Common Mistakes in Processing that Lead to Product Quality Issues

Transcription

1 Common Mistakes in Processing that Lead to Product Quality Issues Presented by: Ron Alexander, R. Alexander Associates, Inc. 3/08/11

2 What are you selling? Compost pile REALLY!?!?..a product or just brown stuff? The marketplace has become more sophisticated

3 Buyer s Requirements What are they willing to buy? Soil Incorporant Growing Media Component Agricultural crop estab. Turf establishment Garden bed preparation Reclamation/remediation Nursery production Roadside Vegetation Buyers have different requirements Container/potting substrates Landscape (e.g. rooftop, raised planters) Backfill mixes (tree/shrub) Golf course (e.g. tee, green, divot mixes) Manufactured topsoil

4 Monitor Product Quality & Process INTERNAL PURPOSES Assists in optimizing the composting process Generate data for use in facility problem solving QA/QC EXTERNAL PURPOSES Illustrate product characteristics & consistency Generate data crucial for product sales QA/QC - Certification programs are helpful

5 Compost Certification and Registration Helping to promote and justify proper/on-going testing

6 Use an experienced organics testing lab! Use proper lab test methods, sampling and sample handling procedures

7 Organic Matter Based ByProducts / Feedstocks Municipal Industrial Agricultural Energy Other Understand that incoming feedstock(s) affects finished product characteristics

8 EXAMPLES Spent Mushroom Soil Compost Often high in Soluble salts Nutrients - ammonia and Calcium Physical contaminants HOT/IMMATURE

9 Factors Affecting Product Characteristics Feedstocks already discussed Composting process completeness, proper Post processes

10 Compost Characterization Poor job as an industry collecting and analyzing (studying) data

11 Compost Parameters and their Rationale for Inclusion Compost Parameters Rationale for Inclusion ph Necessary for system management - Effect on ph adjustment. Soluble Salt Concentration Necessary for system management Potential toxicity, effect on watering regime, effect on fertilizer application rates. Nutrient Content (N-P-K, Ca, Mg) Necessary for system management - Effect on fertilizer requirements. Moisture Content Product handling and transportation issue. Organic Matter Content Necessary for system management Relevant in determining application rates. Some use as a basis to measure cost effectiveness, value. Standardize testing characteristics

12 Compost Parameters and their Rationale for Inclusion Particle Size Necessary for system management Effect on porosity. May determine usability in specific applications Trace Elements/ Heavy Metals Necessary for system management - Effect on fertilizer requirements, potential toxicity. Necessary to address and reduce public concern. Pathogens Necessary to address and reduce public concern. Stability Necessary for system management - Effect on nutrient availability (nitrogen), odor generation. Growth Screening Necessary for system management Effect of seed germination/plant growth.

13 National Compost Data Moisture Organic Ash Matter % Bulk Density ph % Dry lb/cu ft wt wet EC5 Carbonate ds/m as CaCO3 lb/ton dry Germination Vigor % relative to pos. control % relative to pos. control % % Dry wt MIN MAX AVE Important to track industry trends, but needs to evaluated by feedstock, geography, etc. Compiled data (1 lab)

14 National Compost Data N C C/N NH -N NO -N Organic 4 3 N Ratio % % Dry Dry wt wt MIN MAX 13.3 AVE 1.7 mg/kg mg/kg dry wt dry wt 2.8 P % Dry wt mg/kg Dry wt K Ca Mg SO4 % Dry wt % Dry wt % Dry wt mg/kg dry wt , , , , Nutrient data very important to ag (& other) markets Evaluate quality of data, remove outliers, etc.

15 Single Composting Facility Compiled Data Characteristics Units of Measure Average Min Max NUTRIENTS Total Nitrogen %, wet wt. basis Ammonia (NH4) ppm, wet wt. basis Nitrate (NO3) ppm, wet wt. basis Org. Nitrogen %, wet wt. basis Phosphorus (P2O5) %, wet wt. basis Potassium (K2O) %, wet wt. basis Calcium %, wet wt. basis Magnesium %, wet wt. basis Sulfate (SO4-S) ppm, wet wt. basis 1, Iron ppm, dry wt. basis 19,077 14,000 24,000 Compiled for ease of evaluation, and to understand trends, consistency, etc.

16 OTHER PARAMETERS Units of Measure Average Min Max PHYSICAL Moisture %, wet wt. basis Organic Matter %, dry wt. basis Bulk Density lbs/cy, wet wt ph Value Units Electrical Conductivity ds/m2 (mmhos/cm), dry wt. basis Particle size % passing 9.5mm sieves, dry wt. basis C:N Ratio Ratio Stability mg CO2-C/g OM/day Maturity Emergence average % of control Maturity Vigor average % of control BIOLOGICAL Understand what you are producing / selling, know who to sell to Get help interpreting (opinions, interests in data differ)

17 Remember, not all composts are alike! Wood Primary Feedstock Compost PHYSICAL Moisture Content (%) 28.3 Total Solids (%) 71.8 CHEMICAL ph 5.9 EC (ds/m) 0.3 PO4-P (mg/l) 2.0 TKN (% w/w) 0.3 NO3-N (mg/kg) 5.5 NH4-N (mg/kg) 1.2 NH4-N / NO3-N (Ratio) 2.0 Fe (mg/kg) 4,734 C:N (Ratio) CCE (% w/w) 2.8 BIOLOGICAL Seedling Emergence (%) 99.0 Seedling Vigor (%) 5.5 CO2 Evolution (mg/gts/d) 0.5 Salmonella (MPN/g dw basis) 0.0 T. Coliform Bacteria (MPN/g dw basis) 1,400 MSW Compost Yard Cotton Trimmings Boll Compost Compost Cattle manure Compost , , , ,

18 Composting Process Material Collected and Delivered to the Facility Product characteristics can be modified to better suit specific applications and user requirements Feedstock Recovery Recyclable Materials Feedstock Preparation Odor Treatment Composting Finished Product Compost Screening and Refining Finished Product Compost Curing Finished Product Compost Storing and Packaging Finished Product

19 Composting is a manufacturing process and composters are product manufacturers! So consistency is key

20 Acceptable characteristics vary by application (use) Quality means different things to different people

21 Acceptability of both product characteristic ranges and ongoing variance of those characteristics is dependant upon the market segment

22 Modifying Compost Characteristics

23 Composting Process Material Collected and Delivered to the Facility Modification of product characteristics can done at different stages of the process (some easier than others) Feedstock Recovery Recyclable Materials Feedstock Preparation Odor Treatment Composting Finished Product Compost Screening and Refining Finished Product Compost Curing Finished Product Compost Storing and Packaging Finished Product

24 Modifying Compost Characteristics Can only be done to a certain degree, based on feedstock characteristics and economics Complete through process stages - Feedstock preparation - Composting/curing/maturing - Screening/refining/storage Examples

25 Organic Matter Content Feedstock Preparation Add organic matter rich bulking agent Finer bulking agent don t remove during screening Add another organic matter rich feedstock Composting/Curing Decrease age/curing retention time Issue in areas of high mineralization Screening/Refining Remove stones/large trash Keep soil out of product

26 Soluble Salts Feedstock Preparation Increase bulking agent content Add feedstocks lower in soluble salts Finished Product Add low salt content material (soil, compost, additives) Suggest lower inclusion/application rates Suggest watering in plants Modify loading procedures Salts can migrate in pile

27 Maturity/Stability Composting/Curing Maintain proper pile porosity and aeration Use correct composting principles (takes time) Finished Product Evaluate soluble salt content, ph, nutrient content, stability to determine specific issue Manipulate product as necessary to address specific quality issues Blend with soil or soil additives, dilute

28 Common Mistakes Effecting Product Quality Feedstock Preparation Improper C:N ratio Inert contaminants in feedstocks Density/lack of porosity

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30 Common Mistakes Effecting Product Quality Composting/curing/maturing Improper understanding of science - microbe require food, water, oxygen - be realistic with your feedstocks! (odor, speed of degradation) Anaerobic conditions density, porosity, turning, piling to high Trying to push the system to fast

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32 Common Mistakes Effecting Product Quality Screening/refining/storage Making wrong screen sizing choices based on economics, not market requirements Poor storage conditions or practices - weed seeds, moisture, inert contaminants - need enough storage space

33 Wet Compost

34 Monitor Product Quality Prove product characteristics, consistency Assists in optimizing process Saves money Produce product faster Produce better compost Generate data for use in facility problem solving Certification programs are helpful for QA/QC

35 Questions?