| 摘要 |
<p>The present invention relates to a process for treating settlings formed during the biological purification of municipal and industrial waste water and may be used in various fields of industry, in particular in paper and pulp production. A pre-thickened surplus activated sludge is subjected to treatment with white slime obtained at the state of causticizing green liquour in the sulfate-pulp production, while stirring. White slime is used in a volume ratio to the surplus activated sludge equal to 1 : 5 - 10. Thereupon, the sludge so treated is subjected to dehydration by filtering, preferably at a temperature of between 75 and 104 °C. The dehydrated settlings are dried and burned down. An ash residue so obtained as well as a clarified alkaline hydrolyzate are used in the manufacturing process of the sulfate-pulp production. The present process for treating the surplus activated sludge allows intensification of the filtration process, avoiding the use of expensive chemical reagents, a complete utilization of products obtained when treating the sludge as well as utilization of the sulfate-pulp production waste, that is white slime, with simplification of the production procedures and techniques and significant reduction of material costs.</p> |
