Coking wastewater treatment system

Abstract

The present invention belongs to the technical field of coking wastewater treatment, and relates to a coking wastewater treatment system, which comprises: a resin adsorption assembly, which is used for in-situ removal of organic pollutants in coking wastewater; the resin elution and regeneration assembly is used for carrying out elution and regeneration treatment on the adsorption saturated resin; the resin elution and regeneration assembly is connected with the resin adsorption assembly; the electrocatalytic oxidation assembly is used for carrying out mineralization treatment on the elution waste liquid enriched with the organic pollutants; the electrocatalytic oxidation assembly is connected with the resin elution and regeneration assembly. According to the coking wastewater treatment system provided by the invention, high-efficiency removal of macromolecular organic pollutants difficult to degrade can be realized, the adsorption resin and the eluent can be recycled, and a technical closed loop is formed; the technological process is simple, operation and operation are easy and convenient, and one-time investment and operation cost are remarkably reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of coking wastewater treatment, and particularly relates to a coking wastewater treatment system. Background Art

[0002] As a typical high-salt and refractory organic wastewater, the refractory organic pollutants such as high-concentration phenol, humic acid, nitrogen- and sulfur-containing heterocyclic compounds, polycyclic aromatic hydrocarbons, and cyanide in coking wastewater have always been the treatment difficulties in the fields of industrial water treatment and environmental protection. At present, the "biochemical + advanced oxidation" combined process is generally adopted at home and abroad to degrade the organic pollutants in coking wastewater, and then enter the deep treatment units such as membrane concentration and water production reuse. Some enterprises have realized zero-emission treatment such as further salt separation and quality improvement, and evaporation and salt transportation.

[0003] The biochemical method is widely used and is also the most important coking wastewater treatment process. However, coking wastewater has the water quality characteristics of complex composition, high toxicity, high salt content, and refractory degradation, resulting in unstable traditional biochemical systems and large fluctuations in the quality of biochemical effluent. In particular, the fluctuations of high-concentration refractory organic pollutants in the biochemical effluent will lead to a serious imbalance between the best treatment effect and the lowest energy consumption cost of the advanced oxidation treatment process. Most of the refractory organic pollutants in coking wastewater are aromatic macromolecular organic compounds containing benzene rings. When performing reverse osmosis membrane concentration, they block the membrane pores under the action of π-π bonds with the membrane material, causing serious organic fouling of the membrane, greatly shortening the membrane cleaning cycle and the service life of the membrane. In addition, the refractory organic pollutants and salt content are further concentrated in the deep treatment unit and the zero-emission process. Generally, these characteristic pollutants and salt content in the coking reverse osmosis concentrate generated by the deep treatment unit are concentrated by 3-10 times, and the concentration multiple of the evaporation salt mother liquor is even higher. As the concentration multiple continuously increases during the evaporation salt process, the high-concentration refractory organic pollutants will adhere to the surface of the heat exchanger of the evaporation salt device, affecting the heat exchange efficiency and also the whiteness of the product salt.

[0004] The high-fold concentration of refractory organic pollutants and salt content severely limits the applicability of biochemical and advanced oxidation technologies in treating coking concentrated water and evaporation salt mother liquor. On the one hand, the concentration of refractory organic pollutants in coking concentrated water and evaporation salt mother liquor is generally high, and the biodegradability is poor; on the other hand, the higher the salt content, the worse the advanced oxidation treatment effect, the stricter the requirements for equipment materials, and the higher the chemical agent cost and energy consumption. Among them, Fenton oxidation, ozone catalytic oxidation, photocatalytic oxidation, and persulfate oxidation technologies are suitable for treating low-salt wastewater. For electrocatalytic oxidation, the higher the salt content of the wastewater, the better the conductivity and the lower the electrocatalytic energy consumption.

[0005] However, the high concentration of fluoride ions in coking wastewater can easily cause corrosion of the electrode plates, and the service life of the electrode plates is much lower than the designed service life. Frequent replacement of the electrode plates leads to expensive replacement costs, greatly weakening the energy consumption advantage of electrocatalytic oxidation for treating high-salt coking wastewater. To remove refractory organic pollutants, a variety of advanced oxidation technologies are combined and repeatedly set in each link of the advanced treatment and zero discharge of coking wastewater, greatly increasing the treatment cost. Summary of the Invention

[0006] In view of this, the present invention provides a coking wastewater treatment system.

[0007] Specifically, the present invention is realized through the following technical solutions:

[0008] According to a first aspect of the present invention, there is provided a coking wastewater treatment system, comprising:

[0009] A resin adsorption assembly for in-situ removal of organic pollutants in coking wastewater;

[0010] A resin elution and regeneration assembly for eluting and regenerating the saturated resin; the resin elution and regeneration assembly is connected to the resin adsorption assembly;

[0011] An electrocatalytic oxidation assembly for mineralizing the elution waste liquid enriched with organic pollutants; the electrocatalytic oxidation assembly is connected to the resin elution and regeneration assembly.

[0012] Optionally, the resin adsorption assembly includes: a main resin adsorption tank, and the main resin adsorption tank is connected to the resin elution and regeneration assembly.

[0013] Optionally, the resin adsorption assembly further includes: a standby resin adsorption tank, the standby resin adsorption tank is connected to the resin elution and regeneration assembly and is in parallel with the main resin adsorption tank.

[0014] Optionally, the resin elution and regeneration assembly includes: a resin desorption tank, an elution waste liquid pool, an elution liquid comprehensive adjustment pool and a steam delivery pipe. Among them, the resin desorption tank is respectively connected to the elution waste liquid pool, the elution liquid comprehensive adjustment pool, the steam delivery pipe, the main resin adsorption tank and the standby resin adsorption tank in the resin adsorption assembly, and the electrocatalytic oxidation assembly is respectively connected to the elution waste liquid pool and the elution liquid comprehensive adjustment pool.

[0015] Optionally, the resin elution and regeneration assembly further includes: a water storage tank, and the water storage tank is connected to the resin desorption tank.

[0016] Optionally, the resin elution and regeneration assembly further includes: an acid liquid metering tank, and the acid liquid metering tank is connected to the resin desorption tank.

[0017] Optionally, the resin elution and regeneration assembly further includes: an alkali solution metering tank, which is connected to the eluent comprehensive regulation tank.

[0018] Optionally, the electrocatalytic oxidation assembly includes: an electrocatalytic oxidation reactor and a reducing agent delivery pipe. Among them, the electrocatalytic oxidation reactor is respectively connected to the elution waste liquid tank and the eluent comprehensive regulation tank in the resin elution and regeneration assembly.

[0019] Optionally, it further includes: a pretreatment assembly for preliminarily treating coking wastewater; the pretreatment assembly is connected to the resin adsorption assembly.

[0020] Optionally, the pretreatment assembly includes: a coagulation sedimentation tank, a sludge processor, and a security filter. Among them, the security filter is respectively connected to the coagulation sedimentation tank, the main resin adsorption tank, and the standby resin adsorption tank in the resin adsorption assembly, and the coagulation sedimentation tank is connected to the sludge processor.

[0021] The technical solution provided by the present invention at least brings the following beneficial effects:

[0022] A coking wastewater treatment system provided by the present application can achieve efficient removal of refractory macromolecular organic pollutants. The adsorption resin and the eluent can be recycled, forming a technical closed loop; the process flow is simple, the operation is convenient, and the one-time investment and operation cost are significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention.

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is a schematic structural diagram of Embodiment 1 of a coking wastewater treatment system provided by an embodiment of the present invention;

[0026] Figure 2 It is a schematic structural diagram of Embodiments 2 and 3 of a coking wastewater treatment system provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0028] Figure 1 Schematically shows a coking wastewater treatment system applicable to the embodiments of the present invention.

[0029] Referring Figure 1 and 2 as shown, the present application provides a coking wastewater treatment system, including:

[0030] A resin adsorption component 10 for in-situ removal of organic pollutants in coking wastewater;

[0031] A resin elution and regeneration component 20 for eluting and regenerating the adsorption-saturated resin; the resin elution and regeneration component 20 is connected to the resin adsorption component 10;

[0032] An electrocatalytic oxidation component 30 for mineralizing the elution waste liquid enriched with organic pollutants; the electrocatalytic oxidation component 30 is connected to the resin elution and regeneration component 20.

[0033] In the embodiments of the present application, coking wastewater enters the resin adsorption component 10 for treatment, and selectively adsorbs the refractory organic pollutants in the wastewater; the adsorption-saturated resin enters the resin elution and regeneration component 20 for treatment, and the resin is eluted and regenerated by acid solution, hot saline-alkali solution to obtain an elution waste liquid enriched with high-concentration refractory organic pollutants. The regenerated resin is recycled to the resin adsorption component 10 for adsorbing and treating coking wastewater; the elution waste liquid enters the electrocatalytic oxidation component 30 for mineralization treatment, and the elution liquid after adding an appropriate amount of reducing agent can be recycled to the resin elution and regeneration component 20 for eluting and regenerating the adsorption-saturated resin. The principle and creativity of this technical solution are as follows:

[0034] 1. The synergistic and enhancing mechanism of resin adsorption and electrocatalytic oxidation

[0035] This solution realizes the selective enrichment and directional degradation of pollutants through the series process of resin adsorption - elution regeneration - electrocatalytic oxidation. Its creativity is reflected in the following technical principles:

[0036] Selective separation and concentration improvement of pollutants: The resin adsorption component (such as macroporous adsorption resin) selectively adsorbs organic pollutants (such as phenols, polycyclic aromatic hydrocarbons, etc.) in coking wastewater through molecular sieve effect and surface functional groups, achieving in-situ removal and significantly reducing the amount of elution and concentration waste liquid to be treated subsequently. The concentrated waste liquid (containing high-concentration organic pollutants and inorganic salts) formed after elution and regeneration enters the electrocatalytic oxidation section. By increasing the concentration of organic pollutants and inorganic salts, the mass transfer efficiency and current utilization rate of the electrocatalytic reaction are enhanced.

[0037] Fundamentally avoiding the corrosion problem of fluoride ions on electrocatalytic electrodes: Usually, coking wastewater contains high-concentration fluoride ions. When directly using electrocatalytic technology to treat coking wastewater, the high-concentration fluoride ions directly corrode the electrocatalytic electrodes. However, the large-pore adsorption resin used in this scheme does not have any adsorption effect on fluoride ions, and at the same time, the concentrated waste liquid formed after resin elution and regeneration does not contain fluoride ions, completely avoiding the corrosion risk of fluoride ions to the electrodes, thereby prolonging the electrode life.

[0038] 2. Technical optimization of the electrocatalytic oxidation component

[0039] Regarding the electrode corrosion problem in the existing technology, the following innovative points are implicitly included in the design of the electrocatalytic oxidation component in this scheme:

[0040] Intelligent regulation of current density: By controlling pulsed current or staged current, the formation of the passivation layer on the electrode surface is reduced, and the catalytic activity is maintained. For example, in the low current density stage, small molecule organic substances are preferentially degraded, and in the high current stage, refractory pollutants are treated, reducing electrode loss.

[0041] 3. System integration and process innovation

[0042] Simplifying the organic pollutant degradation process: The existing technology requires multiple combinations of advanced oxidation processes (such as Fenton-ozone-electrocatalysis). In this scheme, organic pollutants are enriched by resin adsorption, so that electrocatalytic oxidation only needs to treat the concentrated waste liquid, avoiding repeated oxidation in multiple links and greatly reducing energy consumption and treatment costs. For example, the comparison of the resin adsorption-Fenton combined process in the existing technology shows that a single electrocatalysis can replace Fenton and reduce the by-product of iron mud.

[0043] Recycling of resin and eluent: The adsorption resin realizes the in-situ removal of organic pollutants in coking wastewater. The concentrated waste liquid enriched with high-concentration organic pollutants can be recycled for resin regeneration after electrocatalytic oxidation treatment, and the regenerated resin can be recycled. The recycling of resin and eluent is realized through the series process of resin adsorption-elution regeneration-electrocatalytic oxidation.

[0044] 4. Technical comparison and advantage analysis

[0045] Compared with the prior art (such as resin adsorption - Fenton method, O3 - H2O2 oxidation - resin adsorption method), the creativity of this solution lies in:

[0046] Balance between energy consumption and efficiency: Electro - catalytic oxidation directly uses electric energy to drive the reaction without adding chemical reagents (such as H2O2 and Fe in Fenton reagent), reducing reagent costs and secondary pollution. At the same time, the amount of concentrated waste liquid directly treated by electro - catalytic oxidation is only 1 - 2% of the amount of coking wastewater treated, greatly reducing the treatment cost of coking wastewater. 2+ ) and reducing the reagent cost and secondary pollution. At the same time, the amount of concentrated waste liquid directly treated by electro - catalytic oxidation is only 1 - 2% of the amount of coking wastewater treated, greatly reducing the treatment cost of coking wastewater.

[0047] Exemplarily, the resin adsorption assembly 10 includes: a main resin adsorption tank 11, and the main resin adsorption tank 11 is connected to the resin elution and regeneration assembly 20.

[0048] In the embodiment of the present application, the main resin adsorption tank 11 is used to provide space for resin to adsorb refractory organic pollutants in coking wastewater.

[0049] Exemplarily, the resin adsorption assembly 10 further includes: a spare resin adsorption tank 12, the spare resin adsorption tank 12 is connected to the resin elution and regeneration assembly 20 and is in parallel with the main resin adsorption tank 11.

[0050] In the embodiment of the present application, the spare resin adsorption tank 12 is in parallel with the main resin adsorption tank 11 and is used to provide space for resin to adsorb refractory organic pollutants in coking wastewater.

[0051] In the embodiment of the present application, the main resin adsorption tank 11 and the spare resin adsorption tank 12 need to use large - pore composite functional resins to highly selectively adsorb refractory organic pollutants.

[0052] Exemplarily, the resin elution and regeneration assembly 20 includes: a resin desorption tank 21, an elution waste liquid pool 22, an elution liquid comprehensive regulation pool 23, and a steam delivery pipe 24. Among them, the resin desorption tank 21 is respectively connected to the elution waste liquid pool 22, the elution liquid comprehensive regulation pool 23, the steam delivery pipe 24, and the main resin adsorption tank 11 and the spare resin adsorption tank 12 in the resin adsorption assembly 10, and the electro - catalytic oxidation assembly 30 is respectively connected to the elution waste liquid pool 22 and the elution liquid comprehensive regulation pool 23.

[0053] In the embodiment of the present application, the resin desorption tank 21 is connected to the standby resin adsorption tank 12 and the main resin adsorption tank 11 in parallel through a resin transfer pipeline, providing space for eluting and regenerating the saturated resin; the elution waste liquid pool 22 is connected to the resin desorption tank 21 through a pipeline, storing the resin elution waste liquid; the eluent comprehensive adjustment pool 23 is connected to the resin desorption tank 21 through a pipeline, storing sodium chloride for saline-alkali regeneration of the resin; the steam delivery pipe 24 delivers saturated steam to the resin desorption tank 21 through a pipeline, heating the resin and the eluent in the resin desorption tank 21.

[0054] Exemplarily, the resin elution and regeneration assembly 20 further includes: a water storage tank 25, and the water storage tank 25 is connected to the resin desorption tank 21.

[0055] In the embodiment of the present application, the water storage tank 25 is connected to the resin desorption tank 21 through a pipeline, storing water for resin transfer and water for washing the resin desorption tank 21.

[0056] Exemplarily, the resin elution and regeneration assembly 20 further includes: an acid solution metering tank 26, and the acid solution metering tank 26 is connected to the resin desorption tank 21.

[0057] In the embodiment of the present application, the acid solution metering tank 26 is connected to the resin desorption tank 21 through a pipeline, storing hydrochloric acid for pickling the resin.

[0058] Exemplarily, the resin elution and regeneration assembly 20 further includes: an alkali solution metering tank 27, and the alkali solution metering tank 27 is connected to the eluent comprehensive adjustment pool 23.

[0059] In the embodiment of the present application, the alkali solution metering tank 27 is connected to the resin desorption tank 21 through a pipeline, storing sodium hydroxide for saline-alkali regeneration of the resin.

[0060] In the embodiment of the present application, the resin elution and regeneration assembly 20 adopts an off-site regeneration method to desorb and regenerate the saturated resin, that is, the saturated resin in the main resin adsorption tank 11 and the standby resin adsorption tank 12 is transferred to the resin desorption tank 21 through recycled water for elution and regeneration treatment. First, use (6 - 8) wt% sodium chloride + (1 - 2) wt% sodium hydroxide, with a flow rate of 2 - 4 BV / h and a temperature of 60°C - 65°C, for saline-alkali elution for 1 - 2 hours, then use (1 - 2) wt% hydrochloric acid, with a flow rate of 0.5 - 1 BV / h, for pickling for 0.5 - 1 hour, and finally use recycled water, with a flow rate of 1 - 2 BV / h, for rinsing for 1 hour.

[0061] Exemplarily, the electrocatalytic oxidation assembly 30 includes: an electrocatalytic oxidation reactor 31 and a reductant delivery pipe 32. Among them, the electrocatalytic oxidation reactor 31 is respectively connected to the elution waste liquid pool 22 and the elution liquid comprehensive regulation pool 23 in the resin elution and regeneration assembly 20.

[0062] In the embodiment of the present application, the electrocatalytic oxidation reactor 31 is connected to the elution waste liquid pool 22 through a pipeline, and is used for performing electrocatalytic oxidation reaction on the resin elution waste liquid. The elution liquid after electrocatalytic treatment is transported to the elution liquid comprehensive regulation pool 23 through a pipeline; the reductant delivery pipe 32 transports reductant to the elution liquid comprehensive regulation pool 23 through a pipeline, and is used for adjusting the oxidation-reduction potential of the elution liquid in the elution liquid comprehensive regulation pool 23; the water outlet pipeline connecting the elution liquid comprehensive regulation pool 23 is used for regularly discharging the elution liquid in the elution liquid comprehensive regulation pool 23.

[0063] In the embodiment of the present application, it is necessary to first adjust the pH of the elution waste liquid to 5.5 - 6.0 with (1 - 2) wt% hydrochloric acid, and then pump it into the electrocatalytic oxidation reactor 31. The electrocatalytic oxidation reactor 31 adopts an external electrode. The anode is a BDD electrode prepared by a microwave plasma processing technology, and the cathode is an electrode made of graphene material. The distance between the electrode plates is 2 - 3 cm.

[0064] In the embodiment of the present application, during the electrocatalytic oxidation treatment of the elution waste liquid, it is powered by a DC power supply, and the current density is 1000 - 1500 A / m 2 , and the action time is 100 - 120 minutes. The electrocatalytic oxidation reactor 31 processes the elution waste liquid in a batch mode to ensure that all the elution waste liquid is completed with electrocatalytic oxidation regeneration treatment before the next resin elution and regeneration cycle. An appropriate amount of reductant is added to the elution liquid after electrocatalytic oxidation treatment to adjust the oxidation-reduction potential.

[0065] Exemplarily, it further includes: a pretreatment assembly 40, which is used for preliminarily treating coking wastewater; the pretreatment assembly 40 is connected to the resin adsorption assembly 10.

[0066] In the embodiment of the present application, the coking wastewater is preliminarily treated in the pretreatment assembly 40 to remove suspended solids, sediment, poorly soluble organic matter, heavy metals such as iron and manganese in the wastewater.

[0067] Exemplarily, the pretreatment assembly 40 includes: a coagulation sedimentation tank 41, a sludge processor 42 and a security filter 43. Among them, the security filter 43 is respectively connected to the coagulation sedimentation tank 41 and the main resin adsorption tank 11 and the standby resin adsorption tank 12 in the resin adsorption assembly 10, and the coagulation sedimentation tank 41 is connected to the sludge processor 42.

[0068] In the embodiment of the present application, the coagulation sedimentation tank 41 is used to remove suspended solids, sediment, poorly soluble organic matter, heavy metals such as iron and manganese in the biochemical effluent of coking wastewater; the sludge processor 42 is connected to the coagulation sedimentation tank 41 through a pipeline, and is used for dehydrating and transporting the sludge at the bottom of the coagulation sedimentation tank 41; the security filter 43 is connected to the coagulation sedimentation tank 41 through an outlet pipeline, and is used to remove suspended particulate matter in the effluent of the coagulation sedimentation tank 41.

[0069] Example 1:

[0070] Taking the biochemical effluent of coking wastewater as the influent, the influent flow rate is 100 m 3 / h, the total dissolved solid content (TDS) is 11000 mg / L, and the COD index is higher than 150 mg / L. After the biochemical effluent of coking wastewater passes through the coagulation sedimentation tank and ultrafiltration treatment in sequence, the turbidity of the produced water is 0.8 NTU, and then it passes through the resin adsorption tank, and the effluent COD is lower than 40 mg / L. In particular, volatile phenols, polycyclic aromatic hydrocarbons, cyanides, etc. are far lower than the direct pollutant discharge standards in the "Pollutant Discharge Standards for the Coking Chemical Industry GB16171-2012". The resin after adsorption saturation is regenerated by hot saline-alkali elution, and the generated amount of elution waste liquid is 1.5 m 3 / h, and the production ratio is 1.5%. The elution waste liquid is enriched with high-concentration refractory organic pollutants, including nitrogen and sulfur heterocyclic compounds higher than 700 mg / L, humic acids higher than 800 mg / L, polycyclic aromatic hydrocarbons higher than 300 mg / L, cyanides higher than 60 mg / L, and the total COD is as high as 9300 mg / L. After electrocatalytic oxidation treatment, the mineralization rate of organic matter in the elution waste liquid is higher than 95%. After adding appropriate amounts of sodium bisulfite and sodium hydroxide, it meets the resin regeneration requirements and can be recycled.

[0071] Table 1: Comparison table of water quality of each treatment unit in Example 1 (taking the biochemical effluent of coking wastewater as the influent)

[0072]

[0073]

[0074]

[0075] Example 2:

[0076] Figure 2 This is the second embodiment of the present invention. Different from Example 1, this embodiment takes the coking reverse osmosis concentrate as the influent, and the influent flow rate is 50 m 3 / h, the TDS is 23,090 mg / L, and the COD index is higher than 250 mg / L. The turbidity of the coking reverse osmosis concentrate is 1.1 NTU, meeting the water quality requirements for entering the resin adsorption tank. It directly enters the resin adsorption unit, and the effluent COD is 65 mg / L. Volatile phenols, polycyclic aromatic hydrocarbons, cyanides, etc. meet the direct pollutant discharge standards in the "Pollutant Discharge Standards for the Coking Chemical Industry GB16171-2012". After the resin is saturated with adsorption, it is regenerated by hot saline-alkali elution. The generated amount of elution waste liquid is 1.1 m 3 / h, and the generation ratio is 2%. The elution waste liquid is enriched with high-concentration and difficult-to-degrade organic pollutants, including 710 mg / L of nitrogen and sulfur heterocyclic compounds, 1,270 mg / L of humic acids, 240 mg / L of polycyclic aromatic hydrocarbons, and 25 mg / L of cyanides. After electrocatalytic oxidation treatment, the mineralization rate of organic matter in the elution waste liquid is 96%. After adding appropriate amounts of sodium bisulfite and sodium hydroxide, it can be used for resin regeneration.

[0077] Table 2: Water Quality Comparison Table of Each Treatment Unit in Example 2 (Taking Coking Reverse Osmosis Concentrate as Inlet Water)

[0078]

[0079]

[0080] Example 3:

[0081] In this example, coking nanofiltration concentrate is used as the inlet water, and the influent volume is 30 m 3 / h, the TDS is 25,080 mg / L, and the COD index is higher than 250 mg / L. Similar to Example 2, the turbidity of the coking nanofiltration concentrate is 1.6 NTU, and it directly enters the resin adsorption tank for treatment. The effluent COD is 78 mg / L. Volatile phenols, polycyclic aromatic hydrocarbons, cyanides, etc. meet the direct pollutant discharge standards in the "Pollutant Discharge Standards for the Coking Chemical Industry GB16171-2012". After the resin is saturated with adsorption, it is regenerated by hot saline-alkali elution. The generated amount of elution waste liquid is 0.7 m 3 / h, and the generation ratio is 2.2%. The elution waste liquid is enriched with high-concentration and difficult-to-degrade organic pollutants, with a COD as high as over 10,000 mg / L, including 820 mg / L of nitrogen and sulfur heterocyclic compounds, 1,350 mg / L of humic acids, 190 mg / L of polycyclic aromatic hydrocarbons, and 21 mg / L of cyanides. After electrocatalytic oxidation treatment, the mineralization rate of organic matter in the elution waste liquid is higher than 96%. After adding appropriate amounts of sodium bisulfite and sodium hydroxide, it can be used for resin regeneration.

[0082] Table 3: Water Quality Comparison Table of Each Treatment Unit in Example 3 (Taking Coking Nanofiltration Concentrate as Inlet Water)

[0083]

[0084]

[0085] A coking wastewater treatment system provided by the present application can achieve efficient removal of refractory macromolecular organic pollutants, and the adsorption resin and the eluent can be recycled, forming a technical closed loop; the process flow is simple, the operation is convenient, and the one-time investment and operation cost are significantly reduced.

[0086] It should be noted that in the present application, the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit that the indicated device, element or component must have a specific orientation, or be constructed and operated in a specific orientation.

[0087] Moreover, in addition to being used to represent the orientation or positional relationship, some of the above terms can also be used to represent other meanings. For example, the term "upper" can also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present application can be understood according to specific circumstances.

[0088] In addition, the terms "installed", "set", "provided with", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there is an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0089] In addition, terms such as "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures can be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, the meaning of "a plurality" is two or more.

[0090] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A coking wastewater treatment system, characterized in that, Comprising: A resin adsorption component for in-situ removal of organic pollutants in coking wastewater; A resin elution and regeneration component for eluting and regenerating the saturated adsorbed resin; the resin elution and regeneration component is connected to the resin adsorption component; An electrocatalytic oxidation component for mineralizing the elution waste liquid enriched with organic pollutants; the electrocatalytic oxidation component is connected to the resin elution and regeneration component.

2. The coking wastewater treatment system according to claim 1, wherein The resin adsorption component includes: a main resin adsorption tank, and the main resin adsorption tank is connected to the resin elution and regeneration component.

3. The coking wastewater treatment system according to claim 2, characterized in that, The resin adsorption component further includes: a standby resin adsorption tank, the standby resin adsorption tank is connected to the resin elution and regeneration component and is in parallel with the main resin adsorption tank.

4. The coking wastewater treatment system according to claim 1, wherein, The resin elution and regeneration component includes: a resin desorption tank, an elution waste liquid pool, an elution liquid comprehensive regulation pool and a steam delivery pipe. Among them, the resin desorption tank is respectively connected to the elution waste liquid pool, the elution liquid comprehensive regulation pool, the steam delivery pipe, the main resin adsorption tank and the standby resin adsorption tank in the resin adsorption component, and the electrocatalytic oxidation component is respectively connected to the elution waste liquid pool and the elution liquid comprehensive regulation pool.

5. The coking wastewater treatment system according to claim 4, wherein The resin elution and regeneration component further includes: a water storage tank, and the water storage tank is connected to the resin desorption tank.

6. The coking wastewater treatment system according to claim 4, wherein The resin elution and regeneration component further includes: an acid solution metering tank, and the acid solution metering tank is connected to the resin desorption tank.

7. The coking wastewater treatment system according to claim 4, characterized in that, The resin elution and regeneration component further includes: an alkali solution metering tank, and the alkali solution metering tank is connected to the elution liquid comprehensive regulation pool.

8. The coking wastewater treatment system according to claim 1, characterized in that, The electrocatalytic oxidation component includes: an electrocatalytic oxidation reactor and a reductant delivery pipe. Among them, the electrocatalytic oxidation reactor is respectively connected to the elution waste liquid pool and the elution liquid comprehensive regulation pool in the resin elution and regeneration component.

9. The coking wastewater treatment system according to claim 1, characterized in that, Further comprising: A pretreatment component for preliminarily treating coking wastewater; The pretreatment component is connected to the resin adsorption component.

10. The coking wastewater treatment system according to claim 9, characterized in that, The pretreatment component includes: a coagulation sedimentation tank, a sludge processor and a security filter. Among them, the security filter is respectively connected to the coagulation sedimentation tank, the main resin adsorption tank and the standby resin adsorption tank in the resin adsorption component, and the coagulation sedimentation tank is connected to the sludge processor.

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