修复植物生物解吸脱除重金属实验研究

Experimental study on the removal of heavy metals from phytoremediating plant by biological desorption

以天津市公路绿化带大叶黄杨为修复植物,采用生物解吸法及火焰原子吸收分光光度法,研究了标准筛筛径、浸泡温度、浸泡时间、真空度和减压时间对脱除材料内重金属Cr、Cu、Zn和Pb的脱除作用。结果表明,真空度、浸泡时间对Cr、Cu、Zn和Pb的脱除作用较明显,减压时间对Cr、Cu、Zn和Pb的相对脱除率最为显著。Zn和Cu的迁移性较高,调节各操作参数对脱除Zn、Cu的作用较明显,其平均脱除值和平均脱除率均较高。本底值高低对脱除Zn、Cu和Cr、Pb影响较大。Cr和Pb对筛径和减压时间敏感性较强,对浸泡温度、浸泡时间及真空度敏感性较差。认为基于生物解吸法通过选择适宜的操作参数对脱除修复植物内部分重金属有积极的作用。

Taking Euonymus japonicus picked from the highway green belt of Tianjin as the phytoremediating plant,the removal of heavy metals（Cr,Cu,Zn and Pb） from selected plant by biological desorption was conducted.The influence of standard sieve diameter,soaking temperature,soaking time,vacuum degree and duration under reduced pressure on the removal of the heavy metals was investigated by means of atomic absorption spectrophotometry.The results showed that the soaking time and vacuum degree have a significant effect on the removal of these metals.The duration under reduced pressure has a positive effect on the relative percentage removal of these metals.Because of a high mobility,the removal of Zn and Cu can be achieved by adjusting operating parameters,obtaining a high average removal and the average removal percentage.The original contents of Cr,Cu,Zn and Pb have an obvious influence on the removal of them.The removal of Cr,Cu,Zn and Pb was sensitive to the sieve diameter and the duration under reduced pressure,while less sensitive to soaking temperature,soaking time and vacuum degree.It was demonstrated that,selecting appropriate operating conditions,the heavy metals can be effectively removed from phytoremediating plants by biological desorption method.