Contaminated Soil Morphological Characteristics Of Mercury And Its Release Of Preliminary Research

This article focuses on the natural contaminated soil samples from a deposed smelt factory's region in Shenyang and the simulative contaminated soil which are all meadow soil as the tested soils, the soils' mercury species are analyzed by sequential extraction species method can be divided the following kinds: water soluble species, exchangeable species, species combined with carbonate and Fe and Mn oxides, species combined with humic acid, species combined with easily oxidized and degraded organic matter, species combined with hardly oxidized and degraded organic matter and residual species existing in mineral lattice et al. seven groups. And investigated their underlying toxicity used the means of the first balance. The results show the following main conclusions:1.The mercury species distribution in the tested soil exist greatly differences. In these soil, mercury existed in water soluble species are all very low, the highest is in simulative contaminated soil which is 0.50 percent of total, but distinctly higher than the natural contaminated soil; mercury existed in exchangeable species is the highest in simulative contaminated soil and lower pH of made acid plant soil, which are 25.63 and 19.99 percent of total; mercury existed in species combined with carbonate and Fe and Mn oxides is the highest in made acid plant soil, which is 20.33% of total; mercury existed in species combined with humic acid is higher in contaminated soil and lower pH of made acid plant soil, which are all higher than 10%; mercury existed in species combined with easily oxidized and degraded organic matter is the highest in drained waste water region soil of 43.06%, the second is contaminated soil which percent is 35.47%; mercury existed in species combined with hardly oxidized and degraded organic matter is the highest in testing farmland soil which is antitheses, is 14.81%; mercury existed in residual species existing in mineral lattice is the highest in raw material storeroom section soil and produced workshop soil, which are 87.04 and 87.66 percent of total, but the lowest is in simulative contaminated soil which is only 18.28%.2.In 10-2000 mmol·L^-1 concentration range, the mercury releasing amount enhanced with the increment of SO₄^2-,Cl^-,Na⁺ and Ca²⁺, but CO₃^2-and OH^-can't put up this uniform disciplinarian. The mercury releasing amount can't take on positive correlativity with the total mercury in tested soil. In the same abio-ion under the uniform concentration, the mercury releasing amount in the simulative contaminated soil are distinct fatter than the natural contaminated soil.3.From the characteristic curves of Hg released by different ions for the contaminated soil, the mercury releasing ability (namely: underlying toxicity) in the tasted soil approximately behaves: Cl^->OH^->CO₃^2->SO₄^2-;Ca²⁺>Na⁺.4.Acidity is one of the importance factors which affects the underlying toxicity of mercury in contaminated soil. The mercury releasing rate increases with the increment of hydrochloric acid concentration.5.In all released experiments, mercury existed in residual species existing in mineral lattice is primary in raw material storeroom section soil and produced workshop soil which put up accordant released character.6.In the tasted all abio-ions, with the exception of OH^- and CO₃^2-, the connection with concentration (mol·L^-1) and the mercury releasing amount (mg·kg^-1) in contaminated soil can primly be described by multinomial equation: y=ax³+bx²+cx+d. All correlative relations reach prominent level (p<0.05).