METHOD OF PRODUCING COAGULANT OF ALUMINIUM SULPHATE FROM SLUDGE OF WATER PRE-TREATMENT PLANTS Russian patent published in 2025 - IPC C01F7/74 C02F1/52 C02F11/12 

FIELD: water treatment.

SUBSTANCE: invention relates to purification of natural water by coagulation method, namely to production of coagulant of aluminium sulphate from sludge of water pre-treatment plants in order to ensure possibility of its reuse at water treatment plants of various branches of national economy. Method of producing a coagulant from aluminium-containing sludge of water treatment involves preliminary settling of the aluminium-containing sludge for 3-5 hours. Then aluminium-containing sludge in form of sol is decanted to density of 1.4-1.6 g/cm³. Further, the aluminium-containing sludge is treated with 2% solution of sulphuric acid with temperature of 30-40 °C in ratio of 10:1 by volume with stirring for 30-40 minutes. After that, the aluminium-containing sludge is settled for 5-6 hours and decanted to obtain a solution of the reduced coagulant.

EFFECT: enabling the possibility of extracting the coagulant of aluminium sulphate from the aluminium-containing sludge of pre-treatment plants with good coagulating properties and a good coagulant oxidability index, as well as reduced probability of sticking and hardening of decanted sludge during its treatment with sulphuric acid solution.

1 cl, 1 dwg, 5 tbl