Commercial Bakery Wastewater Treatment

Large commercial bakeries producing products including cakes, pies, cookies, biscuits, brownies, rolls and a variety of other desserts generate wastewater with loads of contaminants too high for municipal discharge without pretreatment. Bakeries use large volumes of butter, flour, shortening, eggs, fillings of various types which produce on average the following level of contaminants in the resultant wastewater.

The table below shows the high level of BOD, suspended solids and fats, oils and grease in the wastewater.

COD BOD TSS TP TKN FOG
7,000 3,200 6,000 6.8 36 820
Legend: COD (Chemical oxygen demand), BOD (Biological oxygen demand), TSS (Total Suspended solids), TP (Total phosporous), TKN (Total kjeldahl nitrogen)

Pretreatment of bakery wastewater to dramatically reduce FOG, TSS

Pretreatment of wastewater from a bakery is necessary before discharging to a municipal sewer system. A very efficient way to accomplish this is through the operation of a Dissolved Air Flotation (DAF) system. These systems are the optimal solution for removal of materials such as solids, oil and grease (FOG). A DAF system utilizes a separation technique that injects tiny air bubbles in the DAF tank, which attach to the insoluble pollutant materials and float them to the surface. Certain materials used in the baking process are heavier than water and thus require the addition of flocculants and air, that when combined cause the pollutants to join in clusters and are forced to float to the vessel's surface. These accumulating contaminants at the surface of the DAF vessel are what's known as "sludge," and are scraped off the surface of the water and removed from the treatment process. Clean water can exit the bottom of the DAF vessel, which can then be safely discharged to the sewer.

Pretreatment using a DAF system in a commercial bakery will allow for reduction of FOG by up to 99% and Total Suspended Solids (TSS) by up to 97%. The requirement for flocculants as well as pH adjustment of the water for effective FOG removal can be fully automated using the Ecologix VLT Series Dissolved Air Flotation System.