Research The Distribution And Desorption Characteristics Of Heavy Metal In Different Medium For Water System In Lugu Iron Mine

With the development of modern industrialization,the mining industry had entered into large-scale mining,the extensive mining at the pasthascaused large amount of waste water containing heavy metals being discharged into the environment,the accumulation of heavy metals in the soil and water continuously intensified.As a result,heavy metals have become one of the most important pollutants in natural water and sediment,which not only pollute the soil and water and reduce its value,but also cause seriously harm to human health.In a word,heavy metal pollution has a great influence on social construction,regional development and human survival.Iron Mine in Lu Guis a concentrated distribution area of mining activities,which stage development features are prominent.The way of mining acticities impacting environment mainly is water.Ascertaining geochemical characteristics and migration and transformation of elements in different media of water system is important for the treatment of mine environment and the planning of land use in the lower reaches of the mine.The paper based on the project of"Identification and Pollution Risk Assessment of Heavy Metals Pollution Sources in Groundwater in Southwest Mining Area",this paper finds out the distribution characteristics of overlying water and sediment elements on water system in mining area.The distribution characteristics and analytical kinetic processes of heavy metals in different water systems are discussed in combination with the distribution of effective state content and vertical distribution of element tested by DGT.The results show that:?1?The water in the study area is weakly acidic and have high oxygen content.Concentration of Cu,Zn,Co,As,Cd,is high in points SY03 and SY04 controlled by mine water system,which is related to the upstream mining activities.?2?The content of most elements in surface sediments exceeded the background value of surface soil in Xi Chang city,and the contents of elements changed obviously in the upper and lower reaches of Sun Shui River and the inlet of An Ning River.The precentage of exchangeable state content of Cr,Cu,As,Pb is the largest at the CJ04,indicating that the potential environmental risk of this point is high.The relative release capacity of elements in the study area is quite different.The values of K_d of Cr,Cu,Zn,Cd,Ni and Fe are both the largest at CJ04,which indicates that the potential environmental risk at this point is high.?3?The effective state contents of the element DGT varied significantly from-20mm to-25 mm and-70 mmat the DGT01.The DGT available states of the elements Cr,Pb,Co,Ni and Fe increased sharply between-75 mm and-80mm at DGT02,indicating a sharp change in the soil particle replenishment capacity at this location,which may be related to the changes of sediments and abnormal environmental events.At the DGT03,the effective state of the element DGT increases in varying degrees under the interface.The R values of the elements are large,indicating that the two elements have a good ability to replenish the elements from soil to solution at this point.The location of the highest value of element content measured by centrifugal method and DGT method is not consistent,which shows the difference between the two methods in evaluating biological availability.R is an essentially index reflected the ability of sediment maintain pore water concentration,The solid phase particles of the elements Cu,Co,Ni and Fe have strong ability to replenish the metal solutionat LDGT01.The solid particles of Co,Ni and Fe have better ability to replenish the metal solution at the LDGT02.The solid phase particles of Co and Fe have strong ability to replenish metal solution at LDGT03,while Pb has the worst recharge ability.?4?The span of the characteristic reaction time Tc and desorption rate constant K_-11 span are both large show by DIFS model,which causes the different recharge capacity of elements from solid particles to solution at different locations.The K_d value of some elements is larger,but the characteristic reaction time Tc is larger,the desorption rate constant K_-1 is smaller,and the ability of solid particles to recharge the solution is small.As a result,R value is small and the element has relatively small biological availability.The characteristic reaction time of some elements is smaller,the desorption rate constant K_-1 is smaller,and the ability of solid particles to recharge the solution is small.As a result,whichR value is high,and the element has relatively large biological availability.