Abstract: Research on bio-membrane in treating wastewater from regenerated papermaking by bio-contact oxidation was carried out, and the result indicated that active thickness of the bio-membrane was between 70 and 100 μm. During the course of membrane formation, filamentous bacteria are the main biota, with less flagellated protozoan and ciliates, so that the activity of the membrane is relatively poor. In case of normal running, fixed ciliates are the dominant protozoan, the biota of the bio-membrane is relatively stable, and the removal rate of COD is kept steadily around 88%.

Key words: wastewater from papermaking, wastepaper, bio-membrane, biota, bio-contact oxidation