Optimal cadmium separation over copper with D2EHPA occurs
at more acidic and restricted pH than cadmium optimum
extraction pH, whilst MEX separated copper over cadmium with
grater separation factor and extended domain of pH. Loading
capacity studies revealed that 1 g/L cadmium and 1 g/L copper
could be extracted by using 30–35% D2EHPA and 2.5–3% MEX,
respectively. Then, whereas separation and recovery of these
elements was aimed, MEX is more effective extractant. Coextraction
studies demonstrated that MEX has inconsiderable
extraction capability toward cadmium whilst D2EHPA can extract
both metals, although, D2EHPA’s capacity for copper is almost 10
times less than cadmium. So, whenever only removing of these
elements from wastes was concerned, D2EHPA can be more
suitable.