| 摘要 |
<p>1. A method of sewage treatment in a multistage biological treatment process, characterized in that during the multistage biological treatment process, at the primary stage A, a portion of sludge O is separated and treated separately by means of anaerobic fermentation in tank Bf, and where the supernatant Qf separated during anaerobic fermentation of this portion of sludge O is diluted with treated effluent Qn and used for agricultural application because of nutrients it contains, while the remaining portion of sludge O from the primary stage A and all additional sludge accumulating progressively in the next stage A1 and consecutive stages of the treatment cascade A2, A3...An of the biological process, is thickened at least during stages A1 and A2 of the treatment cascade and retained in the system of multistage purification process, and after aerobic stabilisation that sludge is disposed of at time intervals different for each stage, and when the mass of the sludge separated from the primary stage is below 65 g/M x day while the total mass of sludge separated from all other stages of the treatment process is over 10g/M x day.<IMAGE></p> |
