| 摘要 |
<p>By means of a biological waste water purification process, on the one hand clarified water and on the other hand products for soil treatment are obtained which, in a cyclic process, return to the soil those substances which were previously withdrawn from it by biological processes. In this process the sedimented sludge is subjected to anaerobic fermentation which is prematurely terminated by adjusting the pH to below 6.3. The overflow of the sludge tank is passed via a filter bed which preferably comprises ion-exchanging and adsorptive mineral solids, if appropriate activated carbon, and basic substances. The laden filter mass, together with the sludge, is subjected to a final digestion process. <IMAGE></p> |
