中文摘要：

为了研究纳米TiO2对土壤中Al、Fe和Mn形态转化的影响,以三峡水库消落区土壤为研究对象,采用室外模拟淹水试验,分析不同浓度的2种纳米TiO2对土壤中Al、Fe和Mn释放及形态的影响。结果表明,淹水2个月后,纳米TiO2颗粒处理引起上覆水Al和Fe浓度显著升高;促进土壤残渣态和可氧化态Al的释放,且锐钛矿颗粒的作用大于金红石颗粒,高浓度锐钛矿颗粒处理导致12.31%的Al释放到水中;纳米TiO2颗粒对土壤Fe和Mn总量影响较小,但对Fe形态转化影响较大,主要表现为可还原态和可氧化态Fe转化为酸可交换态Fe,促进Fe的活化,其中低浓度金红石颗粒与高浓度锐钛矿颗粒影响相对较大;纳米TiO2颗粒对Mn形态转化影响较小,仅低浓度金红石颗粒与高浓度锐钛矿颗粒处理组促进少量可还原态Mn的转化,其他均无明显变化。因此,不同结构纳米TiO2对土壤中Al、Fe和Mn形态转化的影响存在较大差异,在进行纳米TiO2的环境风险评估时需要区别对待。

英文摘要：

To investigate the effects of nano-TiO2 on transformation of aluminum,iron and manganese in soil,the soil in water-level-fluctuating zone of Three Gorges reservoir area was took as the study case,flooding simulation experiments were conducted in the outdoor.The results showed that nano-TiO2 particles caused the significant increasing of aluminum and iron concentrations in overlying water.In soil,nano-TiO2 particles promoted the release of residual and oxidizable aluminum.And the effect of anatase particles was stronger than one of rutile particles.High concentration of anatase particles caused the release of 12.31% aluminum from soil.Nano-TiO2 particles had little effect on the total contents of iron and manganese in soil.However,it had significant effect on the transformation of iron species.Nano-TiO2 particles facilitated the transformation of reducible and oxidizable iron to acid exchangeable iron,especially low concentration of rutile particles and high concentration of anatase particles treatments.In addition,Nano-TiO2 particles had little effect on the transformation of manganese species,only low concentration of rutile and high concentration of anatase particles promoted the transformation of reducible manganese.Thus there was a big difference in the impact of nano-TiO2 with different structures on the transformation of aluminum,iron and manganese in soil.It must be treated differently when assessed its environmental risk.