Petroleum-contaminated soil has been remediated in situ with plants added to enhance the degradation processes. The biodegradation of phenol, oil, gasoline, jet fuel, and other petroleum hydrocarbons occurs in soil. When plants are present, soil erosion is reduced and more microbes are present in the plant root zone. Methyl tertiary butyl ether (MTBE), used in gasoline to enhance the octane rating of the fuel, is difficult to remediate because it is very soluble in water and is hard to break down using microbes normally present in soil. In vegetation-based bioremediation, MTBE is moved from the soil to the atmosphere along with the water that plants take up from soil and release to the air. The MTBE breaks down rapidly in the atmosphere. Benzotriazoles, used as corrosion inhibitors in antifreeze and aircraft deicer fluids, are treated by plant-based bioremediation. The benzotriazole adsorbs or sticks to the plant roots and ends up as part of the plant biomass. Trichloroethylene (TCE) is a common chlorinated solvent that is biotransformed in the soil. It can be taken up by plants along with water. Then the TCE diffuses into the atmosphere where it is destroyed by atmospheric processes.