A procedure that should be implemented for the evaluation of materials suitability, in terms of their use as metal retention agents, is presented. It derives from a review of materials and waste treatment mechanisms, which has been studied and is also presented. Lignite fly ash, agricultural ashes...

The effects of effluent from Thessaloniki, the second most populated Greek city, reclaimed either by activated sludge or by stabilization ponds, were studied on field-grown corn. The experimental layout was that of a split- plot design with six replications, three water qualities and two irrigation...