ABSTRACT
Today, the techniques for the control of various pollution forms constitute a complex advanced technology with great possibilities. Pollution control can be achieved by methods aiming either at the decrease of generated pollutants, i.e. through preventive action, or at better treatment and disposal of generated pollutants, i.e. through repressive action. Liquid waste of cities is usually collected by a subterranean drainage network and conveyed to a facility where it undergoes the proper treatment for each case. The kind and degree of treatment of the cities’ liquid waste depend on the characteristics of the receptor or the kind of reuse. The tertiary treatment stage is a combination of several units that varies according to the pollutants undergoing treatment. Dealing with the atmospheric pollution of cities presents increased difficulties because of the large number and variety of the sources of pollutants’ emissions.
