Study On Emission Characteristics And Emission Reduction Measures Of NH₃,CO₂ And CH₄ During Simulated Cow Manure Storage

Ammonia emission is one of the main sources of anthropogenic ammonia emissions during manure storage,ammonia is one of an important air and water pollutants.There are less study about manure ammonia emissions during storage on the Qinghai-Tibet Plateau,Therefore,in this paper we had studied characteristics of ammonia emission simulated by measuring the emission flux of cow dung in the storage process and characteristics of ammonia volatilization of different ammonia under the law to explore the dung of ammonia volatilization on the Qinghai-Tibet Plateau,providing manure nitrogen preserving and the necessary control measures and some scientific parameters and basis.The research adopts ventilation method,set up 4 inhibitors of ammonia volatilization control treatment,monitored for 14 days,estimated of physicochemical properties of manure,discusses the ammonia emission characteristics of different storage time.The relationship between the physical and chemical properties of the manure and ammonia emission was studied in detail,and the treatment mode of ammonia volatilization was proposed.The main conclusions are as follows:?1?During the simulated storage of cow dung,the water content decreased from625% to 350%?14th day?,the temperature of cow dung showed the trend of increasing first and then descending,and the highest temperature appeared on the second day?16.5 ° C?The lowest temperature appears on day thirteenth day?13.6 ° C?.During the storage period,the pH value of the dung manure was alkaline,the average pH was 10.06,the maximum value of 2.2 g.kg-1was reached on the second day,and the lowest value on 13 th day?2.2 g.kg-1?.The average content of ammonium nitrate was 4.7 g.kg-1 during the simulated storage of cow dung,and the nitrate nitrogen in the dairy cow showed a decreasing trend in the storage period.The average content of nitrate nitrogen was 0.062 g.kg-1 during the simulated storage of cow dung.?2?The overall change rule of NH₃ emission rate of cow dung during simulated storage is gradually decreased with time.NH₃ emissions on the first day of the lowest,only 37.6 mg,on 3th day to reach the maximum 170.0 mg.Storage period cow manure NH₃ cumulative emissions of 1773.7 mg.The CO₂ emission rate of cow dungduring storage showed a tendency to increase first and then decrease.The CO₂ emission rate was the lowest on first day is 7.2 ?mol.m-2.s-1,the highest CO₂ emission rate was 17?mol.m-2.s-1 on 7th day,and the CO₂ emission rate was 10.9 ?mol.m-2.s-1on 14 th day.The average emission rate of CO₂ in the dairy cow was 12.7 ?mol.m-2.s-1and the cumulative CO₂ emission was 674.36 g.m-2.The CH₄ gas emission rate gradually increased during the storage of cow dung,the CH₄ emission rate was only0.01?mol.m-2.s-1,on the first day and the discharge rate on the 14 th day was 0.15?mol.m-2.s-1.The average discharge rate of CH₄ in the whole storage period was0.06?mol.m-2.s-1,and the cumulative discharge of CH₄ was 2.98 g.m-2.?3?The cumulative ammonia volatilization?NH₃-N?during the simulated storage of cow dung accounted for 29.73% of the total nitrogen content of cow dung.Cumulative carbon volatiles?CO₂-C and CH₄-C?accounted for 6.60% of the total carbon content of cow dung.?4?The ammonia emission rate after the addition of different types of inhibitors increased the following dynamic characteristics: NH₃ emissions showed two emission peaks on 3th day and 8th day,respectively,and gradually decreased from 8th day to day fourteenth NH₃ emissions to the lowest value.The accumulation of NH₃ in the 14 days was 1773.7 mg,the cumulative NH₃ emission of N was 1258.4 mg,the cumulative NH₃ accumulation was 1713.5 mg,the cumulative NH₃ accumulation of N+D was 1252.9 mg,and the cumulative amount of M was 1832.7 mg.In general,The best effect of suppressing NH₃ volatilization was N treatment and N+D treatment,with 29.05% and 29.06% NH₃ emissions,respectively.Compared with the control.?5?After the addition of different types of inhibitors,the emission rate of CO₂ increased at first and then decreased gradually,but the CH₄ emission rate showed a stable and late exponential growth trend.After the addition of different types of inhibitors,the total CO₂ emissions of CK was 674.36 g.m-2for 14 days,664.63 g.m-2for M treatment and 616.00 g.m-2 for D treatment.N+D treatment emissions of 524.18 g.m-2,N treatment processing cumulative emissions of 559.77 g.m-2.CK,M,D,N+D,N for 14 days CH₄ cumulative emissions were 2.98 g.m-2,2.63 g.m-2,0.64 g.m-2,2.08 g.m-2 and 1.03 g.m-2,respectively.The addition of urease inhibitor NBPT to cow dung can also reduce CO₂ and CH₄ emissions from cow dung.