1. Conventional" continuous physico-chemical treatment

The general processing flow chart is shown in figure 1 . The main processing stages are :

• storage ;

• any pre-treatments (de-oiling of degreasing effluents, reduction of chromium VI ions, oxidation of cyanide anions);

• metal ion neutralization/precipitation ;

• flocculation if necessary;

• solid/liquid separation ;

• sludge treatment ;

• any liquid refining treatments;

• effluent controls.