INFLUENCE OF AERATION RATE AND LIQUID TEMPERATURE ON AMMONIA EMISSION RATE AND MANURE DEGRADATION IN BATCH AEROBIC TREATMENT

Abstract

The influence of aeration rates (26, 63, and 100 .g O2 g VS-1 min-1) at different temperatures (5°C, 15°C, and 25°C) on ammonia emission and breakdown of organic materials was studied using 15.3 L batch reactors for 21 days. The removal of total Kjeldahl nitrogen (TKN) ranged from 9.7% to 37.7% during the experiment, with higher values corresponding to higher manure temperatures and aeration rates. Ammonia loss ranged from 0.7% to 25.8% of initial TKN and increased with increase in manure temperature and aeration rate. In a similar pattern, the ratio of volatilized ammonia gas to removed TKN varied from 6.5 to 68.5. In addition, high BOD5 removal was also observed when both the temperature and the aeration rate were high, with the exception for airflow rates between 26 and 63 .g O2 g VS-1 min-1 for the manure at temperatures between 5°C and 15°C. The combinations of high aeration rate (100 .g O2 g VS-1 min-1) with low temperature (5°C) or low aeration rate (26 .g O2 g VS-1 min-1) with high temperature (15°C to 25°C) were found to be desirable to reduce ammonia emission while still achieving satisfactory BOD5 removal at the same time.