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 discharge to a municipal sewer system. A very efficient way to accomplish this is through installation of a Dissolved Air Flotation (DAF) system. These systems are the optimal solution for removal of materials such as fats, oil and grease (FOG). A DAF system utilizes a gravity separation technique that uses air bubbles in the wastewater holding tank to attach to the insoluble 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 that when introduced cause the materials to join in clusters that are light enough to then also float to the surface. These contaminants then accumulate on the surface of the DAF tank as sludge and are then scraped off and removed from the wastewater.

Pretreatment using a DAF in a commercial bakery will allow for a reduction of FOG by 99% and Total Suspended Solids (TSS) by 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.