Variation characteristics and influencing factors of mercury exchange flux on asphalt ground

Abstract

Surface mercury release is an important source of atmospheric mercury, and asphalt pavement occupies a high proportion. However, the current characteristics of mercury exchange flux on asphalt ground are unclear, which is not conducive to assessing the contribution of surface mercury release to atmospheric mercury. Therefore, the dynamic flux chamber method was used to measure the variation characteristics of mercury exchange flux on the underlying surface of typical artificial asphalt in Qingdao in four seasons. The average mercury exchange flux of the asphalt ground surface was 0.12±0.38 ng/(m2•h). The mercury flux was mainly released in spring, summer, and autumn, the highest in summer was twice that in spring, and the deposition occurred mainly in winter. Under the influence of meteorological factors and atmospheric mercury concentration, the mercury exchange flux reached its peak value when the light intensity and surface temperature were the highest in spring and autumn, while the peak value in summer occurred after the maximum light intensity and reached its maximum peak value at the highest surface temperature.