Department of Biosystems Engineering, Aarhus University, Blichers Alle 20, DK-8830 Tjele, Denmark.
Environ Sci Technol. 2010 Aug 1;44(15):5894-900. doi: 10.1021/es100483s.
Emission of odorous compounds from intensive livestock production is a cause of nuisance in populated rural areas. Knowledge on the chemical composition of odor and temporal variations in emissions are needed in order to identify factors of importance for emission rates and select proper abatement technologies. In this work, a method based on proton-transfer-reaction mass spectrometry (PTR-MS) has been developed and tested for continuous measurements of odorant emissions from intensive pig production facilities. The method is assessed to cover all presently known important odorants from this type of animal production with adequate sensitivity and a time resolution of less than one minute. The sensitivity toward hydrogen sulfide is demonstrated to exhibit a pronounced humidity dependency, which can be included in the calibration procedure in order to achieve quantitative results for this compound. Application of the method at an experimental pig facility demonstrated strong temporal variations in emissions, including diurnal variation. Based on these first results, air exchange and animal activity are suggested to be of importance for emission rates of odorants. Highest emissions are seen for hydrogen sulfide and acetic acid, whereas key odorants are evaluated from tabulated odor threshold values to be hydrogen sulfide, methanethiol, 4-methylphenol, and butanoic acid.
集约化畜牧业排放的恶臭化合物是农村人口密集地区产生异味的一个原因。为了确定对排放率有重要影响的因素并选择合适的减排技术，需要了解气味的化学组成和排放的时间变化。在这项工作中，开发并测试了一种基于质子转移反应质谱（PTR-MS）的方法，用于连续测量集约化养猪场的恶臭排放物。该方法被评估为能够以足够的灵敏度和小于一分钟的时间分辨率覆盖这种动物生产中所有已知的重要气味物质。对硫化氢的灵敏度表现出明显的湿度依赖性，这可以包括在校准程序中，以实现该化合物的定量结果。该方法在一个实验性养猪场的应用表明，排放具有很强的时间变化，包括昼夜变化。基于这些初步结果，建议空气交换和动物活动对恶臭物质的排放率很重要。硫化氢和乙酸的排放量最大，而根据气味阈值表评估的关键气味物质为硫化氢、甲硫醇、4-甲基苯酚和丁酸。
