Method for indirect determination of dry deposition rate of PM2.5 on plant surfaces

Abstract

The invention provides a method for indirectly measuring the dry deposition velocity of PM2.5 on the surface of a plant. The method comprises the following steps: preparing simulated PM2.5 with the particle size of 2.5 [mu]m; determining the initial concentration and measurement time length of the PM2.5 in a smog chamber in a testing process, wherein a concentration time-varying rule of the PM2.5 is consistent with a stable exponential decaying rule; measuring concentration time-varying rules of the PM2.5 in the smog chamber under an empty condition and a condition of existence of a leaf sample respectively, and performing data fitting to calculate decaying velocity constants j and k of two curves respectively; calculating the dry deposition velocity Vd of the PM2.5 on the leaf sample to be measured according to formula (I) (specified in the original document) on the basis of the above data. According to the method, the formula obtained by observation data fitting is adopted for calculation, so that system errors can be greatly reduced, the measurement accuracy can be improved, and moreover, the method is low in experimental cost and experimental time consumption and more convenient and easier to operate.

Description

technical field [0001] The invention relates to an indirect measurement of plant surface PM 2.5 The dry sedimentation rate method belongs to the field of plant surface physical properties. Background technique [0002] In today's increasingly serious air pollution, more and more attention is focused on the issue of air pollution. Fine particulate pollutants in the atmosphere with a diameter less than or equal to 2.5 microns, referred to as PM 2.5 , because of its long transmission distance and great impact on human health, it has become the primary target of air pollution prevention and control. Determination of PM 2.5 The dry deposition rate on plant leaves provides a scientific basis for haze control and pollution prevention and control, which is imminent. [0003] Studies have shown that dry deposition is the main mechanism for vegetation to purify atmospheric particulate matter. The dust retention capacity of plants can be measured by PM on plant leaves per unit are...

AI Technical Summary

Problems solved by technology

However, the elution method is only suitable for insoluble coarse particles. At the same time, because the weighing amount is very small, it is easy to generate cumulative errors in weighing, and it is not suitable for fine PM. 2.5 The measurement of the dry deposition rate of particulate matter; while the wind tunnel experiment method uses NaCl or KNO 3 It is used as a tracer to simulate particulate matter in the atmosphere, and its particle size is about 0.8 μm, which cannot represent PM in the atmosphere 2.5 The real particle size, and the cost of the experiment is very high, the experimental conditions are more demanding, and the operation is more difficult

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