Recovery and Transport of Heavy Metals by 'Spartina Alterniflora' from Dredging Spoils

摘要

The capacity of smooth cordgrass (Spartina alterniflora) a dominant grass of Atlantic tidal salt marshes, to transport heavy metal from sediments to estuarine waters was studied. The DTPA extractable heavy metal content of marsh sediments from upper Narragansett Bay was correlated with the metal content of S. alterniflora growing in those sediments. The plant zinc content correlated well with the extractable zinc levels in the sediments. The plant content of cadmium, copper and nickel was best correlated with the sediment content of other metals. Plant cadmium was particularly well correlated with sediment zinc. The mobility of cadmium and zinc within S alterniflora was determined in solution cultured plants grown in 0 and 15 ppt NaCl. Salinity reduced the root absorption rate of cadmium and zinc by almost fifty percent.