赤泥、骨炭和石灰对玉米吸收积累As、Pb和Zn的影响

Effect of Red Mud,Bone Char and Lime on Uptake and Accumulation of As,Pb and Zn by Maize(Zea mays)Planted in Contaminated Soil

为探索添加剂(赤泥、骨炭和石灰)对土壤重金属的钝化效果,筛选有效的土壤重金属钝化剂,在温室条件下通过土壤盆栽试验研究赤泥、骨炭和石灰对玉米吸收积累Pb、Zn和As的影响。结果表明,施用不同的改良剂均显著地提高了玉米地上部生物量,其中5%骨炭处理玉米地上部生物量最大,比对照处理提高5.3倍。污染土壤中施用不同的改良剂(5%赤泥、5%骨炭、5%石灰、2.5%赤泥+2.5%骨炭),可导致玉米地上部Pb和Zn含量分别比对照降低70.9%～89.1%和78.3%～89.7%,根部Pb和Zn含量分别降低50.0%～67.5%和91.0%～94.3%。应用改良剂对玉米植株As含量影响不一样,与对照处理相比,5%赤泥和2.5%赤泥+2.5%骨炭处理显著地降低了玉米地上部和根部的As含量,而5%骨炭和5%石灰处理显著地提高了玉米地上部的As含量。不同的改良剂应用均显著地降低土壤中Pb和Zn的植物有效态含量,提高土壤中As的植物有效态含量。研究结果表明赤泥、骨炭和石灰是较具有潜力的修复重金属污染酸性土壤的改良剂,为重金属污染土壤钝化修复提供了新材料。

In order to explore the passivation effect on phytoavailable heavy metals with different amendments（red mud,bone char and lime）and select scientific and effective heavy metals passivator,the effect of red mud,bone char and lime on the uptake and accumulation of lead（Pb）,zinc（Zn）and arsenic（As）by maize（Zea mays）planted in soil contaminated by heavy metals was studied.Five different treatments were designed：control,5% red mud,5% bone char,5% lime,and 2.5% red mud ＋ 2.5% bone char by weight.The maize was harvested 8 weeks after planting,and the concentrations of As,Pb and Zn in the shoots and roots as well as the amount of phytoavailable heavy metals in the soil was measured.The results showed that the different amendments could all increase the shoot biomass significantly,with the largest increase by the 5% bone char treatment.The amendments decreased the concentration of Pb and Zn in the shoots by 70.9%～89.1% and 78.3%～89.7%,and in root by 50.0%～67.5% and 91.0%～94.3%,respectively,compared with the control.The effect of the amendments on the concentration of As in maize differed compared to the control.As concentrations in both the shoots and roots decreased significantly when treated with 5% red mud and 2.5% red mud ＋ 2.5% bone char,while the concentrations increased markedly when treated by 5% bone char and 5% lime.The applications of different amendments decreased the amount of Pb and Zn in soils that was available for uptake by plants,but increased the availability of As.The results indicated that red mud,bone char and lime are potential amendments for modifying acidic soil contaminated by heavy metals.The study provided new potential materials for remediation of heavy metal contaminated soils.