导　　师： 李惠卓;刘树庆;陈世宝

学科专业： I0301

授予学位： 硕士

作　　者： ;

机构地区： 河北农业大学

摘　　要： 土壤酸化程度的不断加剧,致使土壤中的铝离子和重金属离子活化度不断提高。环境中活性的重金属离子含量的增加,致使重金属进入土壤-植物的食物链从而产生危害的风险大大增加。目前,针对土壤酸化引起的污染土壤中铜的结合形态变化,以致铜在污染土壤中的生物有效性、毒性的变化及其影响因素的研究还鲜见报道。本试验着重研究不同程度及不同的土壤酸化措施对铜在土壤中的结合形态变化和对铜的生物有效性影响机制,添加修复剂/(蒙脱石,高岭石/)后对铜在土壤中的形态变化及对植物毒性效应的影响,为铜污染土壤的修复及其环境风险评价提供依据。 1.不同pH条件下添加纳米型蒙脱石和高岭石对溶液中铜的去除效果研究 纳米型高岭石、蒙脱石对溶液中铜的吸附效果及吸附机理的试验结果表明,纳米型蒙脱石和高岭石对溶液中的铜具有很好的去除效果,相比而言,蒙脱石比高岭石具有较高的吸附量和吸附亲和力参数。在溶液中铜离子浓度低于120 mg//L时的最大去除率分别达到99.5/%和94.3/%,对溶液中铜的去除率随铜离子浓度增加和溶液的pH降低而降低。 2.不同酸化措施/(添加硫酸溶液,添加硫酸铵溶液和模拟酸雨/)对土壤中铜的有效性研究 在三种酸化措施下,土壤中铜的交换态、碳酸盐态、铁锰氧化物结合态和有机态都是随着pH的降低而增大,而残留态则相反。由于有效态的增大,则植物对铜的吸收也逐渐增大,分别添加蒙脱石和高岭石可以有效的降低铜的有效性,从而使铜的有效态向残留态转化,阻碍植物对铜的吸收。添加蒙脱石的寿光土在模拟酸雨的处理中,pH6.0水平下残留态增加最显著,比对照增加了28.22/%,添加高岭石的在添加硫酸溶液的处理中,pH6.3水平下残留态增加最显著,比对照增加17.30/%。添加蒙脱石的大冶土在添加硫酸溶液处理中,pH6.0水平下的残留态增加最显著,比对照增加了12.40/%,添加高岭石在添加硫酸溶液的处理中,pH6.3水平下高岭石处理的残留态增加最显著,比对照增加了5.35/%。 3.添加不同修复剂对铜污染土壤的修复效果 盆栽实验结果表明SOD活性随着pH的降低而升高,表明pH的降低使植物受到的胁迫也越大。而添加蒙脱石和高岭石后,植株茎叶的SOD活性均有不同程度的下降,添加蒙脱石的植株中SOD下降幅度明显大于添加高岭石的。添加蒙脱石的寿光土在添加硫酸溶液的处理中,pH6.6水平下蒙脱石处理的SOD活性下降最为显著,比对照下降了15.02/%,添加高岭石的在模拟酸雨的处理中,pH6.6水平下的SOD活性下降最为显著,比对照下降了10.03/%。添加蒙脱石的大冶土在添加硫酸溶液处理中,pH6.5水平下的SOD活性下降最为显著,比对照下降了19.84/%,添加高岭石在三种酸化措施下都是pH7.1水平下SOD活性下降最为显著,比对照下降了14.78/%。 Because of the growing soil acidification, the activation degree of aluminum ion and heavy metal ions in the soil is increased day by day. The risk that heavy metals join the food chain in the soil to plant is enhanced owing to the content of heavy metal ions increasing in the environment, In addition, the groundwater is polluted with the soil water infiltration when the concentration of heavy metal ions is increased. At present, The experiment rarely studies the morphological changes of the copper in the different soil and the bioavailability of the copper. Our study will provide the theoretical basis for the repair of contaminated soil and environmental risk assessment. This study focuses on the change of combination morphology of copper in the soil and the bioavailability of copper in the different acidification measures and different degree acidification of soil, and the morphological changes of copper and the effect on plants after adding the repairing agent /(montmorillonite, kaolinite/) in the soil. 1 Removal of aqueous Cu /(II/) ion by nanoscale montmorillonite and kaolinnite under different pH value The ability and the mechanism of the nanoscale montmorillonite /(MMT/) and kaolinnite /(Kao/) adsorbing aqueous Cu /(II/) ions were investigated in this study,Langmuir and Freundlich isotherm equations had studied the sorption constants under different pH value in the solution. The results showed that the MMT and Kao can remove Cu /(II/) in the solution efficiently. The adsorption results indicated that the sorption affinity and sorption maximum on nano-MMT for Cu /(II/) were always higher than that of nano-Kao; the removal efficiency reached 99.5/% and 94.3/% respectively with the Cu /(II/) concentration less than 120 mg//L in the solution. Solution pH was an important parameter in controlling Cu ions sorption onto the MMT and Kao, the removal efficiency of the MMT and Kao decreased with increasing Cu /(II/) concentration in solution and decreasing pH in solution. 2 Acidification of different measures /(adding sulfuric acid solution, add ammonium sulfate and acid rain/) on the effectiveness of copper in soil Researching on the copper effectiveness under different acidification treatments /(adding acid solution and ammonium sulfate solution and simulation of soil acid/), with the reduction of the pH, the copper′s exchange, except residue and bound to carbonate, copper bound to Fe-Mn oxides and organic matters both increased under three different acidification treatments, with the rising effective state of copper, the contents absorbed by plants also increased gradually, adding montmorillonite clay and kaolinite both can lessen the effectiveness of copper, which can promote the ability of copper’s transformation from effective state to residue , and block the absorption of plant. The montmorillonite treatment simulated acid rain state, residue state rised more rapidly than another treaments under pH 6.0, and increased 28.22/% compared with the control, The kaolin treatments is in the acid solutions, residue state rises more quickly than another treaments under pH 6.3, and increased 17.3/% compared with the control, and the montmorillonite clay treatment is in the acid solutions, residue state rised more rapidly than another treaments under pH 6.0, and increased 12.4/% compared with the control, the kaolin treatment is in the acid solutions, the residue state in kaolin treatment rised more rapidly than another treaments under pH 6.3, and increased 5.35/% compared with the control. 3 Adding different restoration agent on the effect of copper contaminated soil remediation Add fix under different acidification agent /(MMT, Kao/) in pot experiment, the results showed that SOD activity increased with the decrease of pH, indicating that the pH of the plant by reducing the stress is also greater. The addition montmorillonite and kaolin, the plant stems and leaves, SOD activity decreased in varying degrees, add plants montmorillonite was greater than the decrease in SOD added kaolin. Shouguang add montmorillonite soil solution in the treatment of sulfate, pH6.6 level of SOD activity in MMT treatment significantly decreased the most, down 15.02 /% compared with control, add the Kao in a simulated acid rain treatment, pH6. 6 levels of SOD activity decreased most significantly, decreased by 10.03 /% compared to the control. Daye added montmorillonite soil solution in the treatment of sulfate, pH6.5 level of SOD activity decreased most significantly, decreased by 19.84 /% compared with control, adding the kaolin in the next three measures are pH7.1 acidification level of SOD activity declined most significantly, reduced 14.78 /% compared to the control.

关 键 词： 铜 土壤酸化 修复剂 生物有效性 固定机制

分 类 号： [X53 S15]

领　　域： [环境科学与工程] [农业科学] [农业科学]