1. Water cost: Restaurants use a lot of water to clean tableware, wipe tables, chairs and floors, cook and cool, etc. The water needs to be treated before being put into the environment.

2. Equipment cost: In addition to the purification system, it is also necessary to purchase sludge treatment equipment, filter press equipment, and chemical dosing equipment.

3. Labor cost: The treatment of wastewater requires professional technicians to operate and monitor, and their salaries will also generate costs.

4. Cost of chemicals: Some chemicals need to be added in wastewater treatment to remove pollutants in wastewater, and these chemicals need to be purchased again.

5. repair and maintenance costs: the wastewater treatment equipment needs to be repaired and maintained, and these costs need to be included.