| Heavy metal pollution in the chromium pollution are of universal concern, chromium in the soil by crop absorption into the low coefficient, it is the most difficult elements of the metal was absorbed one of the elements, when the content of chromium in improving soil, the chromium content in plants is also a corresponding increase,endangering human health through the food chain; In the presence of chromium in the soil with irrigation water to the soil depth migration, pollution of groundwater. Based on the previous study on chromium pollution control and on the basis of understanding, through the indoor soil column penetration test, control of water volume, tracer concentration, irrigation and soil depth of four time factor,discussion on the factors and chromium content in soil, the relationship between the main draw the following conclusions:(1) Chromium in the soil and moisture content have the same trend, chromium and that the relocation with the relocation of the water has a good synergy, with the current process of relocation was part of the Loess adsorption, controlled by the strength of its absorption of solute in the water - in the soil of the electrochemical balance; As a tracer migration medium, when the tracer concentration, the higher the moisture content in soil, with the water with chromium-containing plasma, the more layers of chromium in a high absorption.(2) Chromium in the soil water content with the increase of the increase; The same concentration of cases, with the greater volume of irrigation water with the more chromium ions, Therefore, the same soil thickness circumstances, the chromium content in soil also relatively large.(3) Chromium content in the soil with the soil and reduce the depth of the increase, the results showed that, in such non-saturated irrigation conditions, chromium in the soil down with water, soil absorption,as loess has a good absorption of,water can carry on with the full chromium ion adsorption, only when the upper soil absorption or too late to reach the upper soil absorption saturated circumstances, chromium ions will continue with the downward movement of water, because of lower water content and reduce the relative large number of chromium ions were also top soil adsorption, resulting in lower soil chromium in a relatively small, the entire section on the content of chromium showed a downward trend.(4) Chromium content in the soil with tracer concentration of the increase, show that high concentrations of tracer for the soil to provide adequate absorption of non-saturated, as a result of increased soil tracer concentration of chromium content will also increase; When a higher concentration of chromium tracing the circumstances, Cr (VI) will soon reach the surface absorption capacity; Then bring to the downward movement of absorption, leading to lower pollution of the soil, thereby polluting groundwater.(5) Chromium in the soil water content with increased time,this is because the longer the soil irrigation and chromium ion chemical reaction between the more fully, chromium ions can be full of soil absorption, causing the content of chromium in the soil increased.(6) Water and chromium flux as the overall trend is the increasing depth of soil and gradually decreasing; The greater volume of irrigation water and chromium greater flux in the 10 cm to 30 cm of water between the flux and chromium large difference, flux to the deep gap between the smaller, with the increase in time of flux smaller chromium; Use of DPS data processing system, the establishment of a chromium content in soil and water volume, tracer concentration, soil depth, water between the time the comprehensive simulation equation, use integrated model to simulate the single factor on the soil of the content of chromium, simulated and measured the difference between a small, simulated changes in trends and measured changes in the trend line.
|
PDF Full Text Request