Figure 1 shows an overview of the hybrid membrane bioreactor. HMBR is a combination of rotating biological contactor (plus Kaldnes media) and an external membrane. Effluent from bioreactor enters the membrane by a centrifugal pump and the sludge remained behind the membrane, which contains microorganisms, is returned to the bioreactor. Samples were collected from influent/effluent of RBC and effluent of the membrane. Physical properties of RBC and the membrane are shown in Tables 1 and 2, respectively.
Figure 1  Overview of the hybrid membrane.
Table 1  Physical properties of the rotating biological contactor
Length 40 cm  Width 27 cm
Height 20 cm  Total surface 2m2
Total volume 21.6 lit  Effective volume 18 lit
Cylinder diameter 20 cm  Cylinder length 10 cm
Stage 2  Rotational speed 10 rpm
Table 2  Physical properties of the membrane
Membrane type  Ultra filtration
Membrane material Polymer
Internal diameter 1.24 cm
Effective length 33 cm
Surface area 0.0128 m2