Sediment Cap Releases Gases Without Spreading Contamination

摘要

Anew approach to capping oil from contaminated sediment is expected to help address problems related to ebullition, or the generation of gas by decomposing organic matter in sediment. Developed by RMT, Inc., a subsidiary of the Alliant Energy Corporation, of Madison, Wisconsin, the technique involves constructing a cap with permeable and impermeable layers designed to retain sediment contamination borne on gas bubbles, particularly compounds known as non-aqueous-phase liquids (NAPLs). Known as the NAPL Trapping Cap, the system vents the gases themselves to the atmosphere. The technology makes it possible to address certain types of contaminated sediments in rivers, particularly pollution from older manufactured gas plants and similar sources of industrial contamination.