Accumulation of Cadmium, Chromium, and Zinc by the Moss Sphagnum Papillosum Lindle

Abstract

In a series of laboratory experiments employing radiotracer methodology, the uptake of Cd,Cr, and Zn by Sphagnum papillosum Lindle moss from solutions of deionized water and bogwater was investigated. Bioaccumulation of the metals was a passive process, since living anddead moss accumulated metal equally. No significant differences were found in metal uptake ratesfrom single metal solutions and mixed metal solutions, suggesting insignificant competitionbetween the metals occurred at the low concentration range used (10-10 to 10-7 M). Metaluptake conformed with Freundlich adsorption isotherms. Concentration factors of metals inSphagnum papillosum in bog water (103 for Cd and Zn, 102 for Cr) were lower than in deionizedwater (104 for Cd and Zn, 103 for Cr), possibly due to metal complexation by dissolved organicmatter, competition by other major cations present in the bog water (Na+, K+, Mg2+, Ca2+) orcomplexation by chlorides in the bog water. While earlier studies have demonstrated the potentialof using sphagnum mosses for monitoring environmental metal contamination, these experimentsare the first to assess metal uptake in moss using low, environmentally realistic metalconcentrations. The results confirm that mosses would be very effective bioindicators ofenvironmental metal concentrations because the concentration of metal in the moss rapidly anddirectly reflects the metal concentrations in the ambient water.