SU1740324A1 - Method for drilling sewage purification - Google Patents

Abstract

The invention relates to physico-chemical treatment of drilling waste water, in particular, to the reagent treatment of drilling waste water containing dispersed clay, oil and oil products, organic chemical reagents and mineral salts, and allows to increase the degree of purification and reduce the duration of the process of settling. , aluminum sulphate in the amount of 5–10 g / l is introduced into the drilling waste water and flocculant is a mixture of polyacrylamide with copolymer of maleic anhydride with acrylamide taken in molar Ocean 3: 7 and nitriltri- methylphosphonic acid with the following ratio of components, g / l: polyacrylic Lamido 0.5 - 1.0; Maleic anhydride copolymer with acrylamide 0.5-1.0; nitryltrimethylphosphonic acid 0.1-0.2. The drilling water is settled, the sediment is separated. The method allows to increase the degree of purification from suspended substances up to 99.8% of petroleum products 100%, COD 87% and reduce the duration of formation to 5-7 minutes. 2 tab. (L

Description

The invention relates to methods for physico-chemical treatment of drilling wastewater, in particular, to methods for the treatment of drilling wastewater (BSW), containing dispersed clay, oil and oil products, organic chemicals and mineral salts.

A known method of treating drilling wastewaters with flocculant polyacrylamide in the presence of an organic additive, nitrile trimethylphosphonic acid.

The disadvantage of this method is the low degree of purification of BSV from organic pollutants, primarily from oil.

and petroleum products, as well as a significant consumption of flocta nta.

A known method for treating BSV is by introducing coagulant aluminum sulphate and flocculating polyacrylamide, and separating the precipitate by settling.

The disadvantage of it is a low degree of binding of contaminants in a colloidal state of organic pollutants, including oil and oil products, a large consumption of reagents and a long time of settling.

The purpose of the invention is to increase the degree of purification by shortening the process of settling.

h

4 About iCO hO, Al

The method consists in treating drilling waste water with coagulant - aluminum sulphate and flocculant - polyacrylamide and sedimentation of sediment, and aluminum sulphate is introduced in an amount of 5.0-10.0 g / l, and polyacrylamide is pre-mixed with nitrile trimethylphosphonic acid with maleic anhydride copolymer, acacrylamide, obtained at a molar ratio of monomers of 3: 7, respectively, in the following ratio of components, g / l:

Polyacrylamide 0.5 - T-, 0

Maleic copolymer

anhydride with acrylamide 0.5-1.0

Ithriltrimethylphosphonate

acid0.1 - 0.2

The copolymer of maleic anhydride with acrylamide has the following macromolecule structure:

sn2-sn

The copolymer is characterized by the following indicators: copolymer content of 6.3 wt.%; the molar ratio of monomers in the copolymer (maleic anhydride – acrylamide) is 3: 7; specific viscosity of a 1% solution of copolymer 5.2.

At the exit of the proposed range, the degree of binding of contaminants decreases, the time of sedimentation and the consumption of reagents increase.

The method is carried out as follows.

Separate coagulant and flocculant solutions are prepared. To do this, aluminum sulfate is dissolved in a certain amount of water. Separately, polyacrylamide is also dissolved in a certain amount of water; a copolymer of maleic anhydride (MA) with acrylamide (AA) is added with stirring. and then the calculated amount of nitrile trimethylphosphonic acid is introduced. The resulting coagulant and flocculant solutions are successively introduced, with stirring, into the drilling waste water until flocculation (start of coagulation). The flakes formed during the purification are separated by settling.

The tests were carried out on the drilling waste water with the following indicators: chemical oxygen consumption (COD) 2150 mg / l; content of oil and oil industry 5 10

15

20

25

thirty

35 40

45 50 55

Duct (NP) 870 mg / l; suspended matter content (IV) 5178 mg / l.

These indicators are determined by standard methods adopted in the practice of water treatment.

Aluminum sulphate (GOST 12966-75), polyacrylamide (TU 6-01-049-81), nitrile trimethylphosphonic acid (TU 6-02-1171-79) and a copolymer of maleic anhydride with acrylamide are used to carry out the treatment of drilling waste water. obtained by experimental technology.

PRI me R 1 (prototype). 115 g of aluminum sulfate (11.5% by weight) are dissolved in 885 g of water (88.5 wt.%). Then, 18.5 g (1.85% by weight) of polyacrylamide (PAA) are dissolved in 981.5 water (98.15% by weight), then a solution of aluminum sulfate is added to 1 kg of drilling waste water and, after mixing, the solution of floccule nta Such water is left to suck. After the floc has precipitated, water is characterized by the properties given in Table 1.

Example 2. In 950 g of water (95.0 wt.%) 50 g of aluminum sulfate (5.0 wt.%) Are dissolved. Then, 9 g (1.0 wt.%) Of polyacrypamide, 10 g (1.0 wt.%) Of a copolymer of maleic anhydride with acrylamide and 2 g (0.2 wt. .%) nitryltrimethylphosphonic acid. The resulting solution of aluminum sulfate and a solution of a mixture of polyacrylamide, a copolymer of maleic anhydride with acrylamide and nitrile trimethylphosphonic acid are successively added with stirring to 1 kg of drilling waste water. The BSW is then stirred for 2 minutes and allowed to settle. After 7 minutes, the formed flakes precipitate. After precipitation, water has a composition v, characterized by the following properties: COD 87.3%, NP 100%, suspended solids (in a colloidal state) 99.9%; precipitation time 7 min

PRI me R 3. In 900 g of water (90.0 wt.%) 100 g of aluminum sulfate and 10.0 wt.% Are dissolved. Then, 9 g (0.5% by weight) of polyacrylamide, 5 g (0.5% by weight) of a copolymer of maleic anhydride with acrylamide and 1 gO, 1% by weight are dissolved in 989 g of water (98.9% by weight) with stirring. .%) nitryltrimethylphosphonic acid. The resulting aluminum sulphate solution and the solution of a mixture of polyacrylamide, a copolymer of maleic anhydride with an acrylate of nitrile trimethylphosphonic acid Di are subsequently added, with stirring, to 1 kg of drilling waste. The BSV is then stirred for 2 minutes and allowed to suck. After 7 minutes, the formed flakes precipitate. After precipitation, water has the following composition and is characterized by properties: COD 86.0%; NP - 100%; suspended solids 99.8-, precipitation time 5 min.

PRI me R 4. The composition is prepared analogously to examples 2 and 3.

An analysis of the above data suggests that the method allows an increase in the degree of binding of contaminants in the colloidal state, reduces the time of sedimentation and reduces the consumption of reagents.

Table 2 shows the effect of the ratio of monomers in the copolymer of maleic anhydride and polyacrylamide.

Analysis of Tables 1 and 2 shows that outside of the claimed ratio of components, the degree of binding of contaminants in the colloidal state decreases, the settling time and the consumption of reagents increase.

The method increases the degree of binding of contaminants in a colloidal state, from organic contaminants (COD) from 80.8 to 87.3%, for oil and oil products from 88.6 to 100%, for suspended substances from 83.2 to 99.9, reduces the settling time from 16 to 5 min, i.e. 3 times, reduces the consumption of reagents by 25%.

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION A method for purifying drilling waste water, including treating with coagulant aluminum sulphate and flocculant polyacrylamide and separating the sediment by sedimentation, characterized in that in the amount of 5.0 - 10.0 g / l, and the polyacrylamide is pre-mixed with nitrile trimethylphosphonic acid with a copolymer of maleic anhydride with acrylamide, obtained at a molar ratio of monomers of 3: 7, respectively, with a trace present component ratio, g / l: Polyacrylamide 0.500-1.0 Copolymer of maleic anhydride with acrylamide 0.5-1.0 Nitrile trimethylphosphonic acid 0.1 - 0.2 The results of the study of the method of processing drilling wastewater Table 1 The results of the evaluation of the effectiveness of the copolymer obtained at different molar ratios of the initial monomers table 2