EFFECT OF SURFACTANTS ON CONCENTRATION OF HEAVY-METALS FROM NATURAL-WATERS ON CHELEX-100 RESIN

Trace amounts of zinc, cadmium, copper, nickel, manganese, cobalt and lead can be separated from natural waters on Chelex-100 resin (50-100 mesh) in the presence of cationic, anionic and non-ionic detergents, washing powder and sodium tripolyphosphate at concentrations as high as 100 mg l-1. Metal recoveries are better than 92% but are poor in the presence of soap or the potential detergent additive, nitrilotriacetic acid. Although strong adsorption of cationic, and to a lesser extent, anionic and non-ionic detergents, occurs on the resin surface, low recoveries can be attributed to incomplete metal elution rather than to blockage of adsorption sites. Experiments with radiotracers show that the total metal present in natural waters is not adsorbed by Chelex-100 unless metal ions are first released from colloids or strong complexes. © 1978.