奶牛场恶臭污染物扩散规律研究

Diffusion Laws of Odorous Pollutants from Dairy Farms

以山东省某县中等规模的3个奶牛养殖场为试验场地,以臭气浓度为监测指标,在下风向距恶臭排放源不同距离处设置采样点,对规模化奶牛养殖场恶臭污染物的下风向扩散规律及影响扩散规律的部分气象因素进行了研究,并通过数据回归得出了恶臭污染物水平扩散模型。结果表明,奶牛场恶臭污染物的排放浓度随距离的增加迅速减小,通过线性回归得出下风向同一高度处的臭气浓度与监测点距排放源的距离呈指数函数关系;对于气象条件,在27～37℃,风速小于5.4 m.s-1的范围内,风速、空气温度和空气相对湿度对恶臭污染物扩散规律的影响均显著,其中温度和风速对恶臭污染物扩散规律的影响较空气相对湿度大。

Odorous pollutants exhausted from livestock and poultry farms have caused strong dissatisfaction from the surrounding residents.These odorous pollutants not only seriously harm human health,but also seriously affect the surrounding air quality.In this study,odor con-centration was selected as a monitored index of odorous pollutants,and three moderate scale dairy farms in Shandong Province were selected as experimental sites.The horizontal dispersion law of odorous pollutants was studied along different distance between monitoring points and the odor source from 0 meters to 300 meters.The meteorological factors（i.e.wind speed,temperature and atmospheric stability）were also tak-en into consideration.We gained the horizontal dispersion model of odorous pollutants by regressing measurement date,and then according to the related standard we calculated reasonable separation distance to avoid odor nuisance.The results showed odor concentration decreased exponentially as a function of distance between monitoring points and the odor source.For meteorological factors,with outdoor temperature of about 32 ℃ and air relative humidity of about 30%,wind speed had significant influence on odor concentrations（P0.05）.When wind speed was below 2 m.s-1,and air relative humidity was about 30%,outdoor temperature（27～37 ℃）affected odor concentrations significantly at P 0.05,and odor diffusion ability was trongest at 32 ℃;When outdoor temperature was about 32 ℃,wind speed was below 2 m.s-1,odor con-centration decreased significantly with the increase of air relative humidity.Arranging the meteorological factors of odor pollutants diffusion,temperature and wind speed were more important than air relative humidity.