Completely Mix Batch Reactor:
in a closed system where no flow is added or allowed to leave during the design detention tim

Plug Flow Reactor or Tubular-Flow:
Fluid particles pass through the tank and are discharge in the same sequence in which they enter.

Arbitrary Flow Reactor:
is any degree of partial mixing between plug-flow and complete-mix.

Fluidized Bed Reactor:
is filled with the packing material that expands and gets fluidized when wastewater moves upward in the reactor.

Packed Bed Reactor:
Are filled with inert packing media for the growth of biomass

|