A13 Use of biological air scrubbers in poultry housing
Measure | Sector | Net Effect | Impact | Reliability | Tech. rqmt. | |||||
---|---|---|---|---|---|---|---|---|---|---|
NH3 | N2O | NOx | Nr to water | N2 | ||||||
A13 Use of biological air scrubbers in poultry housing | Sector Livestock farming | Net Effect 2 | NH3 1 | N2O 4 | NO2 4 | Nr to water 3 | N2 4 | Reliability Promising | Tech. rqmts. High |
Overview
The application of biological air scrubbers or bio-trickling filters, represents a promising method for enhancing nitrogen management in poultry housing. These systems have demonstrated successful implementation across various countries, effectively mitigating not only ammonia emissions but also addressing concerns related to fine dust and odour (Ndegwa et al., 2008; Bittman et al., 2014; Sutton et al., 2022). Bio-trickling filters reduce ammonia emissions by facilitating microbial conversion of ammonia to less volatile forms, contributing to improved air quality within poultry facilities (Figure 1).
Advanced multi-stage scrubbers have emerged to tackle elevated dust loads, addressing a common challenge in poultry environments. However, the utilisation of bio-filters may introduce a trade-off between ammonia reduction and potential increases in other nitrogen losses, such as nitrous oxide, nitrogen oxide, and di-nitrogen (Bittman et al., 2014; Sutton et al., 2022). The potential recovery (and recycling) of the collected reactive nitrogen from biological air scrubbers could offset this rise, as it may reduce the necessity for additional fresh nitrogen fixation for the manufacture of chemical fertilisers.
Careful consideration of the specific operational parameters and conditions is imperative to achieve a balanced approach, maximising the benefits of reduced ammonia emissions while minimising the potential for elevated nitrogen losses in alternative forms. As such, the implementation of biological air scrubbers holds significant potential in the context of improving nitrogen management within poultry housing, warranting comprehensive evaluation and adaptation to specific operational contexts to ensure sustainable and effective results.
This measure is regarded as promising in terms of nitrogen emissions reduction, but carries high technological requirements.
Figure 1. Biological air scrubber to capture ammonia emissions from livestock housing. Picture source: https://www.hollandaqua.nl/projects/biological-air-scrubber/
Measure Efficiency
Biological air scrubbers have been found to reduce ammonia emissions by 70%, whilst also removing fine dust and odour (Ogink and Bosma, 2007). To deal with the high dust loads, multistage air-scrubbers with pre-filtering of coarse particles have been developed (Melse and Ogink, 2005; Ogink and Bosma, 2007). In a study on pig and poultry houses in the Netherlands, Melse and Ogink, (2005) found the ammonia elimination achieved by Biological air scrubbers displayed ammonia removal ranging from -8% to +100%, averaging at 70%. Conversely, acid scrubbers ranged from 40% to 100%, with a mean of 96%. Notably, odour removal through acid scrubbers ranged between 3% and 51%, with an average of 27%, whereas biological air scrubbers exhibited odour removal ranging from -29% to +87%, averaging at 51%.
In a review of ammonia emission mitigation techniques for concentrated animal feeding operations (mainly pig housing), Ndegwa et al., (2008) provide the following summaries of studies on air filtration to remove ammonia emissions. Sun et al., (2000) assessed a 200 mm deep biofilter composed of a blend of compost and wood chips to ascertain its efficiency in ammonia removal from pig housing ventilation air. At a biofilter moisture content of 50% and a retention time of 20 seconds, this system demonstrated an average ammonia removal rate of 83% from the carrier air. Tanaka et al., (2003) documented a notable ammonia reduction of 94% within the initial 72 hours of treatment using a biofilter comprising finished compost (comprising cattle manure and sawdust) for composting air. Hong and Park, (2005) achieved a 100% ammonia removal efficiency using a biofilter composed of a 500 mm deep mixture of 50:50 manure compost and coconut peel, treating air emanating from a composting pile involving dairy manure and crop residues.
In pilot-scale investigations, Sheridan et al., (2002) evaluated a wood chip biofilter with a depth of 500 mm for diminishing ammonia in exhaust air from a pig finishing building. Depending on the volumetric loading rate, this biofilter, utilising 20 mm screen size wood chips, effectively eliminated between 54% and 93% of ammonia. To uphold biofilter efficiency, a filter bed moisture level of 63% or higher was recommended. A biofilter employing a mix of pine and perlite achieved a substantial ammonia removal rate of 96% from ventilation air originating from a pig rearing facility in a pilot-scale setup (Chang et al., 2004). In the context of a contemporary 2400-sow farrow-to-wean unit, Kastner et al., (2004) demonstrated that a biofilter constructed with pre-screened yard waste compost achieved ammonia reduction rates ranging from 25% to 95%, contingent upon the residence time and inlet ammonia concentration. Lastly, Martinec et al., (2001) conducted an evaluation encompassing diverse biofilter materials (biochips, coconut peels, bark-wood, pellets and bark, and compost) for ammonia reduction in pig operations, resulting in ammonia reduction percentages ranging from 9% to 26%.
How to implement
Installing biological air scrubbers in poultry housing involves a systematic approach to ensure effective ammonia and odour reduction while considering the specific needs of the facility.
- Assessment and Planning: Evaluate the poultry housing layout, ventilation system, and air quality challenges. Determine the specific goals for ammonia and odour reduction. Consider the type of biofilter media suitable for the poultry environment.
- Biofilter Design: Select appropriate biofilter media, such as compost, wood chips, coconut peels, or biochips. Determine the dimensions and depth of the biofilter bed based on air volume and pollutant load. Calculate the empty bed air residence time (EBRT) to optimise contact time between air and biofilter media.
- Biofilter Construction: Construct the biofilter unit or chamber using appropriate materials and design specifications. Ensure proper drainage to manage excess moisture and prevent clogging. Install a distribution system to evenly distribute air across the biofilter bed.
- Inoculation and Startup: Introduce beneficial microorganisms (bacteria) to the biofilter media to promote ammonia degradation. Gradually increase airflow through the biofilter to allow the microbial population to establish.
- Process Control: Implement pH measurement and automatic water discharge to maintain optimal conditions for microbial activity. Regularly monitor and adjust the moisture content within the biofilter bed.
- Monitoring and Maintenance: Regularly monitor ammonia levels and odour within the poultry housing and at the biofilter outlet. Conduct routine inspections to ensure proper biofilter function and structural integrity. Perform maintenance tasks, such as replacing clogged media, cleaning distribution systems, and addressing any technical issues.
- Data Collection and Analysis: Collect data on ammonia removal efficiency, odour reduction, and biofilter performance over time. Analyse the data to identify trends, adjust operational parameters, and optimise biofilter efficiency.
- Employee Training: Train personnel responsible for biofilter operation, maintenance, and monitoring. Educate them about the importance of process control, microbial activity, and maintaining optimal conditions.
- Adaptation and Optimisation: Continuously adjust and optimise the biofilter parameters based on monitoring data and operational experience. Consider modifications or upgrades to improve ammonia and odour removal if needed.
- Documentation and Reporting: Maintain detailed records of biofilter operation, maintenance activities, and performance data. Prepare regular reports on ammonia and odour reduction achievements for internal and regulatory purposes.
Implementing biological air scrubbers requires ongoing dedication to maintaining optimal conditions for microbial activity and ensuring consistent biofilter performance. Collaboration with experts or consultants in the field can provide valuable insights for successful implementation tailored to the specific poultry housing environment.
Benefits
Installing biological air scrubbers in poultry housing offers a range of significant benefits, including:
Overall, implementing biological air scrubbers in poultry housing aligns with a comprehensive approach to sustainable and responsible poultry production, yielding numerous benefits that encompass environmental, economic, and social aspects.
Costs
Captial Costs
Installing biological air scrubbers in poultry housing entails various potential capital costs, including:
The capital costs can vary based on factors such as the size of the poultry housing facility, chosen biofilter technology, local labour and material costs, and specific facility requirements. Conducting a comprehensive cost-benefit analysis is crucial before implementing biological air scrubbers to ensure a clear understanding of potential expenditures and the long-term returns on investment.
Operational Costs
The operational costs associated with installing biological air scrubbers in poultry housing encompass various ongoing expenses, including:
It's important to consider that operational costs can vary depending on factors such as the scale of the poultry housing facility, biofilter technology, local utility rates, and specific operational practices. Conducting a thorough cost analysis, accounting for both capital and operational expenses, is essential to determine the overall financial implications of implementing biological air scrubbers and to assess their long-term viability and benefits.
Risks
Installing biological air scrubbers in poultry housing comes with several potential risks and challenges:
To navigate these risks effectively, thorough risk assessment, expert consultation, continuous monitoring, and contingency planning are essential. Careful consideration of the benefits, challenges, and trade-offs will help poultry operations make informed decisions about adopting biological air scrubbers and implementing them successfully.
References
A. Tanaka, K. Yakushido, and and C. Shimaya. 2003. Adsorption process for odor emission control at a pilot scale dairy manure composting facility. Air Pollution from Agricultural Operations - III. American Society of Agricultural and Biological Engineers, St. Joseph, MI. p. 189–196
Bittman, S., M. Dedina, C.M. Howard, O. Oenema, and M.A. Sutton, editors. 2014. Options for Ammonia Mitigation: Guidance from the UNECE Task Force on Reactive Nitrogen. Centre for Ecology and Hydrology, Edinburgh, UK.
Chang, D.I., S.J. Lee, and W.Y. Choi. 2004. A Pilot-scale Biofilter System to Reduce Odor from Swine Operation. 2004, Ottawa, Canada August 1 - 4, 2004. American Society of Agricultural and Biological Engineers, St. Joseph, MI
Hong, J., and K.J. Park. 2005. Compost biofiltration of ammonia gas from bin composting. Bioresour. Technol. 96(6): 741–745. doi: 10.1016/j.biortech.2004.10.008.
Kastner, J.R., K.C. Das, and B. Crompton. 2004. Kinetics of ammonia removal in a pilot-scale biofilter. Trans. ASAE 47(5): 1867–1878. doi: 10.13031/2013.17588.
Martinec, M., E. Hartung, T. Jungbluth, F. Schneider, and P.H. Wieser. 2001. Reduction of gas, odor and dust emissions from swine operations with biofilters. 2001 Sacramento, CA July 29-August 1,2001. American Society of Agricultural and Biological Engineers, St. Joseph, MI
Melse, R.W., and N.W.M. Ogink. 2005. Air Scrubbing Techniques for Ammonia and odor reduction at livestock operations: Review of on-farm research in the Netherlands. Trans. ASAE 48(6): 2303–2313. doi: 10.13031/2013.20094.
Ndegwa, P.M., A.N. Hristov, J. Arogo, and R.E. Sheffield. 2008. A review of ammonia emission mitigation techniques for concentrated animal feeding operations. Biosyst. Eng. 100(4): 453–469. doi: 10.1016/j.biosystemseng.2008.05.010.
Ogink, N.W.M., and B.J.J. Bosma. 2007. Multi-phase airscrubbers for the combined abatement of ammonia, odor and particulate matter emissions. Proc. Int. Symp. Air Qual. Waste Manag. Agric.
Sheridan, B., T. Curran, V. Dodd, and J. Colligan. 2002. Biofiltration of odour and ammonia from a pig unit - A pilot-scale study. Biosyst. Eng. 82(4): 441–453. doi: 10.1006/bioe.2002.0083.
Sutton, M., C. Howard, K. Mason, W. Brownlie, and Cm. Cordovil, editors. 2022. Nitrogen Opportunities for Agriculture, Food & Environment. UNECE Guidance Document on Integrated Sustainable Nitrogen Management. UK Centre for Ecology & Hydrology, Edinburgh, UK.
Y. Sun, C. J. Clanton, K. A. Janni, and G. L. Malzer. 2000. Sulfur and nitrogen balances in biofilters for odorous gas emission control. Trans. ASAE 43(6): 1861–1875. doi: 10.13031/2013.3091.
Authors
Will Brownlie
UK Centre for Ecology and Hydrology, Scotland