田间原位开顶式臭氧熏蒸系统研究

臭氧污染造成的粮食作物减产及经济损失受到普遍关注,研究植被对臭氧的响应是评估臭氧污染造成影响的重要依据.针对国内外已有开顶式熏蒸系统的缺点,改进布气管的布气孔大小和形状,以保证气室内布气的均匀性;改进风机的供气方式,采用一供三的方式以提高各平行样间的平行性;通过计算机负反馈控制和采用引流装置,以提高臭氧浓度控制和测定的准确性.在国内率先尝试在跟随环境臭氧浓度的基础上增加一定浓度的臭氧作为熏蒸气体.田间实测表明:该装置气室内臭氧浓度与设定浓度一致且分布均匀,平行样的平行性好,气室内外温度、相对湿度及光照强度衰减均达到了国内外同类装置水平,可广泛用于田间原位大气污染物对植被影响的研究.

Study on an In-Situ Open-Top Fumigation Chamber System for Ozone Exposure in Field

Ozone pollution,which results in lower production and economic loss of food crops,has caused widespread concern in recent years.The study of the dose-response relationship between ozone and vegetation is an important basis for assessing the impact of ozone pollution on vegetation.In view of the shortcomings of existing instruments,this study developed an open-top chamber system.Features include: redesigning the size and shape of the holes on the gas distribution tube to ensure uniform gas distribution in the chamber;using one blower to supply gases for three chambers to ensure the same conditions in parallel chambers;and,the use of computer feedback control and a drainage device to ensure the accuracy of the ozone measurement and control.The first attempt in this study was to increase the ambient concentration of ozone as the fumigation gas to certain levels.The results from field studies showed that the ozone concentrations inside the chamber were consistent with the setting values,gases were uniformly distributed,and good consistency among the results from the three parallel chambers was found.The differences between inside and outside the chamber for temperature,humidity and light intensity were comparable with similar devices reported in domestic and foreign studies.The system that was developed can be widely used in field study of the effect of atmospheric pollutant gases on vegetation and provide a technical reference for associated studies.