METHOD OF AFTERPURIFICATION OF WASTE LIQUID FROM PHOSPHATES Russian patent published in 2021 - IPC C02F9/00 C02F1/58 C02F101/10 

FIELD: waste processing and disposal.

SUBSTANCE: invention relates to reagent post-treatment of waste water from phosphates and can be used for post-treatment of urban effluents with their subsequent discharge into coastal zones of seas. Method of post-treatment of waste liquid from phosphates consists in the fact that at stage of physical and chemical treatment in biologically treated waste liquid is introduced concentrate of reverse osmosis plants, formed during desalination of sea water, containing magnesium and calcium ions, in ratio of 1: 0.04–1:0.05, i.e. per 1 m³ of biologically treated waste fluid is fed with 0.04–0.05 m³ of concentrate, with introduction of sodium hydroxide in it, which increases pH to 10.5. To accelerate the process of crystallization soluble salt of orthophosphoric acid in an amount of air supplied 0.5–0.6 m³/m³ of waste liquid. Obtained chemical precipitate can be used as organomineral fertilizer.

EFFECT: technical result consists in reduction of phosphate concentration in biologically treated waste liquid, reduction of operational costs for purchased reagents, as well as reduction of negative impact on environment.

1 cl, 1 dwg, 1 tbl