Establishment And Application Of Real-time Monitoring System For The Swine Harmful Gases Emissions

With the development of modern intensive livestock breeding, environmental pollution caused inthe pig production has drawn increasing attention. The gases emissions are not only great harm to bothswine and humans health, but also endanger the air, water, soil and so on, and even have a significantimpact on global warming due to carbon dioxide, methane, nitrous oxide and other greenhouse gasesemissions. Therefore, energy saving has been a hot topic of research at home and abroad.Great majority of reported harmful gas emissions of pig is estimated by various methods. In thisstudy, we started with the methods and technology, established a system of direct measurement of pigharmful gas emissions, and then explored the factors that influenced harmful gas emissions of pig.Experiment1：Comparison of detection techniques of gas concentration that frequently-used in thelaboratoryThis experiment compared detection techniques of gas concentration that frequently-used in thelaboratory to select appropriate testing instruments for the system. In this part, we did a comparison testof the proposed selection of INNOVA1412of infrared photoacoustic spectra of gas monitor withNessler’s reagent spectrophotometry and gas chromatography method to compare the precision andaccuracy of them, the result is illustrated blow:(1)The precision of Nessler’s reagent spectrophotometrymethod for detection of ammonia is slightly higher than INNOVA1412, accuracy is basicallyconsistent;(2) The precision of INNOVA1412for detection of methane is slightly higher than theAgilent7890A GC, but the accuracy is slightly lower.5.0ppm methane standard gas detection, therecoveries of INNOVA1412and Agilent7890A GC were98.6%and99.2%.Conclusion: The precisionand accuracy of INNOVA1412reach the level of the commonly used laboratory gas detection method.Experiment2: The establishment of real-time monitoring system for the swine harmful airemissionsThe system consists of four parts:①ventilation rate monitoring system;②temperature andhumidity control system;③g as sampling system;④gas analysis system. Among them, the ventilationrate monitoring system and the temperature and humidity control system were already exist, the gassampling system and the gas analysis system were assemble later. After the system assembled, we did aaccuracy test that applied the ethanol combustion method, the result is illustrated blow: Oxygenrecovery of the test chamber1-4was between99.91-101.42%, carbon dioxide recovery was between99.50-101.28%.Conclusion: Test result of the four test chambers of the system is accurate and reliable.Experiment3: The application of real-time monitoring system for the swine harmful air emissionsApplication1: The study of the method that eliminate harmful gases emissions of animal fecesStudied the method to eliminate harmful gases emissions of animal feces by added sulfuric acidand grease covered. The result is illustrated blow:(1)This method couldn’t completely inhibit theemission of ammonia and methane as urine fermented, but reduced their emissions;(2) This methodcouldn’t completely inhibit the emission of ammonia and methane as manure fermented, but reducedtheir emissions, especially methane. Conclusion: This method can’t exclude the impact of manure andurine, so if we want to do some studies about gases emissions of intestinal glycolysis, we need other methods.Application2: The impact of different crude protein levels, temperatures and ventilation rate on thepig gas emissionsThis experiment explored the impact of the crude protein level, temperature and ventilation rate onthe pig gas emissions. Test taken L4(23) orthogonal design.12Large White barrows with similarcondition (55-60kg) were randomly allocated into four groups. Each group had3pigs. Thisexperiment have two phases, each lasting seven days, two days before each phase was pre-feedingperiod, five days after was trial period. Experimental period was14d. The result is illustrated blow:(1)As the trial progresses, ammonia, methane emissions continued to rise until balance. The carbon dioxideemissions was almost no change;(2) All of carbon dioxide, ammonia and methane emissions hadobvious diurnal variations;(3) The impact of temperature on carbon dioxide emissions was highlysignificant (P <0.01). The impact of crude protein level and ventilation rate on carbon dioxide emissionswas not significant (P>0.05);(4) All of crude protein level, temperature and ventilation rate impactedammonia emissions, the crude protein level and temperature had significant effects on ammoniaemissions (P <0.01), ventilation rate was not significant (P>0.05);(5) The impact of temperature onmethane emissions was significant (P <0.05), crude protein level and ventilation rate was not significant(P>0.05). Conclusion: The crude protein level only had a greater impact on ammonia emissions, buthad not significant effect on carbon dioxide and methane emissions; both produced a very significantimpact of temperature on carbon dioxide, ammonia and methane emissions; the impact of ventilationrate on the three gas emissions are not significant.