Technology Type - Surface Aeration - Critical Indicators



Technology Strengths,Weaknesses and Critical Indicators

Aeration:

  • Primarily applicable to flush system after primary solids separation and within a region that has concerns regarding local odor emissions from long-term storage lagoons.
  • Capital costs for the mechanical surface aerators and their platforms/electrical connections are moderate.
  • Operating costs, even with limited aeration can be high due to high utility costs for continuous operation of energy intensive aerators.
  • Well-researched, understood and engineered system with multiple vendor platforms available across industries, including manure treatment.
  • Several types of aerators are available in the market that suit for dairy operations.
  • Specification requirements of aeration equipment and its installation depends on farm size, manure characteristics, and odor mitigation goals of that dairy farm.

image/svg+xml Nitrogen Recovery Phosphorus Recovery Storage Reduction GHG Reduction Odor Control Pathogen Reduction Negative Positive NEAT MATRIX - Peer Reviewed P - Documented D - Expert Opinion E P D E P D E

Overall Summary

Primary Application

  • Surface aeration is primarily applicable to flush system after primary solids separation and within a region that has concerns regarding local odor emissions from long-term storage lagoons.

 

Economic/Return on Investment Considerations

  • Capital costs for the mechanical surface aerators and their platforms/electrical connections are moderate.
  • Operating costs, even with limited aeration can be high due to high utility costs for continuous operation of energy intensive aerators.

 

Industry Uptake

  • Unlike swine, unique conditions of dairy manure (characteristics, location, production timing) have limited interest while in both cases economics have also further limited adoption.
  • To date, very few dairy operations have adopted aeration technology to deal with manure related odor issues.

 

Technology Maturity

  • Surface aeration is a well-researched, understood and engineered system with multiple vendor platforms available across industries, including manure treatment.
  • Several types of aerators are available in the market that suit for dairy operations.

 

Primary Benefits

  • Extremely effective for odor control, particularly control of volatile fatty acids (VFA), a major contributor to odor.
  • Aeration also reduces methane (GHG) emissions from manure lagoons.

 

Secondary Benefits

  • Secondary benefits include loss of total nitrogen from the liquid due to volatilization of ammonia to the atmosphere, which can be of interest to some dairies that are nitrogen-limited in their field application. Correspondingly, air quality is impacted. Additionally, the aeration can lead to increases in total solids, volatile solids, and COD/BOD reduction that would otherwise occur in the storage lagoon.

 

How it works

  • In a typical surface aeration application, mechanical aerators are placed on surface platforms and allowed to continuously or intermittently aerate the first foot or so of the lagoon, creating a stratified lagoon with aerated top zone and anaerobic bulk layer below. Oxygen can be supplied either naturally, mechanically through mixing, or using oxygen diffusion systems, but mechanical aeration is most common. The aeration shifts the oxidation/reduction potential (ORP) of the surface allowing for a zone capable of aerobic bacterial growth and their subsequent degradation of organic material without release of odorous gases attributed to anaerobic action.

 

Pretreatment and/or Post-treatment Required

  • Systems are ideal with low total solids content, on the order of 1% TS, thus flush management alongside solids/liquid separation are preferred if not required to keep costs down.
  • No post-treatment is required.

 

Limitations

  • Energy intensive processes and results higher utility costs.
  • Maintenance of aeration equipment is required especially during winter months.
  • Normal lagoon maintenance is still required to maintain the benefits, including regular removal of accumulating sludge.
  • Nitrogen is lost through volatilization, which can be a concern to air quality.
  • Sludge generation is slightly higher in the manure storage lagoon.

 

Other Considerations

  • Specification requirements of aeration equipment and its installation depends on farm size, manure characteristics, and odor mitigation goals of that dairy farm.

References

Amon, B., Kryvoruchko, V., Amon, T., & Zechmeister-Boltenstern, S. (2006). Methane, nitrous oxide and ammonia emissions during storage and after application of dairy cattle slurry and influence of slurry treatment. Agriculture, ecosystems & environment, 112(2-3), 153-162.

 

Martinez, J., Guiziou, F., Peu, P., & Gueutier, V. (2003). Influence of treatment techniques for pig slurry on methane emissions during subsequent storage. Biosystems Engineering, 85(3), 347-354.

 

Ndegwa, P. M., Wang, L., & Vaddella, V. K. (2007). Stabilisation of dairy wastewater using limited-aeration treatments in batch reactors. Biosystems engineering, 97(3), 379-385.

 

Ndegwa, P. M. (2003). Solids separation coupled with batchaeration treatment for odor control from liquid swine manure. Journal of Environmental Science and Health, Part B, 38(5), 631-643.

 

Westerman, P. W., & Zhang, R. H. (1997). Aeration of livestock manure slurry and lagoon liquid for odor control: A review. Applied Engineering in Agriculture, 13(2), 245-249.

 

Zhang, Z., & Zhu, J. (2005). Effectiveness of short-term aeration in treating swine finishing manure to reduce odour generation potential. Agriculture, ecosystems & environment, 105(1-2), 115-125.

 

Zhang, Z., Zhu, J., & Park, K. J. (2006). A bench-scale aeration study using batch reactors on swine manure stabilization to control odour in post treatment storage. Water research, 40(1), 162-174.

 


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