Tag: animal air quality

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: Poultry (Broiler and Turkey)
Use Area: Animal Housing
Technology Category: Chemical Amendment
Air Mitigated Pollutants: Ammonia

System Summary

Aluminum sulfate (alum) additions to poultry litter have been shown to reduce ammonia concentrations in and emissions from poultry rearing facilities. Adding alum to litter also decreases phosphorus runoff. There are three types of alum can be used in poultry houses; dry, liquid and high acid liquid alum (this paper focuses on dry alum). Typically alum is not applied to fresh bedding material, but added to used bedding prior to each subsequent flock. Ammonia levels in poultry houses receiving alum have been shown to be reduced by over 75% for the first two weeks of the flock, 50% the third week, and 20-30% thereafter. However, the exact length of time that ammonia is controlled is dependent on the rate of alum application, with higher rates resulting in better ammonia control. Recommended rates of alum vary from 0.045 to 0.09 kg/bird. However, these rates were based on broilers weighing 1.82 kg (4 lbs) at market age. Recently, more companies are growing larger broilers, which result in higher manure production and more ammonia emissions. Hence, for large birds the final market weight of the bird should be considered, with the corresponding range in alum application rates being 0.025 to 0.05 kg alum/kg bird. Alum application rates will be dependent on the desired length of time ammonia is controlled and whether or not controlling P runoff is desirable. Rates of 0.09 kg/bird have been shown to control ammonia for six weeks, while 0.045 kg/bird only controls ammonia for three weeks. Other benefits of alum include heavier birds, better feed conversion, lower condemnation, and reduced propane use during cooler months as a result of lower ventilation needs. Crop yields are also higher with alum-treated litter because of higher nitrogen content. Phosphorus, heavy metal and estrogen runoff are also reduced when litter is treated with alum, improving water quality.

Applicability and Mitigating Mechanism

• NH3 volatilization from litter is dependent on pH, moisture content, air velocity, NH4 concentration, and temperature
• Litter pH is an important factor for controlling NH3 volatilization
• Alum applications reduce litter pH and suppresses NH3 emissions
• Alum is applied to the litter before birds are placed

Limitations

• Alum looses its effectiveness with time
• Since alum begins working as soon as applied, birds should be placed 2-5 days after application
• Dry alum results in dusty conditions during application; dust masks and goggles should be worn
• The material has a low pH and can be corrosive to handle
• Cost of alum is variable, dependent upon proximity of the production facility to the supplier

Cost

The cost of alum is dependent upon both the chemical cost, the proximity of the production facility to the supplier, and the charge made by a third party to apply it (if applicable). In the economic evaluation made by Moore et al. in 1999, the cost of alum was $0.26/kg alum applied ($0.12/lb), which was equivalent to $480 for a 1459 m2 house (16,000 ft2) treated with 1816 kg alum(4000 lb). Savings to the grower and integrator from lower propane and electricity use, heavier birds, improved feed conversion and lower condemnation totaled $940, resulting in a benefit cost ratio of 1.96. As a result of these benefits, currently 700-800 million chickens are grown with alum each year.

Authors

Philip Moore¹, Dana Miles², Robert Burns²¹USDA Agricultural Research Service, ² Iowa State University
Point of Contact:
Philip Moore, philipm@uark.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.

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: Poultry (Layer)
Use Area: Animal Housing
Technology Category: Chemical Amendment
Air Mitigated Pollutants: Ammonia

System Summary

The effectiveness of aluminum sulfate (alum, Al2(SO4)3) as a litter amendment in poultry houses has been recognized in several studies. Emission rates of ammonia (NH3) were measured at two 169,000-hen high-rise layer barns in Ohio, for six months. The tests were conducted to evaluate baseline and mitigated emission rates. An alum and aluminum chloride (AlCl3) spraying system was installed in the treated Barn 2. Concentrations of NH3 were measured at the barn exhaust fans and in incoming air, using real-time NH3 analyzers. Temperatures, relative humidity, barn static pressure, and fan operation were also measured.

The average daily mean untreated net NH3 emission rate was 480 g/d-AU (1.35 g/d-hen), where AU is an animal unit or 500 kg (1100 lb) of bird weight. The alum and AlCl3 applications reduced NH3 emission by 23% based on the overall cross-barn comparison of paired emission differences between barns. The NH3 mitigation efficiency of the Al2(SO4)3 application was compromised by clogged nozzles, manure turning, and introduction of a new flock of hens. Higher reductions of 33, 23 and 40% were achieved during later test periods. The application of AlCl3 in the last test was expected to further reduce NH3 emission, but the reduction was only 27%. The lower NH3 emission reduction efficiency of AlCl3 was probably due to higher moisture content of manure in Barn 2.

Applicability and Mitigating Mechanism

• Aluminum sulfate and aluminum chloride can lower manure pH and reduce ammonia emission
• A 3000-gal tank stored the chemicals, and spray tubes and sprinkling nozzles were installed along the barn length
• Solutions were automatically sprayed every hour, for a total of 24 times per day

Limitations

• The nozzles were easily clogged when spraying aluminum sulfate
• The additional chemical solution increased manure moisture content, especially in cold weather, thus reducing its effectiveness
• The spraying system requires training to operate and maintain
• The chemicals were acidic and corrosive
• Manure on second floor was untreated.

Cost

The costs of the alum and AlCl3 were $0.13/L and $0.14/L, respectively, without delivery charges. At each delivery, 5678 L (1500 gal) of alum or AlCl3 was first added into the holding tank, and an equal volume of water was added to produce a 50% solution. The field records showed that five deliveries worth $3700 of alum were used in 85 days, or $44 per barn per day. The automatic spray controller cost about $3000, and the doubled-wall holding tank was $6500. A single wall tank would be less expensive. The labor to maintain the controller, air and water pumps is estimated at 3 hours per week per barn. The air pump provided the pressure for spraying, and the water pump filled the spray pipe with the solution.

Authors

Teng Teeh Lim¹, Chaoyuan Wang², Ji-Qin Ni¹, Albert J. Heber¹, and Lingying Zhao³¹Purdue University, ² China Agricultural University, ³
Ohio State University Point of Contact:
Teng Teeh Lim, limt@purdue.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.