Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Schematic diagram of the flow process of the U-shaped redox front through a contaminated zone. Despite the relative importance of preferential flow paths, contaminants are “swept” by the roll-front. The red circle is the contaminated zone. This zone is transformed to blue the circle upon treatment by the FeII/FeIII front
