Preparation of Granular Forms of Powdered Materials for Their Application in Column Packed Beds

This contribution summarises the possibilities of the application of powdered materials for liquid waste treatment and evaluates the published procedures for the preparation of “engineered” (granular) forms of such materials with regard to their potential application in environmental technologies. The advantages and disadvantages of the procedures used for the granulation of powdered materials are discussed and compared with regard to the properties of an “ideal” granular absorber. The applicability of various groups of granular materials for the treatment of nuclear waste, mixed waste, toxic or hazardous wastes, separation of various contaminants from surface and ground water, or for water pollution control, are compared. In the last part, composite absorbers containing finely divided materials and granulated using a binding matrix based on modified polyacrylonitrile are briefly characterised and the universal character of the respective granulation procedure is demonstrated.