Abstract: An air diffuser includes a mask plate spaced upstream from an orifice plate in a generally parallel relationship. The orifice plate includes openings in a first zone arranged in a non-linear pattern, inside a second zone arranged in a linear pattern. Both zones can be within a peripheral wall defining the spacing between the mask plate and the orifice plate. The mask plate has a large opening for air, with a footprint slightly larger than the first zone. The density and zone arrangement of the mask plate and the orifice plate results in a better umbrella pattern flow of air exiting the diffuser.

Abstract: A system and method are provided for treating biodegradable waste material in a landfill by aerobic degradation. Waste material is deposited in the landfill and covered. The moisture content in the landfill is increased from about 40% to about 70% and a source of oxygen is injected into the landfill to drive and maintain primarily aerobic degradation of the waste material. The temperature in the landfill is increased to substantially eliminate pathogens from the waste material. The temperature in the landfill is controlled within a range of about 130.degree. F. to about 150.degree. F. to sustain the primarily aerobic degradation. Any combination of oxygen content, moisture content, and temperature in the landfill is monitored and varied to sustain and maintain the primarily aerobic degradation in the landfill.

Abstract: A process and apparatus is presented for removing contaminants from particulate materials especially earth materials by converting said materials by mixture with water and additives to slurries which are energized to volume boiling conditions thereby dislodging contaminant components from the particulate materials, said dislodging can be enhanced through centrifugal or cyclone apparatus for example, which contains electrodes in direct contact with the slurry along the walls of the cyclone. An electrical current flows through the slurry as the energizing source.