Lingying Zhao
Ohio State University
Recent research at Ohio poultry facilities has assessed indoor environmental and
air quality, quantified particulate matter (PM) and ammonia emissions, and
evaluated technologies for reducing ammonia and PM emissions. Two different
types of layer facilities were evaluated: 1) high-rise with manure storage below
poultry and 2) belt-battery with removal of manure via belts. Results of the
study indicated increased ammonia concentration within the facilities as
ventilation rates reduced due to decreased outdoor temperatures; however,
emissions from the buildings, while highly variable, overall increased during
the summer months. Although PM10 emissions increased significantly when the
birds were disturbed, overall concentrations inside increased and emissions
decreased as ventilation rate decreased due to decreased outdoor temperature.
For both ammonia concentrations and emissions were significantly higher in the
high rise facility compared to the belt battery which was attributed to the
manure being removed from the belt battery facility. Ammonia emission from
manure removed from the belt battery building was not evaluated.
In summary, the annual average ammonia emission
from the BB barn 0.29 g/day-hen, which is significantly less than 1.03 g/day-hen
of the conventional HR layer barns. According to the emission rates, 44,400
hens from the HR barn or 158,000 hens from the BB barn would emit 100 lb
NH3/day. The mean total suspended particles (TSP) emission rates were 168 and
146 mg/day-hen from the BB and HR barns, respectively. TSP emissions from the
two barns were not statistically different. The belt battery layer barn has a
lower PM10 emission rate of 20 mg/day-bird in comparison with 32.5 mg/day-bird
of the high-rise layer barns. According to the emission rates, it would take
about 4.1 million hens in the BB barn or 4.7 million hens in the HR barn to emit
250 tons of TSP per year. It would take about 13.7 million hens in the BB barn
or 8.5 million hens in the HR barns to emit 100 tons of PM10 per year.
Evaluation of a particulate impaction curtain indicated a significant decrease
in PM10 and TSP but had durability and maintenance problems reducing its
practicality. Feed modification appeared to be effective in reducing ammonia
emissions but additional data analysis is needed. Additional research air
quality research needs include improving measurement methods, developing
emission and dispersion models, as well as evaluating factors affecting
emissions, mitigation strategies, and technological and economic feasibility.
Discussion:
Harry Hoitink (OSU) noted that calculations using mass balance of nitrogen approach produce similar ammonia emissions by the birds (1.03 g/dy/bird).
Jon Rausch (OSU): Question not audible. Zhao responded that the belt battery facility had lower emissions but if emissions from the compost building to which the manure was transported were measured, the total may not be different. However, the reduced concentrations of ammonia and PM10 in the belt battery building can have a positive impact on bird health.
Harold keener (OSU) asked if the producer modified its feeding program as it appears that ammonia was significantly reduced? Zhao responded that the modifications were not adopted due to the cost.