Semi-coke wastewater resourceful treatment method and treatment system thereof

Abstract

The invention belongs to the technical field of semi-coke wastewater treatment, and discloses a semi-coke wastewater resourceful treatment method and a semi-coke wastewater resourceful treatment system, a plurality of components in semi-coke wastewater are separated in a multi-stage treatment mode and are subjected to resourceful treatment respectively and then discharged after reaching the standard, firstly, the wastewater is subjected to pretreatment for deoiling and deamination, and the pH value is adjusted to be within the range of 4-5; then carrying out centrifugal extraction on the pretreated wastewater through multistage centrifugal extraction equipment connected in series, separating to obtain extracted wastewater and sodium phenolate, and recycling the sodium phenolate; carrying out resin adsorption on the extraction wastewater by virtue of multi-stage serial resin adsorption equipment, separating to obtain adsorbed wastewater and sodium phenolate, and recycling the sodium phenolate; and finally, carrying out deep oxidation treatment on the adsorbed wastewater to reduce organic matters, carrying out membrane concentration and / or evaporative crystallization, detecting, and discharging after reaching the standard. Through comprehensive optimization treatment, efficient and long-time stable treatment can be effectively performed on the semi-coke wastewater.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and in particular relates to a method for resource-based treatment of semi-coke wastewater and a treatment system thereof. Background Art

[0002] Semi-coke wastewater, also known as semi-coke wastewater, refers to a type of industrial wastewater generated during the medium- and low-temperature dry distillation (about 600-800°C) of low-metamorphic coal (non-caking coal, weakly caking coal, and long-flame coal), as well as during the gas purification and semi-coke steam quenching process. This type of wastewater has a complex composition and contains a large number of difficult-to-degrade and highly toxic pollutants, such as organic pollutants such as benzene series, phenols, polycyclic aromatic hydrocarbons, nitrogen-oxygen heterocyclic compounds, and inorganic pollutants such as heavy metals. It is a typical highly polluted and highly toxic industrial wastewater.

[0003] Both blue coke and coke are products obtained by dry distillation of raw coal at a certain temperature. Therefore, the main pollutant components of the wastewater produced have many similarities. Therefore, the current treatment of blue coke wastewater mainly draws on the treatment method of coking wastewater. However, the different types of coal used to produce blue coke and coke and the difference in dry distillation temperature have caused a great difference between blue coke wastewater and coking wastewater. The difference in the type of raw coal is an important reason for the difference between blue coke wastewater and coking wastewater. Blue coke production is mainly based on medium and low temperature dry distillation at a dry distillation temperature of 600-800℃, while coke production is mainly based on high temperature dry distillation at about 1000℃. Therefore, in addition to a certain amount of high molecular organic pollutants, blue coke wastewater also contains a large amount of medium and low molecular pollutants that have not been oxidized by high temperature; under high temperature conditions, medium and low molecular organic matter is selectively combined by chemical reaction to form macromolecular organic matter. These organic matters are either retained in tar or retained in coke.

[0004] Among the treatment processes proposed for blue carbon wastewater in the prior art, the typical treatment process flow includes oil removal process, phenol-ammonia recovery process, biochemical treatment process, deep treatment process, desalination treatment process and evaporation crystallization process. Among them, due to the high organic content of blue carbon wastewater, many prior arts use biochemical treatment methods to remove it. However, most of my country's coal mines are located in the northern region, and the temperature in autumn and winter is generally low. For this kind of blue carbon wastewater with high oil and high organic content, the biochemical treatment means at room temperature are relatively heavy, and once the temperature drops, it will inevitably lead to substandard treatment. The method of simply using physical treatment is mostly a combination of membrane treatment and evaporation crystallization treatment. Although this method has a good treatment effect and the effluent is easy to meet the standard, because the various indicators of the influent are all high, the membrane treatment equipment in this method is easy to be blocked, and the evaporation crystallization equipment is also prone to coking, which makes the sustainable operation time of the equipment of the overall treatment process short, and often shuts down for maintenance due to equipment blockage. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a comprehensive treatment process for lignite wastewater, which aims to target the situation where various indicators of lignite wastewater are high, and through a combination of multi-stage treatment methods, it is possible to continuously, stably and efficiently carry out harmless treatment and resource recycling of lignite wastewater.

[0006] The technical solution adopted by the present invention is: The present invention provides a method for resource-based treatment of blue carbon wastewater, which separates several components in blue carbon wastewater through multi-stage treatment and treats them separately for resource-based treatment before discharge in compliance with standards. First, the wastewater is pretreated, the pH value of the wastewater is adjusted to a range of 4-5 for centrifugal deoiling and demulsification, and then the pH value is adjusted to a range of 8-9 for PTFE deamination membrane treatment; Then, the pH value of the pretreated wastewater is adjusted back to within the range of 4-5, and then the wastewater is centrifuged and extracted through a multi-stage centrifugal extraction device connected in series to separate the extracted wastewater and sodium phenolate, and the sodium phenolate is recovered and processed; The extracted wastewater is then subjected to resin adsorption by a multi-stage series-connected resin adsorption device to separate the adsorbed wastewater and sodium phenolate, and the sodium phenolate is recovered for treatment; Finally, the adsorbed wastewater is subjected to deep advanced oxidation treatment to reduce organic matter and then tested for compliance with discharge standards after membrane concentration and / or evaporation crystallization.

[0007] It should be noted that during the deammoniation process, the ammonia removal rate can reach more than 99% through the PTFE deammoniation membrane treatment, and it can be absorbed and utilized. Under alkaline conditions, the ammonia nitrogen ions in the wastewater are converted into ammonia water, and a certain ammonia partial pressure difference is created on both sides of the membrane, allowing ammonia to pass through the membrane wall from the wastewater side with a higher partial pressure difference to the absorption liquid side with a lower ammonia partial pressure, thereby achieving the purpose of reducing ammonia nitrogen in the wastewater. PTFE membrane has the characteristics of strong hydrophobicity and air permeability but not water permeability.

[0008] In combination with the first aspect, the present invention provides a first implementation manner of the first aspect, wherein the specific steps of pretreatment are as follows: First, the wastewater is deoiled, and then deoiled wastewater, sludge, light oil and heavy oil are obtained by combining centrifugal separation and demulsification and oil removal. The sludge is harmlessly treated, and the light oil and heavy oil are recovered and treated; Then, the pH value of the de-oiled wastewater is adjusted to alkaline, and after deammoniation treatment, the pH value is adjusted to within the range of 4-5 to complete the pretreatment process.

[0009] In combination with the first embodiment of the first aspect, the present invention provides a second embodiment of the first aspect, wherein the pretreatment further includes preliminary screening and filtration of suspended matter and sediment, and the screened solid waste is dried and recycled.

[0010] In combination with the first embodiment of the first aspect, the present invention provides a third embodiment of the first aspect, wherein the demulsification and oil removal method is to demulsify the wastewater through a high-frequency and high-voltage pulsed magnetoelectric coupling device, and determine the order of centrifugal separation and demulsification and oil removal of the incoming water according to the emulsification condition of the wastewater.

[0011] In combination with the first aspect or several embodiments of the first aspect, the present invention provides a fourth embodiment of the first aspect, wherein in the centrifugal extraction process, an extractant is added to the pretreated wastewater and subjected to multi-stage centrifugal extraction treatment, the ratio of the water inlet to the extractant feed ratio is maintained in the range of 5-10, and at least three stages of centrifugal extraction are performed at a rotation speed of 15000-20000 rpm; The extract and the extraction wastewater are separated in the last stage of centrifugal extraction equipment. The extract is centrifuged with alkali to obtain the extractant and sodium phenolate. The sodium phenolate is recovered and the extractant is reused.

[0012] In combination with the fourth embodiment of the first aspect, the present invention provides a fifth embodiment of the first aspect, wherein the extractant comprises kerosene and 503 dephenolization extractant in a mixing ratio of 3-5.

[0013] In combination with the first aspect or several embodiments of the first aspect, the present invention provides a sixth embodiment of the first aspect, in which during the resin adsorption process of the extracted wastewater, the adsorption flow rate is controlled at 3-5 BV / h.

[0014] In combination with the first aspect or several embodiments of the first aspect, the present invention provides a seventh embodiment of the first aspect, wherein the deep oxidation treatment is a pulse electrocatalytic oxidation treatment.

[0015] In combination with the first aspect or several embodiments of the first aspect, the present invention provides an eighth embodiment of the first aspect. In the process of evaporation and crystallization treatment, the mother liquor in the evaporator is used in the form of a bypass through multi-energy field pulse catalytic oxidation treatment to reduce the organic matter content and then recycled for evaporation, wherein the amount of mother liquor treated with multi-energy field pulse catalytic oxidation is 3-5% of the amount of wastewater treated with evaporation and crystallization.

[0016] In a second aspect, the present invention further provides a treatment system, which is applied to any of the above-mentioned methods for resource treatment of blue carbon wastewater, comprising: The pretreatment part includes a storage tank for receiving the semi-coke wastewater and performing primary precipitation, as well as a three-phase centrifugal separation device, a high-frequency and high-voltage pulsed magnetic-electric coupling demulsification device, and a PTFE deammoniation membrane device; The centrifugal extraction part includes a multi-stage centrifugal extractor connected to the pre-treated wastewater, and also includes an extractant recovery processing module for providing an extractant to the first-stage centrifugal extractor. The extractant recovery processing module adds alkali to the extract separated from the last-stage centrifugal extractor, stirs and centrifuges to obtain a reused extractant and sodium phenolate; The resin adsorption part includes a multi-stage resin adsorption machine connected to the extraction wastewater for resin adsorption, and also includes a backwashing module for backwashing the resin in the resin adsorption machine to obtain phenolate; and The deep processing part includes membrane processing equipment, evaporation crystallization equipment and multi-energy field pulse catalytic oxidation processing equipment.

[0017] The beneficial effects of the present invention are: The present invention proposes an efficient and long-term stable treatment method and system for blue carbon wastewater through a comprehensive process design. From the initial pretreatment stage, a large amount of oil in the blue carbon wastewater is separated and recovered through effective centrifugal separation and demulsification and oil removal steps, and then a PTFE membrane or low-temperature evaporation method is used for efficient deammoniation, so that the oil and organic matter that may affect the stable operation of the membrane treatment and evaporation crystallization treatment stages are removed in the pretreatment stage; Then, in the deep treatment stage, most of the organic matter and phenolic substances can be removed through the combination of multi-stage centrifugal extraction and resin adsorption. Finally, through multi-energy field pulse catalytic oxidation treatment, membrane treatment and evaporation crystallization, the final effluent can meet the discharge standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flow chart of a preferred blue carbon wastewater treatment process in an embodiment of the present invention; Figure 2 It is a system diagram of the preferred blue carbon wastewater treatment process corresponding to the embodiment of the present invention; Figure 3 1 is a schematic diagram of a centrifugal extraction process in an embodiment of the present invention; Figure 4 This is a schematic diagram of the resin adsorption process in an embodiment of the present invention; Figure 5 It is a diagram of the raw water of blue carbon wastewater treated in an embodiment of the present invention; Figure 6 is a sample comparison diagram during the extraction process in an embodiment of the present invention; Figure 7 Schematic diagram of verifying the effect of pH value on volatile phenol extraction in an embodiment of the present invention; Figure 8 Schematic diagram of verifying the effect of the ratio of the extractant on the extraction rate in an embodiment of the present invention; Fig. 9Schematic diagram of verifying the effect of temperature on extraction rate in an embodiment of the present invention; Fig.10 Schematic diagram of verifying the effect of extraction on benzene series and COD in an embodiment of the present invention; Fig.11 It is a schematic diagram of the resin adsorption process for verifying the extraction wastewater in an embodiment of the present invention; Fig.12 This is an experimental diagram of a multi-energy field pulse catalytic oxidation treatment device in an embodiment of the present invention; Fig.13 Schematic diagram of wastewater treatment by a multi-energy field pulse catalytic oxidation treatment device according to an embodiment of the present invention; Fig.14 It is a schematic diagram showing the change of the removal effect of COD and ammonia nitrogen by the multi-energy field pulse catalytic oxidation treatment device in an embodiment of the present invention over time; Fig.15 This is a schematic diagram of the coking situation caused by excessively high COD entering the evaporator in the experiment of the embodiment of the present invention; Fig.16 is a schematic diagram of the experiment without HFAOP treatment and after HFAOP treatment in the embodiment of the present invention; Fig.17 It is a liquid chromatogram before resin adsorption in the experiment of the embodiment of the present invention; Fig.18 is a liquid chromatogram of water adsorbed by the resin in the experiment of the embodiment of the present invention; Fig.19 It is a liquid chromatogram of the desorption liquid in the experiment of the embodiment of the present invention. DETAILED DESCRIPTION

[0019] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments.

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0023] In the description of this application, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the application is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, if the terms "first", "second", etc. appear in the description of this application, they are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0024] In addition, if the terms "horizontal" or "vertical" appear in the description of this application, it does not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] Embodiment 1: This embodiment discloses a comprehensive treatment and utilization method for lignite wastewater, which aims to treat high-organic and high-fat phenolic substances, obtain and recycle the removal products at each stage, and finally discharge the wastewater in compliance with the standards or reflux for reuse.

[0027] It should be noted that the oil content, phenol content, organic matter content and ammonia nitrogen content of semi-coke wastewater are significantly higher than those of coking wastewater, and its treatment is difficult. It is difficult to achieve long-term stable centralized treatment through one or two simple treatment processes with existing means. The specific reference indicators are as follows: The comprehensive treatment method provided in this embodiment is based on the optimization of the methods used in the existing process to treat different removals, that is, only by treating in sequence through the methods disclosed in this embodiment can the effect of long-term low maintenance cost stable treatment of blue carbon wastewater to be achieved in this application be achieved, as follows: Reference Figure 1 and Figure 2 As shown in the flow chart, first, the semi-coke wastewater to be treated is connected to a storage container for pretreatment. During the pretreatment stage, the insoluble matter in the wastewater is precipitated and filtered through a grid or other physical means, and the insoluble matter is cleaned and dried. After drying, it is recycled according to its type.

[0028] Then the wastewater is deoiled and deammonified. The deoiling stage is divided into two methods: centrifugal separation and demulsification. The processing order is determined according to the emulsification of the wastewater inlet index. In this embodiment, low-emulsification wastewater is taken as an example, and is divided into light oil, heavy oil and deoiled wastewater in the three-phase centrifugal separation equipment. Several three-phase separation equipments can be set up for multi-stage series processing to improve the separation effect.

[0029] The deoiled wastewater after centrifugal separation is demulsified and oil removed. The light tar and emulsified oil are demulsified and oil removed through high-frequency and high-voltage pulsed magneto-electric coupling technology HVES, and pollutants such as suspended matter and sulfides in the wastewater are removed.

[0030] Then deammoniation treatment is carried out. Before deammoniation treatment, the pH value of the wastewater is adjusted to 8-9, and then it is treated by PTFE deammoniation membrane, or the wastewater is treated by low-temperature evaporation method. The ammonia removal rate can reach more than 99% and be absorbed and utilized.

[0031] After the above three-step pretreatment process, the pH value of the pretreated wastewater is adjusted to within the range of 4-5 to meet the deammoniation requirements and thus complete the pretreatment process.

[0032] The pre-treated wastewater removes oil, insoluble matter and ammonia nitrogen, thereby avoiding interference from the above components and carrying out a more in-depth second step treatment.

[0033] The second step of treatment includes two steps: centrifugal extraction and resin adsorption, which mainly targets volatile phenolic substances and can also further adsorb and remove remaining organic matter.

[0034] Specifically, refer to Figure 3, the pretreated wastewater is passed through a multi-stage series of centrifugal extractors, and an extractant is added to the first-stage centrifugal extractor. The extract in this embodiment is N503: kerosene, and the volume ratio of the two is 1:3-1:5. Methyl isobutyl ketone (MIBK) and the like can also be used as a substitute. Then the extract and wastewater separated in each centrifugal extractor are continuously passed into the next-stage centrifugal extractor until the centrifugal extraction process is completed. In this process, the extract discharged from the last-stage centrifugal extractor is mixed with alkali (sodium hydroxide) and then further separated in the centrifuge, so that the sodium phenol salt in the extract is separated, collected and recycled, and the separated clean extractant is refluxed into the first-stage centrifugal extractor for reuse. Among them, the water inlet of the centrifugal extractor and the extract feed ratio are preferably 5:1-10:1, and 2-5 stages of series extraction are performed. The extraction efficiency is preferably greater than 90%, and the optimal series number of stages is 3-4 as shown in the figure. Too high a centrifugal speed can easily cause excessive oxidation loss of the extract, so the speed should not exceed the range of 15,000-20,000 rpm.

[0035] Reference Figure 4 , the extraction wastewater is then passed into a multi-stage series resin adsorption tank, after contacting with the regeneration resin, the phenolic substances and part of the organic matter therein are adsorbed by the regeneration resin, and then all the resin adsorption tanks are backwashed and regenerated regularly, and the water after flushing enters the stirring tank and adds alkali and stirs to obtain sodium phenolate collection and recovery. The adsorption method in this embodiment can adopt a double-column countercurrent method to improve the adsorption efficiency, and the adsorption level is preferably such that the adsorption effluent phenol removal rate is greater than 99%, the adsorption flow rate is optimal at 3-5BV, and the resin adsorption is best operated with a 2-3-stage series setting.

[0036] After the above two steps, most of the substances in the blue carbon wastewater are removed, but some organic matter still remains, which needs to be removed by deep oxidation treatment. The deep oxidation treatment method in this embodiment adopts the multi-energy field pulse catalytic oxidation treatment device HFAOP technology. Theoretically, the power consumption per kilogram of COD removed is about 20kwh, which is low in cost and high in efficiency. The wastewater after deep oxidation treatment can be treated by evaporation and crystallization treatment, or membrane treatment, or a combination of the two, and the wastewater is treated to meet the discharge standards, completing the comprehensive treatment and resource utilization of the entire blue carbon wastewater.

[0037] It should be noted that the technical core of this embodiment is a strict step sequence limitation, that is, it is necessary to follow the pretreatment-adsorption treatment-deep treatment in this embodiment to ensure that the high-index blue carbon wastewater can be treated. In order to verify the treatment effect of this method, a corresponding system is built in the laboratory for treatment verification. Based on the above method, this embodiment also provides a treatment system, including: The pretreatment part includes a storage tank for receiving the semi-coke wastewater and performing primary precipitation, as well as a three-phase centrifugal separation device, a pulsed magnetic-electric coupling demulsification device, and a PTFE deammoniation device; The centrifugal extraction part includes a multi-stage centrifugal extractor connected to the pre-treated wastewater, and also includes an extractant recovery processing module for providing an extractant to the first-stage centrifugal extractor. The extractant recovery processing module adds alkali to the extract separated from the last-stage centrifugal extractor, stirs and centrifuges to obtain a reused extractant and sodium phenolate; The resin adsorption part includes a multi-stage resin adsorption machine connected to the extraction wastewater for resin adsorption, and also includes a backwashing module for backwashing the resin in the resin adsorption machine to obtain sodium phenolate; and The deep processing part includes membrane processing equipment, evaporation crystallization equipment and multi-energy field pulse catalytic oxidation processing equipment.

[0038] The above systems are replaced by corresponding experimental equipment in the laboratory. The multi-energy field pulse catalytic oxidation treatment device effectively reduces the outer electron energy barrier of pollutant molecules under multi-energy fields (magnetic, electric, and wave). Under the action of multi-metal doped catalytic coatings, it produces a variety of oxidizing species such as strongly oxidizing hydroxyl free radicals and oxygen free radicals, which break the pollutant molecules and break their chains. Under the coupled synergistic effect of medium-strong magnetic fields and ultrasonic waves, large molecules are oxidized into small molecules until non-toxic and harmless inorganic substances (CO2, N2, water, etc.) are formed.

[0039] Reference Figure 5 The figure shows the original liquid sample collected on site. The original liquid of the semi-coke wastewater in the figure is turbid and has a high viscosity. Its specific indicators are as follows: Reference Figure 6 The figure shows the changes in wastewater after the pretreatment process and the extraction process. After pretreatment, the COD of the sample dropped to 14265ppm, with a removal rate of 58.5%; the oil index dropped to 26ppm, with a removal rate of 98.1%; the ammonia nitrogen removal rate was low, at 12.5%, while the volatile phenol index dropped to 510ppm, with a removal rate of 87.2%.

[0040] However, if the oil is not pre-treated and removed first, but the extraction process is carried out directly, the oil removal rate and volatile phenol removal rate will be lower than the previous value, and the consumption of the extractant will be large, especially the centrifugal separation of the extract will be more difficult. If the concentration of oil, volatile phenol, etc. in the influent water is high, more stages of extraction and separation are required. Since the extract of high-speed centrifugation will have a loss of 0.3~0.5% during the high-speed separation process, the number of separation stages of multi-stage centrifugation should not be too many, and 2~5 stages are more appropriate. Moreover, the influent oil and volatile phenol are not treated accordingly, resulting in the need to separate multiple substances during the primary extraction and separation, which reduces the separation efficiency and has a high processing cost. In addition, the operating stability of the primary extraction and separation equipment is poor.

[0041] Reference Figure 7-Figure 10 , Figure 7 The figure shows the effect of pH value on the extraction of volatile phenols. It can be seen that the overall phenol concentration is significantly increased only when the pH value is higher than 9. Therefore, the optimal extraction pH value is pH = 4~6.

[0042] Figure 8 This is the effect of the ratio of the extractant on the extraction rate. Fig. 9 The effect of temperature on extraction. As mentioned above, most of the domestic coal resources are distributed in the northern region, and there will be a large-scale and long-term low temperature environment in winter. For the treatment of semi-coal wastewater, the temperature below 35°C has a greater impact on extraction. In cold regions, heating or electric auxiliary heating is required to achieve better extraction effects. It also shows that it is difficult to overcome the impact of temperature by using biochemical treatment methods for semi-coal wastewater. Fig.10 It shows the removal rate of benzene and COD in the extraction process.

[0043] Fig.11 The resin adsorption process was simulated in the laboratory. It can be seen in the beaker at the bottom that the wastewater after filtration in this step has become transparent. The COD of the influent is 14265ppm in the above step. After the resin adsorption process of single-column countercurrent treatment, its COD dropped to 3567ppm on average, while that of double-column countercurrent treatment dropped to 1580ppm, with a removal rate of 88.9%. After single-column countercurrent treatment, volatile phenol dropped from 510ppm in the above data to 6.6, while that of double-column countercurrent treatment dropped to an average of 1.5, with a removal rate of 99.7%.

[0044] Reference Figure 17-Figure 19 , respectively, are the liquid chromatograms before and after resin adsorption. It can be seen that the phenolic substances in the wastewater have been basically removed after resin adsorption, and the concentration in the desorption liquid has increased significantly.

[0045] If the above extraction process is not performed and the volatile phenols and some organic matter are directly removed by resin adsorption, the primary resin adsorption tank connected in series will easily fail, and its recoil regeneration cycle will be short, and the removal rate will be significantly lower than the above process. Due to the saturation capacity limitation of the adsorption resin, excessive concentration of phenolic substances and organic matter in the influent will cause the adsorption capacity of the adsorption resin to be saturated too quickly and the resin must be regenerated. Frequent resin regeneration is not only not conducive to the working life of the resin, but also causes secondary treatment difficulties caused by excessive regeneration liquid. The regeneration frequency of the adsorption resin is more suitable at 2~3 times / week.

[0046] Taking a certain brand of adsorption resin as an example, its resin adsorption capacity is 50mg / g. Based on the influent phenol concentration of 4000mg / L, if the wastewater treatment volume is 10 tons / hour, the flow rate is 5BV / h, the resin configuration is 2m3, the pore volume (ml / g) is 1.2, and the saturated capacity of the resin is about 84000g, the treatment system will reach the saturated capacity in 2.1 hours, and the resin needs to be regenerated, which makes it unsuitable for actual engineering application.

[0047] In addition, if multi-stage extraction separation is used to replace the resin adsorption process, as mentioned above, 2-3 stage centrifugal extraction cannot completely remove the pollutants, but increasing the number of stages will lead to greater loss of extract liquid, which cannot meet the requirements of recycling, and the cost is high and the boundary effect caused by increasing the number of stages increases.

[0048] Reference Fig.12 and Fig.13 , which shows the multi-energy field pulse catalytic oxidation treatment device in the laboratory. Fig.14 The removal effect of HFAOP on COD and ammonia nitrogen is demonstrated in the figure. Similarly, if advanced electrolytic oxidation treatment is carried out directly without going through pre-processes such as extraction and resin adsorption, the energy consumption of the entire multi-energy field coupled environmental treatment system will increase significantly and the processing capacity of a single device will decrease significantly.

[0049] Reference Figure 15-16 The figure shows the coking situation caused by excessive COD in wastewater entering the evaporator. Fig.16 The front figure in the middle is an illustration of the evaporation experiment without HFAOP treatment, while the back figure is an illustration of the evaporation experiment after HFAOP treatment. It can be seen that there is obvious coking without HFAOP treatment, while the crystals after HFAOP treatment are loose and non-sticky. Catalytic oxidation residence time (hours) 0 hours 1 hour 2 hours 3 hours COD (ppm) 1580 1130 477 66 Ammonia nitrogen (ppm) 2490 312 9 0

[0050] As shown in the table above, the indicators of wastewater changed after HFAOP treatment.

[0051] The present invention is not limited to the above optional implementations, and anyone can derive other various forms of products under the enlightenment of the present invention. The above specific implementations should not be understood as limiting the scope of protection of the present invention. The scope of protection of the present invention should be based on the definition in the claims, and the description can be used to interpret the claims.

Claims

1. A method for recycling semi-coke wastewater, which separates several components in semi-coke wastewater by multi-stage treatment and then treats them separately and meets the discharge standards, characterized by: First, the wastewater is pretreated, the pH value of the wastewater is adjusted to a range of 4-5 for centrifugal deoiling and demulsification, and then the pH value is adjusted to a range of 8-9 for PTFE deamination membrane treatment; Then, the pH value of the pretreated wastewater is adjusted back to within the range of 4-5, and then the wastewater is centrifuged and extracted through a multi-stage centrifugal extraction device connected in series to separate the extracted wastewater and sodium phenolate, and the sodium phenolate is recovered and processed; The extracted wastewater is then subjected to resin adsorption by a multi-stage series-connected resin adsorption device to separate the adsorbed wastewater and sodium phenolate, and the sodium phenolate is recovered for treatment; Finally, the adsorbed wastewater is subjected to deep advanced oxidation treatment to reduce organic matter and then tested for compliance with discharge standards after membrane concentration and / or evaporation crystallization.

2. A method for resource treatment of blue carbon wastewater according to claim 1, characterized in that: The specific steps of preprocessing are as follows: First, the wastewater is deoiled, and then deoiled wastewater, sludge, light oil and heavy oil are obtained by combining centrifugal separation and demulsification and oil removal. The sludge is harmlessly treated, and the light oil and heavy oil are recovered and treated; Then, the pH value of the de-oiled wastewater is adjusted to alkaline, and after deammoniation treatment, the pH value is adjusted to within the range of 4-5 to complete the pretreatment process.

3. A method for resource treatment of blue carbon wastewater according to claim 2, characterized in that: The pretreatment also includes the initial screening and filtration of suspended matter and sediment, and the screened solid waste is dried and recycled.

4. A method for resource treatment of blue carbon wastewater according to claim 2, characterized in that: The demulsification and oil removal method is to demulsify the wastewater through a pulse magnetoelectric coupling device, and determine the sequence of centrifugal separation and demulsification and oil removal of the influent according to the emulsification condition of the wastewater.

5. A method for resource treatment of blue carbon wastewater according to any one of claims 1 to 4, characterized in that: In the centrifugal extraction process, an extractant is added to the pretreated wastewater and subjected to multi-stage centrifugal extraction treatment, the ratio of the water inlet to the extractant feed ratio is maintained in the range of 5-10, and at least three stages of centrifugal extraction are performed at a rotation speed of 15000-20000 rpm; The extract and the extraction wastewater are separated in the last stage of centrifugal extraction equipment. The extract is centrifuged with alkali to obtain the extractant and sodium phenolate. The sodium phenolate is recovered and the extractant is reused.

6. A method for resource treatment of blue carbon wastewater according to claim 5, characterized in that: The extractant comprises kerosene and 503 dephenolizing extractant in a volume ratio of 3-5.

7. A method for resource treatment of blue carbon wastewater according to any one of claims 1 to 4, characterized in that: During the resin adsorption process of the extracted wastewater, the adsorption flow rate is controlled at 3-5 BV / h.

8. A method for recycling blue carbon wastewater according to any one of claims 1 to 4, characterized in that: The deep oxidation treatment is a multi-energy field pulse catalytic oxidation treatment method.

9. A method for resource treatment of blue carbon wastewater according to any one of claims 1 to 4, characterized in that: In the process of evaporation and crystallization, the mother liquor in the evaporator is used in the form of a bypass through multi-energy field pulse catalytic oxidation treatment to reduce the organic matter content and then recycled for evaporation. The amount of mother liquor treated by multi-energy field pulse catalytic oxidation is 3-5% of the amount of wastewater treated by evaporation and crystallization.

10. A processing system, characterized in that: The method for recycling blue carbon wastewater as described in any one of claims 1 to 4 above comprises: The pretreatment part includes a storage tank for receiving the semi-coke wastewater and performing primary precipitation, as well as a three-phase centrifugal separation device, a pulsed magnetic-electric coupling demulsification device, and a PTFE deammoniation membrane device; The centrifugal extraction part includes a multi-stage centrifugal extractor connected to the pre-treated wastewater, and also includes an extractant recovery processing module for providing an extractant to the first-stage centrifugal extractor. The extractant recovery processing module adds alkali to the extract separated from the last-stage centrifugal extractor, stirs and centrifuges to obtain a reused extractant and sodium phenolate; The resin adsorption part includes a multi-stage resin adsorption machine connected to the extraction wastewater for resin adsorption, and also includes a backwashing module for backwashing the resin in the resin adsorption machine to obtain sodium phenolate; and The deep processing part includes membrane processing equipment, evaporation crystallization equipment and multi-energy field pulse catalytic oxidation processing equipment.

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