Reprinted, with permission, from the proceedings of: Mitigating Air Emissions From Animal Feeding Operations Conference.
This Technology is Applicable To:
Species: Poultry (Broiler and Turkey)
Use Area: Animal Housing
Technology Category: Amendment (Chemical)
Air Mitigated Pollutants: Ammonia
System Summary
Application of liquid aluminum sulfate to poultry litter has been demonstrated to effectively reduce litter ammonia emissions in broiler and turkey production systems. Liquid alum should be applied prior to bird placement in the house. The length of ammonia emission control ranges from 2.5 to 3.5 weeks following application and increases with increasing application rate (Armstrong, et. al, 2003). In addition to reducing overall house ammonia emissions, liquid alum can be used to hold in-house ammonia levels below 25 ppm during the first two weeks of a grow-out, which is considered to have a positive effect on bird performance
Selection of a liquid alum application rate is dependent upon the amount of and length of ammonia control desired. Tested liquid alum application rates (48.5% alum Al Clear product) of 0.82 and 1.64 L/m2 (0.02 and 0.04 gal/ft2), were considered low and high rates, respectively. When tested in poultry broiler production housing, the low rate suppressed in-house ammonia levels for 2.5 weeks, and the high rate suppressed ammonia levels for 3.5 weeks. In addition to reducing in house ammonia levels, there is some evidence that using liquid alum will also reduce mortalities through improved bird health and reduce propane use during cooler months because of reduced ventilation requirements.
Applicability and Mitigating Mechanism
- NH3 volatilization from litter is dependent on pH, moisture content, in-house air velocity, NH4 concentration, and temperature
- Litter pH is an important factor for controlling NH3 volatilization
- Application of liquid alum reduces litter pH and suppresses NH3 emission
- Liquid alum is applied to the litter before birds are in place
Limitations
- Liquid alum application looses its effectiveness ~ three weeks after initial application
- Since liquid alum begins working immediately, and birds are typically placed 1 week after application, a two week period of effectiveness can be expected once birds are placed.
- The material has a low pH and can be corrosive to handle
- Liquid alum is recommended to be applied by a commercial applicator, since transport is regulated.
Cost
The delivered cost of liquid alum is dependent upon the proximity of the production facility to a liquid alum distributor. Distributor cost is reflective of transport and chemical costs. For the costs presented here, the production facility was 370 km (230 miles) from the distributer and the delivered cost for liquid alum was 0.16 cents/L (0.60 cents/gal). The costs associated with liquid alum as an amendment to mitigate ammonia is the cost of the material and transport plus the application fee. In this case, the application fee was $40/house. Preparation for liquid alum placement in the house requires the same steps that are taken in preparing the production house for the next grow out, so no additional house preparation costs are incurred. The cost per 1,824 m2 (20,000 ft2) production house is $262 for an application rate of 0.82 L/m2 (0.02 gal/ft2) and $504 for an application rate of 1.64 L/m2 (0.04 gal/ft2); this is equivalent to $0.009 and $0.017 per bird produced. In this case, the proximity of the production facility to the distributor was favorable, and the cost of applying liquid alum was less than the cost of applying the equivalent amount of dry alum.
Authors
Robert Burns1, Philip Moore2, Lara Moody11Iowa State University, 2 USDA Agricultural Research Service
Point of Contact:
Robert Burns, rburns@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.