Chemical studies on the recovery of certain hazardous elements from waste solutions

Waste water produced from phosphoric acid and phosphate industries which is released in the water streams, is generally contaminated with hazardous elements which can have severe environmental impacts. Among these, uranium and cadmium are of main concern. The present work is directed to develop suitable technique to remove such toxic elements before discharge to the environment. Liquid membrane is an improved solvent extraction technique and found applications in industrial waster treatment and hydrometallurgical separation. It is characterized by the simplicity and high efficiency in separating or concentrating elements from highly dilute solutions. Compared to conventional solvent extraction process. Liquid membranes allow the use of selective extractants which are not always required appreciable high concentration.The present contribution is directed to develop a method for separating U (V I) and Cd (II) from low phosphoric acid concentration, simulating the waste water from phosphate industries. As Fe (III) represents a main part in waste solutions. the behaviour of Fe (III) in different systems was also studied. Two type of liquid membranes, a liquid emulsion membrane (LEM) and a supported liquid membrane (SLM), have been developed by employing di (2-ethylhexyl) phosphoric acid (HDEHP) as a mobile carrier. The different parameters affecting the permeation of U (V I), fe (III) and carried out to assess the different parameters controlling the permeation of the investigated elements. 42 figs., 13 tabs., 94 refs