The Leaching Deposition Of Iron Manganese In Sa Nd And Soil Column And Its Impact To The Migratio N And Adsorption Of Lead And Cadmium

In this paper, different concentrations (0-0.08mol/L) of FeSO4and MnCl2hybrid or single solution to simultaneously or alternately (each leaching manganese iron ten times) two types leaching quartz column on the basis of40times to70times, yellow brown loam column to60times,to analysis the iron manganese oxide deposition characteristics. And the60times’ yellow brown soil and40times’ of brown soil were used as the materials.On the one hand, continue leaching of heavy metals lead (10mg/L) and cadmium (1mg/L) on soil column, to studying the characteristics of the dynamic adsorption and migration of lead and cadmium by the soils, and the kinds of existence forms of heavy metals; On the other hand the static adsorption and desorption of heavy metals by the two kinds of soil in the columns were studied to know the isothermal adsorption characteristics of lead. The results showed that:1、 As the number of leaching from40to60times, the pH value of the sand column fluctuate faintly, and the pH of yellow brown soil leaching liquid showed a trend of weak lower;both types of Manganese iron leaching liquid content are more little than the leaching solution;Free and amorphous iron manganese content was significantly increased, and the amount of free and amorphous iron are more than the free and amorphous manganese content;The same process on the surface of quartz sand by the irregular distribution of class ball into distributed tabular or irregular columnar.2、 When the concentration of FeSO4are the same, with the increase of concentration of MnCl2, the pH of quartz sand column and yellow brown loam column trend to decrease;The iron content of the leaching liquid is not so different, the content of manganese is gradually increasing; the free and amorphous iron content on Quartz sand had no obvious difference, but the free and the amorphous manganese content increased;And the free and amorphous iron content on yellow brown soil hows have the tendency of decrease, free and amorphous manganese trend to increase.3、 The free and amorphous iron in quartz sand between the layer having trend of the lower layer> the upper> the middle, free and amorphous manganese between layer hange trend to the lower layer> middle> upper.The free and amorphous iron manganese in Yellow brown loam column from top to bottom, the upper often more than the lower.The samples of the same process, middle and lower iron manganese oxide from class spherical to tabular form change, and the distribution tend to irregular.4、 The lead and cadmium content in soil is significantly lower than the quartz sand, but the content in leaching little change between1to6times.Lead in this experiment mainly exist in residual state, followed by carbonate combination patterns and ion exchange.Cadmium in this experiment mainly exist in the organic combination state, followed by iron and manganese oxide carbonate combined with state combination patterns.And iron manganese combination leaching processing of lead or cadmium state manganese oxide content in iron are better than the corresponding high leaching manganese iron processing.5、 The yellow brown soil samples take the Pb2+up to166.76mmol/L, the lower195.02mmol/L;And brown soil upper299.07mmol/L, the lower146.72mmol/L.The adsorption of Pb2+in the leaching yellow brown soil and brown soil oil increased with the increase of the amount of deposition.The lower layer adsorption Pb2+ionic on Yellow brown soil and brown soil samples strength increases as the background, present the downward trend.Iron manganese leaching solution at the same time dealing with single iron or manganese leaching solution treatment, compared to the former are greatly influenced by the background ionic strength.In addition, palm red soil and yellow brown soil fter the leaching maximum adsorption of heavy metal Pb2+free manganese was significantly positively related with the upper layer, the correlation coefficient is0.882and0.882, respectively.6、 The lead ion desorption curve on yellow brown soil and brown soil samples have the similar change rule. In0-0.25mmol/L samples the desorption rate for Pb2+rise abruptly, and there has a peak between0-0.5mmol/L.Comparing the two soil can see the peak appeared desorption rate equilibrium concentrations of Pb2+yellow brown soil are lower than those of brown soil.And the desorption rate of palm red soil is higher than the yellow brown soil, up to more than70%, that brown soil surface adsorption Pb2+more easy to desorption.