Purification of waste water

The high affinity of tetraazacycloalkanes for transition metals, actinides and lanthanides allows their use for the decontamination of waste waters. The selectivity of the macrocycle towards the metallic cations might be tuned by changing the nature, the number and the relative position of the functional groups. Especially for this application, two kinds of pendant arms might be introduced: one for the coordination of the metal and the other for the grafting onto a solid support such as silica gel or organic polymers. The modified materials obtained have been used in solid-liquid extraction process.