| 摘要 |
PURPOSE:To lower the water content of a dehydrated cake, by a method wherein soluble silicate is added to org. sludge and, thereafter, an org. cationic high- molecular flocculant and water soluble multivalent metal salt are added to the sludge to form flocs which are then dehydrated. CONSTITUTION:An org. cationic high-molecular flocculant such as demethylaminoethyl acrylate and water soluble multivalent metal salt such as aluminum sulfate or ferrous sulfate are added to org. sludge such as sludge from an excretion purifying tank to which water soluble silicate such as sodium silicate is preliminarily added to form flocs. The cationic high-molecular flocculant and the water soluble multivalent metal salt may be added simultaneously or successively in this order. The flocs formed by flocculation are subjected to dehydration directly or after separated water is removed by a centrifugal dehydrator or a vacuum dehydrator. The obtained dehydrated cake can be subjected to drying, incinerating and composting treatments.
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