| S.No. | Flocs | Anaerobic Sludge Digester |
| (i) | Breakdown organic matter aerobically. | Breakdown organic matter anaerobically. |
| (ii) | Breakdown organic matter present in primary effluent. | Breakdown organic matter in secondary effluent. |
| (iii) | They do not produce biogas. | They produce biogas (mixture of methane, H2S and CO2). |
Detailed Answer:
Flocs are the mixtures of heterotrophic aerobic microbes that grow in aeration tank during secondary treatment of effluent. They consume a major part of the organic matter of the effluent. In anaerobic sludge digesters, anaerobic bacteria grow and digest the rest of the organic compounds and produce biogas.
