Phytoremediation of chromated copper arsenate contaminated soil by maize (Zea mays L.)

This study investigated the use of maize in removing arsenic, chromium and copper from chromated copper arsenate (CCA) contaminated soil in a pot experiment. Heavy metal levels in the CCA contaminated soil analysed showed high concentration of As, Cr and Cu. Total values of (39.55mg/kg) As, (313.97mg/kg) Cr and (200.00mg/kg) Cu were obtained in the CCA soil before planting. At the end of 60 days germination, the amount of the metals in the CCA contaminated soil reduced significantly (P > 0.01) accounting for 29% As, 3% Cr and 30% Cu of the initial concentration in the contaminated soil. Transfer factor and contamination factor were calculated to determine the accumulative factor of the metals in the plants and soils and this was used to interpret the state of the environment and ability of the maize to accumulate the metals. The contamination factor obtained for the chromated copper arsenate soil categorized the soil as highly contaminated while the transfer factors obtained for the various metals shows low metal accumulation in the plant.