SU1000420A1 - Process and apparatus for biologically purifying effluents containing synthetic fatty acids - Google Patents

Description

This invention relates to aerobic / biological wastewater treatment. the oil refineries having shops of synthetic fatty kis-. lot (FFA and can beat, used for sewage treatment, production of synthetic fat substitutes containing fatty acids and their sols, PCST, aldehydes and other organic compounds.

: Wastewater from the production of synthetic fatty acids belongs to the category of highly concentrated waters. The total amount of impurities in the effluent water of the FFA in terms of dichrophic acidity (COD) is 1100019000 mg O / l, and in terms of biochemical oxygen consumption (GIC) g - 10,00017000 mg. Wastewater character: risen by elevated temperature (40 -45 ° C). By concentration of hydrogen ions, wastewater is acidic (pH 2.5-3.5). Even after neutralization of these waters, biological treatment is impossible due to their toxicity to microorganisms of activated sludge. After neutralization, the required dilution of wastewater is 20–25 times, which is practically impossible under production conditions,

The known method of biological: Wastewater treatment of production of Si1; Tetichi fatty acids from organic compounds with activated sludge in the aeration tank mixer with regenerator

tlJ.

The disadvantage of this method is that the neutralization of wastewater before entering them in aerotanks

10 is carried out with a reagent that produces significant amounts of sludge, for which water is removed through the contact reserve. P enters the sludge separators, and the sediment is pumped out of them by means of a pump into the storage tank. Even after neutralizing the waste water, a further dilution of about 20-30 times is required. Period. Aeration 40 hours. Creme addition, in wastewater treatment

20 FFA in active sludge is dominated by filamentous bacteria. The silt index drops to 350, and the silt settles poorly. Even the introduction of a regenerator, in which the performance of the aeration pool is three times larger, its performance check without a regenerator, and the condition of the sludge improves, does not guarantee the absence of swelling.

Closest to the proposed

30 by technical essence and achieved result is the method of biological purification of wastewaters, the production of fatty acids by activated sludge containing microorganisms of the genera Bacillus, Bacterium and microorganisms of the genera Planococcus, Planosarci pa at a concentration of sludge of 7-15 g / LЕ2 The known method reduces peri | However, aeEtion and increases the oxidizing capacity of the structure, however, an increase in purification efficiency is achieved with the fact that the treatment of waste water will be carried out at high concentrations of activated sludge, which requires a significantly higher air flow. In addition, despite the fact that bacteria are one of the main groups of organisms during purification with active sludge, they, unlike algae, do not contribute to an increase in dissolved oxygen, which is a very important factor in the purification of FFA wastewaters that consume significant amounts of oxygen. A known method of biological treatment of wastewater is the production of CI; tetic fatty acids is carried out by a system that includes an aerotene: a mixer with a regenerator and a device for supplying air to an aerotechnical mixer. This system provides wastewater treatment with a high concentration of contaminants. The degree of purification is. However, a disadvantage of the known system is the need to cultivate microorganisms on a specific agarized nutrient medium. The purpose of the invention is to increase the cleaning efficiency during combined treatment of wastewater containing synthetic fatty acids and petroleum products, by reducing the aeration period and air consumption, increasing the dissolved oxygen content and improving the sedimentation properties of activated sludge. : The goal is achieved by neutralizing the wastewater containing fatty acids to a pH of 6-6.5, mixing with the culture of Chlorella vulgaris algae in an amount of (, 3-6) 10 cells / ml and after keeping the mixture of algae with wastewater flotation and treatment; they are washed together with wastewater containing petroleum products in the Azrotec with activated sludge. It is preferable to hold the standing water with the algae culture for 4-6 days at; 20-25 C in natural light with aeration at night. The combined treatment of waste water containing synthetic oily;: Acids and petroleum products, with active sludge, is carried out at a concentration of the last 2.5-3.0 g / l with aeration time of 20-22 hours and an amount ensuring the content of oxygen in oxygen secondary clarifier 1-3 mg / l. : The ratio of wastewater containing synthetic fatty acids and petroleum products is 1: 6-1: 9. Phosphorus in the amount of 7-8 mg / l is additionally introduced as a biogenic additive to the stage of mixing wastewater with the Chlorella vulgar algae culture. A device for biological wastewater treatment, including an aeration tank with an air supply unit, is equipped with cultivators in the form of tanks directly adjacent to the aeration tank with overflow thresholds made in their common walls. At the same time, the device is equipped with a shield installed in the overflow threshold with the possibility of vertical movement as well as air release. by them, devices placed in the bottom part of the cultivator tanks and communicated with the air supply unit. The neutralization of wastewater FFA is carried out to a pH of 6.0-6.5. Under laboratory conditions, the ability of Chlorella Vulgaris algae to develop on FFA wastewater is tested at different pH ranges from 5.5 to 7.0. It was established that at pH below 6 (5.5-5, 7 wastewaters show toxic effect on algae, as a result of which over the course of the whole experiment (12 days) the number of algae cells does not reach the original and is much lower than at pH 6 , 06, 5. The use of artificial aeration at night (in the absence of photosynthetic activity of algae) increases the number of algae cells and significantly changes the ratio of living and dead cells in samples at pH 6.0-6.5 and slightly affects the ratio of living and dead cells at pH 5.5. With the presence of toxic action of sewage, water at pH 5.5, alkalinization to the indicated pH is excluded, since pH 6.0–6.5 is sufficient for normal development of algae in the cultivator, and alkalization to pH 7.0-7. , 5 does not significantly change the biomass buildup, but requires a large consumption of reagent. In addition, as a result of photosynthesis, the pH increases in the direction of alkalization and effluent with a higher pH enters the aeration tanks. Introduction to the algae cultivator Chlorella vujgaris in an amount, t3-6) - 10 cells / ml. Due to the fact that

when the amount of algae is less than 3 10 ° C / ml, the decrease in the concentration of organic substances and ammonium nitrogen is significantly less than with higher amounts of algae. In the case of the lower amount, the toxic effect of wastewater is more pronounced. Thus, with the initial amount of alga, drink 2, 5 O cells / ml higher, the percentage of dead algae cells and, moreover, biomass is growing more slowly. In this connection, in order to increase the effect of clearing at lower initial alumina concentration, it is necessary to increase the residence time of the wastewater in the cultivator, which is practically impossible. With the release of a specified amount of feeds, it is possible to periodically empty the cultivator by 60-70% and at the same time, new portions of algae are not introduced. The introduction of algae over a specified amount does not significantly improve the cleaning effect, but requires additional air flow for aeration at night time. .

Keeping in the cultivator waste water containing synthetic fatty acids with algae culture for 4–6 days at 20–25 ° C reduces the concentration of ammonium nitrogen by 60%, increasing the concentration of organic substances by 30–40%. 7.0-7.5, saturation of wastewater in the cultivator with oxygen. Maintain / process at 20-25 0 provides algae biomass build-up.

Growing algae in a cultivator under natural light with aeration at night makes it possible to provide normal conditions for the life of algae without an additional light source and round-the-clock aeration, since during the daytime oxygen is released as a result of the photosynthesis process, at night, in the absence of Photosynthesis is carried out by artificial aeration, as a result of which the algae is mixed and the environment is saturated with oxygen.

The results of the development of algae dilution water with natural and artificial aeration are given in TabjWl

When feeding wastewater from the cultivator to the aeration tank mixer, the cultivator is emptied by 6070%, i.e. they are not emptied with full flow. This makes it possible to fill in new portions of wastewater, which, in the presence of nutrient elements, algae are used as a nutrient medium, and also allows

to maintain a continuous build-up of algae biomass.

Joint treatment of wastewater in the aero-mixer with an active sludge concentration of 2.5-3.0 g / l and aeration period of 20-22 hours makes it possible to mineralize organic matter in the aeration tank-mixer, resulting in wastewater leaving the aeration basin m, imposed on wastewater entering the bioponds for purification.

Air is supplied to the aeration tank in an amount that provides the content of dissolved oxygen in the secondary clarifier of 1-3 mg / l. The lower limit is due to the fact that when the oxygen concentration is below 1 mg / l, anaerobic processes may occur in the sump. The optimum oxygen content is l / 2 mg / l; therefore, the upper limit (3 mg / l) is chosen for economic reasons, since the air consumption increases at a higher concentration.

The introduction of phosphorus ensures the normal viability of micro: active sludge and algae organisms, with small amounts of phosphorus. Filamentous forms of organisms predominate and absorption of organic nitrogen is reduced.

The ratio of wastewater containing FFA and petroleum products, 1: 6-1: 9. Wastewater SFA is classified as highly concentrated water. The amount of impurities contained in the said effluent; unstable and bichromatic oxidative capacity is 1100-19000 mg The ratio 1: 6 is used in the COD of FFA wastewater to 1100.0 mg O / l, a dilution of 1: 9 is impractical because the wastewater produced by FLC contains organic substances that are well oxidized biochemically , and serve as a nutrient medium for microorganisms of activated sludge.

For the implementation of the method of purification of waste water containing synthetic fatty acids and petroleum products, a system has been proposed that includes a cultivator for growing microorganisms, an aeration tank-mixer with a re-generator and an air supply unit.

Performing a cultivator in the form of two or more tanks ensures the continuous buildup of the pre-algae biomass in one of the tanks and the simultaneous emptying of the second tank by 60-70% into the aeration tank-mixer where the waste water enters with the algae.

The walls of the tanks adjacent to the aero-mix / 1-nd tank are made in the vice overflow threshold, which ensures a uniform supply of algae from the tanks to the aeration tank-mixer and at the same time allows us to leave sufficient amount of algae for subsequent biomass growth. In addition, the proposal to supply each of the tanks of the cultivator with air-guiding devices connected, for example, with a compressor, makes it possible to carry out aeration at night, which contributes to an increase in the content of dissolved oxygen in the medium and allows the algae to be evenly distributed in the tanks. The overflow threshold, equipped with a shield that is installed with the possibility of moving in a vertical direction, ensures the emptying of the tanks into the aeration tank for a given volume and in a certain mode, i.e. provides the ability to regulate the process. . The air outlet is installed at the bottom of the cultivator's tanks, which mixes the wastewater and lifts the algae that settle on. bottom in the upper layers of water, i.e. creates a flotation effect. Fig. 1 shows a system for the treatment of waste water containing synthetic fatty acids and petroleum products; a plan; Fig. 2 shows a section A-A in FIG. A system for treating wastewater containing synthetic fatty acids and petroleum products includes a cultivator 1 for growing microorganisms, an aeration tank-mixer 2 and a device 3 for supplying air to an aeration tank-mixer 2, the Cultivator 1 is made in the form of tanks adjacent to the aeration tank-mixer. there may be two or more adjacent walls 4 and 5 of these containers made in the form of overflow thresholds and provided with shields b and 7, each of which is installed in vertical guides 8 with the ability to move in ticking direction. Each of the tanks of the cultivator 1 is equipped with an air outlet device 9 connected, for example, to a compressor 10, to which the air supply device 3 to the aeration tank-mixer 2 is connected. The air outlet device 9 is installed in the bottom part of each of the tanks of the cultivator 1. Each of The containers of the cultivator 1 have a supply pipe 11 that supplies wastewater, and each of the latter is equipped with a controllable gate 12. The pipelines 11 are introduced into the bottom part of the containers of the cultivator 1. The method is carried out as follows. 0 Pipeline 11 into the cultivator 1 is fed with neutralized 23-25% ammonia solution to a pH of 6.0-6.5 and contains wastewater containing synthetic fatty acids. Depending on the opening of one or another controlled valve 12, the wastewater flows into one or to another pre-emptied cultivator capacity 11. After filling with water up to the level below the upper face of the shields 6 and 7, the culture of algae Chlorella vulgaris is added to the wastewater in an amount (3-6.10 cells / ml while controlling the initial concentration of the dissolved in water oxygen C and maintain the C concentration at night less than 3.0 mg / l by aerating the waste water with air supply through the air discharge devices 9. The flow of compressed air discharged through the Air discharge device 9 into the cultivator 1 to maintain the optimum concentration of oxygen dissolved in water, required for normal algae breeding in the cultivator 1, is calculated by the formula Cp-Cj where C is the equilibrium concentration of oxygen at a given temperature, g / m, the concentration of oxygen in the waste water poured into the capacity of the cultivator 1, the oxygen concentration that must be maintained during aeration to build up algae in the tank, g / m, the aerator constant, (for perforated pipes A 0.75); The depth of the air exhaust device 4 in the tanks of the cultivator 1, m / a, the amount of air supplied to the cultivator 1 directly: before discharging water from algae into the aeration tank 2, is calculated by formode - the vertical rate of water rising from algae from the air outlet to the surface water capacity of cultivator 1 (for effective flotation of algae in each individual case must be determined experimentally), m / s A. — acceleration of gravity, L — total length of air outlet device (for example, pipes), m. Since the cultivator 1 is open from above, natural light is provided, artificial lighting is possible if necessary. The treated wastewater from the production of synthetic fatty acids is also characterized by the fact that they have a constantly elevated temperature (40 ° C). The content of ammonium nitrogen in this wastewater reaches 300 mg / l. The lighting, temperature, and nitrogen content create favorable conditions for the development of water, and the phosphorus necessary for vital activity is introduced into the culture of 1 mg in the amount of 8 mg / l. In order to intensify the reproduction of fhlorella vulqaris at night, when the photosynthesis process ceases, aeration is carried out by supplying air from compressor 10 to devices 9. Compressed air supply to the bottom part of the cylinder 1 produces mixing (flotation of water and algae, m. E. The uniform distribution of algae in cultivar 1. The algal biomass increases 1.5 times on the fifth day. During the logarithmic growth phase of algae (5-6 days), the pH of the medium increases from 8.5 to as a result of photosynthesis. what happens is the preliminary per waste water. As a result of this preliminary treatment of wastewater from the production of synthetic fatty acids, the content of organic substances is reduced to 50%, and ammonia to 60%. After such a preliminary incubation for 5-6 days in one of the tanks of the cooler 1, the shield 6 is lowered below the water level fi of the tank of the cultivator 1 and the upper layers of the water, filled with algae, are dumped into the adjacent sludge cultivator 1 of the aeration tank 2 for further IIIIJ of treatment of saline water using active sludge concentration dissolved v 2,5-3,0 g / l. From the tank of the cultivator 1 to the aeration tank-mixer 2, such an amount of the mixture of sewage and algae is discharged so that the number of algae in the tank of the cultivator 1 remains at least .4 x 10 C / ml to reliably ensure a further continuous cultivation process. . After dumping the mixture of water with hydrogens from the same cultivator tank into the aeration tank-mixer 2, the shield 6 is lifted again, and waste water is supplied to the tank through pipeline 11, and the water is supplied to the set maximum mark and again kept for 5-6 days. At this time, in the aerotonic mixer 2, similarly, waste water with algae is discharged from the second tank of the cultivator 1. Depending on the volume of waste water, the number of tanks of the cultivator 1 is determined and their mode of operation and sequence are set. In the aero mixer 2, wastewater containing synthetic fatty acids is mixed after preliminary treatment and wastewater containing petroleum products. Algae / coming from the cultivator 1 in the aeration tank-mixer 2, intensify the cleaning process, improve the sedimentation properties of activated sludge, reduce the concentration of organic substances. Example. Sewage water production of synthetic fatty acids with pH 3.5 COD 8000 mg O / l 1 VPKPo, c. mg (l, the amount of dissolved oxygen equal to O is neutralized with a 23% ammonia solution to a pH of 6.0. Then this wastewater is fed into the cultivator in both sections, where the biogenic element phosphorus at the rate of 50 mg / l and the algae culture are introduced Chi vulqarts from such a calculation that the cell size was 4-10 cells / ml. The culture mixture was kept for 5 days at 20-25 seconds, the ammonium nitrogen content was maintained at 300 mg / l, and the phosphorus-containing substances were within 50 mg / l "Organic substances from waste water FFA should be squeezed by source carbon for microorganisms developing in a chultivator. The content of dissolved acid (kind is not less than 5 Mg / l supported by aeration with compressed air and thanks to the photosynthetic activity of algae, by the end of 5 days the amount of algae increases by 2 times) compared to the original At the same time, the content of organic substances in SECOND water is reduced by 40%, the COD of waste water of FFA for 5 days is 5000 mg O / l, the content of afLo-nitrogen is 75 mg / l. Then the water with algae is sent to the aeration tank, where it is mixed with wastewater containing petroleum products. The ratio of waste water SFA and containing petroleum 1: 6. After mixing, the waste water has the following characteristics: pH 7.0; COD 1000 mg O / l; BPKpg;, 950 mm All; ammonium nitrogen 25 MG / L} phosphorus e mg / l. The amount of dissolved oxygen is 2.0 mg / l. Wastewater treatment in aeroTenk takes place at a sludge concentration of 3 g / l and aeration period of 22 hours. The sludge index is 120 (before the application of algae, the sludge index is 400500). The amount of dissolved oxygen in the sump not less than 2 mg / l.

Processes and nitrification are satisfactory. - Wastewater pos-; The following cleaning agents have the following purification: COD 60.5 mg O / L, MIC 10.5 mg The degree of purification is 98.8%.

Comparative data of changes in the water quality of FLC after neutralization and treatment with a symbiotic culture of algae, the results of purification of wastewater containing FFA and oil products in aerotanks are given in Table 2.

The invention at its use in popular economics will allow to increase the efficiency of the wastewater treatment plants that receive water; synthetic fatty acids; as a result of improving the quality of activated sludge - termination of the removal of egs | | of sewage treatment plants, which when-J

leads to silting of the bottom of reservoirs and disturbance of the oxygen regime;

- to intensify wastewater treatment, since microorganisms of alp – bacterial communities use carbon of synthetic fatty acids

and petroleum products as sources of nutrition

- to improve the content of dissolved oxygen in the wastewater of the production of FLC before entering them in aerotanks,

-use of the proposed cultivator control will allow you to use it simultaneously for cultivation

5 Growth of algae, saturation of wastewater produced by FFA with oxygen and for pretreatment of rting waters before entering the biological treatment plant.

production day

5.5 It is 6.1

5.6 7.3

five

5.6 7.5

5.7 8.2

12

5.9 8.7

100

ye. detected

100

35

65,100

Not found

45 2

55 98

45

55 97

3

, 0

65 94

35

6, 0 00 Not detected, - 6040 90, 10 982 4555 6535 7525 4852 7228 7822 7525 7030 6535

N

oh oh

mn

GI

I

ABOUT

about r

about in

in r- o

PTS

I

oh oh

with

about in

mn

I

oh oh

g-1

oh oh

CN

.hh I

oh oh

about

1L go ID

I

o cho r w

oh oh oh

about ohm st

oh oh oh. -i i

n m

oh oh

VO 3

HF I

about i

Yu

R

tn

with

0

00

VO

oh oo

hVO

Claims (2)

and The claims 1. A method of biological treatment of waste water containing synthetic fatty acids with activated sludge, which is aimed at increasing the efficiency of cleaning with combined treatment of stationary waters containing synthetic fatty acids and petroleum products for reducing the aeration period and. air consumption, increasing the content of dissolved oxygen and improving (sedimentation properties of auxiliary sludge, waste water containing (synthetic synthetic fatty acids, neutralized to a pH of 6.0-6.5. mixed with a culture of Chlore algae On jvulgari.s in quantity). 10 cells / ml and after keeping the mixture of algae with sewage is floated and treated together with the wastewater containing oil products; you are in active aeration sludge. 2. The POP.1 method is different from that withstanding the waste water containing synthetic cie fatty acids, with water culture | grows for 4–6 days at 20–25 s under intense illumination at the radio at night; 3. The method according to claim 1, characterized by the fact that the joint treatment of waste water containing synthetic oily acids and oil products, with active sludge, are carried out at a concentration of 2.5–3.0 g / l of the last aeration time equal to 20–22 h and an Amount providing the content of dissolved oxygen in the second (JPH4HOM septic tank 1-3 mg / l 4. The method according to PP.1-3, about tl and ch and jo and and the fact that the ratio of the wastewater containing synthetic. What kind of fatty acids and petroleum products | 1gb-1: 9. 5. The method according to claims 1-4, characterized by the fact that at the stage of discharging waste water from the Chlorella vulgaris iodine culture, there is additionally apo G as a biogenic additive phosphorus in the amount of 7-8 mg / l. . 6. A device for the biological treatment of wastewater containing synthetic fatty acids, including an aeration tank mixer with an air supply device, characterized in that, in order to increase the efficiency of treatment during the joint treatment of wastewater containing synthetic fatty acids and petroleum products, by reducing the period of aeration and air consumption, increasing the content of dissolved oxygen. and improving the sedimentation properties of activated sludge, it is equipped with cultivators in the form of | directly adjacent to the ae I-7 the device according to claim 6, with the fact that it is equipped with | a shield installed in the overflow inopora with movements: In the vertical direction, as well as in the air outlet devices, placed in the bottom part of the cultivator's bones and communicating with the air supply device. I Sources of information, taken into account during the examination I 1. Baz kina.N.А . Concentrated industrial wastewater treatment. Moscow, publishing house of construction literature, 1958, pp.19-32. 2. USSR author's certificate No. 655658, cl. C 02 F 3/34., 1979.