The Characteristics Study On Vertical Distribution And Adsorption-desorption Of Water-soluble Salts And Heavy Metals In Soil

With the development and utilization of mineral resources and industrial development, human activities would drag a lot of toxic and hazardous substances into the soil, caused permanent damage for self-purification capacity of the soil, destruction soil’s internal structure, composition, thus affecting the normal growth and development of crops. In order to study the vertical distribution of heavy metals in contaminated soils around mine and a wate rsoluble salt ions and water-soluble salts in the ion effects of heavy metals in soil adsorption-desorption characteristics furtherly, this paper selected typical northern China Rare Metal Mining- Tongguan County, Shaanxi mining as a study area, select the area are three main types of soil(piedmont alluvial oblique plateau landform, river alluvial Terraces, loess tableland gully region).Which is more scientific guidance soil heavy metal pollution mitigation, mining irrigation and fertilization, improve farmland environment provides a theoretical basis. The main conclusions of this article are as follows:(1) Different Soil Moisture topography, p H, conductivity, mineral content, loss on ignition and other physical and chemical properties analysis, the results can be obtained: Three 20-40 cm layer of soil water content relative to the lower section at each other the overall trend was increasing; p H value increases with increasing depth; overall conductivity showed an increasing trend; soil minerals are most Si O2 content, and more uniform distribution of various types of minerals in the soil, with soil depth little change.(2) Soil soluble salt ions change of its electrical conductivity changes consistent with the trend in the vertical direction overall showed an increasing trend, in which the soil profile anion: HCO3-> SO42-> Cl-, cation: Ca2 +> Mg2 +> K + and Na +; Three Species of soil Heavy Metal content landscape area with increasing depth, the overall decreasing trend, mainly concentrated in the heavy metal pollution 20-40 cm depth; Geoaccumulation index method available pollution degree 1-4, pollution order: Cd> Zn> Pb> Cr> Cu.(3) Results of soil analysis correlation between water-soluble salt ions: three kinds of soil in the landscape area mainly HCO3-, SO42-, Cl- affect the water-soluble salts in the soil profile. Analysis of heavy metals in the correlation between the results: The main sources of pollution of heavy metals in the same. The relevance of heavy metal elements and water-soluble salts can be obtained between ions: Cl-, HCO3-, SO42- and heavy metals Pb, Zn significantly correlated. Design interactive adsorption-desorption experiments can be obtained: Cl- can reduce soil adsorption to Zn, SO42- concentration change less on Cd adsorption of heavy metals adsorbed more difficult to be desorbed.(4) Evidenced by laboratory experiments study low concentrations of Na Cl pot can promote seed germination and growth; Zn and Na Cl can enhance the effect of compound on wheat growth inhibition.(5) Improved irrigation methods and planting plants can reduce the soluble salt content in soil, thus reducing soil heavy metal pollution.