CN111438177B

CN111438177B - A system for synergistic remediation of petroleum hydrocarbon-contaminated soil by chemical oxidation and microorganisms

Info

Publication number: CN111438177B
Application number: CN202010284852.3A
Authority: CN
Inventors: 王丽萍; 黄少萌; 李丹; 周敏
Original assignee: China University of Mining and Technology Beijing CUMTB
Current assignee: China University of Mining and Technology Beijing CUMTB
Priority date: 2020-04-13
Filing date: 2020-04-13
Publication date: 2021-06-25
Anticipated expiration: 2040-04-13
Also published as: CN111438177A

Abstract

The invention discloses a system for synergistically repairing petroleum hydrocarbon-contaminated soil by chemical oxidation and microorganisms. The system includes an air compressor, a carbon dioxide filter, a gas flow meter, a gas detector, a soil degradation tank, a dosing pump set, and a gas detector. Instrument 2 and computer control system. The soil degradation tank includes a chemical oxidation part at the upper part and a microbial degradation part at the lower part. The soil degradation tank is equipped with a vertical main stirring shaft and a horizontal stirrer, both of which are driven by forward and reverse motors. The invention can realize the integrated and coordinated process of treating petroleum hydrocarbon polluted soil by chemical oxidation in the upper part of the tank and biodegradation in the lower part, and can realize the flow operation of feeding at the upper end and discharging at the lower end, greatly shortening the treatment period, and reducing energy consumption and cost.

Description

System for chemical oxidation and microbial remediation cooperate with petroleum hydrocarbon contaminated soil

Technical Field

The invention relates to the technical field of polluted soil remediation, in particular to a system for remediating petroleum hydrocarbon polluted soil through chemical oxidation and microbial cooperation.

Background

The petroleum hydrocarbon polluted soil contains a large amount of polycyclic aromatic hydrocarbon, so the treatment difficulty is high, the biotoxicity is strong, the treatment period is long, and the cost is high.

At present, the remediation technology of petroleum hydrocarbon contaminated soil can be divided into an in-situ remediation technology and an ex-situ remediation technology, wherein the ex-situ remediation technology refers to a technology of excavating contaminated soil from a contaminated position and then treating the contaminated soil within an original site range or after transportation. The ectopic repair technology is more commonly used in methods of chemical oxidation, microbial treatment or chemical oxidation-microbial treatment step-by-step treatment. The chemical oxidation method has high cost, is easy to cause secondary pollution and destroy soil; microbial treatment is very slow and bacteria have poor general tolerance to polycyclic aromatic hydrocarbons; the step-by-step treatment method has the disadvantages of complex operation, more required equipment, high transportation and operation cost and long period. Therefore, it is necessary to develop a system capable of carrying out integrated and efficient continuous treatment of chemical oxidation and microbial degradation.

Disclosure of Invention

The invention aims to provide a system for remediating petroleum hydrocarbon contaminated soil through chemical oxidation and microbial cooperation, which is simple to operate, can continuously and efficiently operate, and has low remediation cost and high organic pollutant degradation rate.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a system for remediating petroleum hydrocarbon polluted soil by chemical oxidation and microorganism synergism comprises an air compressor, a carbon dioxide filter, a gas flowmeter, a first gas detector, a soil degradation tank, a drug feeding pump set, a second gas detector and a computer control system,

the soil degradation tank comprises a first tank body, a second tank body, a third tank body and a fourth tank body which are stacked from top to bottom, wherein two adjacent tank bodies are connected through a flange, the joint of each tank body is respectively provided with a temperature sensor, a humidity sensor, a pH sensor and a heating rod, the top of the first tank body is provided with a liquid inlet and a gas outlet, the side wall of the first tank body is provided with a feed inlet, the bottom of the fourth tank body is provided with a discharge outlet, a liquid outlet and a gas inlet, the center of the inside of the soil degradation tank is vertically provided with a main stirring shaft, the upper end of the main stirring shaft extends out of the first tank body and is in transmission connection with a positive and negative rotation motor, the lower end of the main stirring shaft extends into the fourth tank body, four helical blades are uniformly arranged on the main stirring shaft at intervals and are respectively positioned in the four tank bodies, and two horizontal stirrers, the soil degradation tank is characterized in that a liquid distributor is further arranged inside the soil degradation tank, the liquid distributor comprises a liquid distribution disc and a plurality of liquid distribution pipes, the liquid distribution disc is of an annular hollow structure and is arranged above the first tank body, the liquid distribution pipes are vertically arranged, the upper ends of the liquid distribution pipes are communicated with the liquid distribution disc, the lower ends of the liquid distribution pipes extend into the fourth tank body, clear water pipes, acid liquid pipes, alkali liquid pipes, oxidant pipes and nutrient liquid pipes are further arranged in the liquid distribution disc and the liquid distribution pipes, clear water holes, acid liquid holes and alkali liquid holes are further formed in the liquid distribution pipes in each tank body, oxidant holes are further formed in the liquid distribution pipes in the first tank body and the second tank body, and bacteria liquid holes and nutrient liquid holes are further formed in the liquid distribution pipes in the third tank body and the fourth tank body,

the medicine-adding pump group comprises a clean water pump, an acid liquid pump, an alkaline liquid pump, an oxidant pump, a microbial liquid pump and a nutrient liquid pump, wherein the clean water pump, the acid liquid pump, the alkaline liquid pump, the oxidant pump, the microbial liquid pump and the nutrient liquid pump are sequentially communicated with a clean water pipe, an acid liquid pipe, an alkaline liquid pipe, an oxidant pipe, a bacterial liquid pipe and a nutrient liquid pipe through liquid inlets, the clean water pipe is sequentially communicated with a clean water hole, the acid liquid pipe is sequentially communicated with an acid liquid hole, the alkaline liquid pipe is sequentially communicated with an alkaline liquid hole, the oxidant pipe is sequentially communicated with an oxidant hole, the bacterial liquid pipe is,

air compressor, carbon dioxide filter, gas flowmeter, gas detection appearance first connect gradually through the pipeline, gas detection appearance first with the air inlet of soil degradation jar is connected, gas detection appearance second with the gas outlet of soil degradation jar is connected, gas flowmeter, add medicine pump package, positive reverse motor one, positive reverse motor two, temperature sensor, humidity transducer, pH sensor and heating rod respectively with computer control system electricity is connected.

Furthermore, be equipped with the thief hole on the lateral wall of the first jar of body, the second jar of body, the third jar of body and the fourth jar of body respectively, and the thief hole position of the first jar of body with the feed inlet position is symmetrical.

Further, the sampling hole is provided with a sealing cover matched with the sampling hole, so that external air is prevented from entering the soil degradation tank during sampling.

Preferably, the liquid distribution pipes are provided with four liquid distribution pipes which are uniformly distributed according to the circumference.

Preferably, the soil degradation tank is of a cylindrical structure.

Compared with the prior art, the invention has the following beneficial effects:

1. the system for remedying the petroleum hydrocarbon polluted soil by the cooperation of the chemical oxidation and the microorganisms has the advantages of simple structure, convenient use and small influence by the external environment, and can control the temperature, the humidity, the pH value, the oxygen content, the oxidant content, the bacterial liquid content and the nutrient solution content in the soil treatment process by a computer to realize automatic feedback regulation;

2. the invention can realize the integrated cooperative treatment process of the upper part chemical oxidation and the lower part biodegradation in the tank body on the petroleum hydrocarbon polluted soil, and can realize the line production of feeding at the upper end and discharging at the lower end, thereby greatly shortening the treatment period and reducing the energy consumption and the cost.

Drawings

FIG. 1 is a schematic diagram of a system for the synergistic remediation of petroleum hydrocarbon contaminated soil by chemical oxidation and microorganisms in accordance with the present invention;

FIG. 2 is a schematic view of the structure of the soil degradation tank of FIG. 1;

FIG. 3 is a top view of the dispenser of FIG. 2;

in the figure, 1 an air compressor, 2 a carbon dioxide filter, 3 a gas flowmeter, 4 a gas detector I, 5 a soil degradation tank, 51 a first tank body, 52 a second tank body, 53 a third tank body, 54 a fourth tank body, 6 a medicine adding pump set, 7 a gas detector II, 8 a computer control system, 9 a liquid inlet, 10 a gas outlet, 11 a material inlet, 12 a gas inlet, 13 a material outlet, 14 a liquid outlet, 15 a positive and negative rotation motor I, 16 a main stirring shaft, 17 helical blades, 18 a horizontal stirrer, 19 a liquid distribution disc, 20 a liquid distribution pipe and 21 sampling holes.

Detailed Description

The invention is described in further detail below with reference to the figures and specific examples.

As shown in figure 1, the system for remediating petroleum hydrocarbon contaminated soil through chemical oxidation and microbial cooperation comprises an air compressor 1, a carbon dioxide filter 2, a gas flow meter 3, a first gas detector 4, a soil degradation tank 5, a drug-adding pump unit 6, a second gas detector 7 and a computer control system 8.

As shown in fig. 1 and 2, in this embodiment, the soil degradation tank 5 is preferably a cylindrical structure. The soil degradation tank 5 comprises a first tank body 51, a second tank body 52, a third tank body 53 and a fourth tank body 54 which are stacked from top to bottom, wherein the adjacent two tank bodies are connected through flanges, and are convenient to disassemble, clean or overhaul, the first tank body 51 and the second tank body 52 are chemical oxidation parts, and the third tank body 53 and the fourth tank body 54 are microbial degradation parts.

Every jar body junction is provided with temperature sensor, humidity transducer, pH sensor and heating rod respectively, and temperature sensor is used for detecting the reaction temperature of jar body different positions department, and humidity transducer is used for detecting the moisture content of jar body different positions department, and pH sensor is used for detecting the pH value of jar body different positions department, and the heating rod is used for heating the reaction system to reach the required temperature of reaction.

The top of the first tank 51 is provided with a liquid inlet 9 and a gas outlet 10, the side wall of the first tank 51 is provided with a feed inlet 11, and the bottom of the fourth tank 54 is provided with a discharge outlet 13, a liquid outlet 14 and a gas inlet 12. Materials and liquid are added from the upper part of the soil degradation tank 5, the bottom is discharged, oxygen is introduced from the bottom of the soil degradation tank 5, and the top is released.

The inside central authorities of soil degradation jar 5 are vertically equipped with main (mixing) shaft 16, the upper end of main (mixing) shaft 16 stretches out first jar of body 51 and is connected with the transmission of positive reverse motor 15, the lower extreme of main (mixing) shaft 16 stretches into the fourth jar of body 54, evenly be provided with four helical blade 17 at the interval on the main (mixing) shaft 16, four helical blade 17 are located four jar of bodies respectively, still the symmetry is provided with two horizontal mixer 18 of positive reverse motor two driven on every jar of internal side wall. Two groups of stirring devices are arranged, so that soil can be pushed up or pushed down on one hand, and left or right on the other hand, and the purposes of mixing, stirring and uniform degradation are achieved.

As shown in fig. 2 and 3, a liquid distributor is further disposed inside the soil degradation tank 5, the liquid distributor includes a liquid distribution disc 19 and a plurality of liquid distribution pipes 20, the liquid distribution disc 19 is an annular hollow structure, and is disposed above the inside of the first tank 51, preferably four liquid distribution tubes 20 are disposed in this embodiment, and are uniformly distributed along the circumference, the liquid distribution pipe 20 is vertically arranged, the upper end of the liquid distribution pipe 20 is communicated with the liquid distribution disc 19, the lower end of the liquid distribution pipe 20 extends into the fourth tank body 54, clear water pipes, acid liquid pipes, alkaline liquid pipes, oxidant pipes, bacteria liquid pipes and nutrient liquid pipes are further arranged in the liquid distribution disc 19 and the liquid distribution pipe 20, clear water holes, acid liquid holes and alkaline liquid holes are respectively formed in the middle of the liquid distribution pipe 20 in each tank body, oxidant holes are further formed in the liquid distribution pipes 20 in the first tank body 51 and the second tank body 52, and bacteria liquid holes and nutrient liquid holes are further formed in the liquid distribution pipes 20 in the third tank body 53 and the fourth tank body 54.

Medicine pump package 6 contains the clarified water pump, the sour liquid pump, the lye pump, the oxidant pump, microbial bacteria liquid pump and nutrient solution pump, the clarified water pump, the sour liquid pump, the lye pump, the oxidant pump, the microbial bacteria liquid pump, the nutrient solution pump passes through inlet 9 and clean water pipe, sour liquid pipe, the lye pipe, the oxidant pipe, fungus liquid pipe and nutrient solution pipe communicate in proper order, clean water pipe and clear water hole, sour liquid pipe and sour liquid hole, alkali liquid pipe and alkali liquid hole, oxidant pipe and oxidant hole, fungus liquid pipe and fungus liquid hole, nutrient solution pipe and nutrient solution hole communicate in proper order.

Air compressor 1, carbon dioxide filter 2, gas flowmeter 3, gas detection appearance 4 connect gradually through the pipeline, gas detection appearance 4 with the air inlet 12 of soil degradation jar 5 is connected, gas detection appearance two 7 with the gas outlet 10 of soil degradation jar 5 is connected.

The gas flowmeter 3, the medicine adding pump group 6, the forward and reverse rotation motor I15, the forward and reverse rotation motor II, the temperature sensor, the humidity sensor, the pH sensor and the heating rod are respectively and electrically connected with the computer control system 8. Controlling the content of oxygen introduced into the soil degradation tank 5 by controlling the gas flowmeter 3; the content of the oxidant, the content of the bacterial liquid and the content of the nutrient solution which are led into the soil degradation tank 5 are controlled by controlling the drug adding pump unit 6, and the pH value in the tank body is adjusted; the stirring direction of the main stirring shaft 16 is controlled by controlling the forward rotation or the reverse rotation of the forward and reverse rotation motor I15, so that the soil is controlled to ascend or descend; controlling the stirring direction of the horizontal stirrer by controlling the forward rotation or the reverse rotation of a forward and reverse rotation motor II, so as to control the left movement or the right movement of the soil; the operation of the gas flowmeter 3, the medicine adding pump set 6 and the heating rod is controlled by receiving soil data fed back by the temperature sensor, the humidity sensor and the pH sensor.

As a further improvement of the present invention, sampling holes 21 are respectively disposed on the side walls of the first tank 51, the second tank 52, the third tank 53 and the fourth tank 54, and the position of the sampling hole 21 of the first tank 51 is symmetrical to the position of the feed port 11.

As a further improvement of the invention, the sampling hole 21 is provided with a sealing cover matched with the sampling hole, so that external air is prevented from entering the soil degradation tank 5 during sampling.

When the device is used, pre-crushed petroleum hydrocarbon polluted soil (the particle size is less than 2mm) is added into the soil degradation tank 5 from the feeding hole 11, the forward and reverse rotating motor I15 and the forward and reverse rotating motor II are started, the stirring directions and the rotating speeds of the main stirring shaft 16 and the horizontal stirrer 18 are automatically adjusted through a preset program, the soil is controlled to ascend or descend, the opening position of the oxidant hole on the liquid distribution pipe 20 is automatically adjusted through the preset program, the release amount of the oxidant A is controlled, the polluted soil is fully mixed at the upper part of the tank body, and chemical oxidation is completed under the action of the oxidant A. The positions of the bacteria liquid holes and the opening positions of the nutrient liquid holes on the liquid distribution pipe 20 are automatically adjusted through a preset program, and the release amount of the bacteria liquid B and the nutrient liquid C is controlled, so that the chemically oxidized soil is further subjected to microbial degradation.

Based on the feedback signals of the temperature, humidity and pH sensors and the gas measuring instrument, the liquid distribution pipe 20 is automatically controlled to release a proper amount of clear water and acid-alkali liquid by setting the parameters of temperature, humidity and pH, the heating rod is controlled to control the temperature, the amount of oxygen introduced into the gas flowmeter 3 is controlled, and the different positions of the tank body are ensured to reach the respective proper temperature, humidity, pH and dissolved oxygen content, wherein the temperature of the upper chemical oxidation part is 25 ℃, the pH is 7-8, the temperature of the lower microbial degradation part is 35 ℃, and the pH is 6.5-7.5. The stirring procedure of the main stirring shaft is that the stirring is pushed upwards for 10 circles/day and pushed downwards for 11 circles/day, and the stirring procedure of the horizontal stirrer is that the stirring is pushed leftwards for 10 circles/day and rightwards for 10 circles/day. The excess liquid is discharged from the liquid outlet 14, and the excess gas is discharged from the gas outlet 10. After the treatment period is finished, the soil is discharged from a lower discharge hole 13, and the degradation rate of main pollutants can reach 91.2%.

The microbial degradation and chemical oxidation technologies both require a certain degree of dissolved oxygen content, on one hand, the dissolved oxygen can create an aerobic environment for microbial degradation, and on the other hand, the increase of the dissolved oxygen content can also improve the strength of the chemical oxidation reaction. The chemical oxidation technology and the microbial degradation technology are combined to establish a multiphase integrated reactor, and the petroleum hydrocarbon polluted soil is efficiently and continuously treated in a synergistic manner. The technical problems that continuous operation cannot be carried out, cost is high and treatment period is long in the prior art are solved.

Claims

1. A system for synergistically repairing petroleum hydrocarbon-contaminated soil by chemical oxidation and microorganisms, characterized in that it comprises an air compressor (1), a carbon dioxide filter (2), a gas flow meter (3), a gas detector one (4) , soil degradation tank (5), dosing pump group (6), gas detector two (7) and computer control system (8),

The soil degradation tank (5) includes a first tank body (51), a second tank body (52), a third tank body (53) and a fourth tank body (54) that are stacked from top to bottom, adjacent to each other. The two tanks are connected by flanges, and each tank connection is provided with a temperature sensor, a humidity sensor, a pH sensor and a heating rod, and the top of the first tank (51) is provided with a liquid inlet (9) and The air outlet (10), the side wall of the first tank (51) is provided with a feed port (11), the bottom of the fourth tank (54) is provided with a material outlet (13) and a liquid outlet (14) ) and the air inlet (12), the inner center of the soil degradation tank (5) is vertically provided with a main stirring shaft (16), and the upper end of the main stirring shaft (16) extends out of the first tank (51) And it is connected with the forward and reverse rotation motor one (15), the lower end of the main stirring shaft (16) extends into the fourth tank (54), and the main stirring shaft (16) is provided with four spiral blades evenly spaced (17), the four helical blades (17) are respectively located in the four tanks, and two horizontal agitators (18) driven by two forward and reverse motors are symmetrically arranged on the inner wall of each tank, and the soil degrades The inside of the tank (5) is also provided with a liquid distributor, the liquid distributor includes a liquid distribution tray (19) and a plurality of liquid distribution pipes (20), the liquid distribution tray (19) is an annular hollow structure, and is provided with Above the inside of the first tank body (51), the liquid distribution pipe (20) is vertically arranged, and the upper end of the liquid distribution pipe (20) communicates with the liquid distribution tray (19), and the liquid distribution pipe (20) The lower end extends into the fourth tank (54), and the liquid distribution tray (19) and the liquid distribution pipe (20) are also provided with a clear water pipe, an acid liquid pipe, an alkaline liquid pipe, an oxidant pipe, a bacterial liquid pipe and a nutrient solution The liquid distribution pipes (20) in each tank body are respectively provided with clean water holes, acid liquid holes and alkali liquid holes, and the liquid distribution pipes ( 20) is also provided with oxidant holes, and the liquid distribution pipes (20) in the third tank (53) and the fourth tank (54) are also provided with bacteria liquid holes and nutrient liquid holes,

The dosing pump group (6) includes a clean water pump, an acid liquid pump, an alkaline liquid pump, an oxidant pump, a microbial bacterial liquid pump and a nutrient liquid pump. The bacterial liquid pump and the nutrient liquid pump are sequentially connected with the clean water pipe, the acid liquid pipe, the lye liquid pipe, the oxidant pipe, the bacterial liquid pipe and the nutrient liquid pipe through the liquid inlet (9). The liquid pipe and the acid liquid hole, the lye liquid pipe and the alkali liquid hole, the oxidant pipe and the oxidant hole, the bacterial liquid pipe and the bacterial liquid hole, and the nutrient liquid pipe and the nutrient liquid hole are connected in sequence,

The air compressor (1), carbon dioxide filter (2), gas flow meter (3), and gas detector one (4) are connected in sequence through pipelines, and the gas detector one (4) is connected to the soil degradation The air inlet (12) of the tank (5) is connected, the second gas detector (7) is connected with the air outlet (10) of the soil degradation tank (5), the gas flow meter (3), the dosing The pump set (6), the first forward and reverse rotation motors (15), the second forward and reverse rotation motors, the temperature sensor, the humidity sensor, the pH sensor and the heating rod are respectively electrically connected to the computer control system (8); the main stirring shaft (16 ) The stirring program is 10 circles/day for pushing up, 11 circles/day for pushing down, and 10 circles/day for pushing left and 10 circles/day for pushing down the horizontal mixer (18).

2. A system for synergistically remediating petroleum hydrocarbon-contaminated soil by chemical oxidation and microorganisms according to claim 1, wherein the first tank (51), the second tank (52), and the third tank are ( 53 ) and the side walls of the fourth tank ( 54 ) are respectively provided with sampling holes ( 21 ), and the positions of the sampling holes of the first tank ( 51 ) are symmetrical with the position of the feed port ( 11 ).

3. A system for synergistically remediating petroleum hydrocarbon-contaminated soil by chemical oxidation and microorganisms according to claim 2, wherein the sampling hole (21) is provided with a matching sealing cover to prevent outside air from entering the soil degradation tank during sampling .

4. A system for synergistically remediating petroleum hydrocarbon-contaminated soil by chemical oxidation and microorganisms according to claim 1, characterized in that, the liquid distribution pipes (20) are provided with four pipes and are evenly distributed around the circumference.

5 . The system for synergistically remediating petroleum hydrocarbon-contaminated soil by chemical oxidation and microorganisms according to claim 1 , wherein the soil degradation tank ( 5 ) has a cylindrical structure. 6 .