ENHANCING SILT QUALITY Russian patent published in 2009 - IPC C02F1/50 C02F11/14 A01N57/34 A01N31/12 

FIELD: chemistry.

SUBSTANCE: invention relates to application of efficient amount of non-oxidising water-soluble biocide in order to enhance silt quality due to reduction of silt propensity for swelling. For processing silt from industrial or household sewage, from industrial processes, including paper production, food industry and chemical industry, from household and municipal sewage of settlements for human living and activity, etc. is used. Biocide represents alkyl-substituted phosphonic compound. As alkyl-substituted phosphonic compound, sulphate, chloride, bromide, acetate or phosphate of tetrakis(hydroxymethyl)phosphonium (THPS) is used. Biocide efficiency is calculated by reduction of index of silt volume, determined by index Mohlman, which has to be not more than 200 cm³/g. Formulation of water-soluble biocide in preferable version can additionally include one or several following chemicals: surface-active substance, foam-extinguisher, anti-scale preparation, corrosion inhibitor, biocide, flocculating agent, additive for dehydration and dispersive agent.

EFFECT: enhancing silt quality due to considerable reduction of number of filamentous bacteria in processed silt, which reduces its propensity for swelling, with increase of useful microorganisms, for instance protozoa and worms in silt.

28 cl, 2 dwg, 3 ex, 3 tbl