- 3.38% and 0.15 - 5.49%, respectively. The result
revealed that flow rate of wastewater (influent)
affected the SS removal whereas it was no effect on
BOD and FOG removals. The high flow rate also
reduced the SS removal. BOD removal of grease trap
depended on the microorganism activities in the
treatment tank [12]. The higher HRT increased the SS,
BOD, and FOG removals. It was found that the
optimal flow rate and HRT for the simple and modified
grease traps were at 2 L/min and 10 hrs. At the optimal
condition, the reductions of SS, BOD, and FOG were
over 87, 70, and 87%, respectively, whereas there was
no effect on the treatment of pH value. They were