肉鸡密闭养殖箱的氨气排放检测方法

准确获取肉鸡养殖过程中氨气(NH3)排放规律及排放系数是评估其排放量的基础,并可为NH3减排提供依据。为了研究肉鸡模拟养殖环境条件下肉鸡质量、排泄量、采食量和饮水量等参数对NH3排放情况的影响,该文设计了由肉鸡养殖箱、气体采样管路和红外光声谱气体监测仪构成的肉鸡养殖箱NH3浓度检测装置,对养殖箱的静态气密性、检测装置的性能和肉鸡短期养殖NH3排放情况进行了研究。研究结果表明:静态试验时,养殖箱内NH3质量浓度的平均变化率为-4.40%,气密性能良好;动态试验时,将质量浓度为37.95 mg/m3 NH3通入养殖箱,检测NH3质量浓度最大值36.75 mg/m3,最小值35.22 mg/m3,平均值为35.65 mg/m3,准确度达到93.94%,检测装置性能稳定,能够较精确检测到养殖箱内标准气体的质量浓度。肉鸡短期养殖试验结果表明:在非光照时期(22:00-次日06:00)养殖箱内NH3质量浓度大于光照时期(06:00-22:00)质量浓度;养殖前期肉鸡排泄量与NH3浓度变化趋势呈正相关,养殖后期排泄量与NH3浓度变化趋势呈负相关;箱内粪便累积到第4天,NH3质量浓度急剧上升。该检测装置为后期进一步研究肉鸡养殖生长过程中NH3排放特征提供了前期研究设施基础。

Detection method of ammonia emissions from broiler chamber

Abstract: Broiler breeding will produce many pollutant gases such as ammonia (NH3). Acquiring the information of the orderliness and rates of NH3 emissions accurately during the broiler breeding is the foundation to estimate NH3 emissions. It can provide the theoretical support for the study of the mitigation and control of NH3 emissions during the broiler breeding. The broiler houses mostly use natural ventilation in China, the air flow field is complex and changeable, and it is difficult to measure and calculate the NH3 emissions accurately. Compared with the site test, breeding chamber test is more convenient and easier to control the environment variation. The purpose of this work was to study the NH3 emissions in simulated environment. In this study, a detection device was designed, which was used for broiler weight, waste, feed intake, water consumption and NH3 emission detection, and composed of broiler breeding chamber, gas sampling devices and parallel-connected gas detection instruments. The investigation to the sealing property of the chamber and the accuracy of the detection system, and the determination of the NH3 in the broiler breeding chamber were conducted. All of NH3 data were recorded automatically. In static test, standard gas concentration of 7.59, 22.77 and 37.95 mg/m3 were injected in the chamber, respectively. The results indicated that the average change rate of NH3 concentration was -4.40% in the chamber after 24 h, which meant that the breeding chamber sealing was good. The dynamic test showed the detection device had a stable performance. The NH3 of mass concentration of 37.95 mg/m3 passed through the broiler breeding chamber detection system in 6 h, the maximum and minimum mass concentration of NH3 measured were 36.75 and 35.22 mg/m3, respectively. The average concentration was 35.65 mg/m3 and the accuracy reached 93.94%. It meant that we could determinate the concentration of the standard gases in the chamber by using the detection system. We also carried out the short-term test of broiler breeding using the detection device. Through the measurement of the gaseous contaminant in the broiler chamber, the result showed that the concentration of NH3 in the dark period (10 p.m. to next day 6 a.m.) was greater than that in the light period (6 a.m. to 10 p.m.) in the breeding stage. The correlation between the broiler excretion amount and the NH3 concentration was positive at the early stage of the test, but it became negative in the later stge. What was more, the concentration of NH3 increased sharply on the 4th day after the manure was accumulated. The NH3 concentration test of broiler in short-term breeding reveals that the detection system has a good sealing performance, stability and detection accuracy. The detection system provides a facility for studying the relationship between the process of broiler breeding and the characteristics of NH3 emissions. Further research is needed to coordinate the ventilation quantity with the breeding quantity and fecal cleaning management.