| 摘要 |
<p>Sludge is subjected to anaerobic digestion and the digested sludge is subjected to wet-air oxidation at at least 120 DEG C. to reduce the COD by less than 55%. At least a portion of the resulting effluent is separated from residual solids, cooled so that on its return to the digester the temperature is maintained between 30 DEG and 60 DEG C. while the ammonial nitrogen content of the digester is maintained below 1 gm./litre, e.g. by evaporation.</p> |
