Pyrolysis of Used Hyperaccumulator Plants in Phytoremediation of Soil Contaminated with Zinc

Abstract

In this study, phytoremediation of zinc (Zn) contaminated soil and pyrolysis of used hyperaccumulator plants were carried out. In the first stage of the study, rape (Brassica napus), sunflower (Helianthus annuus) and corn (Zea mays) seeds were sowed in model soils which had been prepared with addition of Zn compounds in laboratory. The effect of chelate on the remediation capacity of the plants was investigated by addition of EDTA in different concentrations. After that, transportation amount of Zn from contaminated soils to plants was examined. In the second stage, initially plants compositions were determined by elemental analysis (C, H, N, S), moisture, ash, volatile matter and fixed carbon analysis. Contaminated hyperaccumulator plants were pyrolyzed at 600°C with the heating rate of 35 °C/min in a fixed bed stainless steel (380 S) 240 cm³ reactor. After pyrolysis, Zn content of solid and liquid products were determined. Also, Toxicity Characteristic Leaching Procedure (TCLP) analysis was realized for the solid product.