PLANT UPTAKE OF METHYL tert-BUTYL ETHER (MTBE) FROM GROUND WATER

Methyl tert-butyl ether (MTBE) is an important ground-water contaminant. Gasoline spills and leaks from pipelines, underground and aboveground storage tanks, and other transport modes are major sources of MTBE contamination. A six-channel system was set up and used to examine the effect of alfalfa plants on the fate and transport of MTBE. Contamination by MTBE was established by continuously feeding a solution of 0.84 mM MTBE into each channel at 1 L/day. The concentrations of MTBE in the channel ground-water effluent, at the channel soil surface, and within alfalfa plant stems were monitored. By incorporating plant water use with the concentrations of MTBE in plant water, the authors obtained the mass fluxes of MTBE transported by alfalfa plants grown in soil channels. Even with the same contaminant concentration in the growth channel, alfalfa plants took up MTBE nonuniformly. The more vigorous the growth of plants, the higher the MTBE concentration in the plant water, and the more MTBE removed by the plants.