Study On Ammonia Emission Characteristics Of Large-scale Pig And Beef Farms In Jiangxi Province

The ammonia emitted by livestock and poultry houses is one of the important emission sources that cause air pollution.China livestock and poultry breeding industry has a strong potential for ammonia nitrogen emissions.In this study,the large-scale pig and beef cattle farms in Jiangxi Province were selected as the monitoring objects,and the main ammonia emission nodes inside and outside the livestock and poultry houses were explored to explore the daily variation characteristics of ammonia emission,calculate the ammonia emission coefficient of pig and beef cattle,and explore the influence of temperature and humidity on ammonia emission rate.To provide data support for ammonia pollution of livestock and poultry breeding in Jiangxi Province,and provide treatment methods for ammonia emission reduction of livestock and poultry.The main results are as follows:(1)The results show that there is a diurnal variation process of ammonia nitrogen emission inside and outside the piggery,which is high in the daytime and low at night.The average daily maximum hourly ammonia emission rates of fattening pigs I,II and III were 124.27,203.71 and 294.85 mg/(h·head),respectively.The average daily minimum hourly ammonia emission rates were 79.73,170.47 and 181.14 mg/(h·head),respectively.Emission coefficients of fattening pigs I,II,III were 3.46,4.99 and 5.68g/(head·d),respectively.Total emissions per day were 1243.59,1648.07 and 1892.01g/d.The average ammonia emission coefficient in March,April and May was4.71g/(head·d),and the average daily total emission was 1594.56 g/(head·d).There is a significant difference in the linear regression relationship between the temperature and humidity of finishing pigs and the ammonia release rate,the correlation coefficients were 0.911,0.609,0.956,and the comprehensive analysis coefficient was0.377.(2)The results of ammonia emission in beef cattle barn showed that the diurnal variation of ammonia concentration inside and outside the barn showed that the ammonia concentration increased in the daytime,and decreased from afternoon to night.The maximum hourly ammonia emission rates during the monitoring period were 2799.52 mg/m~3,3215.78 mg/m~3,3567.67 mg/m~3,3379.88 mg/m~3and 3325.98mg/m~3,respectively.The minimum hourly ammonia emission rates were 2015.34mg/m~3,2432.43 mg/m~3,1554.86 mg/m~3,1895.56 mg/m~3,1723.11 mg/m~3,respectively.ammonia emission coefficients were 50.23,59.82,39.96,36.47 and 55.82 g/(head·d),respectively;The average value was 48.46 g/(head·d).The total ammonia emissions were 9544.61,11366.61,3103.44,2734.62 and 3516.71 g/d,respectively.The linear regression correlation between temperature and humidity and ammonia emission rate of beef cattle barn in different seasons was quite different,and the correlation coefficients were 0.794,0.957,0.922,0.831 and 0.861,respectively.The comprehensive analysis coefficient was 0.910.(3)Study on the geographical distribution of ammonia emissions from pig and beef cattle farming in Jiangxi Province:the annual ammonia emissions from pig farming were about 7.06 million t/a,7.00 million t/a,8.47 million t/a and 9.12 million t/a,respectively;the annual ammonia emissions from beef cattle farming were about10.62 million t,10.69 million t,9.08 million t and 1.01 million t,respectively.The total pollution of pig production in 11 prefecture-level cities in Jiangxi Province was967.69 million tons,945.94 million tons,1160.59 million tons and 1250.78 million tons,respectively.The total pollution of beef cattle was 30.11.09 million tons,30.3155 million tons,25.74 million tons and 28.3759 million tons,respectively.