Description

The activated sludge bioreactor node provides a set of calculations for designing and analyzing systems involved in wastewater treatment using activated sludge. The primary functionalities include:

• Reactor Volume: Calculates the volume required for the bioreactor to ensure effective wastewater treatment.
• Biomass Concentration: Determines the concentration of microorganisms present in the reactor.
• Sludge Age: Estimates the time the sludge remains in the system (also known as mean cell residence time).
• Reactor Dimensions: Defines the dimensions for designing the reactor based on the calculated volume.
• Limiting Flow: Identifies the maximum influent flow rate that the bioreactor can handle.
• Surface Area: Calculates the surface area needed for aeration to support biological processes.
• Total Area: Determines the overall area required for setting up the bioreactor system.

Inputs

Parameter	Units	Description
Sludge age	days (d)	The average age of the sludge in the system.
Biomass in reactor	kg/m³	The concentration of biomass in the reactor.
Removed BOD load	mg/L	The concentration of removed biological oxygen demand (BOD).
Recirculation ratio	-	The ratio of recirculated sludge flow to influent flow.
Endogenous respiration coefficient	-	The coefficient for endogenous respiration in microorganisms.
Cell production coefficient	-	The coefficient that represents microbial growth rate.

Outputs

Parameter	Units	Description
Concentration of suspended solids in reactor	mg/L	The concentration of solids in the reactor.
Volume	m³	The calculated volume of the bioreactor.
Sludge production	kg	The amount of sludge produced in the system.
Recycle concentration	mg/L	Concentration of recycled sludge.