Reduction of fluid chemical contamination of polluted earth materials e.g. for removal of hydrocarbon and halogen compounds by repeated vacuum and air purge treatment in a batch process

摘要

Fluid substances, particularly hydrocarbons, are removed from earth by holding in an evacuated chamber for a predetermined time, and periodically allowing ingress of air. at reduced pressure. An Independent claim is also included for a process for the decontamination of earth (12) in a chamber, evacuated by a pump (18) , and periodically sparged by air via a distributor pipe (4) and a valve (10) comprising condensing abstracted volatile organic compounds in the liquid ring vacuum pump system, and/or adsorbed on an activated carbon bed. The chamber may be constructed with either rigid or flexible foil walls (2), and may contain a heater.