Research of manure gas emission

Abstract

Carbon dioxide and ammonia emission from manure of different animals was determined, after the experimental research on laboratory test bench. The lowest rate of ammonia emission was recorded from manure with lesser proportion of free urine. The highest amount of ammonia emits from liquid manure - 198,4 ±5,8 mg/(m² h); emission from semi-liquid manure is equal to 125,1 ±3,5 mg/(m2h)and from thick manure - 92,0 ± 2,9 mg/(m² h). Linear dependence of gas emission on temperature conditions was determined. Temperature increment of 1 °C causes increase of carbon dioxide emission by 17,6 mg/(m² h) on average, whilst for ammonia from liquid manure - by 4,5 mg/(m² h), at temperature range from 14,5 to 48,5 °C. The regression equation was proposed for predicting correlation of ammonia and carbon dioxide gaseous emissions from different cattle manure. Ammonia emission is more intensive at a higher rate of CO2 emission and correlation of these factors is linear. When carbon dioxide emission increases by 12,2 times, ammonia emission from liquid manure increases by multiplication factor 6,4 and from thick manure - by 4,6. We proposed the following measures for reduction of atmosphere pollution with ammonia: lower temperature in a barn, moving out cattle manure and especially urine from a bam as soon as possible and intensive littering. However, mixing manure with litter is not advisable. The most important thing in manure handling is aiming for reduction of fresh manure contacts with air and unbreaked crust on a surface. It was determined that calculation of air circulation on terms of water vapour content was sufficient for designing of cattle-housing ventilation systems. If low level of air humidity in a barn will be ensured, low concentrations of carbon dioxide and ammonia will be guaranteed as well.