SLUDGE TREATMENT METHOD Russian patent published in 2012 - IPC C02F11/14 C02F1/56 B01D21/01 

FIELD: chemistry.

SUBSTANCE: invention can be used to treat organic and oily sludge at treatment facilities for municipal wastes, agricultural and food industry wastes. To realise the method, a lime-based alkaline agent and at least one anionic organic flocculant are added to the sludge, the sludge undergoes flocculation and the flocculated sludge is separated into dehydrated sludge and a liquid phase. The sludge meant for dehydration has pH lower than 9. The lime-based alkaline agent is selected from a group comprising unslaked lime, powdered lime which is partially or completely slaked, or slaked lime in form of a suspension in an aqueous phase which, in order to achieve pH=12 in the aqueous NH₄Cl/(NH₄)₂HPO₄ solution having pH=7.5, a time t_pH12 equal to or less than 90 s is required. The anionic organic flocculant is an anionic polymer, having average molecular weight higher than 500000 Da, preferably higher than 1000000 Da, more preferably from 5·10⁶ to 35·10⁶ Da and even more preferably from 15·10⁶ to 30·10⁶ Da.

EFFECT: method provides a simple, fast and continuous technique while achieving complete flocculation and obtaining a homogeneous, stable, dehydrated sludge.

10 cl, 6 ex, 3 tbl