Evaluation Of A Sequential Precipitation Sampler To Obtain High Resolution Rain Water Chemistry

Human activities have emitted a lot of pollutants into air.When it rains,the raindrop washes out the pollutants in air and carries them to the ground,causing many environmental problems such as acid rain and excessive heavy metals in soil.As a globalizing city,Shenzhen has a lot of traffics and factories which discharge a lot of pollutant to air.As a result,the rain water in Shenzhen has a potential menace to the citizens and the environment.Studying the rain water chemistry is meaningful for the construction of urban ecology in Shenzhen.We used a self-developed sequential precipitation sampler to collect high resolution rain water samples to study:1)Composition of rain water chemistry in Shenzhen;2)variations and factors affecting the variations of rain water chemistry during rain events;3)sources of rain water chemistry.The results show that:1)The concentrations of rain water chemistry do not decrease during all the rain events,but also would increase or fluctuate during rain events.2)Although SO₄^2-and Cl^-come from marine sources in the most rain events,SO₄^2-and Cl^-are also from anthropogenic sources in some events.3)The fluxes of Cl^-?NO₃^-?NH₄⁺?Cr?Co?Ni?Cu?Zn?As?Se?Ag?Cd and Pb in rain water to surface water in Shenzhen are 70.98 t/year,64.51 t/year,43.58 t/year,128.87 t/year,0.99t/year,64.83t/year,13.58 t/year,145.45 t/year,0.99t/year,7.09t/year,0.60 t/year,0.13t/year and16.44t/year respectively.