Uptake of Heavy Metals from Contaminated Sediments by Salt-Marsh Plants

摘要

Spartina anglica, Puccinellia maritima, and Aster tripolium, three common salt-marsh species in Western Europe, were grown in contaminated sediment from the port area of Antwerp, Belgium. Growth and levels of heavy metal contamination were compared with those of Spartina alterniflora, a common salt-marsh species from the United States. The plants were grown under waterlogged and drained soil conditions. In both cases, high and low soil salinities were maintained. The levels of heavy metals in the shoots of the plants were generally higher under drained conditions. The difference in salinity gave no obvious differences in metal levels of the shoots. Plants grown in the same sediment which had been aerated and allowed to dry out had higher levels of heavy metals in their shoots. The four plant species showed different levels of metals in the shoots when grown under the same conditions: P. maritima had the lowest levels, and A. tripolium had the highest. Aster tripolium also showed a significant difference in metal levels in leaf and stem material. The results of P. maritima grown at low salt conditions and of S. alterniflora were statistically analyzed. Levels of Cadmium (Cd), manganese (Mn), and copper (Cu) in the regrowth shoots of the second harvest were in general higher than in shoots of the first harvest. In contrast, levels of iron (Fe) were generally lower. Comparisons of lead (Pb), zinc (Zn), and arsenic (As) levels gave variable results. (aw)