Environmental restoration of a TiO2 plant.

Titanium dioxide is a brilliant white, nontoxic pigment. It is used worldwide to obtain vivid whites, clean tints, and brillant colors in paints, lacquers, printing inks, plastics, rubber, floorings, paper, fibers, cosmetics, vitreous applications, and other industries. It can be produced through two industrial routes: the sulfate or the chloride process. Whatever production route is used, it produces effluents during the process. In the past, such effluents were freely discharged into the environment (air, water, land) without special care. Today, environmental legislation requires specific treatments and sets strict limits, often differing from country to country. We present a case of a TiO2 plant, located in central Italy (Tuscany), where several steps have been taken during the last 20 years concerning the effluent treatment to become one of the more advanced examples of total treatment in the TiO2 industry worldwide. Details are presented concerning the treatment systems for gaseous, liquid, and solids effluents.