYSIS REPORT

30 IN-FIELD COMPOST QUALITY INDICATORS Crumb structure Smell odor (NH 3 ) aroma (earthy) Moisture (Optimum)

31 IN-FIELD COMPOST ANALYSIS Smell Test Moisture Test Particle Size Contaminants Solvita Test Heat Test

32 EFFECTIVENESS OF COMPOST Iowa DOT 2-4 in. compost blanket runoff H 2 O 80% Research Review compost berm compost berm SS + TSS 66% > silt fence SS + TSS 90% > control

33 EFFECTIVENESS OF COMPOST (continued) Filtrexx Inter. Compared 13 types compost filter socks 6 removed 100% motor oil 7 removed 85% motor oil motor oil concentration 1,000 to 10,000 mg/l

34 EFFECTIVENESS OF COMPOST 2005 Study (continued) compost higher in elements (metals) than top soil compost blankets + berms runoff N 63% compost blankets + berms runoff P 32% compared to hydro seeding or silt fence

35 WASHINGTON STATE RESEARCH Compost filter strip P 60% Cu Pb Zn, SS, COD 63-97%

36 EFFECTIVENESS OF COMPOST (continued) 2004 Study MSW compost absorb 85% of rainfall control areas absorb 42-52% of rainfall

37 EFFECTIVENESS OF COMPOST USEPA 1998 (continued) pollutants has degraded in days petroleum hydrocarbons (gasoline, diesel, oil, grease) polynuclear aromatic hydrocarbons (wood preservatives, refinery wastes) pesticides

38 APPLICATION RATES Depends on Purpose Fertilizer / Soil Amendment Runoff Control / Reduction Contaminant Capture Short Term Erosion Control Long Term Plant Establishment

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41 OUTCOMES EXPECTED Reduce Runoff Increase Storm Water Infiltration Filter Pollutants Oils Elements (metals) Pesticides Fertilizer Increase Plant Growth

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43 ORDER OF SEDIMENT LOSS low Low density residential Ag land in rotation crops Ag land in row crops w. BMP Medium density residential Freeways Ag land in row crops w.o. BMP high Areas under development

44 BMP WHERE COMPOST HELPS Erosion Control Blanket Filter Strip Grass Lined Channel Inlet Protection Sod Filter Mulching Permanent Vegetation Right-of-way Diversion Compost Fence Temporary Seeding Top Soiling

45 Compost sock (8-12 in. dia) replaces silt fence (24 high) straw bale barrier can be dispersed after use when mixed with seed can be left in place

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48 COMPOST RULES OF THUMB 10T:Ac = 1/8 inch layer 80T:Ac = 1 inch layer Compost absorbs 4 x weight in water

49 SOIL AMENDMENT 1 Part Compost 3 Parts Soil 10T Compost:acre 40 lbs:100 sq. ft. (cannot see it) NOTE: 1 lb. salt:1 sq. ft. = Frosted Look

50 COMPARATIVE COST OF COMPOST/STRAW Assumptions One bale straw spread 1 in. deep = 111 sq. ft. 80T compost:ac = 1 in. deep 400 lbs/20% of 1 ton = 1 in. deep = 111 sq. ft. Transport and application costs = same Compost Cost $ / T $ / 111 sq ft $ / straw bale 2.00 to 5.00

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