RU2309128C1 - Method for treatment of bottoms in oil-slime collectors - Google Patents

Abstract

FIELD: oil-extracting and petrochemical processing industry.

SUBSTANCE: invention relates to a method for treatment of bottoms in oil-slime collectors formed in processing process of industrial waste, in particular, in oil-extracting and petrochemical processing plants. Deposit is mixed with lime material in the ratio = 3:1 into collector directly and prepared mixture is mixed with clay material additional with residual moisture 20-40% into collector also wherein the ratio deposit : lime material : clay material = 3:1:1. Then mixture from collector is fed to drying under natural conditions up to 30-40% of moisture. After partial drying the mixture is subjected for anaerobic biological treatment in the presence of nutrient medium wherein nitrogen-phosphorus compounds are used as nutrient medium, for example, ready fertilizers, and as lime material waste from heat and electric power plant are used: lumpy lime (incompletely burned material) or slime from chemical water treatment. Additional treatment is carried out with clay or drilling slime. Invention provides enhancing effectiveness for protection of environment from effect of processing waste of bottoms based on liquidation of oil-slime collectors and possibility for obtaining commercial products.

EFFECT: improved treatment method.

4 cl, 5 dwg, 9 tbl, 2 ex

Description

The invention relates to a method for cleaning bottom sediments of oil sludge accumulators formed during the processing of industrial wastewater, in particular at oil producing, oil refining enterprises.

A known line for the processing of oil sludge and bottom sediments of oil traps, flotators and sludge collectors (RF patent 2078739, С02F 9/00, 1993), in which oil sludge and bottom sediment are separated at a temperature of 45 ° C, the bottom sediment is subjected to heat treatment with steam at a temperature of 80 ° C in the presence of a demulsifier and the three layers formed are separated: purified oil product, purified water and mechanical impurities.

The disadvantage of this method is the high content of petroleum products in mechanical impurities (5.8-7.3 vol.%).

A known method for the treatment of sewage sludge (RF patent 2121982, С02F 11/00, 1995), in which the primary sludge and excess sludge is subjected to anaerobic digestion for 6 days, aerated one day, washed with two volumes of water together with the flocculant anion and condense. Then 10% of the precipitate is subjected to aerobic stabilization for 6 days, the precipitate is treated with a cationic flocculant and mechanically dehydrated.

The disadvantage of this method when processing sludge at an oil refinery is the high content of oil products (3.8-4.1 vol.%).

A known method of biological wastewater treatment (US patent 4915840, C02F 11/02, 1990), in which the compacted excess activated sludge is subjected to mechanical dehydration using flocculants. Dehydrated sludge is fed to aerobic mineralization for 18 days at a temperature of 35-75 ° C and / or anaerobic digestion at a temperature of 20-50 ° C or 45-60 ° C for 15-30 days. The precipitate after aerobic and / or anaerobic treatments is composted or subjected to either acidic or alkaline treatment.

The disadvantage of this method is the high residual oil content in the resulting precipitate (4.2-5.1 vol.%).

A known method for the purification of oil sludge and soil (patent of the Russian Federation 2116265, С02F 11/00, 1996), according to which oil sludge is heated to 40-50 ° C with a demulsifier and defended with its separation into oil, water, sludge and oiled mechanical impurities. Then the mechanical impurities are washed with a solvent and steam and neutralized under aerobic conditions at a temperature of 30-35 ° C for 2-3 days and the cleaned mechanical impurities are transported to the environment or used in the production of building materials.

The disadvantage of this method is the high content of residual oil in purified mechanical impurities (3.1-3.8 vol.%).

The closest in technical essence is a method for cleaning bottom sediments (RF patent 2 246 451 С02F 11/02, 2003), including dewatering a suspension of bottom sediments and water, heat treatment of sediment, biological treatment, then the sediment is mixed with soil and sawdust in a volume ratio 1: 1: 1 and subjected to aerobic purification at a temperature of 20-30 ° C, humidity 40-60%, biomass flow rate of 0.1-0.2 m ³ / m ³ with a concentration of 3-5 kg / m ³ .

The disadvantages of the prototype are:

1. The need for preliminary preparation of a suspension of bottom sediments with water;

2. For the implementation of the invention requires an additional site and a project on it, as well as special equipment. According to Federal Law No. 89-ФЗ On Production and Consumption Wastes, the project is approved in the established manner.

3. The disadvantage of the prototype is also the process of anaerobic biological treatment within 24 hours is clearly insufficient, since the process takes place for at least 6 months at a temperature of at least 10 degrees and in the presence of oxygen.

In addition, the short-term bioprocessing of sediments in laboratory conditions does not give confidence that in industrial conditions the results will be similar.

The resulting soil in an industrial environment according to the prototype will differ from laboratory ones in the increased content of oil products and cannot be used for economic purposes. This soil does not meet the standard for GOST or TU.

The basis of the proposed invention is the task of increasing the efficiency of environmental protection from the impact of waste from processing bottom sediments due to the elimination of oil sludge collectors, the possibility of obtaining marketable products and the rehabilitation of oil sludge accumulators.

The problem is solved in that in the method of cleaning bottom sediments of oil sludge accumulators, including biological treatment of sludge, mixing it with waste, according to the invention, the sludge is directly mixed in the reservoir with lime material in a ratio of 3: 1. Then, the resulting mixture is additionally mixed with clay material with a residual moisture content of 20–40% in the ratio of the total mixture 3: 1: 1 in the accumulator, then the mixture from the accumulator is sent for drying under natural conditions to 30–40% humidity, after partial drying the mixture is subjected to anaerobic biological treatment in the presence of a nutrient medium, while nitrogen-phosphorus compounds, for example, prepared fertilizers, are used as a nutrient medium, and waste from thermal power plants: limestone in lump form is used as lime material ) Demineralizer or slurry, and additional processing or produce clay cuttings.

The technical characteristics of limestone in lumpy form (not finished) of chemical water treatment sludge, clay and drill cuttings are given in tables 1-5.

The liquid layer — floating oil and water — is centrifuged, and the remaining bottom sediment has a hazard class III for the environment (OPS).

Mixing directly in the accumulator of bottom sediment with lime material (limestone in lumpy form or chemical water treatment slurry) in the ratio 3: 1 is carried out by an excavator or bottom cultivator (Fig. 1 is a top view of the sludge collector, Fig. 2 is a view of the accumulator along section A-A).

1 - pipe layer; 2 - bottom cultivator; 3 - sludge collector; 4 - cable; 5 - oil layer; 6 - water layer; 7 - bottom sediment (sediment).

The resulting mixture corresponds to hazard class 4 for OPS, but the remaining oil can be desorbed, i.e. Separate as a result of precipitation.

Clays and drill cuttings contain structural elements of the montmorillonite group | (ОН) ₄ Si ₈ Al ₄ O ₂₀ | Н ₂ О of a layered structure, which is a highly effective adsorbent for the oil part of the bottom sediment.

The prepared mixture in the drive is additionally mixed with clay material (clay or drill cuttings) in the ratio of the total mixture 3: 1: 1. Pre-clay material is dried to a residual moisture content of 20-40%.

The quality of the mixture thoroughly mixed in the drive corresponds to the marketable product - insulating material IM-1 TU-5717-01-48855219-2004, the composition and technical requirements of which are given in Table 6.

In the insulating material IM-1, the oil part is firmly adsorbed in the montmorillonite mineral and is not desorbed by atmospheric precipitation.

The insulating material made in the drive is not controlled by Rostekhnadzor (environmental authority), and therefore it is discharged from the drive to the site, and thus the sludge collector is cleaned.

At the site, the material IM-1 is partially dehydrated, the separated water is subjected to centrifugation.

As a result of partial dehydration, IM-1 pores are saturated with atmospheric oxygen. A nutrient medium (nitrogen and phosphorus compounds), for example, mineral fertilizers, is introduced into IM-1.

The nutrient medium is introduced in the summer during loosening and shoveling 2-3 times at an air temperature of at least 5 ° C. In this case, the mass of IM-1 is additionally saturated with atmospheric oxygen and natural microorganisms multiply rapidly.

Examples of the invention.

Laboratory studies and industrial tests were carried out using bottom sediments from storage unit 13 located at the Ufa city landfill for municipal solid waste in the village. Cherkasy (figure 3)

Pos. 7-20 - sludge collectors 40 × 200 m, depth 5 m. I-II - storage area for household and non-toxic industrial waste; III - storage area for industrial waste; IV - old disposal of industrial waste; V - storage area of OJSC “Ufaorgsintez”.

Floating oil and water, the composition of which is given in table 7, was pumped to the treatment facilities of Ufaneftekhim OJSC. Physico-chemical characteristics of the bottom sediment from sludge collector No. 13 are shown in table 8.

The degree of harmful effect of bottom sediment from sludge collector No. 13 on OPS is average. Waste hazard class III (1000> K _i = 179> 100) is a moderately hazardous substance.

The moisture content of clay materials (clay or drill cuttings) is limited to a residual moisture content of 20-40% due to the content of structural elements of the montmorillonite group, which swells from water. The higher the content of montmorillonite groups, the higher the apparent clay moisture extracted in the quarries, but the clay easily crumbles.

The main clay groups shown in Table 5 are characterized by the content of montmorillonite (M) and career humidity (H ₂ O), respectively.

I - M (50-70%), H ₂ O (35-40%);

II - M (30-50%), H ₂ O (25-35%);

III - M (20-30%), H ₂ O (22-25%);

IV - M (0-20%), H ₂ O (20-22%).

Within the specified humidity, the process of mixing the mixture (sediment - calcareous material) with clay in a ratio of 3: 1: 1 passes technical easily. In case of excess of humidity above 40%, the total mixture is sticky liquid dirt and the mixture is not sufficiently mixed.

The cuttings water cut is 91.07% (Table 3) and the dried cuttings contain ~ 60-90% montmorillonite and 10-40% cuttings. High humidity does not allow to obtain high-quality insulating material IM-1. Therefore, drill cuttings are dried to a residual water content of 20-40%.

Received IM-1 from sludge collector No. 13 is sent for drying to a residual moisture content of 30-40%. At humidity above 40%, the pores are not sufficiently released from water, while they are slightly saturated with oxygen. Residual humidity of 30-40% is the optimal moisture level for the life of natural bacteria.

Example 1

The laboratory test results shown in Table 9 show that mixtures of 3 hours of bottom sediment and 0.5 hours of lumpy form limestone (or chemical water treatment sludge) have a hazard class III for OPS.

To obtain a mixture of the IV hazard class, the ratio of components should be 3: 1.

The main technical requirement of TU for the insulating material IM-1 is that the filtration coefficient should not exceed not more than 0.864 m / day.

With the ratio of the components of the mixture of 3 parts of the bottom sediment from the 1st part of limestone in lumpy form (or chemical sludge cuttings) and an additional 1 part clay (or drill cuttings), the filtration coefficient is in the range 0.68-0.75 m / day which is less than 0.864 for technical requirements.

Example 2

Industrial tests were carried out using the following components: bottom sediment from reservoir No. 13 - 3 hours, limestone in lump form - 1 hour, drill cuttings - 1 hour, i.e. 3: 1: 1 ratio.

According to the invention, limestone in a lumpy form (not finished) in an amount of 4000 m ³ , a ratio of 3: 1, was unloaded to the bottom sediment in the accumulator No. 13 in an amount of 12,000 m ³ .

The mixture was thoroughly mixed with a bottom cultivator. The degree of harmful effect of a mixture of oil sludge with nepal on OPS low hazard, hazard class IV (10 <ΣK _i = 17.1 <100).

The pre-dried drill cuttings with a moisture content of 30% in an amount of 4000 m ^{3 were} unloaded onto the prepared mixture.

The mixture was again thoroughly mixed. The quality of the product obtained in the pit corresponds to the insulation material IM-1 TU 5717-001-48855219-2004, the actual filtration coefficient was 0.55 m / day, which is significantly less than the technical requirements (not higher than 0.864).

The insulating material obtained in the accumulator No. 13 in an amount of 20,000 m ³ has an IV hazard class for OPS.

IM-1 in an amount of 10,000 m ^{3 was} used as an insulating material in the municipal landfill of municipal solid waste (MSW) in Ufa.

Test results

1. During the testing period of the insulating material IM-1, used as an insulating layer for the disposal of municipal solid waste, at the landfill, the maximum permissible concentrations of pollutants were not exceeded in the atmosphere, soil and groundwater.

2. The insulating material IM-1 complies with the technical specifications TU 5717-001-48855219-2004.

3. The Federal Service for Ecological, Technological and Nuclear Supervision (Rostekhnadzor) issued a positive opinion on the use of IM-1 for the reclamation of solid waste landfills. The insulating material IM-1 obtained in drive No. 13 is not subject to the supervision of Rostekhnadzor. Therefore, the prepared material was folded by an excavator on an inclined platform and the drive No. 13 was completely cleaned.

In the process of natural dehydration, the pores of IM-1 were freed from water, and at the same time they were saturated with oxygen. With such a residual oil content, IM-1 is still characterized by hazard class IV.

Partially neutralized to a residual moisture content of 30% IM-1 was composted with nitrogen-phosphorus compounds to accelerate the propagation of natural microorganisms contained in the bottom sediment.

The remainder of IM-1 in an amount of 10,000 m ³ for 2 years in the summer 2-3 times was shoveled with an excavator to saturate the pores with oxygen and nitrogen-phosphorus compounds were additionally introduced to feed natural microorganisms. As a result, the content of oil products in IM-1 decreased by 80-85%. The resulting compost IM-1 corresponds to the V hazard class and can be used for the rehabilitation of landfills, barns, as well as for applying to the soil.

Figure 4 shows the bottom sediment from the accumulator No. 13 before processing, and figure 5 presents IM-1 after 2 years of bioremediation by natural microorganisms.

Using the proposed method can reduce environmental pollution. Labor costs for cleaning bottom sediments are reduced. In addition, there is no need for the presence of environmental regulatory authorities, since the production of the environmentally friendly product IM-1 is carried out directly in the drive. IM-1 can be used for reclamation of the drive. The moistened bottom sediment in the reservoir is effectively and evenly mixed with components (lime, clay materials), and therefore their consumption is reduced by 20-30% and savings of 150-200 rubles are achieved. per cubic meter of cooked IM-1.

The high efficiency of mixing the IM-1 components in a storage ring makes it possible to sharply accelerate the reproduction of resting natural microorganisms, which within 2 years utilized up to 80% of oil products in an insulating material.

Table 1 The chemical composition of limestone in lump form (Ufa CHPP-4) Name of oxides The composition of the oxides, wt.% CaO General 54.7 CaO Act. 25.7 MgO 3.15 Al ₂ O ₃ 3.17 Fe ₂ About ₃ 1.45 SO ₃ 0.19 Na ₂ About ₃ 1,60 SiO ₂ 5.63 CO ₂ 23.17 ppp 30.68

table 2 Physical properties of HVO (Ufa CHPP-4) Name of physical properties Indicators Humidity, wt.% 45-60 Specific surface, m ² / g 1.5-2.3 Porosity,% 55-68

Table 3 The composition of the drilling fluid under-river crossings of the Belaya River Mud components The content of components,% 1.Water (H20) 91.07 2. Bentonite (clay), Attapulgite (clay) 7.0 3. Purified Na-carboxymethyl cellulose (CMC HV, CMC LV) 0.7 4. Partially hydrolyzed polyacrylamide (IR-CTABL (S)) 0.28 5. Bactericide (IKBAK-0, IKBAK11L, IKBIOCID) 0,03 6. Drilling detergent (ICD) 0.2 7. Sodium hydroxide (caustic soda) NaOH 0.1 8. Disodium carbonate (soda ash) Na ₂ CO ₃ 0.1 9. Environmentally friendly lubricant additive (ICLUB) 0.5 10. Antifoam (IKDEFOM) 0.02

Table 4 The composition of the cuttings Components The content of components,% 1. Loam, clay 15.0 2. Sandy loam 10.0 3. Sand gravel 60.0 4. Sand of medium size 15.0

Table 6 These specifications apply to the insulating material IM-1 TU 5717-001-48855219-2004, intended for the disposal of municipal solid waste (MSW), the rehabilitation of landfills for solid waste, for the construction of roads, dams, dams, etc. Name of production waste and inert materials FCCC Code The content of the component in the insulating material (IM - 1), mass fraction in% option 1 option 2 option 3 1. Oil sludge (waste oil and oil refining) 5460000000004 Content limit Average value Content limit Average value Content limit Average values 40-50 45 40-60 fifty 5-20 10 2. Calcareous materials (limestone in small-sized form, quicklime, chemical water treatment sludge from thermal power plants) 9410000000004

25-30

27

-

-

2-10

5 3. Drilling waste (drill cuttings) 3410000000004 - - - - 78-85 85 4. Inert materials (clay rocks, sand deposits of the seas and oceans) 25-30 28 40-60 fifty - - 5. Biological products (Devoroil, Dostroil, Olevorin, Batsispetsin) According to passport data

Technical requirements

3.1 The insulating material IM-1 must comply with the requirements of these specifications:

3.1.1 Filtration coefficient not more than 10 ^-3 cm / s 0.864 m / day;

3.1.2 compaction coefficient of not less than 0.98;

3.1.3 coefficient of frost resistance not less than 0.65;

3.1.4 Hazard Class - IV.

Table 7 The chemical composition of water from the drive №13 Component unit of measurement Sample Numbers No. 1 Number 2 Number 3 Number 4 COD mgO / dm ³ 595 480 480 480 Oil products mg / dm ³ 14.8 6.3 16.1 8.8 Suspended matter mg / dm ³ 25 28 40 40 Ammonium ion mg / dm ³ 70 63 57 57 Nitrite mg / dm ³ 1.8 1.4 1.4 0.86 Nitrates mg / dm ³ 5,4 5.2 5,0 5,0 Phosphates (PO R205) mg / dm ³ 8.7 8.0 8.0 7.2 Chlorides mg / dm ³ 737.4 815 818.9 818.9 Sulphates mg / dm ³ twenty 36 46 46 Dry residue mg / dm ³ 2980 2940 3300 3310 Sulfides mg / dm ³ 12.9 7.1 3.6 3.2 Stiffness commonly. mEq / dm ³ 2.27 1,999 2.18 2.18 constant mEq / dm ³ 0,909 0.87 0.87 0.87 temporary mEq / dm ³ 1.36 1,129 1.48 1.48 Ether-recoverable mg / dm ³ 90 57.2 58 57 Phenol mg / dm ³ 0.0119 0.0089 0.0042 0.0019 BOD5 mgO ₂ / dm ³ 89 71 67 69 BOD floor. mgO ₂ / dm ³ 266 210 207 212

Table 8 Physicochemical Characterization Name of quality indicators Indicator value 1. Density at 20 ° C, kg / m ³ 1012 2. Coking ability,% 17.7 3. Content, wt.% - water 37.5 - fur. impurities 4.3 - sulfur 1,57 4. Softening point, ° C 16 5. Flash point, ° С more than 100 6. Fractional composition: - beginning of boiling, ° С 251 - 10% boils, ° С 359 - 50% boils, ° С 482 - end of boiling, ° С 493 (62%) 7. Kinematic viscosity, cSt - at 50 ° C 24.4 - at 100 ° C 5,6 8. The flash point of dehydrated sludge, ° C 238

Table 9 Laboratory Results Mixture components Technical requirements for IM-1 TU 5717-001-48855219-2004 Bottom sediment Calcareous material Hazard Class Clay material Filtration coefficient, m / day Hazard class for OPS Limestone in lump form (not finished) Kasimov clay (Ufa) Fact. TU Fact. TU 3 h 0.5 h III 0.5 h 0.91 not> 0.864 IV IV 3 h 1.0 h IV 1.0 h 0.75 not> 0.864 IV IV

3 h
3 h HWO sludge

III
IV Drill cuttings

0.90
0.68

not> 0.864
not> 0.864

IV
IV

IV
IV 0.5
1,0 0.5 h
1.0 h

Claims (4)

1. The method of cleaning bottom sediments of oil sludge reservoirs, including biological treatment of the sludge, mixing with waste, characterized in that the sludge directly in the reservoir is mixed with lime material in a ratio of 3: 1, then the resulting mixture is additionally mixed with clay material with a residual moisture content of 20-40 %, while the ratio of sediment: calcareous material: clay material is 3: 1: 1, then the mixture from the drive is sent for drying in natural conditions to 30-40% humidity, after partial drying the mixture dvergayut anaerobic biological treatment in the presence of nutrient medium. 2. The method according to claim 1, characterized in that nitrogen-phosphorus compounds are used as a nutrient medium. 3. The method according to claim 1, characterized in that as the calcareous material, waste from the CHP plant is used: limestone in lump form or chemical water treatment slurry. 4. The method according to claim 1, characterized in that clay or drill cuttings are used as the clay material.

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