CN205313314U - Coking waste water treatment system - Google Patents

Abstract

The utility model discloses a coking wastewater treatment system, which comprises a gas energy flocculation device, at least one multi-element catalytic oxidation device and at least one biochemical device arranged in sequence. The utility model has the advantages that: coking wastewater has complex organic components and contains relatively high concentrations of refractory organics, which cannot be degraded simply by biochemical processes, resulting in excessive COD in the effluent; coking wastewater contains a large amount of biologically toxic substances. Such substances are not only non-biodegradable, but will inhibit microorganisms and affect the normal treatment effect of microorganisms; in addition to organic pollutants, coking wastewater also contains high concentrations of ammonia nitrogen and total nitrogen, which will also affect the normal operation of biological treatment processes.

Description

Coking wastewater treatment system

technical field

The utility model relates to a coking wastewater treatment system, which belongs to the field of environmental engineering.

Background technique

Coking wastewater is a kind of toxic, harmful, high-concentration and refractory organic wastewater produced by high-temperature dry distillation of raw coal, gas purification and chemical product recovery and refining. It mainly contains phenolic compounds, aliphatic compounds, heterocyclic compounds, polycyclic aromatic hydrocarbons, ammonia nitrogen, Sulfide, cyanide, sulfur cyanide and other pollutants. Previously, coking wastewater treatment mainly consisted of processes such as oil removal, phenol removal, ammonia distillation, and biochemistry to remove most of the organic pollutants and ammonia nitrogen in the wastewater. Nowadays, with the implementation of the "Discharge Standards for Pollutants in the Coking Chemical Industry" (GB16171-2012 instead of GB16171-1996), COD _cr , NH ₃ -N, TN, cyanide, polycyclic aromatic hydrocarbons, benzo(a ) Removal of pollutants such as pyrene puts forward stricter requirements.

The up-to-standard treatment of coking wastewater is a recognized problem in the industry, and there is no effective standard process so far. The treatment process is divided into three process sections of "pre-treatment, biological treatment, and advanced treatment", and the current domestic treatment technology status and level are described as follows:

(1) Pre-treatment: The pre-treatment of coking wastewater in the wastewater station includes facilities such as gravity oil separation, homogenization and equalization, air flotation and oil removal. When the wastewater contains a high concentration of cyanide, it needs to be removed by iron salt precipitation in the pretreatment. Air flotation usually adopts three-phase vortex mixer concave air flotation or dissolved air flotation.

(2) Biological treatment: Biological treatment includes functions such as denitrification, nitrification, COD degradation, and decyanation, and the process forms include A/O, A/A/O, O/A/O, etc. Bio-augmentation treatment technologies include adding special-effect bacteria, adding biological enzymes, installing special biological fillers, or using membrane bioreactor technology (MBR), etc.

(3) Advanced treatment: the most common ones are the addition of specific agents, advanced chemical oxidation and membrane separation technology. The specific agent includes one or more functions such as coagulation, flocculation, oxidation and adsorption. The most common advanced chemical oxidation is Fenton and ozone catalytic oxidation. Membrane technology generally uses nanofiltration or reverse osmosis. In addition, advanced treatment also uses electrochemical technologies such as electrocoagulation and electrolytic oxidation.

The effluent water quality of each stage of the above three treatment stages is roughly as follows:

Table 1 Water quality in each treatment stage of coking wastewater

pre-processing biological treatment Advanced processing COD _cr (mg/L) 2500～4000 180～250 80～150 NH ₃ -N (mg/L) 150～250 5～10 5～10 T-N(mg/L) 300～350 150～200 150～200

In the biological treatment process, common problems include unstable nitrification and the generation of large amounts of biofoam:

(1) Coking wastewater contains phenol, cyanide, thiocyanide and other large amounts of biologically toxic substances, which can inhibit nitrifying bacteria at a specific concentration, resulting in large fluctuations in the NH ₃ -N index of biologically treated effluent; And because the growth rate of nitrifying bacteria is slow, once it is inhibited, it takes a long time to return to normal function.

(2) A large amount of foam is generated during biochemical treatment of coking wastewater (especially activated sludge method), and defoaming agent or industrial water must be used for defoaming. When the above-mentioned defoaming measures are adopted, the former is expensive; the latter will cause a substantial increase in the biological treatment effluent (up to 100%). Although the concentration of effluent pollutants is reduced, the total removal rate is not high.

In the advanced treatment process segment, the problems existing in each technology are shown in the following table:

Table 2 Problems in coking wastewater advanced treatment technology

According to the "Coking Chemical Industry Pollutant Discharge Standard" (GB16171-2012), the main pollutant limits for coking wastewater treatment to direct discharge are: COD _cr <80mg/L, NH ₃ -N<10mg/L, TN<20mg/L L. According to the current actual situation of coking wastewater treatment, it is difficult to meet the discharge requirements of the new standard only through enhanced biological treatment, or relying solely on advanced treatment methods such as special agents and chemical oxidation. In addition, the reduction in water discharge per ton of coke required in the standard means that the current method of adding a large amount of industrial water to dilute coking wastewater to meet the standard will no longer be feasible, and more and more consideration will be given to reusing coking wastewater or even zero emission.

The reasons why domestic coking wastewater treatment is generally difficult to meet the standard are analyzed as follows:

(1) The organic matter in the coking wastewater is complex and contains a high concentration of refractory organic matter, which cannot be degraded through biochemical processes alone, resulting in excessive COD in the effluent;

(2) Coking wastewater contains a large amount of biologically toxic substances, which are not only non-biodegradable, but will inhibit microorganisms and affect the normal treatment effect of microorganisms;

(3) In addition to organic pollutants, coking wastewater also contains high concentrations of ammonia nitrogen and total nitrogen, which will also affect the normal operation of the biological treatment process.

Utility model content

The purpose of the utility model is to provide a coking wastewater treatment system to solve the above-mentioned problems in the prior art.

In order to achieve the above object, the technical scheme of the utility model is as follows:

A coking wastewater treatment system, which includes a gas energy flocculation device, at least one multi-component catalytic oxidation device and at least one biochemical device arranged in sequence.

As a preferred solution, the gas energy flocculation device includes a water inlet pump, a three-phase vortex mixer 1, an air compressor, a three-phase vortex mixer 2, a three-phase vortex mixer 3, a three-phase vortex mixer 4, and a floc separation tank and the slag scraper, the three-phase vortex mixer one is connected with the water inlet pump, the three-phase vortex mixer two is connected with the three-phase vortex mixer one, and the three-phase vortex mixer three and the three-phase vortex mix The second phase of the vortex mixer is connected, and the fourth phase vortex mixer is connected with the three phase vortex mixer. The floc separation tank is provided with a vertical partition and a horizontal perforated water collection plate. The partition The floc separation tank is divided into a floc growth zone and a floc separation zone, the perforated water collecting plate is arranged in the clear water zone at the lower part of the floc separation zone, and the three-phase vortex mixer 4 is connected with the floc growth zone, The slag scraper is arranged at the mouth of the floc separation tank.

The air energy flocculation device uses a three-phase vortex mixer as the core component, and can complete the stretching and efficiency improvement of pharmaceutical molecules, coagulation and flocculation stirring (pollutant capture), floc formation, bubble crystal nucleus generation and ultra-light hollow flocs in one step. All steps of formation. In this way, the pollutants in the water are fully captured by using a small amount of precise chemical agents; at the same time, hollow flocs with extremely light specific gravity are formed, which float to the surface of the pool body and are scraped off.

The essential difference between air energy flocculation technology and traditional air flotation technology lies in the different contact forms between bubbles and flocs: the latter adopts simple "bubbles and flocs contact attachment", and the bubbles are easy to desorb with flocs; while the former uses "flocculation Bubble growth technology" - the bubbles generate crystal nuclei and grow inside and around the floc, and the two become an organic whole.

As a preferred solution, the second three-phase vortex mixer is also connected with an air compressor.

As a preferred solution, the gas energy flocculation device further includes a slag tank and a scum delivery pump.

As a preferred solution, the multi-component catalytic oxidation device includes a multi-component catalytic oxidation reaction tank, and the multi-component catalytic oxidation reaction tank is sequentially provided with an air diffusion device and a catalyst support filter plate from bottom to top, and the catalyst support filter plate is Two cathode plates and one anode plate are vertically arranged, and the anode plate is arranged between the two cathode plates. The mouth of the multi-component catalytic oxidation reaction tank is provided with a water distribution tank, and one end of the water distribution tank is connected to the water inlet pump. The other end of the water distribution tank is connected with a backflow valve and a water outlet valve at the same time, and the backflow valve and the water outlet valve are controlled by a circulating pump.

Multi-component catalytic oxidation technology is a new type of water treatment equipment developed by combining advanced oxidation technology and advanced catalytic technology, electrical control technology and corresponding solid catalyst research, comprehensively using titanium-based coating electrodes, fixed composite catalysts and desorption technology. Its working principle is described as follows: Under normal temperature and pressure conditions, an electromagnetic field is formed between special coating electrodes through a DC power supply, and a multi-electrode effect is formed through a solid composite catalyst filled between the electrodes. Rapidly promotes the generation of hydroxyl radicals (·OH). OH has a strong oxidizing ability. Using its extremely high oxidation electrode potential, it is easy to attack the high electron cloud density points of organic molecules, and non-selectively break the chain of high-concentration and difficult-to-biodegradable organic pollutants, and oxidize them into CO2 , H2O, or simple organics.

As a preferred solution, the biochemical device includes: anoxic tank, aerobic tank, blower, nitrification liquid return pump, microporous aeration pipe, sedimentation tank and mud scraper, and the aerobic tank is arranged between the anoxic tank and the sedimentation tank. between the pools and communicate with the anoxic pool, the aerobic pool is equipped with biological filler, the microporous aeration tube is arranged at the bottom of the aerobic pool, the blower is connected with the microporous aeration tube, the The nitrification return pump is connected between the aerobic tank and the anoxic tank, and a mud scraper is installed in the sedimentation tank.

Therefore, compared with the prior art, the utility model has the following advantages:

(1) Air energy flocculation technology is used as the pretreatment of coking wastewater. The unique three-phase vortex mixer flow three-phase mixing technology of air energy flocculation can maximize the use of chemicals, fully capture fine pollution particles and colloids, and make coking wastewater turbid. The removal rate is high, which can effectively guarantee the influent water quality requirements of subsequent multi-component catalytic oxidation and biochemistry.

(2) Multi-element catalytic oxidation technology can generate strong oxidant hydroxyl radical [ OH] with lower energy consumption. Compared with other advanced oxidation technologies, the reaction conditions are mild, no chemicals are used in the reaction process, and no sludge or Concentrate.

(3) The biochemical pretreatment of coking wastewater by gas energy flocculation and multi-component catalytic oxidation can effectively reduce the biological toxicity of wastewater, reduce the load of biochemical treatment, and improve the biodegradability of wastewater, making the subsequent biochemical treatment simple and efficient.

(4) After multi-component catalytic oxidation is used as biochemical pretreatment, the amount of foam on the surface of the aeration tank of the biochemical device is greatly reduced compared with the direct treatment of coking wastewater by the biochemical device, or there is basically no foam, and no defoaming measures are required.

(5) Industrial tests have shown that the COD _cr , NH ₃ -N and TN in the effluent are less than 80mg/L, 10mg/L and 20mg/L respectively, which meets the requirements of the Pollutant Discharge of Coking Chemical Industry Standard" (GB16171-2012) requirements.

Description of drawings

Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

Fig. 1 is a process roadmap of the present utility model;

Fig. 2 is the structural representation of three-phase vortex mixer in the utility model;

Fig. 3 is the structural representation of multi-element catalytic oxidation device in the utility model;

Fig. 4 is the structural representation of the biochemical device in the utility model;

In the figure: 101, air energy device inlet pump; 102, air compressor; 103, three-phase vortex mixer one; 104, three-phase vortex mixer two; 105, three-phase vortex mixer three; 106, three-phase vortex mixer Device four; 107, floc growth area; 108, clapboard; 109, floc separation tank; 110, perforated water collection plate; 111, air energy device slag scraper; 112, slag tank; 113, scum delivery pump; 201. Oxidation tank inlet pump; 202. Multi-component catalytic oxidation reaction tank; 203. Air diffusion device; 204. Circulation pump; 205. Catalyst supporting filter plate; 206. Composite catalyst; 207. Cathode plate; 208. Anode plate; 209 , distribution tank; 210, DC power supply; 211, return valve; 212, outlet valve; 301, anoxic pool; 302, aerobic pool; 303, blower; 304, nitrifying liquid return pump; Hole aeration pipe; 307, sedimentation tank; 308, mud scraper for sedimentation tank; 309, sludge pump.

detailed description

The utility model is described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present utility model. These all belong to the protection domain of the present utility model.

A coking wastewater treatment system, which includes gas energy flocculation devices, at least one multi-component catalytic oxidation device and at least one biochemical device arranged in sequence. In this embodiment, the number of multi-component catalytic oxidation devices is two, and the number of biochemical devices is also two.

The structure of the air energy flocculation device is shown in Figure 2, including the air energy device inlet pump 101, three-phase vortex mixer one 103, air compressor 102, three-phase vortex mixer two 104, three-phase vortex mixer three 105, three-phase vortex mixer three Phase vortex mixer four 106, floc separation tank 109 and air energy device slag scraper 111, three-phase vortex mixer one 103 communicates with air energy device inlet pump 101, three-phase vortex mixer two 104 and three-phase vortex mixer One 103 is connected, the three-phase vortex mixer 105 is connected with the three-phase vortex mixer two 104, the three-phase vortex mixer four 106 is connected with the three-phase vortex mixer 105, and the floc separation tank 109 is provided with a vertical The dividing plate 108 in the vertical direction and the perforated water collecting plate 110 in the horizontal direction, the dividing plate 108 divides the floc separation tank 109 into a floc growth zone 107 and a floc separation zone, and the perforated water collecting plate 110 is arranged in the floc separation zone, The three-phase vortex mixer 106 is connected with the floc growth area 107, and the air energy device slag scraper 111 is installed at the mouth of the floc separation tank 109, and the waste slag scraped by the air energy device slag scraper is sent into the slag tank 112 , The bottom of the slag tank 112 communicates with a scum delivery pump 113, and the scum delivery pump 113 drains the waste slag in the slag tank 112 away. The second three-phase vortex mixer 104 is also in communication with the air compressor 102 .

The air energy flocculation device uses a three-phase vortex mixer as the core component, and can complete the stretching and efficiency improvement of pharmaceutical molecules, coagulation and flocculation stirring (pollutant capture), floc formation, bubble crystal nucleus generation and ultra-light hollow flocs in one step. All steps of formation. In this way, the pollutants in the water are fully captured by using a small amount of precise chemical agents; at the same time, hollow flocs with extremely light specific gravity are formed, which float to the surface of the pool body and are scraped off.

The essential difference between air energy flocculation technology and traditional air flotation technology lies in the different contact forms between bubbles and flocs: the latter adopts simple "bubbles and flocs contact attachment", and the bubbles are easy to desorb with flocs; while the former uses "flocculation Bubble growth technology" - the bubbles generate crystal nuclei and grow inside and around the floc, and the two become an organic whole.

The structure of multi-element catalytic oxidation device comprises multi-element catalytic oxidation reaction tank 202 as shown in Figure 3, and multi-element catalytic oxidation reaction tank 202 is provided with air diffusion device 203 and catalyst support filter plate 205 successively from bottom to top, catalyst support filter plate Two cathode plates 207 and an anode plate 208 are vertically arranged on the 205, the anode plate 208 is arranged between the two cathode plates 207, the mouth of the multi-component catalytic oxidation reaction tank 202 is provided with a water distribution tank 209, and one end of the water distribution tank 209 is connected to the The oxidation tank inlet pump 201 is connected, and the other end of the water distribution tank 209 is connected with a backflow valve 211 and a water outlet valve 212 at the same time, and the backflow valve 211 and the water outlet valve 212 are controlled by a circulation pump 204 . During use, two cathode plates 207 are electrically connected to the negative pole of the DC power supply 210 , one anode plate 208 is electrically connected to the positive pole of the DC power supply 210 , and the composite catalyst 206 is paved on the catalyst supporting filter plate 205 .

Multi-component catalytic oxidation technology is a new type of water treatment equipment developed by combining advanced oxidation technology and advanced catalytic technology, electrical control technology and corresponding solid catalyst research, comprehensively using titanium-based coating electrodes, fixed composite catalysts and desorption technology. Its working principle is described as follows: Under normal temperature and pressure conditions, an electromagnetic field is formed between special coating electrodes through a DC power supply, and a multi-electrode effect is formed through a solid composite catalyst filled between the electrodes. Rapidly promotes the generation of hydroxyl radicals (·OH). OH has a strong oxidizing ability. Using its extremely high oxidation electrode potential, it is easy to attack the high electron cloud density points of organic molecules, and unselectively break the chain of high-concentration and difficult-to-biodegradable organic pollutants, and oxidize them into CO _2. H ₂ O or simple organic matter.

The structure of the biochemical device is shown in Figure 4, including: anoxic tank 301, aerobic tank 302, blower 303, nitrification liquid return pump 304, microporous aeration pipe 306, sedimentation tank 307 and sedimentation tank mud scraper 308, good Oxygen tank 302 is arranged between anoxic tank 301 and sedimentation tank 307, and communicates with anoxic tank 301, and biological filler 305 is housed in aerobic tank 302, and microporous aeration pipe 306 is arranged at the bottom of aerobic tank 302, Blower 303 is connected with microporous aeration pipe 306, nitrification return pump 304 is connected between aerobic tank 302 and anoxic tank 301, sedimentation tank scraper 308 is arranged in sedimentation tank 307, sedimentation tank scraper 308 and A sludge pump 309 is connected, and the sludge pump 309 can discharge the sludge scraped by the sludge scraper 308 in the sedimentation tank.

A coking wastewater treatment system, which includes a gas energy flocculation device, at least one multi-component catalytic oxidation device and at least one biochemical device arranged in sequence.

As a preferred solution, the gas energy flocculation device includes a water inlet pump, a three-phase vortex mixer one, an air compressor, a three-phase vortex mixer two, a three-phase vortex mixer four, a floc separation tank and a slag scraper. The first three-phase vortex mixer is connected to the water inlet pump, the second three-phase vortex mixer is connected to the first three-phase vortex mixer, the third three-phase vortex mixer is connected to the second three-phase vortex mixer, and the three-phase vortex mixer two is connected to each other. The three-phase vortex mixer and the three-phase vortex mixer are connected in three phases, and the floc separation tank is provided with a vertical partition and a horizontal perforated water collecting plate, and the partition separates the floc separation tank. Divided into a floc growth zone and a floc separation zone, the perforated water collecting plate is set in the clear water zone at the lower part of the floc separation zone, the three-phase vortex mixer 4 is connected with the floc growth zone, and the slag scraper is set At the mouth of the floc separation tank.

The air energy flocculation device uses a three-phase vortex mixer as the core component, and can complete the stretching and efficiency improvement of pharmaceutical molecules, coagulation and flocculation stirring (pollutant capture), floc formation, bubble crystal nucleus generation and ultra-light hollow flocs in one step. All steps of formation. In this way, the pollutants in the water are fully captured by using a small amount of precise chemical agents; at the same time, hollow flocs with extremely light specific gravity are formed, which float to the surface of the pool body and are scraped off.

The essential difference between air energy flocculation technology and traditional air flotation technology lies in the different contact forms between bubbles and flocs: the latter adopts simple "bubbles and flocs contact attachment", and the bubbles are easy to desorb with flocs; while the former uses "flocculation Bubble growth technology" - the bubbles generate crystal nuclei and grow inside and around the floc, and the two become an organic whole.

As a preferred solution, the second three-phase vortex mixer is also connected with an air compressor.

As a preferred solution, the gas energy flocculation device further includes a slag tank and a scum delivery pump.

As a preferred solution, the multi-component catalytic oxidation device includes a multi-component catalytic oxidation reaction tank, and the multi-component catalytic oxidation reaction tank is sequentially provided with an air diffusion device and a catalyst support filter plate from bottom to top, and the catalyst support filter plate is Two cathode plates and one anode plate are vertically arranged, and the anode plate is arranged between the two cathode plates. The mouth of the multi-component catalytic oxidation reaction tank is provided with a water distribution tank, and one end of the water distribution tank is connected to the water inlet pump. The other end of the water distribution tank is connected with a backflow valve and a water outlet valve at the same time, and the backflow valve and the water outlet valve are controlled by a circulating pump.

Multi-component catalytic oxidation technology is a new type of water treatment equipment developed by combining advanced oxidation technology and advanced catalytic technology, electrical control technology and corresponding solid catalyst research, comprehensively using titanium-based coating electrodes, fixed composite catalysts and desorption technology. Its working principle is described as follows: Under normal temperature and pressure conditions, an electromagnetic field is formed between special coating electrodes through a DC power supply, and a multi-electrode effect is formed through a solid composite catalyst filled between the electrodes. Rapidly promotes the generation of hydroxyl radicals (·OH). OH has a strong oxidizing ability. Using its extremely high oxidation electrode potential, it is easy to attack the high electron cloud density points of organic molecules, and unselectively break the chain of high-concentration and difficult-to-biodegradable organic pollutants, and oxidize them into CO _2. H ₂ O or simple organic matter.

As a preferred solution, the biochemical device includes: anoxic tank, aerobic tank, blower, nitrification liquid return pump, microporous aeration pipe, sedimentation tank and mud scraper, and the aerobic tank is arranged between the anoxic tank and the sedimentation tank. between the pools and communicate with the anoxic pool, the aerobic pool is equipped with biological filler, the microporous aeration tube is arranged at the bottom of the aerobic pool, the blower is connected with the microporous aeration tube, the The nitrification return pump is connected between the aerobic tank and the anoxic tank, and a mud scraper is installed in the sedimentation tank.

A coking wastewater treatment method based on the aforementioned coking wastewater treatment system, including gas energy flocculation pretreatment, a step of primary multi-component catalytic oxidation treatment, a step of primary biochemical treatment, a step of secondary biochemical oxidation, and a step of secondary biochemical treatment step.

The coking wastewater first passes through the gravity grease trap to remove heavy oil and slick oil, then passes through the gas energy flocculation device to remove the emulsified oil and reduce the turbidity, and then enters the regulating pond to balance the water quality and quantity.

The wastewater in the regulating tank is pumped into the first-stage multi-component catalytic oxidation device, and the strong oxidant hydroxyl radical [ OH] generated in the reaction process is used to detoxify ketenes, phenols, condensed-ring aromatic hydrocarbons, and nitrogen-containing impurities in the coking wastewater. Oxidation of cyclic compounds (such as quinoline, indole, pyridine, anthracene, quinone, etc.) .

The first-level multi-component catalytic oxidation effluent enters the first-level biochemical treatment. The first-level biochemical treatment adopts the A/O (anoxic/aerobic) process. In the anoxic section, the assimilable carbon source in the influent is used to denitrify the total nitrogen. Most of the phenolic substances are completely degraded and transformed; in the aerobic section, COD is further oxidized and degraded (most of the ketones are completely removed), NH ₃ -N undergoes nitrification reaction, and the nitrification solution flows back into the anoxic section.

In order to meet the emission requirements of T-N and COD, a second-stage multi-component catalytic oxidation process is set up for advanced treatment of coking wastewater: oxidize the residual refractory organic matter in the waste water, convert it into biodegradable substances or directly remove them; use the generated biodegradable Degraded substances and supplemented carbon sources are denitrified to remove total nitrogen in the subsequent secondary biochemical A/O (anoxic/aerobic) process. The final effluent quality can reach the limit value of the new discharge standard.

Of course, if the physical and chemical indicators of the coking wastewater after one multi-component catalytic oxidation or one-time biochemical treatment can reach the corresponding standards, subsequent multi-component catalytic oxidation or biochemical treatment may not be performed on the wastewater.

As a preferred solution, the gas energy flocculation pretreatment specifically includes the following operations:

In three-phase vortex mixer 1, three-phase vortex mixer 3 and three-phase vortex mixer 4, polyaluminum chloride coagulant, cationic polymer flocculant, and anionic polymer flocculant were respectively added. Compressed air is introduced into the mixer two;

The three-phase mixer forms a three-phase vortex mixer flow under high pressure, which can complete the three-phase mixing of medicament and pollutant particles (solid), water and gas.

Input the coking waste water into three-phase vortex mixer 1, make the coking waste water go through three-phase vortex mixer 1, three-phase vortex mixer 2, three-phase vortex mixer 3 and three-phase vortex mixer 4 successively after flocculation, then pass into The floc growth zone of the floc separation tank;

The scum formed in the floc growth area is scraped off in the floc separation tank by the slag scraper installed on the top of the tank, and the clear liquid collected by the perforated water collecting plate at the bottom of the floc separation tank is discharged, and enters the next treatment process.

The flocs gradually formed in the three-phase vortex mixer are a solid-liquid-gas three-state mixture under pressure. In the floc growth zone, the pressure is released to normal pressure, and the dissolved gas in the flocs is released and grows up, which can dissociate the flocs. The water is squeezed out; the gas and solid flocs form a porous and hollow form, the water content is significantly reduced and its own specific gravity is getting lighter and lighter, and it can float by itself without external force.

The scum formed in the floc growth area is scraped out in the floc separation tank by the slag scraper installed on the top of the tank, collected in the scum tank, and discharged to the dehydration device through the scum conveying pump; the bottom of the floc separation tank is equipped with a perforated water collection compartment plate, collect the clean supernatant and discharge it, and enter the next processing procedure.

The dosing order and dosing data of the polymerization wastewater treated by gas energy flocculation are shown in Table 2:

Table 2 Gas energy flocculation dosing sequence and dosing amount

Table 3 Working pressure of three-phase vortex mixer

Working pressure (MPa) Three-phase vortex mixer one 0.70 Three-phase vortex mixer II 0.58 Three-phase vortex mixer three 0.54 Three-phase vortex mixer four 0.05

Effect of gas energy flocculation treatment on coking wastewater

Air energy flocculation has obvious effect on removing turbidity and chroma of coking wastewater. At the same time, air energy flocculation can also remove COD _cr of coking wastewater to a certain extent: when the influent COD _cr is about 1800mg/L-2300mg/L, the treated effluent COD _cr About 1700mg/L～1950mg/L.

In addition, the scum formed by gas energy flocculation treatment of coking wastewater is relatively dense, and the amount of scum produced is about 5-6L/m ³ wastewater.

The one-stage multi-component catalytic oxidation treatment specifically includes the following operations:

Pave the catalyst on the catalyst supporting filter plate of the multi-component catalytic oxidation device;

Input the coking wastewater flocculated by gas energy into the water distribution tank, control the liquid level of the coking wastewater to be higher than the surface of the catalyst, and then stop the water intake;

The coking wastewater in the reaction tank is aerated and oxygenated through the air diffusion device, and at the same time, the positive and negative electrodes are respectively transmitted to the anode plate and the cathode plate to start the aeration reaction;

After the aeration reaction has been carried out for 15 to 20 minutes, stop the aeration and oxygenation, turn on the circulation pump, and start the circulation reaction;

After the cycle reaction has been carried out for 15 to 20 minutes, the circulation pump is turned off, the power supply to the anode plate and the cathode plate is stopped, and the entire multi-component catalytic oxidation reaction is completed, and the wastewater is lifted from the outlet pump to the next-level multi-component catalytic oxidation reaction or discharged into the subsequent stage. Biochemical treatment device.

The working parameters of the first stage multi-component catalytic oxidation are shown in Table 4

Table 4

The effect of the first-stage multi-component catalytic oxidation treatment is as follows:

The COD _cr of the reaction influent water (that is, the gas energy flocculation effluent) is about 1600mg/L-2100mg/L, the COD _cr of the first-stage multi-component catalytic oxidation water is about 900mg/L-1400mg/L, and the removal rate reaches 30%-45%.

The concentration of volatile phenols in the reaction water was 301.8mg/L, and the concentration of volatile phenols in the effluent was 127.4mg/L, with a removal rate of 57.8%.

The concentration of NO ₃ -N in the reaction water is about 160mg/L-180mg/L, and the NO ₃ -N in the effluent water is about 105mg/L-130mg/L through one-stage multi-component catalytic oxidation, and the removal rate reaches 25%-35%.

The NH ₃ -N in coking wastewater was not significantly removed by one-stage multi-component catalytic oxidation, and the concentration of NH ₃ -N in the reaction water was often higher than that of the influent, which may be due to the fact that some refractory organisms The degraded nitrogen-containing heterocyclic organic compound undergoes a decomposition reaction to generate NH ₃ -N, which leads to an increase in the concentration of NH ₃ -N in the reaction water.

Primary biochemical treatment specifically includes the following operations:

Anoxic treatment is performed on the wastewater that has undergone multi-component catalytic oxidation;

After the anoxic treatment is finished, carry out aerobic treatment;

After the aerobic treatment is finished, carry out precipitation flocculation;

After the precipitation flocculation is completed, the sludge is discharged through the sludge pump, and the supernatant is subjected to the next stage of treatment.

The wastewater first enters the anoxic tank for treatment, and the biological filler is installed in the anoxic tank, and microorganisms are attached to the filler for denitrification reaction, and the organic matter in the influent is used as a carbon source to degrade the nitrate nitrogen in the reflux nitrification liquid. Potassium dihydrogen phosphate is added to the wastewater influent as a biological nutrient salt, and glucose is added as a supplementary denitrification carbon source.

The effluent from the anoxic pool flows into the aerobic pool. Microporous aeration pipes are installed at the bottom of the aerobic pool, and biological fillers are installed in the pool. The dissolved oxygen in the pool is controlled above 2 mg/L. The microorganisms in the aerobic pool degrade the organic matter and ammonia nitrogen in the coking wastewater. The nitrifying liquid in the oxygen tank is returned to the anoxic tank through the return pump, and the return ratio is ~300%. Sodium carbonate is added to the aerobic pool to supplement the alkalinity for the nitrification reaction of ammonia nitrogen.

The effluent from the aerobic tank flows into the sedimentation tank, and a mud scraper is installed in the sedimentation tank. A coagulant is added to the water inlet pipe of the sedimentation tank, and a flocculant is added to the central reaction cylinder of the sedimentation tank. The supernatant of the sedimentation tank flows into the next-level treatment device, and the sludge at the bottom of the sedimentation tank is discharged through the sludge pump.

The process and operating parameters of the first-level biochemical treatment are as shown in Table 5 and Table 6:

Table 5 First-level biochemical treatment process parameters

Table 6 The operating parameters of the first-stage biochemical treatment

flooded anoxic pool Aerobic pool pH 6.5～7 7.5～8.0 7～7.5 DO (mg/L) - 0.05～0.1 3.0～4.0 ORP(mV) -300～250 -200～-150 250～300

The effect of primary biochemical treatment is shown in Table 7

Table 7 Treatment effect of first-level biochemical treatment

The first level of biochemical treatment of influent water First stage biochemical treatment effluent COD _cr (mg/L) 950～1500 90～135 NH ₃ -N (mg/L) 80～140 5～10 T-N(mg/L) 140～320 20～25

Two-stage multi-component catalytic oxidation treatment

Since the first-stage multi-component catalytic oxidation synergistic biochemical treatment of coking wastewater can not meet the standard requirements of COD _cr (<80mg/L), the second-level multi-component catalytic oxidation and secondary biochemical treatment are carried out.

The first-stage biochemical effluent enters the second-stage multi-component catalytic oxidation device for treatment, and the treatment process and working principle of the second-stage multi-component catalytic oxidation are the same as those of the first-stage multi-component catalytic oxidation.

The working parameters of the two-stage multi-component catalytic oxidation are shown in Table 8.

Table 8

The effect of the second-stage multi-component catalytic oxidation treatment is as follows:

The COD _{cr of the reaction influent water (that is, the first-stage multi-component catalytic oxidation effluent) is about 90mg/L-135mg/L, and the COD cr of} the second-stage multi-component catalytic oxidation effluent is about 80mg/L-100mg/L.

Second-level biochemical treatment, the effluent from the second-level multi-component catalytic oxidation enters the second-level biochemical device for treatment, and the treatment process and working principle of the second-level biochemical treatment are the same as those of the first-level biochemical treatment.

The process and operating parameters of the secondary biochemical treatment are shown in Table 9 and Table 10 respectively:

Table 9 Second-stage biochemical treatment process parameters

HRT (hydraulic retention time) ～8h (among them A section 4h, O section 4h) Nitrification solution reflux ratio ~200% water temperature 25～30℃

Table 10 Second-stage biochemical treatment operating parameters

flooded anoxic pool Aerobic pool pH ~7 ~7 ~7 DO (mg/L) - 0.05～0.1 2.0～3.0

The effect of the second level of biochemical treatment is as follows:

The COD _cr of the second-stage biochemical treatment effluent is 52-72 mg/L, which meets the requirements of the discharge standard.

In the industrial application test of coking wastewater treatment carried out by a certain company. Adopting the technical route of the utility model, the continuous treatment water volume is 1m ³ /h, and the treatment water quality results are as follows:

Table 11 coking wastewater treatment results

In summary, it is only a preferred embodiment of the present utility model, and is not used to limit the scope of the utility model implementation. All the shapes, structures, features and spirits described in the scope of the claims of the utility model are equal. Changes and modifications should be included in the scope of claims of the present utility model.

Claims (5)

1. a coking wastewater processing system, it is characterised in that include the gas energy flocculation plant, at least one multiple catalyzing oxidation unit and at least one biochemical device that set gradually;

Described gas energy flocculation plant includes intake pump, three-phase vortex blender one, air compressor machine, three-phase vortex blender two, three-phase vortex blender three and three-phase vortex blender four, flco separating tank and Slag Scraping Device, three-phase vortex blender one is connected with intake pump, described three-phase vortex blender two is connected with three-phase vortex blender one, described three-phase vortex blender three is connected with three-phase vortex blender two, described three-phase vortex blender four is connected with three-phase vortex blender three, the dividing plate of vertical direction and the perforation water collection sheet of horizontal direction it is provided with in described flco separating tank, described dividing plate will be divided into flco growth district and flco Disengagement zone in flco separating tank, described perforation water collection sheet is arranged at the clear water zone of bottom, flco Disengagement zone, described three-phase vortex blender four is connected with flco growth district, described Slag Scraping Device is arranged at the oral area of flco separating tank.

2. coking wastewater processing system as claimed in claim 1, it is characterised in that described three-phase vortex blender two is also connected with an air compressor machine.

3. coking wastewater processing system as claimed in claim 1, it is characterised in that described gas energy flocculation plant also includes slag chute and scum silica frost delivery pump.

4. coking wastewater processing system as claimed in claim 1, it is characterized in that, described multiple catalyzing oxidation unit includes multiple catalyzing oxidation reaction groove, air-diffuser and catalyst support filter plate it is sequentially provided with from down to up in described multiple catalyzing oxidation reaction groove, described catalyst support filter plate is vertically provided with two pieces of minus plates and one piece of positive plate, described positive plate is arranged between two pieces of described minus plates, the oral area of multiple catalyzing oxidation reaction groove is provided with cloth tank, one end of described cloth tank is connected with intake pump, the other end of cloth tank is connected with a reflux inlet and an outlet valve simultaneously, described reflux inlet and outlet valve are controlled by a circulating pump.

5. coking wastewater processing system as claimed in claim 1, it is characterized in that, described biochemical device includes: anoxic pond, Aerobic Pond, aerator, nitrification liquid reflux pump, micropore aeration pipe, sedimentation tank and mud scraper, described Aerobic Pond is arranged between anoxic pond and sedimentation tank, and be connected with anoxic pond, described Aerobic Pond is built with biologic packing material, described micropore aeration pipe is arranged at the bottom of Aerobic Pond, described aerator is connected with micropore aeration pipe, described nitrification liquid reflux pump is communicated between Aerobic Pond and anoxic pond, is provided with mud scraper in described sedimentation tank.