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چکیده
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The exhaust air expelled from laboratory animal housing systems is the main source of the NH3 emissions to the atmosphere. On this basis and regarding the environmental impact of NH3 emissions, more insights into the air scrubbers as one of the ways to mitigate the NH3 emission from animal houses are needed. The detailed evaluation of a pilot chemical scrubber system was performed for the elimination of NH3 gas by various oxidants such as NaOCl, H2O2, and KMnO4 over a two months period. The removal performance and elimination capacity were applied as technical indexes for appraisal of pilot-scale function against off-gases. Also, the influence of empty bed residential time (EBRT) and pH of scrubbing solution on the chemical scrubber acting mechanism was investigated. The obtained results indicated that the removal efficiency and elimination capacity of NH3 by scrubber in the presence of H2O2 had more robustness against changes of mass loading rate and empty bed residential time (EBRT) than other oxidants, with a removal efficiency of 99.31 % to 88.12 % in EBRTs of 12.81 to 1.6 s, respectively. Furthermore, for the economic assessment of the oxidants, the oxidant-consumed (mg)/NH3-removed (mg) fraction was obtained for oxidants, which was 7.5–9.2, 1.35–2.5, and 11.5–12.4 for NaClO, H2O2, and KMnO4, respectively. On this basis, employing the hydrogen peroxide oxidant can be beneficial in terms of economic viewpoint. Ultimately, chemical scrubber along with H2O2 oxidant seems to be a more efficient applicable NH3 mitigating method in treating waste gas of animal house.
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