Study On Soil-Environmental Capacity Of Dinitrotoluene And Diaminotoluene

It is also the central link of the contract of inorganic and organic sphere, soil is the sources and final place of pollutants. Because of chemical fertilizer and pesticide use, wastewater irrigation, atmospheric subsidence and other reasons, the soil has been polluted to some extent. Soil contamination in China has showed a multi-source, complex, broad, lasting, harmful characteristics of the modern environmental pollution, is turned constant pollutants from to trace persistent toxic pollutants. Soil contamination may lead to decreased crop yield and crop production quality, and greatly damage to the ecological environment and human health. Studying on of environmental capacity will be helpful to contribute to a correct understanding of the bearing capacity of the soil environment, and control the total amount of pollutants into the soil.In this paper, distribution characteristics of dinitrotoluene and diaminotoluene were studied, and also the accumulation of pollutants by dominant plants which grown on this research area. Limited values of dinitrotoluene and diaminotoluene for different land use type were. studied through the health risk assessment. And the soil-environment capacity of pollutants was studied through the limited values. It can provide technical support and scientific basis for the control total amount of pollutants into the soil, keep the balance of ecological environment, provides protection of human health. The main conclusions of this article are as follows:1. The concentration of Dinitrotoluene and diaminotoluene are very low in the region, dinitrotoluene concentration is higher than diaminotoluene concentration; there are significant differences between separated areas:Greening areas which irrigated by wastewater have higher concentration, and the areas away from the factory irrigated by wastewater have a much lower pollutants concentration, that indicates wastewater will result in the accumulation of pollutants in soil.2. Pollutants concentration in surface and deep soil showed little difference of the wastewater irrigation area. The concentration of pollutants is higher in surface soil, it is mainly because of adsorbing and intercepting of pollutants on the surface soil during the process of wastewater irrigation.3. The accumulation ability (bioconcentration factor, BCF) of pollutants in different plants showed conspicuous differences, the gramineae BCF is much higher than woody plants.4. The limited values of the pollutant are different for land which is endowed with different types. The limited value of dinitrotoluene is1.0mg/kg for agricultural and residential land,4.0mg/kg for industrial and commercial land, respectively; the limited value of diaminotoluene is0.17mg/kg for agricultural and residential land,0.63mg/kg for industrial and commercial land, respectively.5. The average dynamic capacity of dinitrotoluene is bigger than the average static capacity in soil, showed that the soils not only has certain capacity in the scope of environmental thresholds, but also has certain capacity are by plants absorption, leaching, runoff migration of the soils. Soils static capacity and dynamic capacity are related with soil environmental limited values standard and background value of pollutants. Dynamic capacity is also related with control period, the time is longer, the average dynamic capacity is smaller. But the total capacity of dynamic is bigger.