SU998385A1 - Process for biochemically purifying effluents from the hydrolysis production - Google Patents

Description

fSt) METHOD OF BIOCHEMICAL PURIFICATION OF WASTE WATER OF HYDROLYTIC PRODUCTION

1 The invention relates to methods for the biochemical treatment of wastewater and can be used to purify wastewater from hydrolysis plants, as well as in other industries.

Methods for wastewater treatment are known, including pretreatment of effluent to increase the degree of purification by electrolysis 1 and the introduction of hydrogen peroxide into the effluent 2.

However, these methods are characterized by the complexity of pretreatment, the use of scarce and expensive reagents.

The closest in technical essence and the achieved result is a method of biochemical treatment of wastewater fermentation industries, in particular hydrolysis industries, including the preliminary introduction of fat-containing substances into wastewater, such as waste

oil and fat industry - soap stock 3.

The disadvantage of this method is the relatively low degree of purification.

The purpose of the invention is to increase the degree of wastewater treatment.

This goal is achieved by pretreatment of wastewater with titanium chloride production waste, which is preferably introduced in an amount of 0, g / l and the treatment process is carried out at pH 7-8, followed by biochemical treatment.

15

Chloride waste from the production of titanium (for example, sublimates of dust chambers, melts of slurry processing furnaces) is mainly a mixture of various metal chlorides - Al,

20, Fe, Ti, Ca, Mg, Hn, Na, Cr, Cu, J /, Zr, etc., among which are trace elements. In the treatment of wastewater, in particular, the hydrolysis production of BOflCtB, with chloride waste from the production of titanium, part of the organic pollutants that inhibit the biochemical treatment process (for example, lignohumic substances) precipitate. This is due to the formation of water-insoluble compounds between organic soils and polyvalent metal ions, as well as the formation of water-insoluble metal hydroxides and sorption of organic soils on their surface. The transfer of contaminants inhibiting the process of biochemical purification into sediment, as well as the introduction of trace elements with chloride waste into wastewater, leads to a sharp increase in the depth of their purification. In this case, the synergism of the stages of the process takes place, and the pretreatment of the effluent with chloride waste makes it possible to achieve a much greater depth of subsequent biochemical treatment than the preliminary dilution of the wastewater to the same concentrations of contaminants. The amount of chloride waste produced in titanium production is introduced into the waste water is 0.5-3.0 g / l, as at doses lower than 0.5 g / l the amount of COD mg 9980

BOD,

mg Oi / l 3620

Example 2. A post-harvest brew of a hydrolysis-yeast plant is treated with various doses of the melt 5 furnaces for the processing of titanium-mag pulps, g / l COD, mg 9810 9600 9230 9030 8620 BOD5, mg 02 / l “JlOO 4010 3990

780

360

23

nium plant according to example 1. The results of the dependence of the degree of pre-treatment of the dose of chloride waste are given in table. 2

Table2 P §-Atel of cleaning at a dose of chloride waste, g / l O o, 1 I 0,2 I OZ J 0,5 J, 0 2,0 j 3,0 G it, about 5,0 as pollution, remove at the pretreatment stage, it is very small, and an increase in the dose of more than 3 g / l practically does not lead to a further increase in the degree of pretreatment. For a more complete hydrolysis of chloride waste from the production of titanium, neutralization of hydrochloric acid formed during this process, and the conversion of polyvalent metal ions into insoluble hydroxides, the pretreatment process at pH 7–8 is alkalized with water, for example, with lime milk. Example. The post-harvest brew (PDR) of the hydrolysis plant is pretreated by adding to it the melt processing furnaces of the titanium-magnesium pulp processing plant in the amount of 2 g / l and alkalizing the flow with lime milk to fAi 8; the resulting sus-. The pension is stirred for 1 hour and the precipitate is separated by settling. Next, the waste water is subjected to biochemical purification in the aeration tank with adapted active sludge with a period of aeration of 24 hours and an active sludge concentration of 5 + 0.5 g / l. The cleaning results are given in the table. 1. Table 1 3770 ЗббО 3620 ЗБОО ЗБОО From the given data it is seen that at a dose of chloride waste less than 0.5 g / l, the decrease in the concentration of contaminants is insignificant, and the increase in dose over 3 g / l is almost leads to a further decrease in the concentration of contamination:% nenii, therefore, the pre-treatment process is preferably carried out at a dose of chloride waste in the range of 0,, 0 g / l. EXAMPLE 3. To prove the synergism of the stages of the proposed method, when the total purification effect exceeds the purification effect of each stage separately, the post-harvest brew of the hydrolysis plant is treated with chloride sublimates of the second dust chamber of the titanium-magnesium plant according to the conditions of Example 1; Parallel, the PDB is diluted with tap water to the same concentration in the MIC as after treatment with chloride wastes (and even less in the COD). Then biochemical treatment of wastewater is carried out under the conditions of example T. The results of the tests are shown in Table. 3Table 3

Claims (2)

Claim 1. The method of biochemical wastewater treatment of hydrolysis production, including pretreatment of wastewater, characterized in that, in order to increase the degree of purification, pretreatment is carried out by titanium chloride waste. 2. The method of pop. ^ characterized in that the treatment with chloride waste from titanium production is carried out in an amount of O, 5 ^- Zkg / m at pH 7 “8.