The researchers studied how to clean wastewater from a bakery. They found that using alum or FeCl3 as chemicals helped remove pollutants like COD and SS. The best results were seen at a pH of 6.0. Dissolved air flotation also worked well, removing almost half of COD and most of SS in 10 minutes. Adding alum improved SS removal, but not COD. Short flocculation time helped with COD removal, but longer time didn't help. FeCl3 was better than alum. In conclusion, both methods were good for cleaning the wastewater, each with its own pros and cons.