| 摘要 |
1468091 Recovering fatty substances from aqueous effluents APOTHEKERNES LABORATORIUM FOR SPECIALPRAEPARATER AS 8 Feb 1974 [9 Feb 1973] 05893/74 Heading C5C [Also in Divisions C1 and C3] Fatty and/or proteinaceous substances are recovered from aqueous effluents by adding an acid hydrolysing metal salt to complex with the substance, reducing the pH to 5 or below if it is above 5, and precipitating the complex in the presence of added alkaline earth metal ions by raising the pH to 6 or more. The acid hydrolysing salt can be ferric sulphate, ferric chloride or aluminium sulphate. The pH can be reduced by adding mineral acid such as sulphuric acid. A calcium salt can be added in aqueous solution together with the acid hydrolysing salt to provide the alkaline earth metal ions and the pH can be raised by alkali metal hydroxide; alternatively CaO or Ca(OH) 2 can be added to both provide the alkaline earth metal ions and to raise the pH. The precipitated complex can be separated from the purified effluent by flotation achieved by the release of air dissolved in the water under pressure, sedimentation or centrifugation. The examples describe the treatment of effluents from a margarine factory, a tallow melting plant and a slaughterhouse. The precipitated complexes are resistant to autoxidation and can be included in animal fodder mixtures. |
