改良剂对苎麻修复镉、铅污染土壤的影响

Effect of Different Amendments Substances on Soil Restoration of Cadmium, Lead Pollution in Ramie

为了探明不同修复措施下苎麻对重金属污染土壤的修复效果,通过盆栽试验研究了镉、铅复合污染土壤施加有机肥、石灰和海泡石等3种改良剂对苎麻生物量、叶绿素及重金属镉、铅积累特性的影响。结果表明,不同改良剂及其组合处理,都能促进叶绿素含量及a/b值增加,改善光合作用以致生物量显著增多,以3种改良剂组合处理最佳,有机肥及其与海泡石组合稍次。不同修复措施下苎麻根系和地上部镉、铅积累浓度均明显减少,分别以单施石灰和海泡石处理减幅最多,二者组合处理降幅稍次,单施有机肥处理降幅最少。改良剂处理均能促进苎麻转运系数增加,但增幅不明显。综合而言,以施加有机肥及其与石灰、海泡石组合处理效果较佳,能有效降低污染土壤中有效镉、铅,改善土壤理化性能,促进苎麻生长,具有较理想植物修复效果。

In order to investigate the restoration effect of ramie on heavy metals contaminated soils under different repair measures, a pot experiment was conducted to observe the effect of three amendment substances （organic compound fertilizer, lime and sepiolite） on biomass, chlorophyll and heavy metals cadmium and lead accumulation characteristics of ramie （Boehmeria nivea） in soils contaminated with cadmium and lead. The results showed that different amendment substances and their combination treatment could increase the chlorophyll content and a/b ratio, improve the photosynthesis, and result in a significant increase in biomass. The combination treatment of three amendments accumulated the maximum biomass, organic fertilizer and its combination with sepiolite slightly times. The accumulation levels of cadmium, lead in roots and shoots in ramie significantly reduced under different applications. Single application of lime and sepiolite processing reduced largely, both combination treatments lesser decreased, declined in at least of single organic fertilizer processing. Different modifiers could promote the raise of ramie transfer coefficient, but the increase in amplitude was not obvious. In general, single application of organic fertilizer and its combination with lime and sepiolite had better results, which could effectively reduce the content of cadmium and lead in contaminated soil, improve soil physical and chemical properties, promote the growth of ramie, and have an ideal effect of plant restoration.