SU1265151A1 - Method of preparing waste water for biological treatment with active silt - Google Patents

Abstract

The invention relates to the treatment of wastewater of tanneries, mainly the drainage of tannin tanning from organic matter, and allows an increase in the degree of purification. For carrying out the process, the spent tanning solution is moistened with a milk extract. Calcium hydroxide is added to the mixture until pH 9-10. The solution is stirred and the precipitate is separated by centrifugation. To purify wastewater, the clarified liquid is filtered through activated carbon. The method makes it possible to achieve the degree of purification of wastewater containing sewage for COD 73.7% and for tandeas 89%. 1 hp ff, 1 tab.

Description

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SP The invention relates to the treatment of wastewater of tanneries, mainly drain tannic tanning. The purpose of the invention is to increase the degree of wastewater treatment from tannds. Example 1. The spent tanning solution is mixed with whey. The serum solution is 1 g of proteins per 1 g of tanning agents. Calcium hydroxide is added to the mixture until pH 8-9; ten; 11.5; 12. The solution is stirred for 30 minutes. The coarse 11 flakes are separated from the liquid by centrifuging for 5 minutes at a speed of 8000 rpm. The clarified liquid is purified from organic impurities by filtration through activated carbon. The minimum contact time is 10 minutes. The indicators characterizing the original spent tanning solution, the following: COD 190 g / l, the content of tannides 83.2 g / l. The results of purification of tanniferous wastewater are presented in the table.

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From the obtained results it can be seen that the optimum pH of the process is 9-10.

Claims (2)

Example 2. A spent tanning solution is mixed with milk serum. Calcium hydroxide is added to the resulting mixture to a pH of 9-10. Whey protein consumption is O, Si 1.0; 1.5; 2.0 g white 50 per 1 g of tanning agents. The solution is stirred for 30 minutes. The YKf pellets are separated from the liquid by centrifugation for 5 minutes at a speed of 8000 rpm. The 0c55 veterinary liquid is purified from organic impurities by filtration through activated carbon. The minimum contact time is 10 minutes. COD; T - the content of tannides; tanidov. 31 The results of purification of tanniferous wastewater are presented in the table. From the obtained results it can be seen that the optimal consumption of the milk curd should be taken at the rate of 1-2 g of proteins per 1 g of tannides. In the examples given, in all the cases considered, no purified tannides were found in the treated wastewater after filtration through activated carbon; the water was completely discolored. The proposed purification method provides a fairly high degree of purification by COD 68.4 - 73, /% after coagulation and separation of the precipitate and 99.5 99, 8% after filtration through activated carbon versus 54% by a known method, a high degree of purification from tannides 84.6 -88.8% after coagulation and separation of sediment and 100% after filtration through activated carbon. 14 Tlo, compared with the well-known proposed method of purification of thistine-containing water, provides an increase in the effect of purification from organic tanning substances, saving synthetic flocculants, as well as reducing reagent costs. Claims 1. A method for purifying tannins-containing sewage from organic impurities, including flocculating treatment and separating sludge, characterized in that whey protein is used as flocculant in order to increase the purification rate and the process is carried out in an alkaline medium . 2. The method according to claim 1, which is otdichusch and with the fact that the process is carried out at a pH of 9-10 and protein is administered in the amount of 1-2 g per 1 g of tannides.