Castellini Company

Process wastewater is generated at the facility from washing and packaging fruits and vegetables for home delivery.  This makes the wastewater high in dissolved biochemical oxygen demand (BOD).  To remove dissolved BOD, CWS conducted a design/build of a moving bed bioreactor (MBBR) pretreatment system with secondary dissolved air flotation (DAF) for the removal of sloughed biomass.

• Pretreatment of fairly high BOD concentrations
• No room to install system components inside existing facility
• No outside space for a separate pretreatment building
• Use existing Equalization Tank
• System had to be installed in only two truck unloading bays
• Unloading bays were partially covered by a canopy
• System had to be accessible by forklifts and pumper trucks
• Effluent to go back through existing monitoring station

The pretreatment system is comprised of the following major components:

• 40’ Conex container for system components; 20’ Conex container for chemical feed equipment
• Rotary screen
• Surge Tank with rough pH adjustment and aeration
• Bioreactor with biofilm carriers and aeration
• Dissolved Air Flotation (DAF) unit with Reactor and Floc Tanks
• Sludge Tank with aeration

Installed within two truck bays, CWS designed and installed an MBBR biological pretreatment system with secondary DAF.  Equipment housed in two Conex containers eliminated the need for a separate treatment building.  Even though the system is compact, it provides a full pretreatment system that consistently meets permit requirements.