Foaming in Deep-pit Manure Storages: Understanding the Causes

Transcription

1 Foaming in Deep-pit Manure Storages: Understanding the Causes Laura Pepple Livestock Extension Specialist University of Illinois

2 Presentation Outline Background on Foaming Dangers of Foam What s being done Iowa Pork Producers Association grant Outline of current research Considerations for Foaming Storages

3 Background Spontaneous Foaming in Deep-pit Manure Storages 2 to 6 feet deep Foam production is sporadic Foam depth is highly variable Not caused by Agitation Regional problem Midwestern US and Parts of Canada 3

4 What We Know Occasional reports of foaming in last 20 years Since fall 2009 reports of pit foaming in Midwest states have drastically increased Survey by UMN (2010) found 1 in 4 barns were experiencing varying levels of foam production Number of foaming incidences reported went down in

5 Why Is this a Problem? Potential to reduce pit ventilation Captures biogases released by manure CH 4 build up can lead to flash fires/explosions Extensive foaming can cause catastrophic mortatlities Photo courtesy of University of Minnesota 5

6 Dangers of Methane & Foam Methane is always produced during anaerobic breakdown of manure Foam captures methane Foaming deep-pits produce significantly more methane Methane concentrations inside the foam is between 60-70%, above explosive concentration When foam bubbles are broken, methane dilutes in barn space above pit and becomes explosive at concentrations of 5-15%. 6

7 Working Hypothesis: Explosions No Foam Barn Brown = manure Red = methane at high concentrations Yellow = methane at flammable concentrations Foam Barn Foam breaks causing large release of methane 7

8 Foam on Fire below the Slatted Floors of a Deep Pit Facility

9 Flash Fires Have Resulted in Varying Levels of Damage 9

10 So what are we doing about it

11 Iowa Pork Producers Association Funded Research Project GOAL: Finding and Correcting Root-cause of Foaming Photo credit: Ken Folie, Dodge County Environmental Services Ken Folie, Dodge County Environmental Services 11

12 IPPA Funded Research Effort Multi-state effort (ISU, UMN, UILL) involving 20+ academic - professionals with expertise in manure management, chemistry, microbiology, feed rations, and digestibility $1M investment over three years (we are currently 9 months into this research) Project managed by Iowa State University Our team is working diligently to solve this problem; and we will 12

13 Multi-state Research Collaboration ISU Analysis Methane production Foaming potential testing Surface Tension, Viscosity, Particle Size and Density Short and Long Chain Fatty Acid UMN Analysis Extensive producer survey Microbial analysis Foaming potential testing UIUC Analysis Organize all manure sampling and distribution Microbial Community Analysis On-Farm Factor Correlation 13

14 Iowa State University (Kurt Rosentrator (PI), Dan Andersen, Brian Kerr, Steve Trabue) Physical and Chemical Analysis Methane Production Rates Short and Long Chain Fatty Acids Surface Tension Viscosity and Density Foaming Capacity and Stability 14

15 University of Minnesota (Chuck Clanton (PI), Larry Jacobson, Bo Hu, David Schmidt, Neslihan Akdeniz, Brian Hetchler) Developing an on farm foaming index - to identify high risk barns Foaming Index Developed Surveyed producers to determine extent and commonalities between foaming facilities 15

16 University of Illinois (Rich Gates (PI), Angela Kent, Laura Pepple, Ted Funk) Sample Coordination for all 3 institutions Microbial Community Analysis Microbe Census Dominant Microbe Identification On Farm Factor Database Environmental and Management Factors Feed, Site, etc.. Correlate Farm Factors to Foaming Phenomenon 16

17 Current site, management, and environmental factors being collected and stored in project database

18 IPPA Preliminary Results Large Scale Study 60+ sites 105 barns Multiple integrators Feed and Animal Information Collected

19 Manure Sampling Schematic A B foam/crust transi2on Samples were collected from discrete depths in the manure storage pit. C slurry Three Classes Non-foaming Moderate Foaming Extensive Foaming >10 inches D sludge

20 Temporal summary of foaming status NonCFoaming# Moderate# Extensive# 60# 50# 46# 47# 48# Number'of'Barns' 40# 30# 20# 10# 28# 12# 18# 24# 3# 39# 35# 4# 36# 30# 5# 41# 40# 26# 26# 7# 9# 37# 37# 8# 16# 0# October# November#December# January# February# March# April# May#

21 Sample Analysis

22 Preliminary ARISA analysis results of samples from consistently foaming and non-foaming facilities during the sample collection period.

23 Microbial communities differ among foaming and non-foaming samples Distinct microbial communities were observed in foaming and nonfoaming samples Across many sites and sampling dates, we see consistently different communities in foaming and nonfoaming samples NMDS based on ARISA from consistently foaming and non-foaming samples, B layer only Each point represents a sample Distance represents dissimilarity ANOSIM R = 0.565, p<0.001

24 Microbial richness is reduced in foaming sites Significantly fewer microbial populations are detected in the foaming slurry Based on ARISA from consistently foaming and non-foaming samples

25 Different dominant microbes were observed in foaming samples Specific microbes were much more abundant in foaming storages Based on ARISA from consistently foaming and non-foaming samples

26 Differences in microbial communities were correlated with management factors Higher fiber, methane production, and depth are associated with foaming samples. Correspondence analysis based on ARISA from consistently foaming and non-foaming samples Distance represents dissimilarity in community composition Arrows represent potential explanatory variables B layer only

27 Higher fiber content in hog feed is correlated with foam production Consistently foaming sites used feed with higher % crude fiber Correspondence analysis based on ARISA from consistently foaming and non-foaming samples Each bubble represents a sample Distance represents dissimilarity in community composition Bubble size represents relative fiber content of feed B layer only

28 Higher methane production is correlated with foam production Consistently foaming sites had significantly higher methane production rates Correspondence analysis based on ARISA from consistently foaming and non-foaming samples Each bubble represents a sample Distance represents dissimilarity in community composition Bubble size represents methane production rates B layer only

29 Higher methane production is correlated with foam production Consistently foaming sites had significantly higher methane production rates foaming non-foaming MPR data from Dan Andersen

30 Next Steps

31 Further exploration of explanatory variables Explore correlations between feed, manure and management variables and foaming status Provide further validation of specific factors or specific microbes that are associated with foaming Explore whether microbial changes are a cause or an indicator of foaming

32 Expand on correlation between fiber and foaming Manure foaming is correlated with dietary fiber Does the kind of fiber matter? Or all fiber? DDGS Soybean meal Corn meal Wheat midds Bakery by-products

33 Safety Concerns for Removing Manure from Deep-pits when Foam is Present 33

34 So I have foam... What can I do? Sprinkling or soaking (use extreme caution) Anti-foamers (highly variable, reduce storage volume) Microbial Enhancements Feed additives (evaluation phase) Manure additives (highly variable) Microbial Control ph shift (lime addition) Oxygen Photo credit: Ken Folie, Dodge County Environmental Services

35 My Theory on fu fu dust There are a lot of products available to combat foaming. Very few have been tested and even fewer have been validated. That said - producers are still finding success with various products. Just keep in mind what works for your neighbor may not work for you.

36 Precautionary Measures Ø Any attempt to break-up foam WILL release explosive levels of methane. Therefore. 1. All ignition sources OFF (i.e. pilot lights, welding), 2. Set ventilation at 30 cfm/space minimum, - Use open curtains if 5 mph wind, OR, - Use fans* + ceiling inlets if calm 3. Make sure ceiling inlets operational, 4. Vacate barn, then finally, 5. Foam/pit can be disturbed. * In a 1000-hd barn, equates to 2-48 or 3-36 or 6-24 fans

37 Ventilation Strategies (1000-hd Finisher) 6-24 fans or 3-36 fans or 2-48 fans + operational ceiling inlet system + curtains closed OR Curtains Open with Wind of 5 mph But NOT Curtains Open, Calm Conditions Reliance on Fans

38 Increased Methane Concentra6ons with Foam Disturbance Non-DDGS Barn Methane Concentrations 8/18/10 Methane, ppm Stage 1 Stage 2 Stage 3 Manure Sample Collected 0 0:00 6:00 12:00 18:00 0:00 Time hr:mm

39 Ventilation Dilution Time 1,000-hd finisher Methane Concentration (ppm) 800, , , , , , , ,000 0 Trapped methane in foam measured at 70% or more 2 min at 90,000 cfm 3 min at 60,000 cfm 6 min at 30,000 cfm Ventilation Time (min) V=30,000 cfm V=60,000 cfm V=90,000 cfm LEL CH4 =5.1% (51,000 ppm)

40 If a flash fire starts what should I do Do NOT enter the facility Do NOT attempt to spray water into pit, especially is foam is still present Call Emergency Personnel folks Owner, fire department, etc 40

41 Hydrogen Sulfide Safety In addition to methane foam also contains high concentrations of H 2 S (up to 250 ppm) What are some indicators of HIGH H 2 S levels in the barn? WATCH THE PIGS!!! 41

42 Hydrogen sulfide exposure symptoms for swine H2S Concentration, ppm Swestka, 2010 Symptoms Exhibited Fear of Light Loss of Appetite Nervousness Vomiting Diarrhea High-Pitch Squealing Site Avoidance Sudden Nausea Unconsciousness Death 42

43 Hydrogen Sulfide Levels LOW MODERATE HIGH 0-10 ppm ppm ppm Irritation of the eyes, nose and throat Headache Dizziness Nausea and vomiting Coughing and breathing difficulty Severe respiratory tract irritation Eye irritation / acute conjunctivitis Shock Convulsions Coma Death in severe cases 43

44 Summary Foaming is still a serious problem We are working to determine causality Maybe be related to dietary fiber Precautionary steps should be taken prior to foam disturbance

45 Questions? Laura Pepple (217)