Effects Of Different Carbon Amendments Of Copper In The Combined Contamination Soil

With economic development, through the exploitation of metals mines, wet and dry atmospheric deposition, sewage irrigation, heavy metals penetrate into the soil,resulting serious heavy metal pollution in soil. Among them, a large copper smelter emissions Cu, Cd and other heavy metals into the soil environment, cause the combined pollution of Cu-Cd and the accumulation of large amounts of Cu. The paper used the uncontaminated soil as the tested soil, meantime, people added exogenous copper and cadmium in amounts of 400mg/g, 5mg/g in order to simulate the surrounding copper smelter’s soil. The paper would select activated carbon, HNO3 modified carbon, Na OH modified carbon, KMn O₄ modified carbon, phosphorus carbon, Radix biochar, Radix dregs biochar and other 13 kinds of carbon materials as modifiers,it based on adsorption of Cu and screened out the good adsorption modifiers.According to the activated carbon and KMn O₄ modified carbon adsorpted rate of Cu in 9 different kinds of contaminated soil as the culture experiment and pot experiment tested soil. In order to analyze several passivating agent repairing effect and mechanism of polluted soils to Cu, Cd. The major findings were as follows:Amendments on different carbon passivation contaminated paddy soil showed that in the acidic soil over a single copper pollution and Cu-Cd combined pollution,the above nine kinds of charcoal amendment Cu²⁺ absorption of varying degrees are of increase, which 0.05mol/L KMn O₄ modified carbon for removal of Cu²⁺ is much better, and if in the additional level of 2%, Cu²⁺ adsorption rate would reach to80.56%.Using activated carbon and KMn O₄ modified carbon to passivated different types of soil pollution of Cu, the results show that: those two kinds of red-soil improvers charcoa（CHR0,CHR1）, yellow soil（HUR0）, yellow-brown（HZR0）, Guangzhou red soil（HOR0）, Jiangxi red soil（HHR0,GYR0,NJR0）, dark brown（AZR0）, the nine different kinds of contaminated soil Cu²⁺ adsorption rate was increased in some degrees, and the modified carbon adsorption effect of Cu²⁺ was slightly higher than activated carbon adsorption. Soil treatment of the single copper pollution, the modified carbon of Cu²⁺ adsorption rates were 95.73%, 83.00%, 86.69%, 77.81%,87.14%, 70.55%, 95.43%,98.82%, 54.06%; during the Cu-Cd combined pollution soil treatment, the p H was in the range of 4.07⁵.89, whose adsorption rate was good forCu²⁺, modified carbon in Jiangxi red soil’s（NJR0） adsorption rate reached 98.82%.The soil incubation experiment was conducted to study activated carbon and modified carbon on soil properties and dyramin changes of copper fractions in soil.The result showed that: in a single copper pollution soil, the sol catalyses activity compared with the control has been improved significantly, increasing 45.45%,68.18% respectively; meantime, the urease activity also increased 42.09%, 32.97%. In the Cu-Cd combined pollution soil, the sol catalyses activity compared with the control has improved significantly, increasing 61.9%, 71.4%. In a single copper pollution soil, the modified carbon improved better than activated carbon, the acid extractable oxide bound proportion decreased 5.79%, 5.46%, the combination of state and residual increased 2.00%, 9.25%; in the copper and cadmium combined pollution soil, the acid extractable proportion compared to a single copper contamination treatment increased large amplitude respectively increased 21.46%, 5.73%, having an acid extractable oxide bound to the organic combined with the trend and residual transformation that effective state steered potentially available state and non-state use,and reduced ecological risk.The pot experiment results showed that: activated carbon, modified carbon and stone could increased the biomass, chlorophyll, root activity of the winter wheat straw,and reduced the accumulation of body Cu in a single copper contaminate soil;modified carbon could decrease the content of Cu leaf, root Cu compared with control of 35.30%,27.05%; in the combined pollution soil, after adding the above-mentioned three kinds of modifiers, leaf Cu, root Cu content compared with control decreased23.65%、32.08%、27.71%,27.41%、20.9%、28.83%. After adding amendments, soil p H and organic matter and soil activity are improved, acid extractable Cu content is reduced, which will enter potential transition of the use of state and unusable state..The carbon amendments has a good passivation effect in the copper and cadimum combined pollution soil, in particular, the use of modified carbon will never bring about new pollutants, can also avoid the risk of secondary pollution, and can effectively improve the soil environment to provide a new method heavy metal contaminated soil passivation repair work.