Efficiency of a phytoimmobilisation strategy for heavy metal contaminated soils using white lupin
Fecha
2012Disciplina/s
Ciencias AmbientalesMateria/s
Lupinus albusRhizosphere
Root degradation
Phytoremediation
Soil metal pollution
Resumen
White lupin (Lupinus albus L.) has been shown to be a useful plant species for phytoimmobilisation of heavy metal contaminated soils. However, since it is an annual species, the heavy metals taken up by the plant and stored in roots can be incorporated back into the soil during root degradation, after plants have been harvested. In this work the efficiency of metal immobilisation by roots of white lupin has been studied in three metal polluted soils (calcareous, neutral and acid) after collection of the aerial part of the plants through an incubation experiment using the intact roots colonised soil. The pattern of C mineralisation in the soil allowed the estimation of the soil microbial activity and the degradation of the root tissues that remained in the soil. The proportion of root tissue degraded in soil was from 47% to 61%, the highest value being found in the calcareous soil. Heavy metal amounts released into the soil after root degradation were very low in comparison with the tot...