The main treatment construction was made up of three
parts: (1) Pipe chute of advection sedimentation tanks. This
unit was used for water pretreatment and could effectually
remove TSS and oil. (2) The active filler unit, which was
the main purification unit for tidal wastewater. The active
filler was the waste oyster shell for which the porosity of
the active filler was 80. (3) Disinfection unit where the
outflow passing through was discharged for use.