富含Cd、Pb植物焚烧处理方法的探讨

On incineration of plants with high concentration of cadmium and lead

植物修复技术在重金属污染土壤修复领域有着良好的应用前景,而焚烧被认为是针对收获植物的一种有效后处理手段。采用富含Cd、Pb的野生植物铁芒萁(Dicranopterispedata),在450、650、850℃不同温度下进行了焚烧模拟试验,对焚烧过程中的灰分、Cd及Pb残留量的变化情况进行了探讨。结果表明,铁芒萁的灰分残留量可以降到10%以下,Cd、Pb在灰化过程中均有很大损失,直接利用底灰来进行Cd、Pb的冶炼回收不可行,烟气中的Cd、Pb可能产生二次污染,应采取措施加以防治。

Phytoremediation is regarded as a promising approach in the field of remediation of soils contaminated by heavy metals (HMs), and incineration is highly recommended for its post-harvest processing of HMs-concentrated plants. An incineration-simulating test was conducted to study the changes of cadmium and lead content in the ash of the wild plant Dicranopteris pedata under 450 ℃, 650 ℃, and 850 ℃ respectively. The results showed that the ash could be reduced to below 10% during the incineration while cadmium and lead in plants would volatize and cause a considerable lose in mass. It is not economical to recycle volatile cadmium and lead from bottom-ash, and measures should be taken to prevent secondary pollution due to flying ash with high concentration of cadmium and lead.