Abstract: A system is provided for removing arsenic from water to safe levels at or below the EPA standards. The system is a hybrid spouted vessel/fixed bed filter system that significantly enhances/improves arsenic removal for drinking water using zero-valent iron (ZVI) particles. Movement of the circulating, iron-containing particles in a dense moving bed that forms on the spouted vessel bottom creates an abrasive “self-polishing” action among them that continuously generates colloidal iron corrosion products. This material then circulates with the water in the vessel and is removed and concentrated in a fixed bed filter. The colloidal material captured and immobilized in the filter has been shown to remove arsenic from contaminated water at very rapid rates.

Abstract: An improved test apparatus and method for assessing visual learning in mammals is provided. The stimuli presented to the mammal are disposed and arranged on the floor of the test apparatus instead of on the walls.