Research Of Arsenic Migration And Transformation In Soil-plant System

Mining,dressing and smelting,tailings pile and coal fly ash has become a major factor in mine soil arsenic contamination and pose a serious potential harm to the ecological environment around the mining area.Taking Fuxin new opencast mine area and the surrounding area Qiu as the main object,through the acquisition of four mining area soil and plant samples foxtail,Artemisia annua,Potentilla grass,lespedeza conducted pot experiments,arsenic in the soil-plant system migration patterns and the flooding,pH,coal dust,iron ions,the time factor affecting soil and transformation of trivalent arsenic and pentavalent arsenic between.Research indicates:With the addition of arsenic concentration,arsenic content of the plant is also gradually increased.Under the same contamination,the growth of plants in natural soil arsenic highest growth in the soil and plants the foot of the Peak soil arsenic followed by plants grown in soil mountainside lowest arsenic,grown in soil and soil the foot of the hill Plants arsenic is between natural soils and hillside soils.Four plant arsenic enrichment capacity: Lespedeza> annua>foxtail> Potentilla grass.Foxtail,Artemisia annua,the largest part of Potentilla grass three plants in various parts of the arsenic concentration is the root of the blade portion,followed by green foxtail,stems least;annua L.,Potentilla grass stems are followed by a minimum blade portion;HU Each branch is part of the largest proportion of arsenic stems,roots,followed by the blade part at least.Experiment with increasing soil plus arsenic levels of arsenic in all parts of the plant was positively correlated with growth.Compare hilltop soil,mountainside soil,the foot of soil,natural soil,four plant parts are each foot of soil and hilltop soil is too large,natural soil and the soil is too small mountainside.Different Forms of arsenic in soil distribution situation is : residual> sulfide fraction>organic fraction> water soluble,exchangeable.Before and after the pot experiment,soluble arsenic in soil,exchangeable arsenic,organic bound arsenic significantly reduced,sulfide phase,residual arsenic content changed little.Flooding,under pH,coal,iron,Fifth time factors,flooding factor experimental trivalent arsenic in soil affect the most obvious effect,followed by the time factor,once again for the iron ion factors,pH and coal dust impact Factors small.Effect of the Effect of various factors pentavalent arsenic is flooded> Time> iron> pH and Dust factors.When the experimental conditions are flooded 1.2V,pH 6,coal 12%,iron 2.5mg / kg,when the time is four weeks,test the soil trivalent arsenic concentration maximum.When the experimental conditions for flooding 0.4V,pH of 7,8% pulverized coal,iron3.5 mg / kg,the time one week,when the soil pentavalent arsenic content maximum,then a minimum of trivalent arsenic content.