Organic Materials Could Improve the Phytoremediation Efficiency of Soil Potentially Hazardous Metal by Sedum alfredii Hance

Abstract

Soil potentially hazardous metal (PHM) is continually attracting public attention worldwide, due to its highly toxic properties and potentially huge damage to human being through food chain. Phytoremediation is an effective and eco-friendly way in remediation technology. A pot experiment was carried out to investigate the effect of different organic materials (biogas residue (BR), mushroom residue (MR), and bamboo-shoot shell (BS)) application on phytoremediation of two PHM-contaminated soils (Fuyang soil as 'heavily-polluted soil' and Wenzhou soil as 'moderately-polluted soil' , respectively) by Sedum alfrecdii Hance. The results indicated: 1) for moderately-polluted soil, the 5% BR treatment had the strongest activation to Cu and Zn, for heavily-polluted soil, 1% BS treatment had the highest activation effect for Cu, Zn, Pb and Cd. 2) the above-ground biomass of Sedum alfredii Hance increased with the addition rate of organic materials. 3) for Cd uptake of Sedum alfredii Hance in moderately-polluted soil, only 1% BS treatment had a better accumulation effect, compared to the control, for Zn element, MR treatments were weaker than the control, while other treatments were better than the control, of which 5% BR, 1% BS and 5% BS accumulated more Zn element by 39.6%, 32.6% and 23.8%, respectively; in heavily-polluted soil, the treatments of 5% BS, 1% BR and 5% BR accumulated more Cd than the control by 12.9%, 12.8% and 6.2%, respectively, the treatments with organic materials addition promoted Zn accumulation in shoots of Sedum alfredii Hance, and the best treatment was 5% BS. Therefore, an appropriate application rate of BS and BR could improve the remediation efficiency for Zn/Cd contaminated soils by Sedum alfredii Hance.