In treatment of detergent wastewater that contains
relatively high COD and low BOD, coagulation process
can be used as a pretreatment process. In this study, FeCl
3
had the lowest COD removal efficiency when it was used
alone and it was determined that addition of
polyelectrolyte and clay minerals to FeCl
3
as coagulant
aids, improved the COD removal efficiency. The highest
removal efficiency was obtained from the combination of
FeCl
3
with clay minerals. Comparing all the results and
possibilities, using clay minerals as coagulant aid
accompanied with FeCl
3
can be advisable and more
economical option for the treatment of detergent
wastewater since it has similar removal efficiency
compared with polyelectrolyte and more economic.