Effect of some additives on heavy metals behavior and phytoavailability in municipal solid waste compost-amended soil

Abstract

The effect of application of municipal solid waste compost (MSWC) on copper (Cu), lead (Pb) and cadmium (Cd) levels in soil and wheat plant was studied. The effectiveness of complementary remediations including compost washing (three levels), wood ash and sawdust application (each at three levels) was also examined. A completely randomized design pot experiment with medium-textured soil was performed. The diethylenetriaminepentaacetic acid–triethanolamine (DTPA–TEA) extracts of the soil and plant shoots were tested for heavy metal content using atomic absorption. The heavy metal contents of plant showed a definite dependence on extractable heavy metals in differently treated soil. The highest metal uptake by plant was observed in unleached compost-amended soil, followed by leaching, sawdust and wood ash remediations. No significant differences were observed within different levels of leaching and wood ash applications. The highest crop yield was obtained for wood ash amendment (1 wt%). Consequently, wood ash is an appropriate remediation for MSWC-treated soil to reduce heavy metal phytoavailability although monitoring of total heavy metal in soil is necessary for long-term application of MSWC.