Investigation of microclimate parameters for the content of toxic gases in poultry houses during air treatment in the scrubber with the use of various fillers
To reduce the content of toxic gases in the emissions of poultry farms, top-priority goal in the system of sanitary and medical and preventive measures is the implementation of a set of measures aimed at reducing the emissions of pollutants into the atmospheric air with the use of scrubbers. The purpose of scientific and economic experiments was to study of microclimate parameters for the content of toxic gases in poultry houses during air treatment in the scrubber with the use of various fillers. The experiments were carried out in an industrial poultry house for egg-laying hens measuring 18 × 96 m, fitted with 4-tier ‘Hellmann’ cage batteries with a belt litter removal system and integrated air ducts. The capacity of the poultry house was 47280 laying hens. In a scrubber, Zeolite, Phosphogypsum, Zeolite with iron sulfate and Zeolite with aluminum chloride in a ratio of 1:1 were used as fillers during three consecutive litter cleaning cycles. The total amount of adsorbent or reagent loaded into the scrubber was 150 ± 0.5 kg. The scrubber was reloaded once every seven days. A poultry house with a standard air mixing unit was used as a control. The amount of contaminated air supplied through a scrubber ranged from 10 to 15 thousand m3/h. Analyzing the results of studies of the use of various substances or mixtures in the scrubber, we can note that the use of a mixture of Zeolite and aluminum chloride in a ratio of 1:1 in the calculation of 150 ± 0.5 kg of the mixture at 15 thousand m3/h of polluted air provided the greatest reduction in ammonia content (up to 6.3 ± 0.55 mg/m3) in the air during the 7 days of accumulation of litter. Somewhat worse results (up to 9.1 ± 0.46 mg/m3 on the 7th day) were obtained by applying a mixture of Zeolite and iron sulfate, and the worst results - with Zeolite (up to 15.1 ± 0.63 mg/m3 with a control of 15.1 ± 0.47 mg/m3). At the same time, the use of all selected substances ensured not exceeding the maximum permissible concentration of ammonia in the air (15 mg/m3) during the first 5 days. Therefore, the choice of a particular substance should first of all be based on the price affordability of a reagent, and in conditions of the equivalence – to choose a more effective reagent. The technological methods of improvement of microclimate in poultry houses for the maintenance of hens in the cage batteries with a belt litter removal system by reducing the content of ammonia in the air have been scientifically substantiated. It was established that the transmission of the polluted air through a scrubber with Phosphogypsum, a mixture of Zeolite and iron sulfate, Zeolite and aluminum chloride provides a decrease in the content of ammonia in the air of the poultry house, by 2.0-1.4; 3.2-1.7 and 4.9-2.5 times, respectively; while worked out fillers (Zeolite, Phosphogypsum, Zeolite+iron sulfate (1:1), Zeolite+aluminum chloride (1:1)) contained from 4.37% to 14.51% of nitrogen.