  Removing suspended solids and colloids are one of the most important water
treatment processes. In this research, experimental tests have been done to
assess the effects of pH and different doses of PACL on turbidity removal
efficiency. The optimum dose of poly aluminum chloride (PACL) for removing
turbidity was also determined. Turbidity was created artificially by adding the
Kaolin with six different initial turbidities between 20 to 300 NTU rested for
half an hour. The results have been showed that the best removal efficiency was
at the pH of natural water. The optimal doses consumption of PACL was about 5
PPM.
