Manure Covers and Biofilters for Managing Odor and Air Emissions

Covers and biofilters are two techniques that can be used to help manage odors and other airborne emissions from animal feeding operations and manure storage units. Watch these two videos to learn about covers and biofilters, how they work, and related costs and benefits of different methods to reduce airborne emissions. Links to additional techniques and information are given below.

Manure Storage Covers for Reducing Odor Emissions

Visit the Feedlot Air Emissions Treatment Cost Calculator website to download a spreadsheet to help calculate costs and benefits of installing technologies to treat odors and gas emissions from animal feeding operations. A good tool to assess current management practices and their impact on air emissions, including odor, is to use the National Air Quality Site Assessment Tool (NAQSAT). Manure Storage Covers includes many more resources on this topic.

Biofilters for Reducing Odors and Gas Emissions

More is available on Biofilters. There are several methods that can be used to manage odor and other airborne emissions from animal feeding operations. Additional techniques and management information include:

More Videos in This Series

Additional educational materials are available at Air Quality in Animal Agriculture including an archived webinar on “Clearing the Air on Biofilters

Acknowledgements

For more information about this video or these resources, contact Dr. Kevin Janni, University of Minnesota kjanni@umn.edu

These materials were based upon work supported by the by the National Institute of Food and Agriculture, U.S. Department of Agriculture under Agreement No. 2010-85112-20520.

Any opinions, findings, conclusions, or recommendations expressed in this video are those of the speaker and do not reflect the view of the U.S. Department of Agriculture.

Feedlot Air Emissions Treatment Cost Calculator

logoThere are several techniques that animal feeding operation owners and managers can use to manage odors and gas emissions. Each technique has different costs and benefits. The Feedlot Air Emissions Treatment Cost Calculator is a tool that can be used to compare alternative technologies and designs with different costs and benefits. The calculator has information on biofilters, covers, scrubbers, manure belts, vegetative buffer and anaerobic digesters.

This spreadsheet tool is intended to assist the operator of a livestock or poultry operation to calculate the costs and benefits of installing technologies to treat odors and gases that could be emitted from the facility.

Download the Air Emissions Treatment Cost Calculator

The tool requires Excel 2007 or later versions. Download the spreadsheet. Note: This is a spreadsheet with active macros. Depending on your security settings, you may have to tell your spreadsheet program that it is OK to open it. The four videos below provide instructions on how to use the decision tool.

Instructional Videos for the Air Emissions Treatment Cost Calculator

Four videos below describe the cost calculator and how to use it.

Introduction

Biofilters and Covers

Scrubbers, Manure Belts, Buffers, Digesters

Benefits and Summary

Acknowledgements

Additional materials in this series (videos):

The Feedlot Air Emissions Treatment Cost Calculator was developed by Dr. Bill Lazarus (wlazraus@umn.edu) in the Applied Economics Department at the University of Minnesota for a multistate USDA funded research and Extension project. The calculator was suggested by stakeholders that included producers and managers of swine, poultry and dairy producing operations, equipment manufacturers and suppliers, human medicine, veterinary medicine, local and state regulators, local and county elected officials, Extension and NRCS.

Supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under Agreement No. 2010-85112-20520. If you have any questions about the project, contact Dr. Kevin Janni, University of Minnesota, kjanni@umn.edu

Multi-pollutant Scrubbers for Removal of Ammonia, Odor, and Particulate Matter from Animal House Exhaust Air

Reprinted, with permission, from the proceedings of: Mitigating Air Emissions From Animal Feeding Operations Conference.

The proceedings, “Mitigating Air Emissions from Animal Feeding Operations”, with expanded versions of these summaries can be purchased through the Midwest Plan Service.

This Technology is Applicable To:

Species: Swine, Poultry
Use Area: Animal Housing
Technology Category: Scrubber
Air Mitigated Pollutants: Ammonia, Odor, Particulate Matter

System Summary

In The Netherlands, Germany and Denmark packed-bed biotrickling filters and acid scrubbers for removal of ammonia from exhaust air of animal houses are off-the-shelf techniques for ammonia removal (70 – 95% average removal). At the moment a new generation of so-called “multi-pollutant scrubbers” is being developed and tested that not only removes ammonia but also aims for significant removal of odor and particulate matter (PM10 and PM2.5) from the air. Recently a 3-year research program has started that monitors and aims to improve the performance of five farm-scale multi-pollutant scrubber from different manufacturers. The preliminary results show that the average ammonia removal is relatively high (83%, n = 7) but that the average removal of odor (40%, n = 8) and particulate matter (PM10: 43%, n = 2; PM2.5: 42%, n = 2) needs to be improved further.

Applicability and Mitigating Mechanism

  • Ammonia scrubbers consist of two types: either acid scrubbers or biotrickling filters
  • Multi-pollutant air scrubbers usually consist of two or more scrubbing stages where subsequent removal of coarse dust, ammonia and odor takes place
  • Scrubber are mainly applied in pig housings with central ventilation ducts; application in poultry housings are scarce because of high dust concentrations
  • Already 10% of all exhaust air from pig houses The Netherlands is treated; this equals a treatment capacity of 79 million m3/hour

Limitations

  • Odor and dust removal is less effective than ammonia removal, at least for now
  • High concentrations of coarse dust result in blockage of packing material and increased energy use (pressure drop)
  • Costs are considered high, but multi-pollutant scrubbers provide an option for large scale livestock operations to remain in operation in areas nearby residential areas and sensitive ecosystems

Cost

Investment and operational cost of scrubbers for newly built production facilities in € / animal space.
Acid Scrubber Biotrickling Filter Multi-pollutant scrubber (3-stage water/acid/biotrickling)
Investment Costs 32.8 43.5 50.3
Operational Costs (year^1):
Depreciation (10%) 2.6 3.4 4.2
Maintenance (3%) 1.5 1.8 2.0
Interest (6%) 0.8 1.0 1.2
Electricity use ((€ 0.11 kWh^-1) 3.3 3.8 3.7
Water use (€ 1.0 m^-3) 0.6 1.7 0.6
Chemical use (€ 0.6 L^-1 H2SO4, 98%) 1.4 n/a 0.7
Water discharge [b 0.6 2.5 1.0
Total operational costs (year^-1) 10.8 14.3 13.5

[a] The investment costs are based on a maximum ventilation capacity of 60 m3 animal place-1 h-1.
[b] Water disposal costs are assumed of € 10/m3 for discharge from acid scrubbing and € 2/m3 for discharge from biotrickling or water scrubbing. For the multi-pollutant scrubber, discharge water from the biotrickling or water scrubbing step is reused in the acid scrubbing step. The systems do not include a denitrification unit which might significantly decrease water discharge costs.
[c] n/a = not applicable.

Authors

Roland W. Melse, Nico W.M. Ogink, Bert J.J. Bosma; Animal Sciences Group, Wageningen University and Research centre, The Netherlands
Point of Contact:
Roland W. Melse, roland.melse@wur.nl

The information provided here was developed for the conference Mitigating Air Emissions From Animal Feeding Operations Conference held in May 2008. To obtain updates, readers are encouraged to contact the author.

Significant Odor Reduction from a Highly Efficient Micro-ecosystem based on Biofiltration

Reprinted, with permission, from the proceedings of: Mitigating Air Emissions From Animal Feeding Operations Conference.

The proceedings, “Mitigating Air Emissions from Animal Feeding Operations”, with expanded versions of these summaries can be purchased through the Midwest Plan Service.

This Technology is Applicable To:

Species: Swine
Use Area: Animal Housing
Technology Category: Biofilter
Air Mitigated Pollutants: Ammonia, Hydrogen Sulfide, Particulate Matter, Odor

System Summary

Odor Cell Technologies LLC manufactures odor filtration technologies that attach to the exhaust ventilation of CAFO’s. These odor cells are approximately 1.2 m (4 feet) square hollow cubes with porous side walls filled with pine bark that vary in thickness depending upon the cfm and actual run-time of each stage of ventilation. Internal and external hydration is provided to the cells by a uniquely designed irrigation system controlled by timers and sensors. Odor cells utilize the principles of physical entrapment, water chemistry and microbial activity to dramatically improve air quality in and around agricultural and industrial facilities. Using the proven odor reducing principles inherent to composting, the organic odorous particles are entrapped, activated with moisture and attacked biologically at the point source. This allows naturally occurring bacteria to break down and cleanse gases and odors commonly found around these facilities. Odor Cell Technologies LLC‘s patented process creates a “micro-ecosystem” that significantly reduces odors and represents an environmentally friendly option to odor control. The successful installation of our technology has occurred on many sites throughout the Midwest.

Applicability and Mitigating Mechanism

  • Captures odorous organic particulate matter commonly produced by CAFO’s
  • Reduces NH3 and H2S concentrations
  • Utilizes an environmentally friendly filtering media, pine bark, that becomes biologically active with controlled hydration intervals
  • Cost efficient, durable, easily installed and maintained with positive aesthetic appeal
  • Ventilation efficiency can be easily monitored through physical inspection and static pressure measurements

You can view this video in full screen by clicking on the icon second from right
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Limitations

  • Biofiltration is most effective on organic based odors and particulate matter
  • Media moisture levels need to be maintained between 30% and 65%
  • Static pressure requirements vary from .05 inches of water upon installation to .08 inches of water on a mature system
  • Pine bark may not be available at local retail outlets
  • Substitution of the recommended media may affect odor cell performance

Cost

Odor cell frames are constructed using stainless steel, DurameshTM hex netting, stainless steel tubing, nylon fittings and brass nozzles. These construction materials were chosen for durability and longevity due to the environment they will operate in. The following represents current pricing for the most common odor cells:

  • Standard P-8, $1200 plus $50 initial media fill
  • 5 inch odor cell, $1425 plus $65 initial media fill
  • 10 inch odor cell, $1650 plus $125 initial media fill
  • Porous rock base, approximately $20 per odor cell
  • Standard hydration package (Approximately $360 – timer, valves, control box, fittings , tubing, and hose)

Operational and maintenance costs are minimal. Media usage is approximately 10% per year. Hydration cycles can be controlled by an irrigation timer and rain sensor. A typical 1200 head swine finishing barn with 6 standard pit exhaust fans using all 10 inch odor cells would cost $11,130 upon installation (excluding shipping and labor) and $75 a year in operational expense. Assuming a complete change of media every 5 years, this equates to $.62 per pig space over 20 years or $.23 per pig produced over 20 years (assuming 2.6 turns per year).

Authors

Robert R. & Roger Treloar, Odor Cell Technologies LLC
Point of Contact:
Odor Cell Technologies LLC, odorcell@southslope.net

The information provided here was developed for the conference Mitigating Air Emissions From Animal Feeding Operations Conference held in May 2008. To obtain updates, readers are encouraged to contact the author.

Biofiltration: Mitigation for Odor and Gas Emissions from Animal Operations

Reprinted, with permission, from the proceedings of: Mitigating Air Emissions From Animal Feeding Operations Conference.

The proceedings, “Mitigating Air Emissions from Animal Feeding Operations”, with expanded versions of these summaries can be purchased through the Midwest Plan Service.

This Technology is Applicable To:

Species: Swine, Dairy
Use Area: Animal Housing
Technology Category: Biofilter
Air Mitigated Pollutants: Hydrogen Sulfide, Ammonia, Methane, Volatile Organic Compounds, Odors

System Summary

A biofilter is simply a porous layer of organic material, typically wood chips or a mixture of compost and wood chips, that supports a population of microbes. Odorous building exhaust air is forced through this material and is converted by the microbes to carbon dioxide and water. The compounds in the air are transferred to a wet biofilm that grows on the filter material where microorganisms breakdown the odorous compounds.

Biofiltration can reduce odor and hydrogen sulfide (H2S) emissions by as much as 95% and ammonia by 65%. The method has been used in industry for many years and was recently adapted for use in livestock and poultry systems. Biofilters work in mechanically ventilated buildings or on the pit fans of naturally ventilated buildings. Biofilters can also treat air vented from covered manure storage.

Two configurations of biofilters are being used to treat exhaust air from swine buildings: a horizontal media bed and a vertical media bed. Horizontal biofilters require more land area but are less expensive than vertical biofilters. Horizontal beds can be shallow (< 0.45 m) or deep (> 0.75 m).

Applicability and Mitigating Mechanism

Key factors influencing biofilter size and performance:

  • time the odorous gases spend in the biofilter
  • volume of air treated
  • moisture content of the filter material
  • sizing the biofilter media volume
  • selecting fans capable to push the air through the biofilter
  • choosing biofilter media

Limitations

  • Biofilters are only effective when there is a captured air stream
  • Media moisture content effects the biofilter performance, i.e. dry media results in poor odor reduction
  • Media porosity is related to the fan’s ability to move air through the biofilter. If media is less than 50% porosity most agriculture ventilation fans will not perform satisfactorily

Cost

Costs to install a biofilter include the cost of the materials—fans, media, ductwork, plenum—and labor. Typically, cost for new horizontal biofilter on mechanically ventilated buildings will be between $150 and $250 per 1,700 m3/hr (1,000 cfm). A vertical biofilter is approximately 1.5 times the cost of a horizontal biofilter. Annual operation/maintenance of the biofilter is estimated to be $5-$10 per 1,700 m3/hr (1,000 cfm). This includes the increase in electrical costs to push the air through the biofilter and the cost of replacing the media after 5 years.

Authors

R.E. Nicolai1, K.J. Janni2, D.R. Schmidt21South Dakota State University, 2University of Minnesota
Point of Contact:
Richard Nicolai, richard.nicolai@sdstate.edu

The information provided here was developed for the conference Mitigating Air Emissions From Animal Feeding Operations Conference held in May 2008. To obtain updates, readers are encouraged to contact the author.

Practical Partial Biofiltration of Swine Exhaust Ventilation Air

Reprinted, with permission, from the proceedings of: Mitigating Air Emissions From Animal Feeding Operations Conference.

This Technology is Applicable To:

Species: Swine
Use Area: Animal Housing
Technology Category: Biofilter
Air Mitigated Pollutants: Odor, Ammonia

System Summary

The mitigation technique discussed is to utilize biofiltration for a portion of swine barn ventilation air. The portion mitigated is that portion of air emitted into stable atmospheres. Stable atmospheres have poor vertical mixing potential and therefore gases and odors emitted tend to remain close to the earth’s surface and can therefore be sensed at longer distances downwind. It is impractical to mitigate all of the exhaust ventilation air required in swine housing. Techniques are needed that apply odor and gas mitigation to a portion of the ventilation air stream, when receptors might experience an odor event. Additionally, many barns incorporate combinations of fans and curtains (i.e. hybrid ventilated) to supply required ventilation air. Any mitigation strategy applied to barn ventilation air must be able to accommodate these hybrid ventilation systems as well.

Ventilation air exhausted during the heat of summer days is exhausted into an atmosphere that is, for the vast majority of times, very unstable providing excellent and natural mixing potential near the building source. In more stable atmospheres, typically present during the evening hours, biofiltration of a critical minimum amount of ventilation air (i.e. partial biofiltration) would reduce ammonia and odor emissions during those times when the potential for odor plumes to travel long distances is greatest. The overall effect would be a more attractive biofiltration strategy that maximizes ammonia and odor reduction potential when most needed.

Applicability and Mitigating Mechanism

  • Biofiltering of a critical minimum amount of ventilation air
  • Applies mainly to hybrid ventilated swine finishing facilities
  • Can be used as an odor “impact based” mitigation strategy

Limitations

  • Requires fan ventilation of barns up to about 81 m3/h-pig (48 ft3/min-pig)
  • Biofilter applications apply added stress to the ventilation system
  • Biofilters require ample water supply to keep the biofilter media in the 50-60% range

Cost

The biofilter application presented in this research required $4,959 for biofilter supplies and equipment including four new biofilter fans (300-head pig finishing room). Biofilter supplies, equipment, and construction labor resulted in a total implementation cost of $6,759 or $22.53/pig space. The added energy to operate the biofilter fans resulted in an additional $0.42/pig-produced.

Authors

Steven J. Hoff1, Jay D. Harmon1, Lide Chen1, Kevin A. Janni2, David R. Schmidt2, Richard E. Nicolai3, Larry D. Jacobson21Iowa State University, 2 University of Minnesota, 3South Dakota State University
Point of Contact:
Steven J. Hoff, hoffer@iastate.edu

The information provided here was developed for the conference Mitigating Air Emissions From Animal Feeding Operations Conference held in May 2008. To obtain updates, readers are encouraged to contact the author.

Biofilter and Scrubber Technologies for Mitigating Air Emissions from Animal Agriculture

Reprinted, with permission, from the proceedings of: Mitigating Air Emissions From Animal Feeding Operations Conference.

 

Biofilters and Scrubbers for Air Emission Mitigation in Animal Agriculture