The chemistry of the influent stream becomes very important to the success of the ion exchange application.
Coagulation–flocculation can also be employed to treat wastewater laden with heavy metals wherein the coagulation process destabilises colloidal particles by adding a chemical agent (coagulant) and results in sedimentation
(Wang et al., 2004).
Coagulation is followed by flocculation of the unstable particles in order to increase their size and form into bulky floccules which can be settled out.
Flotation is employed to separate solids or dispersed liquids from a liquid phase using bubble attachment (Wang et al., 2004). Adsorptive bubble separation employs foaming
to separate the metal impurities.
Ion flotation, precipitate flotation and sorptive flotation are the main flotation process mechanisms for removal of metal ions from solution.
Membrane filtration has received considerable attention for the treatment of inorganic effluent, since it is capable of removing not only suspended solid and organic compounds, but also inorganic contaminants such as heavy
metals.