Speciation of Chlorine and Bromine in Brown Forest Soil and its Vertical Distribution

Abstract

We investigated the speciation and the vertical distributions of chlorine(Cl) and bromine(Br) in forest soil (especially from humic to mineral layer) by using X-ray absorption near edge structure and combustion-ion chromatography. The result indicates that chlorination of soil organic matter ends before humic substances are transformed to mineral soil and, instead, aromatic Cl changes into aliphatic or inorganic Cl. On the other hand, Br are abundant as an aliphatic form at the O-layer and may changes into aromatic Br along with the depth to the A-layer. The difference of vertical distributions of the chemical forms of Cl and Br indicates that the mechanism or dominant factors are different between Cl and Br.