The treatment of wastewater from the Food and Beverage Industry can be quite challenging because of the complex and variable composition of the constituent streams. Also complicating matters is the tightening of environmental discharge regulations, which can make it difficult to operate without violating discharge or NPDES (National Pollutant Discharge Elimination System) permits. Additionally, to conserve water some wastewater treatment facilities are recycling a portion of their water for in-plant use. The requirements of that in-plant use may necessitate an even higher quality of water than what would be required for discharge.


This article will briefly describe a typical wastewater treatment system and the associated sewage treatment equipment. For further explanation including figures and tables, please download the whitepaper by using the link at the end of this article.


Wastewater treatment can be divided into these five processes:


Pretreatment
Primary
Secondary
Tertiary
Disinfection
Wastewater Pretreatment
The combined wastewater streams enter the pretreatment process which may include any of the following: screening to remove large items, comminution which is a physical chopping up of solids, grit removal to protect downstream equipment from excess wear, and flow equalization to damp hydraulic peaks, ensure uniform pH for downstream processes, and even out contaminant loading. 


Wastewater Primary Treatment


The stream which exits the pretreatment enters the primary treatment process which may include clarification by settling, clarification by floating (dissolved, induced air floatation), and physio-chemical treatment (lime addition, phosphate or heavy metal removal). Solids removed during the primary treatment process are taken to sludge thickening, sludge dewatering, and final disposal. The water stream which exits the primary treatment process is fed to secondary treatment.