Evaluation and Comparison of Models for Predicting SO<sub>2</sub> Dry Deposition to the Measurement Using A Water Surface Sampler

Yi, Seung-Muk; Cheong, Jang-Pyo

Environmental Engineering Research 1997;2(2): 127-140.

Evaluation and Comparison of Models for Predicting SO₂ Dry Deposition to the Measurement Using A Water Surface Sampler

¹Department of Environmental Science and Engineering, Ewha Womans University, Seoul, KOREA, 120-750
²Department of Environmental Engineering, Kyungsung University, Pusan, KOREA, 608-736

Corresponding Author: Seung-Muk Yi ,

Received: March 19, 1997; Accepted: April 20, 1997.

ABSTRACT

Sulfur can be deposited to water as both a gas (SO₂) and particulate (SO₄^2-) phases from the atmosphere. To determine the relative importance of these two types of deposition, a circular water surface sampler was used to measure the dry deposition flux of atmospheric SO₂ and sulfate containing particles in Chicago, IL A sharp edged greased surrogate surface was used concurrently to measure the dry deposition flux of atmospheric sulfate containing particles. The total sulfate fluxes to the water surface sampler were consistently higher than the fluxes to the greased surface due to gas phase (SO₂) dry deposition (SO₂ is quickly hydrolized and oxidized to SO₄^2- in water). For each sample the calculated SO₂ flux was calculated as the product of the individual SO₂ gas phase mass transfer coefficient calculated using two different models multiplied by the ambient SO₂ concentration. One model was empirical and accounts for both natural and forced evaporation and the other model was a resistance model developed by analogy to electrical or heat flow through a series of resistances. The SO₂ fluxes measured directly with the water surface sampler were compared to the modeled values and agreed well with those predicted with the two models.

Keywords: Dry deposition. Water surface sampler | Greased surface | Resistance model | SO₂