Removal of solid material content from fibrous suspensions - comprises filtering waste water, drying any solid to specified dry-matter content and mixing with sludge obtd. from further solid-liq. sepn.

摘要

A new procedure for removing solid material from fibrous suspensions, in which the waste water is further cleaned by a liq.-solid sepn., is characterised by the drying of the fibrous solid material in the suspension to a dry-matter content of 35-45 percent, and the mixing of this material with the sludge produced in the further treatment of the liq. which has been sepd. from it. The initial sepn. may be carried out using a rotary drum filter, and the bio-sludge produced in a subsequent microbiological treatment of the sepd. liq. may be blended with the dried material in a mixing machine. Alternatively, the initial sepn. may be performed in a screw press separator, and the sludge sepd. from the removed liq. in a decanting or flotation process, with or without the use of a flocculating agent, may similarly be blendd with the dried material in a mixing machine. USE/ADVANTAGE - Used for treating suspensions such as industrial and agricultural waste water. The foreign material content in the liq. passing to the waste water treatment plant or being used for spreading on the land is reduced, so that energy costs are reduced, nutrients are recovered, and the contamination of the land is reduced.