CN110981156B - Oil sludge three-phase separation method based on alkali modification - Google Patents
Oil sludge three-phase separation method based on alkali modification Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/14—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents
- C02F11/143—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents using inorganic substances
- C02F11/145—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents using inorganic substances using calcium compounds
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/121—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/121—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering
- C02F11/122—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering using filter presses
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/14—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents
- C02F11/143—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents using inorganic substances
Abstract
The invention discloses an alkali modification-based oil sludge three-phase separation method, which comprises the following steps: (1) mixing and reacting oil sludge and alkali to obtain a modified oil sludge mixture; the reaction temperature is at least 50 ℃; with CaCO 3 The mass ratio of alkali to oil sludge is at least 1% by an alkalinity meter; (2) after the modified oil sludge mixture and the separating agent are mixed and react, the separation of an oil phase and a mud-water mixture is realized; (3) and separating mud and water from the mud-water mixture. The separation method has the advantages of high automation degree, simple and efficient operation, stable operation and low failure rate; the method does not consume dilution water, does not need a demulsifier and an extractant, and has low operation cost; the recovery rate of oil products can reach more than 90 percent; the mud-water mixture obtained after the oil phase is separated is easy to separate mud from water, and the oil content of the obtained water phase can be as low as 30-50mg/L; the obtained mud phase is easy to dehydrate, the water content of the mud cake obtained after dehydration can be less than 55%, and the oil content of the obtained filtrate can be as low as 20-40mg/L.
Description
Technical Field
The invention relates to the field of hazardous waste disposal, in particular to an oil sludge three-phase separation method based on alkali modification.
Background
Oil separation tank and secondary coagulation dissolved air floatation are a pretreatment oil separation method commonly adopted in the existing petroleum refining wastewater treatment process, wherein oil-containing sludge (oil sludge for short) formed by tank bottom oil sludge or air floatation scum is listed in code HW08 type hazardous waste products of national hazardous waste record, and accounts for more than 80 percent of the total amount of oil sludge produced by a wastewater treatment plant. The tank bottom oil sludge or the air floatation scum oil sludge is difficult to dehydrate, the water content can only be reduced to 85-90%, the volume reduction effect is poor, and the subsequent hazardous waste disposal cost is high.
The existing oil sludge treatment methods are more and mainly divided into the following two types:
1) The disposal methods aimed at oil decomposition or degradation mainly include a thermal decomposition method and a biological treatment method. The traditional thermal decomposition method is that oil sludge is heated, an oil phase (light component) is gasified, a water phase is evaporated and separated from a solid phase, and the oil phase is subjected to catalytic combustion treatment. However, the oil content of the remaining solid phase is still over 2%, and further disposal is required. The biological treatment method means that the degradation of an oil phase in oil sludge is achieved by microorganisms using petroleum hydrocarbons as a carbon source. The method has the advantages of low energy consumption and no secondary pollution, but has the restriction factors of low treatment rate and low efficiency.
2) A disposal method aiming at oil recovery. Most oil recovery methods are improved by a hot water washing method, which is a recommended sludge treatment method by the Environmental Protection Agency (EPA), and the residual oil content of the sludge can be reduced to below 5 percent by repeatedly washing with hot water. However, this process consumes a large amount of water and the recovery of oil is not high. In order to realize efficient recovery of oil phase, some methods (such as Chinese patent documents CN201310691147.5 and CN201821049436. X) realize oil recovery, sludge dehydration and water treatment by adding water for dilution, heating and stirring and extracting and centrifuging. Some improved methods (such as Chinese patent documents CN201611254205.8 and CN 201610210354.8) finish the treatment of oil sludge by adding water for dilution, demulsification and coagulating sedimentation, and realize oil recovery. And also some improved methods (such as Chinese patent documents CN201711189749.5 and CN 201910051776.9) are used for completely emulsifying oil wrapped with a solid phase with water by an ultrasonic method, separating the oil from a mud phase, and demulsifying and extracting to realize the recovery of an oil phase.
Obviously, compared with the oil decomposition method, the oil sludge disposal method taking oil recovery as the target better conforms to the modern concept of waste reclamation. However, the conventional disposal method mainly has the following problems: 1) The water consumption is huge and usually 2-10 times dilution water is needed. The defect causes that the existing oil sludge treatment method is difficult to popularize and apply in many water-deficient areas in China; 2) The consumption of the demulsifier is large, and the recovery rate is not high. The operation cost is greatly increased, and a large amount of demulsifiers (mostly organic matters difficult to degrade) enter the water phase to bring new pollution; 3) The effect of the demulsifier is not ideal. The main reason is that the floating dross oil sludge contains a large amount of flocculant such as polyaluminium chloride, polyacrylamide and the like; 4) The extractant has large dosage, difficult recovery and high cost.
In view of the foregoing, there is a need to develop an economical and efficient method for recovering and disposing of oil sludge.
Disclosure of Invention
The invention aims to solve the technical problems of large dilution water consumption, large using amount of a demulsifier and an extractant, low oil recovery rate, poor mud dewatering performance and the like of the existing oil sludge treatment method, and provides an economic and effective oil sludge three-phase separation method based on alkali modification. The invention has the advantages of simple and efficient process, stable operation, low failure rate, high automation degree and huge investment and operation cost advantages.
In the process of treating the oil sludge in the prior art, the treatment method is rarely considered from the viewpoint of how the oil sludge comes, and generally the treatment method is stopped at' 1) adding water for dilution: passing the oil from the mud phase into the aqueous phase; or 2) demulsification: separating emulsified oil and dissolved oil in water from water phase; or 3) extraction: recovery of oil from the aqueous phase with similar compatibility "at the conventional and complex processing level. According to the invention, a proper amount of alkali is added for mixing reaction, so that modification of the oil sludge is realized, and the sludge particle structure is reconstructed, and specifically, oil drop particles, sludge particles or oil-in-sludge particles which are connected together by polyaluminium chloride (PAC) and Polyacrylamide (PAM) in the oil sludge are gradually separated from each other, and a stable negative charge state is formed on the surface under the action of the alkali (accumulation of hydroxyl), so that reconstruction of the sludge particle structure is realized, and subsequent effective separation of oil and sludge-water mixture and sludge and water in the sludge-water mixture is facilitated.
The invention solves the technical problems through the following technical scheme.
An alkali modification-based oil sludge three-phase separation method comprises the following steps:
(1) Mixing and reacting oil sludge and alkali to obtain a modified oil sludge mixture;
wherein the temperature of the mixing reaction is at least 50 ℃; with CaCO 3 The mass ratio of the alkali to the oil sludge is at least 1% by a alkalinity meter;
(2) After the modified oil sludge mixture is mixed with a separating agent for reaction, the separation of an oil phase and a mud-water mixture is realized;
(3) And separating mud and water from the mud-water mixture.
In the invention, the oil sludge can be oil-containing sludge formed by tank bottom oil sludge or air floatation scum after the wastewater of the petroleum refinery is pretreated by conventional oil separation. The oil separation pretreatment can adopt a method combining a horizontal flow type oil separation tank and a dissolved air floatation tank which are conventional in the field. The wastewater can be from oil tank water drainage, electric desalting wastewater, refining drainage and other wastewater, and the like, and generally, the COD of the wastewater is 400-3000mg/L, and the oil content is 100-2000mg/L.
In the step (1), the water content of the oil sludge is 50-95% and the oil content is 2-30%, wherein the percentages are mass percentages of water or oil relative to the total amount of the oil sludge respectively. For example, in one embodiment, the oil sludge has an oil content of about 3% to about 5% and an average water content of about 85%.
In step (1), the base may be ionized or hydrolyzed in an aqueous solution to generate OH, as is conventional in the art - Such as one or more of strong bases, medium and strong bases, metal oxides, strong bases, weak acid salts, and the like. Specifically, the base is preferably one or more of an alkali metal hydroxide, an alkali metal carbonate, an alkaline earth metal hydroxide and an alkaline earth metal oxide, more preferably one or more of sodium hydroxide, potassium hydroxide, calcium oxide and sodium carbonate, and most preferably sodium hydroxide or calcium hydroxide. The base may be added as a solid or as a solution, as is known in the art. When the base is added as a solution, the concentration of the base can be conventional in the art. The solvent used is generally water.
In the step (1), the mass ratio of the alkali to the sludge is preferably 1 to 3%, for example, 2%. In the invention, one part of the alkali is used for decomposing a binder in the oil sludge, such as polyaluminium, PAM and the like, and the other part of the alkali is used for modifying the surface charge.
In step (1), the mixing reaction can be performed according to the conventional method in the art, and preferably, a vertical stirring paddle is used for mixing.
In the step (1), in the process of the mixing reaction, the power of the motor with unit cell volume is preferably 1.5-3.0W/m 3 。
In the step (1), the temperature of the mixing reaction is preferably 50 to 70 ℃, more preferably 60 ℃.
In the step (1), the time of the mixing reaction is preferably 6 to 12 hours, and more preferably 10 hours.
In the step (1), the mixing reaction may be performed in an alkali modification reactor. The alkali-modified reactor may be a common apparatus or structure conventionally used in the art of sludge treatment. The alkali modification reactor is provided with a feed inlet and a water outlet. The sludge enters the alkaline modification reactor through the feed port by a transfer device conventional in the art. As mentioned above, in the mixing reaction process, the modification of the sludge is realized, and the sludge particle structure is reconstructed.
In step (2), the process of the mixing reaction is generally carried out in an oil recovery reactor. In the oil recovery reactor, the physicochemical properties (e.g., surface charge, surface tension) of the particles are changed. Specifically, there are three types of particles present in the system: oil droplet particles, mud particles, and mud-in-oil particles; the mud particles and the oil-coated mud particles are subjected to the hydraulic shearing action brought by stirring and the mutual friction action among different phases and particles; under the action of the separating agent, small oil drop particles collide and are gathered together to form large oil drops which gradually float to the surface, and finally the separation of the oil phase and the mud-water mixture is finished.
Wherein the oil recovery reactor may be a common apparatus or structure conventionally used in the field of sludge treatment in the art. The oil recovery reactor is provided with a water inlet, an oil outlet and a water outlet, and the water outlet of the alkali modification reactor is connected with the water inlet of the oil recovery reactor. The liquid level of the oil recovery reactor is provided with a conventional oil recovery device for oil recovery. The oil outlet of the oil recovery reactor is communicated with the inlet of the oil product storage tank, and the oil phase collected by the oil recovery device is conveyed to the oil product storage tank for standby. And the residual mud-water mixture enters a conventional mud-water separation sedimentation tank through a water outlet of the oil recovery reactor.
In step (2), the mixing reaction can be performed according to conventional methods in the art, and preferably, a vertical stirring paddle is used for mixing.
In the step (2), in the process of the mixing reaction, the power of the motor with unit pool volume is preferably 2-10W/m 3 E.g. 4.8W/m 3 。
In step (2), the mixing reaction time may be conventional in the art, and is preferably 2 to 12 hours, for example 6 hours or 12 hours.
In the step (2), the separating agent can be a separating agent which is conventionally used in the field for separating oil phase and muddy water mixture, preferably an oil-displacing agent, and more preferably cationic polyacrylamide.
In step (2), the amount of the separating agent used may be conventional in the art, and is preferably 0.5 to 5mg/g of the oil content of the oil sludge, more preferably 1.5 to 2mg/g of the oil content of the oil sludge.
In the step (2), according to the common knowledge, the separating agent and the modified sludge-water mixture are generally mixed uniformly by a pipeline mixer or a lift pump.
In step (3), the operation and conditions for separating the mud and water may be conventional in the art, and for example, a filtration method or a gravity precipitation method, preferably a gravity precipitation method, which is conventional in the art may be employed.
When the gravity precipitation method is adopted for carrying out mud-water separation, the separation is generally carried out in a mud-water separation sedimentation tank. As mentioned above, the mud-water separation sedimentation tank is provided with a water inlet, a water outlet and a mud discharge port. The water outlet of the oil recovery reactor is communicated with the water inlet of the mud-water separation sedimentation tank, the sludge discharge port of the mud-water separation sedimentation tank is connected with the sludge inlet of the dehydration unit, and the water outlet of the mud-water separation sedimentation tank is connected with a wastewater treatment system. According to the common knowledge in the field, the sludge discharge port of the sludge-water separation sedimentation tank is arranged at the bottom of the sludge-water separation sedimentation tank.
Under the action of self gravity, sludge particles in the mud-water mixture are aggregated and precipitated. The upper water phase passes through a water outlet in the mud-water separation sedimentation tank to enter a wastewater treatment system, and the mud phase precipitated at the lower layer passes through a mud discharge port in the mud-water separation sedimentation tank to enter a dehydration unit. Wherein, the oil content in the upper aqueous phase can be conventional in the field, and is preferably 30-50mg/L.
Wherein the dewatering unit is generally conventional in the art, such as a chamber membrane filter press. The dehydration unit is provided with a sludge inlet, a water outlet and a sludge outlet. And a sludge inlet of the dehydration unit is connected with a sludge discharge port in the sludge-water separation sedimentation tank. And the water outlet of the dehydration unit is connected with a wastewater treatment system. The filtrate from the dewatering unit is typically delivered to a wastewater treatment system by a pump. And a sludge discharge port of the dehydration unit is connected with the temporary sludge storage tank. And the dewatered mud cake enters the temporary sludge storage tank through a conveying device. The mud cake obtained after dehydration is suitable for direct incineration or incineration after low-temperature drying. The water content of the cake obtained after dewatering is preferably less than 55%, for example 52%. The filtrate enters a wastewater treatment system through a water outlet of the dehydration unit, and the oil content is preferably 20-40mg/L.
In the invention, the alkali modification reactor, the oil recovery reactor, the mud-water separation sedimentation tank and the dehydration unit are common equipment or structures in the field.
On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.
The reagents and starting materials used in the present invention are commercially available.
The positive progress effects of the invention are as follows:
the oil sludge three-phase separation method has the advantages of high automation degree, simple and efficient operation, stable operation and low failure rate; the method does not consume dilution water, does not need a demulsifier and an extractant, and has low running cost (if the same amount of oil sludge is treated, the cost estimation of the method is reduced by 50 percent compared with the prior art in terms of raw materials, equipment, manpower and the like).
The invention can realize oil recovery, and the recovery rate can reach more than 90%; after the oil phase is separated, the obtained mud-water mixture is easy to separate mud from water, and the oil content of the obtained water phase can be as low as 30-50mg/L; the obtained mud phase is easy to dehydrate, the water content of the mud cake obtained after dehydration can be less than 55%, and the oil content of the obtained filtrate can be as low as 20-40mg/L.
Detailed Description
The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.
In the following examples and comparative examples, methods for measuring water content, oil content, and Chemical Oxygen Demand (COD) were carried out in accordance with the national standards, water and wastewater monitoring and analysis method, national environmental sciences Press, fourth edition, 2002. Specifically, the detection method of the solid content is a gravimetric method; the detection method of the water content is a gravimetric method; the detection method of oil content (referring to the oil content in water) and oil content (referring to the oil content in solid) is carbon tetrachloride extraction-infrared spectrophotometry; the detection method of the chemical oxygen demand is a potassium dichromate method.
Example 1
In the waste water treatment project of a petroleum refining enterprise in Shandong province, the waste water comes from oil tank cutting water, electric desalting waste water, refining drainage water and other waste water, and the treated water amount is 7000-12000m 3 The COD of the wastewater is 400-3000mg/L and the oil content is 100-2000mg/L.
The oil separation pretreatment of the wastewater adopts a method of combining a horizontal flow type oil separation tank which is conventional in the field and a dissolved air floatation tank which is conventional in the field. The total amount of the generated oil sludge is about 125t (7000-12000 m) per day 3 125t is obtained from the wastewater), the average oil content of the oil sludge is about 4 percent, and the average water content is about 85 percent.
The specific process flow of the oil sludge three-phase separation method is as follows: the device comprises an oil sludge collecting pool → an alkali modification reactor → an oil recovery reactor → a mud-water separation and sedimentation pool → a dehydration unit → a wastewater treatment system, wherein the oil sludge collecting pool, the alkali modification reactor, the oil recovery reactor, the mud-water separation and sedimentation pool, the dehydration unit and the wastewater treatment system are common devices or structures in the field. The method comprises the following specific operations:
(1) Conveying 125t/d oil sludge in the oil sludge collection pool to an alkali modification reactor through a conventional conveying device in the field, adding solid sodium hydroxide into the oil sludge, and carrying out mixing reaction to obtain a modified oil sludge mixture;
wherein, the adding amount of the alkali is 2 percent by calcium carbonate alkalinity, and the percentage is the mass ratio of the alkali to the oil sludge. The reaction temperature is 60 ℃, and the reaction time is about 10h. Effective volume of alkali modified reactor 50m 3 . Mixing deviceThe device is a vertical stirring paddle, the power of a motor is 0.15kW, and the power of the motor with unit tank capacity is 3.0W/m 3 . During the mixing reaction process, sludge modification (such as PAC and PAM dissolution) is realized, and the sludge particle structure is reconstructed.
(2) In an oil recovery reactor, after the modified oil sludge mixture and a separating agent are mixed and react, the separation of an oil phase and a mud-water mixture is realized;
wherein the separating agent is cationic polyacrylamide, and the dosage is 2mg/g of oil content of the oil sludge. The separating agent and the modified sludge mixture are generally mixed uniformly by a pipeline mixer or a lift pump. The reaction time was 12h. Effective volume of oil recovery reactor 62.5m 3 . The mixing equipment is a vertical stirring paddle, the power of a motor is 0.3kW, and the power of the motor with unit tank capacity is 4.8W/m 3 。
Stirring in an oil recovery reactor to realize the separation of an oil phase and a mud-water mixture; the oil recovery reactor is provided with a water inlet, an oil outlet and a water outlet, and the water outlet of the alkali modification reactor in the step 1) is connected with the water inlet of the oil recovery reactor; a conventional oil collector for oil recovery is arranged at the liquid level of the oil recovery reactor; the oil outlet of the oil recovery reactor is communicated with the inlet of the oil product storage tank, and the oil phase collected by the oil recovery device is conveyed to the oil product storage tank for standby. And the residual mud-water mixture enters a conventional mud-water separation sedimentation tank through a water outlet of the oil recovery reactor.
About 4.6t of recovered oil can be obtained by an oil collector every day for 125t of oil sludge every day, and the recovery rate is 92% (4.6 t/(125t 4%)).
(3) The mud-water separation sedimentation tank is a common central water inlet peripheral water outlet type sedimentation tank, the diameter of the sedimentation tank is 5m, and the effective water depth is 3m. And standing for 12 hours in a mud-water separation sedimentation tank by adopting a gravity sedimentation method to realize the separation of mud and water in the mud-water mixture.
The mud-water separation sedimentation tank is provided with a water outlet, a mud discharging port and a water inlet. The water outlet of the oil recovery reactor is communicated with the water inlet of the mud-water separation sedimentation tank; the sludge discharge port of the sludge-water separation sedimentation tank is connected with the sludge inlet of the dewatering unit, and the sludge discharge port of the sludge-water separation sedimentation tank is arranged at the bottom of the sludge-water separation sedimentation tank according to common knowledge in the field; the water outlet of the mud-water separation sedimentation tank is connected with a wastewater treatment system.
Under the action of self gravity, sludge particles in the mud-water mixture are aggregated and precipitated. The upper water phase enters a wastewater treatment system through a water outlet in the mud-water separation sedimentation tank, the treatment time is about 25t/d, and the oil content is 30-50mg/L. The mud phase of lower floor's deposit, through the mud mouth in the mud-water separation sedimentation tank, get into dewatering unit (for example van-type membrane filter press, the mud mouth that dewatering unit produced links with the mud temporary storage pond, the mud after general dehydration gets into through conveyor the mud temporary storage pond), produce the mud cake 27t/d, average moisture content is about 52%, the mud cake is suitable for burning or burning after the low temperature drying directly, the filtrating gets into waste water treatment system through the delivery port of dewatering unit, about 70t/d, the oil content is 20-40mg/L.
Step (1) - (3) a series of devices can treat 125t of oil sludge (corresponding to 7000-12000 m) each day 3 Wastewater), if the same 125t wastewater is treated by the prior art (the process of comparative example 1), the cost is estimated to be twice as expensive in terms of raw materials, equipment, manpower and the like, i.e. the cost of the invention is estimated to be reduced by 50% compared with the prior art.
Comparative example 1
The oil sludge treatment project in the comparative example is the old project before the project in the example 1 is transformed, the source and the total amount of the oil sludge are consistent with those in the example 1, after calcium carbonate (adding amount: 2kg/t of oil sludge) and polyacrylamide (adding amount: 10g/t of oil sludge) are adopted for treatment, and a screw folding machine is used for dehydration, the obtained mud cake has high oil content and water content still exceeds 90%, and then the external transportation treatment is carried out, so that the treatment cost is high; in the oil sludge treatment process, no crude oil is recovered; the oil content of the filtrate after the dehydration of the oil sludge is about 200-400mg/L. This comparative example had no oil recovery, no recovery.
Claims (11)
1. The three-phase separation method of the oil sludge based on alkali modification is characterized by comprising the following steps:
(1) Mixing and reacting oil sludge and alkali to obtain a modified oil sludge mixture;
wherein the temperature of the mixing reaction is at least 60 ℃; with CaCO 3 A alkalinity meter, a mass ratio of the alkali to the sludge1 to 3 percent;
(2) After the modified oil sludge mixture is mixed with a separating agent for reaction, the separation of an oil phase and a mud-water mixture is realized; the separating agent is cationic polyacrylamide;
the dosage of the separating agent is 0.5-5mg/g of the oil content of the oil sludge;
(3) Separating mud and water from the mud-water mixture;
in the step (1), the oil sludge is air flotation scum oil sludge; the water content of the oil sludge is 50-95%, the oil content is 2-30%, and the percentage is the mass percentage of water or oil relative to the total amount of the oil sludge;
in the step (1), the alkali is one or more of strong alkali, medium and strong alkali, metal oxide and strong alkali weak acid salt;
in the step (1), the mixing reaction is carried out in an alkali modification reactor; the alkali modification reactor is provided with a feed inlet and a water outlet;
in the step (2), the mixing reaction process is carried out in an oil recovery reactor, and the oil recovery reactor is provided with a water inlet, an oil outlet and a water outlet;
in the step (3), when the gravity precipitation method is adopted for carrying out mud-water separation, the mud-water separation is carried out in a mud-water separation sedimentation tank; the mud-water separation sedimentation tank is provided with a water inlet, a water outlet and a mud discharge port;
under the action of the alkali, oil drop particles, mud particles or oil-in-mud particles in the oil sludge, which are connected together by the polyaluminum chloride and the polyacrylamide, are gradually separated from each other, and a stable negative charge state is formed on the surface;
under the action of the separating agent, small oil drop particles collide and are gathered together to form large oil drops which gradually float to the surface, and finally the separation of the oil phase and the mud-water mixture is finished;
the oil sludge three-phase separation method based on alkali modification realizes oil product recovery, and the recovery rate reaches more than 90%; the mud-water mixture obtained after the oil phase is separated is easy to separate mud and water, and the oil content of the obtained water phase is as low as 30-50mg/L; the obtained mud phase is easy to dehydrate, the water content of the obtained mud cake after dehydration is less than 55 percent, and the oil content of the obtained filtrate is as low as 20-40mg/L.
2. The three-phase separation method of oil sludge based on alkali modification as claimed in claim 1, wherein in step (1), the alkali is one or more of alkali metal hydroxide, alkali metal carbonate, alkaline earth metal hydroxide and alkaline earth metal oxide.
3. The three-phase separation method of the alkaline-modified oil sludge according to the claim 2, wherein in the step (1), the alkaline is one or more of sodium hydroxide, potassium hydroxide, calcium oxide and sodium carbonate.
4. The three-phase separation method of oil sludge based on alkali modification of claim 3, wherein in the step (1), the alkali is sodium hydroxide or calcium hydroxide.
5. The three-phase separation process of oil sludge based on alkali modification according to claim 1, wherein in the step (1), the mass ratio of the alkali to the oil sludge is 2%.
6. The three-phase separation method of the oil sludge based on the alkali modification of claim 1, wherein in the step (1), the mixing reaction is carried out by using a vertical stirring paddle;
and/or, in the step (1), in the process of the mixing reaction, the power of the motor with unit pool volume is 1.5-3.0W/m 3 ；
And/or, in the step (1), the temperature of the mixing reaction is 60-70 ℃;
and/or in the step (1), the mixing reaction time is 6-12h.
7. The alkaline modification-based three-phase separation method of oil sludge according to claim 6,
in the step (1), the temperature of the mixing reaction is 60 ℃;
and/or in the step (1), the mixing reaction time is 10h.
8. The three-phase separation method of the alkaline-modified oil sludge according to the claim 1, wherein in the step (2), the mixing reaction is carried out by using a vertical stirring paddle;
and/or, in the step (2), in the process of the mixing reaction, the power of the motor with unit pool volume is 2-10W/m 3 ；
And/or in the step (2), the mixing reaction time is 2-12h.
9. The alkaline-modified-based three-phase separation method of oil sludge according to claim 1, wherein in the step (2), the amount of the separating agent is 1.5-2mg/g of the oil content of the oil sludge;
and/or in the step (3), the method for separating the mud and the water is a gravity precipitation method.
10. The three-phase separation method of oil sludge based on alkali modification as claimed in claim 1, wherein the water outlet of the alkali modification reactor is connected with the water inlet of the oil recovery reactor;
an oil collector for oil recovery is arranged at the liquid level of the oil recovery reactor; the oil outlet of the oil recovery reactor is communicated with the inlet of the oil product storage tank; the water outlet of the oil recovery reactor is communicated with the water inlet of the mud-water separation sedimentation tank, the sludge discharge port of the mud-water separation sedimentation tank is connected with the sludge inlet of the dehydration unit, and the water outlet of the mud-water separation sedimentation tank is connected with a wastewater treatment system.
11. The alkaline modification-based three-phase separation method for oil sludge according to claim 10, wherein the dehydration unit is a chamber membrane filter press; the dehydration unit is provided with a sludge inlet, a water outlet and a sludge outlet; the water outlet of the dehydration unit is connected with a wastewater treatment system; and a sludge discharge port of the dehydration unit is connected with a temporary sludge storage tank.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5269906A (en) * | 1987-07-27 | 1993-12-14 | Reynolds Victor R | Process for the recovery of oil from waste oil sludges |
| CN1640830A (en) * | 2004-01-08 | 2005-07-20 | 李国文 | Method for treating oilys ludge using three-phase separating technique |
| CN101088942A (en) * | 2006-06-14 | 2007-12-19 | 中国科学院生态环境研究中心 | Process of treating oil-containing sludge |
| CN108821522A (en) * | 2018-06-05 | 2018-11-16 | 陕西中环信环保科技有限公司 | A kind of technique of waste oil mud extract oil |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5269906A (en) * | 1987-07-27 | 1993-12-14 | Reynolds Victor R | Process for the recovery of oil from waste oil sludges |
| CN1640830A (en) * | 2004-01-08 | 2005-07-20 | 李国文 | Method for treating oilys ludge using three-phase separating technique |
| CN101088942A (en) * | 2006-06-14 | 2007-12-19 | 中国科学院生态环境研究中心 | Process of treating oil-containing sludge |
| CN108821522A (en) * | 2018-06-05 | 2018-11-16 | 陕西中环信环保科技有限公司 | A kind of technique of waste oil mud extract oil |
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