Pollution source identification and waste loading reduction at Chinese fast food restaurants

The sources of chemical oxygen demand (COD) and oil/grease generated from fast food restaurants were identified and some waste reduction strategies proposed in a new standard operating procedure (SOP) for food processing. After the implementation of the new SOP in three test restaurants, there were positive improvements in meeting the governmental discharge standard for small to medium restaurants, but no improvement for larger restaurants. Further analysis involving long-term water bills and revenue in 30 other restaurants substantiated the finding that the ratio between the increment of water consumption and the increment of business revenue was much less than unity. This means that, as more food is prepared in larger restaurants, the increased water usage is not capable of diluting the mass loading of COD and oil/grease that comes from their food processing.