Vibol Sao, Woranan Nakbanpote and Paitip Thiravetyan

pp. 881 - 892

Abstract

This research investigated the phyto-remediation potentials of Cyperus rotundas Linn (Nutgrass) and Axonopus compressus (Sw.) P. Beauv (Carpetgrass) for cadmium removal from cadmium solution and cadmium-zinc contaminated soil. Plants growth in the solution showed that cadmium decreased the relative
growth rate of both grasses. However, the amount of cadmium accumulated in shoot and root was increased with the increase in cadmium concentration and exposure time. Growth in fertile soil mixed with Cd-contaminated zinc silicate residue (65% Si, 19% Ca, 2% Zn, 1% Mg and 0.03% Cd) at the ratio of 50:50 (w/w) for 30 days showed that C. rotundas Linn accumulated cadmium in root and shoot to 2,178 and 1,144 mg kg^-1 dry weight, respectively. A. compressus (Sw.) P. Beauv accumulated cadmium in root and shoot to 1,965 and 669 mg  kg^-1 dry weight, respectively. Scanning electron microscope connected to energy-dispersive X-ray spectroscopy suggested that the mechanism of cadmium accumulation by both grasses involved the cadmium precipitation in the stable form of cadmium silicate, which indicated that C. rotundas Linn and A. compressus (Sw.) P. Beauv could be grown to prevent soil erosion and to remediate cadmium-contaminated soil.

Keywords

• Axonopus compressus (Sw.) P. Beauv
• Cyperus rotundas Linn
• cadmium
• phytoremediation