As it is shown in fig.1 a very considerable decreasing in the value of colour begins from step 5 and keeping this removal trend to the end of the experiments is also remarkable, but the most important matter is the colour value after ozonation which is obvious that this parameter was almost below the standard level for the moment effluent depletion which is 100 (mg/l Pl-Co) except the beginning of ozonation. Considering the biological treatment shows that the recorded data in most steps are above the standard level. It should be mentioned that the standard value of colour for surface water, for leaching pits, and also agricultural use is 75 (mg/l Pl-Co).