CN111573885A

CN111573885A - Method and device for treating ammonia nitrogen in coking wastewater by resin adsorption method

Info

Publication number: CN111573885A
Application number: CN202010377223.5A
Authority: CN
Inventors: 田犀; 蒲灵; 马德武
Original assignee: SICHUAN INDUSTRIAL ENVIRONMENT MONITORING INSTITUTE
Current assignee: SICHUAN INDUSTRIAL ENVIRONMENT MONITORING INSTITUTE
Priority date: 2020-05-07
Filing date: 2020-05-07
Publication date: 2020-08-25

Abstract

The invention belongs to the technical field of wastewater treatment processes, and particularly relates to a method and a device for treating ammonia nitrogen in coking wastewater by a resin adsorption method. Aiming at the problem that a process for treating ammonia nitrogen in coking wastewater is needed in the prior art so as to stably and efficiently treat the coking wastewater, the technical scheme of the invention is as follows: the method comprises three steps of pretreatment, resin adsorption and desorption regeneration of resin, wherein the resin adsorption step and the desorption regeneration step are carried out in at least three adsorption tanks which are circularly connected in series, and the resin adsorption step is carried out in one or at least two adsorption tanks which are connected in series. The invention also provides a treatment device for the process. The method is suitable for removing ammonia nitrogen in the coking wastewater.

Description

Method and device for treating ammonia nitrogen in coking wastewater by resin adsorption method

Technical Field

The invention belongs to the technical field of wastewater treatment processes, and particularly relates to a method and a device for treating ammonia nitrogen in coking wastewater by a resin adsorption method.

Background

With the rapid development of economy in China, the demand of steel and coal is increasing day by day, and the coking industry is gradually developed and strengthened under the form. However, the coking wastewater generated in the coking industry causes serious pollution to the environment due to complex components, large yield and heavy pollution. The coking wastewater mainly comes from coal gas final cooling water, residual ammonia water and chemical product separation water generated in the coking process; the main components include ammonia nitrogen, phenols, benzenes, quinolines, cyanides and the like. Because the coking wastewater has complex components, particularly has very high ammonia nitrogen content, is difficult to remove and has very strong inhibiting effect on microorganisms, the coking wastewater treatment is always a big problem of industrial water treatment. If ammonia nitrogen can be removed in the pretreatment of the coking wastewater, the treatment difficulty and the treatment cost of the coking wastewater can be greatly reduced, the method is suitable for stricter discharge standards, and the method has important significance for pollution prevention, ecological environment protection and sustainable development.

At present, the deamination method of the coking wastewater mainly comprises the treatment methods of air stripping, chemical precipitation, catalytic wet oxidation, biochemical method, common adsorption method and the like. Although the blow-off method has low capital construction and operation cost, secondary pollution can be caused, and the blow-off efficiency is low; the magnesium ammonium phosphate precipitate generated by the chemical precipitation method can be used as a slow release fertilizer, but the operation cost is high; the catalytic wet oxidation method has high temperature and high pressure, and is easy to corrode equipment; the biochemical method comprises an A/O process, an A2O process and the like, and has the disadvantages of complex process flow, troublesome operation management and easy influence of toxic substances; the common adsorption method is a method for removing ammonia nitrogen by using zeolite, fly ash and the like as adsorbents, but the removal efficiency is not high, and the method is not suitable for the condition of high ammonia nitrogen concentration. Compared with the methods, the resin adsorption method has the advantages of simple process flow, high adsorption efficiency and regenerable resin, and can ensure the stable operation of the process. The treatment of wastewater by the adsorption resin has been reported. For example, patent CN201310569967.7 discloses a process for treating nitrobenzene wastewater by a resin adsorption method, wherein the content of nitrobenzene after adsorption treatment is less than 0-10 ppm. Patent CN200710021456.6 discloses a method for biological toxicity of methane chloride in contact wastewater by a resin adsorption method, after adsorption treatment, the concentration of methane chloride in wastewater reaches the national discharge standard, and biological toxicity caused by methane chloride in wastewater is effectively removed.

In conclusion, the coking wastewater has complex components and high ammonia nitrogen content, and has great influence on subsequent treatment, so a process for treating ammonia nitrogen in the coking wastewater is needed, and the coking wastewater can be stably and efficiently treated.

Disclosure of Invention

Aiming at the problem that the process for treating ammonia nitrogen in coking wastewater is needed in the prior art so as to stably and efficiently treat the coking wastewater, the invention provides a method and a device for treating ammonia nitrogen in coking wastewater by a resin adsorption method, and aims to: the method has the advantages of high ammonia nitrogen removal efficiency in the coking wastewater, simple process, good resin regeneration and continuous and stable water discharge.

The technical scheme adopted by the invention is as follows:

a method for treating ammonia nitrogen in coking wastewater by a resin adsorption method comprises three steps of pretreatment, resin adsorption and desorption regeneration of resin, wherein the resin adsorption step and the desorption regeneration step are carried out in at least three adsorption tanks which are circularly connected in series, and the resin adsorption step is carried out in one or at least two adsorption tanks which are connected in series.

After the technical scheme is adopted, resin adsorption and desorption regeneration of resin are simultaneously carried out in a series of adsorption tanks which are circularly connected in series, one or at least two adsorption tanks which are mutually connected in series are used for carrying out a resin adsorption step, and other adsorption tanks are used for carrying out desorption regeneration steps. Because the resin adsorption and the desorption regeneration of the resin are carried out simultaneously, the adsorption tank with complete regeneration is ensured to carry out the resin adsorption step, the resin adsorption step can not be interrupted due to the resin desorption regeneration, the stable water outlet of the adsorption tank is further ensured, and the continuous work of the process is realized. On the premise of ensuring the ammonia nitrogen removal efficiency, the efficiency of the process is improved.

Preferably, the resin adsorption step and the resin regeneration step are specifically:

step 1: sending the pretreated wastewater into a resin adsorption device for treatment, wherein the resin adsorption device is divided into a tank A, a tank B and a tank C to form a fixed bed series system;

step 2: the pretreated wastewater is firstly subjected to independent adsorption treatment through the tank A, and when the concentration of ammonia nitrogen in effluent of the tank A begins to rise, the tank B is opened and adsorption treatment is carried out in series by adopting the tank A and the tank B;

and step 3: when the ammonia nitrogen concentration of the effluent adsorbed by the tanks A and B in series begins to rise in the step 2, opening the tank C, changing the pretreatment wastewater from the tank A to the tank B, adopting the tanks B and C in series for adsorption treatment, and desorbing and regenerating the resin in the tank A;

and 4, step 4: when the ammonia nitrogen concentration of the effluent after the tank B-tank C series adsorption treatment in the step 3 is increased, opening the tank A, adopting the tank C-tank A series adsorption, and performing desorption regeneration on the tank B resin;

and 5: when the ammonia nitrogen concentration of the effluent adsorbed by the tank C-tank A in series begins to rise in the step 4, opening the tank B, adopting the tank A-tank B in series for adsorption, and desorbing and regenerating the resin in the tank C;

step 6: and (5) performing circulating operation according to the modes from the step 3 to the step 5, and sequentially and repeatedly adopting the adsorption series connection of the tank A and the tank B, the adsorption series connection of the tank B and the tank C and the adsorption series connection of the tank C and the tank A to obtain stable effluent.

This preferred scheme adopts three adsorption tanks, carries out resin adsorption in turn and desorbs the step of regeneration, has realized the effect that the adsorption tank stabilized out water through the mode of simplifying most.

Preferably, the desorption regeneration of the resin specifically comprises the following steps:

step a: feeding the alkali solution into an adsorption tank in a countercurrent mode, and cleaning the resin;

step b: after the step a is carried out, sending the acid solution into an adsorption tank in a countercurrent mode, and cleaning the resin;

step c: and c, after the step b is carried out, feeding clear water into the adsorption tank in a countercurrent mode, and cleaning the resin.

Further preferably, the alkali solution in step a is a 2-4% by mass fraction NaOH solution, and the acid solution in step a is a 5-8% by mass fraction HCl solution.

The above preferred embodiment enables the resin to be regenerated efficiently.

Preferably, the wastewater is coking wastewater with pH of 7.0-9.0 and ammonia nitrogen content of 2000-5000 mg/L.

Preferably, the pretreatment process adopts a coagulation pretreatment method, the coagulation pretreatment adopts PAC and PAM coagulants, the PAC addition amount is 150-250mg/L, and the PAM addition amount is 20-40 mg/L. The optimal selection scheme further optimizes the step of coagulation pretreatment, and is beneficial to the treatment of the subsequent resin adsorption process by removing the oil residue, a part of colloidal substances and oil-containing substances in the wastewater, and the service life of the resin is prolonged to a certain extent.

Preferably, the resin is one of LSD-296, D958, and LSI-010.

The invention also provides a device for the method for treating ammonia nitrogen in the coking wastewater by the resin adsorption method, which comprises a pretreatment tank and an adsorption system, wherein the adsorption system comprises at least adsorption tanks which are connected in series in a circulating manner, and each adsorption tank is provided with a pipeline for water inlet and outlet. Through the technical scheme, the process method for treating ammonia nitrogen in coking wastewater by using the resin adsorption method can be implemented, stable water outlet of the adsorption tank is ensured on the premise of ensuring the ammonia nitrogen removal efficiency, and the process efficiency is improved.

Preferably, the adsorption system comprises a tank A, a tank B and a tank C, a pipeline I is arranged between the pretreatment tank and an inlet of the tank A, a pipeline II is arranged between an outlet of the tank A and an inlet of the tank B, a pipeline III is arranged between an outlet of the tank B and an inlet of the tank C, and an outlet of the tank C is connected with a pipeline IV; the water treatment main pipeline is communicated with the pipeline I, the pipeline II, the pipeline III and the pipeline IV sequentially through a branch pipeline respectively, the flushing main pipeline is communicated with the outlet and the inlet of the C tank, the outlet and the inlet of the B tank and the outlet and the inlet of the A tank sequentially through the branch pipeline respectively, and valves are arranged on the branch pipelines.

After the preferred scheme is adopted, the adsorption tanks which are in resin adsorption in the tank A, the tank B and the tank C are communicated through the main water treatment pipeline, so that inflow and outflow of wastewater to be treated and the adsorbed wastewater are realized; the adsorption tanks which are in desorption regeneration in the tank A, the tank B and the tank C are communicated through the flushing main pipeline, so that the inflow and outflow of the regeneration desorption liquid are realized.

Further preferably, the flushing main pipeline is communicated with the pipeline I through a branch pipe I, the pipeline I is sequentially communicated with the inlet of the pretreatment tank, the water treatment main pipeline, the inlet of the branch pipe I and the inlet of the tank A, and a valve is arranged between a communication point of the water treatment main pipeline on the pipeline I and a communication point of the branch pipe I.

Two places on the washing main pipeline and two places on pipeline II are respectively communicated through a branch pipe II and a branch pipe III, pipeline II is sequentially communicated with an outlet of a tank A, an inlet of a branch pipe II, a water treatment main pipeline, an inlet of a branch pipe III and an inlet of a tank B, a valve is arranged between a communication point of the branch pipe II on pipeline II and a communication point of the water treatment main pipeline, and a valve is arranged between a communication point of the water treatment main pipeline on pipeline II and a communication point of the branch pipe III.

Two positions on the flushing main pipeline and two positions on the pipeline III are communicated through a branch pipe IV and a branch pipe V respectively, the pipeline III is sequentially communicated with an outlet of a tank B, an inlet of the branch pipe IV, an inlet of a water treatment main pipeline, an inlet of the branch pipe V and an inlet of a tank C, a valve is arranged between a communication point of the branch pipe IV on the pipeline III and a communication point of the water treatment main pipeline, and a valve is arranged between a communication point of the water treatment main pipeline on the pipeline III and a communication point of the branch pipe V.

The flushing main pipeline is communicated with a pipeline IV through a branch pipe VI, the pipeline IV is sequentially communicated with an outlet of the tank C, the branch pipe VI and the water treatment main pipeline, and a valve is arranged between a communication point of the branch pipe VI on the pipeline IV and a communication point of the water treatment main pipeline.

A valve is arranged between a communication point of the branch pipe I and a communication point of the branch pipe II on the flushing main pipeline, a valve is arranged between a communication point of the branch pipe III and a communication point of the branch pipe IV on the flushing main pipeline, and a valve is arranged between a communication point of the branch pipe V and a communication point of the branch pipe VI on the flushing main pipeline.

Further preferably, a C water inlet pipe is arranged between the pretreatment tank and the inlet of the C tank, and a valve is arranged on the C water inlet pipe; the outlet of the tank A is also provided with a water outlet pipe A.

The above preferred embodiment provides a simplified piping system, which can realize the function of dividing the tank A, the tank B and the tank C into two groups, and performing desorption regeneration by one group of resin adsorption and the other group of resin adsorption, by opening and closing a plurality of valves. The optimal scheme enables the layout of a pipeline system to be more optimized and the operation of the process to be simpler.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

1. the resin adsorption and the desorption regeneration of the resin are carried out simultaneously, so that the adsorption tank with complete regeneration is ensured to carry out the resin adsorption step, the resin adsorption step cannot be interrupted due to the resin desorption regeneration, the stable water outlet of the adsorption tank is further ensured, and the continuous work of the process is realized. On the premise of ensuring the ammonia nitrogen removal efficiency, the efficiency of the process is improved.

2. The preferred scheme adopts three adsorption tanks, carries out resin adsorption and desorption regeneration's step in turn, has realized the effect that the adsorption tank stabilized out water through the mode of simplifying most.

3. The step of coagulation pretreatment is optimized, and the oil residue, a part of colloidal substances and oil-containing substances in the wastewater are removed, so that the treatment of a subsequent resin adsorption process is facilitated, and the service life of the resin is prolonged to a certain extent.

4. Compared with other wastewater treatment processes, the method has the characteristics of low investment, simple process, convenient operation, low operation cost and stable effect, the treatment efficiency of the ammonia nitrogen in the wastewater can reach 95 percent after the ammonia nitrogen is adsorbed by the resin, the resin can be regenerated, and the method has an important promotion effect on the treatment of the coking wastewater.

5. The device is provided, the technical method for treating ammonia nitrogen in coking wastewater by using the resin adsorption method can be implemented, stable water outlet of the adsorption tank is ensured on the premise of ensuring the ammonia nitrogen removal efficiency, and the technical efficiency is improved.

6. In the preferred scheme, the adsorption tanks which are in resin adsorption in the tank A, the tank B and the tank C are communicated through a main water treatment pipeline, so that inflow and outflow of wastewater to be treated and the wastewater after adsorption are realized; the adsorption tanks which are in desorption regeneration in the tank A, the tank B and the tank C are communicated through the flushing main pipeline, so that the inflow and outflow of the regeneration desorption liquid are realized.

7. The preferred scheme provides a simplified pipeline system, through the opening and closing of several valves, can realize dividing jar A, jar B and jar C into two sets of, and one set carries out resin adsorption and another group carries out desorption regeneration's function. The optimal scheme enables the layout of a pipeline system to be more optimized and the operation of the process to be simpler.

Drawings

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of the structure of an apparatus according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of an apparatus according to another embodiment of the present invention.

The system comprises a waste water tank 1, a waste water tank 2, a water inlet pump 3, a waste water inlet pipe 4, a pretreatment tank 5, a pipeline I, a pipeline 6, a pipeline A, a pipeline 7, a pipeline B, a pipeline 9, a pipeline III, a pipeline 10, a pipeline IV, a pipeline 11, a water outlet tank 12, a branch pipe I, a branch pipe II, a branch pipe 15, a branch pipe III, a branch pipe IV, a branch pipe V, a branch pipe VI, a branch pipe 19, a flushing main pipeline 16, a flushing pump 21, a water treatment main pipeline 22, a regeneration desorption liquid tank 23, a water inlet pipe 23-C and a water outlet pipe 24-A.

Detailed Description

All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.

The method is suitable for coking wastewater with the pH value of 7.0-9.0 and the ammonia nitrogen content of 2000-5000 mg/L.

As a preferable scheme, the pretreatment process adopts a coagulation pretreatment method, the coagulation pretreatment adopts PAC and PAM coagulant, the PAC adding amount is 150-250mg/L, and the PAM adding amount is 20-40 mg/L.

As a preferable technical scheme, the resin is one of LSD-296, D958 and LSI-010. The resin adsorption step and the resin regeneration step are specifically as follows:

As a preferable mode of the above mode, the desorption regeneration of the resin specifically includes the steps of:

As a preferable technical scheme, the alkali solution in the step a is a NaOH solution with the mass fraction of 2-4%, and the acid solution in the step a is an HCl solution with the mass fraction of 5-8%.

The process apparatus used in the embodiment of the present invention will be described in detail with reference to fig. 1.

The device for the method for treating the ammonia nitrogen in the coking wastewater by the resin adsorption method comprises a pretreatment tank 4 and an adsorption system, wherein the adsorption system comprises at least adsorption tanks which are connected in series in a circulating manner, and each adsorption tank is provided with a pipeline for water inlet and outlet. The entrance of pretreatment tank 4 is connected with wastewater tank 1 through wastewater inlet pipe 3, and wastewater inlet pipe 3 is provided with water inlet pump 2.

In the preferred scheme adopted in this embodiment, the adsorption system comprises three adsorption tanks of a tank 6, a tank 8 and a tank 10, which are connected in series in a circulating manner. A jar 6, B jar 8 and C jar 10 all adopt resin adsorption jar or resin adsorption column isotructure commonly used among the prior art, fill resin in resin adsorption jar or the resin adsorption column, the top of resin adsorption jar or resin adsorption column sets up the entry, and the bottom of resin adsorption jar or resin adsorption column sets up the export. Pretreatment tank 4 with be provided with pipeline I5 between the entry of A jar 6, the export of A jar 6 with be provided with pipeline II 7 between the entry of B jar 8, the export of B jar 8 with be provided with pipeline III 9 between the entry of C jar 10, the exit of C jar 10 is connected with pipeline IV 11, and the outlet water groove 12 of process units or be used for the storage water on next step is connected to pipeline IV 11 rear end. Still include water treatment main line 21 and wash main line 19, water treatment main line 21 loops through branch pipeline and pipeline I5, pipeline II 7, pipeline III 9 and pipeline IV 11 intercommunication respectively, wash main line 19 and loop through branch pipeline and C jar 10 export and entry, B jar 8 export and entry and A jar 6 export and entry intercommunication respectively, be provided with the valve on each branch pipeline. One end of the flushing main pipeline 19 is provided with at least one regeneration desorption liquid tank 22 for inputting regeneration desorption liquid, and an outlet of the regeneration desorption liquid tank 22 is provided with a flushing pump 19; the other end of the main flushing pipeline 19 is connected with the next process for treating the regenerated desorption solution after flushing the resin.

After the preferred scheme is adopted, the adsorption tanks which are in resin adsorption in the tank A6, the tank B8 and the tank C10 are communicated through the main water treatment pipeline 21, so that inflow and outflow of wastewater to be treated and the adsorbed wastewater are realized; the adsorption tanks in desorption and regeneration in the A tank 6, the B tank 8 and the C tank 10 are communicated through a main flushing pipeline 19, and inflow and outflow of regeneration desorption liquid are realized.

Specifically, when the tank A6 and the tank B8 are connected in series for resin adsorption and the tank C10 is used for desorption and regeneration, the communication between the pipeline I5 and the pipeline II 7 and the main water treatment pipeline 21 is cut off through a valve, so that the pipeline III 9 and the pipeline IV 11 are respectively communicated with the main water treatment pipeline 21; the communication between the A tank 6 and the B tank 8 and the main flushing pipeline 19 is cut off through valves, and the C tank 10 is communicated with the main flushing pipeline 19. When the tank B8 and the tank C10 are connected in series for resin adsorption and the tank A6 is subjected to desorption regeneration, the communication between the pipeline III 9 and the pipeline IV 11 and the main water treatment pipeline 21 is cut off through a valve, so that the pipeline I5 and the pipeline II 7 are respectively communicated with the main water treatment pipeline 21; the tank A6 is communicated with the main flushing pipeline 19 by cutting off the communication between the tank B8 and the tank C10 and the main flushing pipeline 19 through valves.

When the tank A6 and the tank C10 are connected in series for resin adsorption and the tank B8 is used for desorption regeneration, as a preferable scheme, the pipeline I5 and the pipeline IV 11 are respectively communicated with the main water treatment pipeline 21 through valves, so that the pipeline II 7 and the pipeline III 9 are respectively communicated with the main water treatment pipeline 21; the communication between the C tank 10 and the A tank 6 and the main flushing pipeline 19 is cut off through valves, and the B tank 8 is communicated with the main flushing pipeline 19. In this scheme, pending waste water passes through jar C10 after jar A6 earlier, is unfavorable for jar C10 to adsorb earlier the operation of switching jar A6 and jar B8 series connection after saturation next step.

Therefore, as another preferable scheme, as shown in fig. 2, a C inlet pipe 23 is arranged between the pretreatment tank 4 and the inlet of the C tank 10, and a valve is arranged on the C inlet pipe 23; the outlet of the A tank 6 is also provided with an A drain pipe 24, and the rear end of the A drain pipe 24 is connected with the next process device or a water outlet groove 12 for storing water. In the preferred scheme, when the tank C10 and the tank A6 are connected in series for resin adsorption and the tank B8 is subjected to desorption regeneration, valves on a water discharge pipe A24 and a water inlet pipe C23 are opened, and a pipeline II 7 and a pipeline III 9 are respectively communicated with a main water treatment pipeline 21 through the valves, so that a pipeline I5 and a pipeline IV 11 are respectively communicated with the main water treatment pipeline 21; the communication between the C tank 10 and the A tank 6 and the main flushing pipeline 19 is cut off through valves, and the B tank 8 is communicated with the main flushing pipeline 19.

The technical scheme is further optimized, and the position of the valve in the pipeline system is optimized, so that the operation is more convenient when the process steps of different adsorption tanks are switched.

Wash main line 19 and pipeline I5 and pass through branch pipe I13 intercommunication, pipeline I5 communicates pretreatment tank 4, water treatment main line 21, the entry of branch pipe I13 and A jar 6 in proper order, be provided with the valve between the intercommunication point of water treatment main line 21 and the intercommunication point of branch pipe I13 on pipeline I5.

Two places on the washing main pipeline 19 and two places on the pipeline II 7 are respectively communicated through a branch pipe II 14 and a branch pipe III 15, the pipeline II 7 is sequentially communicated with an outlet of the tank A6, an inlet of the branch pipe II 14, a water treatment main pipeline 21, an inlet of the branch pipe III 15 and an inlet of the tank B8, a valve is arranged between a communication point of the branch pipe II 14 on the pipeline II 7 and a communication point of the water treatment main pipeline 21, and a valve is arranged between a communication point of the water treatment main pipeline 21 on the pipeline II 7 and a communication point of the branch pipe III 15.

Two positions on the flushing main pipeline 19 are communicated with two positions on the pipeline III 9 through a branch pipe IV 16 and a branch pipe V17 respectively, the pipeline III 9 is communicated with an outlet of the tank B8, the branch pipe IV 16, an inlet of the water treatment main pipeline 21, an inlet of the branch pipe V17 and an inlet of the tank C10 in sequence, a valve is arranged between a communication point of the branch pipe IV 16 on the pipeline III 9 and a communication point of the water treatment main pipeline 21, and a valve is arranged between a communication point of the water treatment main pipeline 21 on the pipeline III 9 and a communication point of the branch pipe V17.

The flushing main pipeline 19 is communicated with the pipeline IV 11 through a branch pipe VI 18, the pipeline IV 11 is sequentially communicated with an outlet of the C tank 10, the branch pipe VI 18 and the water treatment main pipeline 21, and a valve is arranged between a communication point of the branch pipe VI 18 on the pipeline IV 11 and a communication point of the water treatment main pipeline 21.

A valve is arranged between a communication point of a branch pipe I13 on the washing main pipeline 19 and a communication point of a branch pipe II 14, a valve is arranged between a communication point of a branch pipe III 15 on the washing main pipeline 19 and a communication point of a branch pipe IV 16, and a valve is arranged between a communication point of a branch pipe V17 on the washing main pipeline 19 and a communication point of a branch pipe VI 18.

After the preferable technical scheme is adopted, the flow paths of the coking wastewater and the regeneration desorption liquid in the system can be flexibly changed according to the opening and closing of each valve. Specifically, when the tank A6 and the tank B8 are connected in series for resin adsorption and the tank C10 is used for desorption and regeneration, the coking wastewater sequentially passes through the pretreatment tank 4, the pipeline I5, the tank A6, the pipeline II 7, the tank B8, the pipeline III 9, the water treatment main pipeline 21 and the pipeline IV 11, and the regenerated desorption liquid sequentially passes through the regenerated desorption liquid tank 22, the flushing main pipeline 19, the branch pipe VI 18, the tank C10, the branch pipe V17 and the flushing main pipeline 19. When the tank B8 and the tank C10 are connected in series for resin adsorption and the tank A6 is subjected to desorption regeneration, the coking wastewater sequentially passes through the pretreatment tank 4, the pipeline I5, the water treatment main pipeline 21, the pipeline II 7, the tank B8, the pipeline III 9, the tank C10 and the pipeline IV 11, and the regeneration desorption liquid sequentially passes through the regeneration desorption liquid tank 22, the flushing main pipeline 19, the branch pipe II 14, the tank A6, the branch pipe I13 and the flushing main pipeline 19. When the tank A6 and the tank C10 are connected in series for resin adsorption and the tank B8 is subjected to desorption regeneration, the coking wastewater sequentially passes through the pretreatment tank 4, the pipeline I5, the tank A6, the pipeline II 7, the main water treatment pipeline 21, the pipeline III 9, the tank C10 and the pipeline IV 11, and the regeneration desorption liquid sequentially passes through the regeneration desorption liquid tank 22, the flushing main pipeline 19, the branch pipe IV 16, the tank B8, the branch pipe III 15 and the flushing main pipeline 19. When the tank C10 and the tank A6 are connected in series for resin adsorption and the tank B8 is subjected to desorption regeneration, the coking wastewater sequentially passes through the pretreatment tank 4, the water inlet pipe C23, the tank C10, the pipeline IV 11, the main water treatment pipeline 21, the pipeline I5, the tank A6 and the drain pipe A24, and the regeneration desorption liquid sequentially passes through the regeneration desorption liquid tank 22, the flushing main pipeline 19, the branch pipe IV 16, the tank B8, the branch pipe III 15 and the flushing main pipeline 19.

As a preferred scheme, an online detection device can be arranged on the pipeline IV 11 to monitor the pH value and the ammonia nitrogen content of the effluent, when the treatment effect of the pH value and the ammonia nitrogen content is reduced, the resin is judged to need to be regenerated, and at the moment, the state change of each valve can be controlled by a PLC (programmable logic controller), so that the adsorption tanks for resin adsorption and desorption regeneration are switched. The control circuits and programs required for this control process can be implemented according to the prior art.

The present invention is further illustrated by the following examples.

Example 1:

a process for treating ammonia nitrogen in coking wastewater by a resin adsorption method comprises the following steps:

(1) sending coking wastewater with the pH value of 8, the COD content of 5000mg/L and the ammonia nitrogen concentration of 2800mg/L to a coagulation oil separation tank for pretreatment, wherein the PAC dosage in the coagulation oil separation tank is 150mg/L, PAM dosage of 25mg/L, and removing colloid substances and oil-containing substances in the wastewater after pretreatment;

(2) pumping the pretreated wastewater into a tank A of a resin adsorption tower through a pump, treating the wastewater by using LSD-296 type resin, and feeding the adsorbed effluent into a sewage treatment tank for subsequent treatment;

(3) when the concentration of ammonia nitrogen in the resin-adsorbed effluent of the tank A is increased, the tank B (LSD-296 type resin) is opened, the tank A and the tank B are connected in series for adsorption treatment, the adsorbed effluent is sent into a sewage treatment tank for subsequent treatment,

(4) when the ammonia nitrogen concentration of the effluent of the tank B in the step (3) begins to rise, opening a tank C (LSD-296 type resin), changing the pretreatment wastewater from the tank A into the tank B, namely adopting the tank B-C series adsorption treatment, and carrying out desorption regeneration on the resin in the tank A by sequentially using a 2% NaOH solution and a 5% HCl solution;

(5) when the ammonia nitrogen concentration of effluent is increased by adopting the series adsorption treatment of the tank B and the tank C, the tank A is opened, the tank C and the tank A are adopted for series adsorption, and the resin in the tank B is sequentially subjected to desorption regeneration by using a 2% NaOH solution and a 5% HCl solution;

(6) and performing cyclic operation according to the steps, namely performing adsorption series connection of the tank A and the tank B, adsorption series connection of the tank B and the tank C, and adsorption series connection of the tank C and the tank A, so as to obtain stable effluent.

The following table is a comparison table of results of raw wastewater, adsorbed effluent and wastewater after traditional ammonia distillation treatment:

example 1	COD(mg/L)	Ammonia nitrogen (mg/L)
			Raw waste water	5000	2800
Adsorbed water	1500	100
			Ammonia distillation treatment of effluent	3800	300

Example 2:

(1) sending coking wastewater with the pH value of 8, the COD content of 5500mg/L and the ammonia nitrogen concentration of 3200mg/L to a coagulation oil separation tank for pretreatment, wherein the PAC dosage in the coagulation oil separation tank is 200mg/L, PAM dosage of 30mg/L, and removing colloid substances and oil-containing substances in the wastewater after pretreatment;

example 3:

(2) the pretreated wastewater is pumped into a tank A of a resin adsorption tower through a pump and is treated by D958 type resin, and the adsorbed effluent is sent into a sewage treatment tank for subsequent treatment;

(3) when the concentration of ammonia nitrogen in the resin-adsorbed effluent of the tank A is increased, the tank B (D958 type resin) is opened, the tank A and the tank B are connected in series for adsorption treatment, the adsorbed effluent is sent to a sewage treatment tank for subsequent treatment,

(4) when the ammonia nitrogen concentration of the effluent of the tank B in the step (3) begins to rise, opening the tank C (D958 type resin), changing the pretreatment wastewater from the tank A to the tank B, namely adopting the tank B-C to carry out adsorption treatment in series, and carrying out desorption regeneration on the resin in the tank A by using a 2% NaOH solution and a 5% HCl solution in sequence;

example 1	COD(mg/L)	Ammonia nitrogen (mg/L)
			Raw waste water	5500	3200
Adsorbed water	1455	100
			Ammonia distillation treatment of effluent	4000	330

Example 4:

(2) pumping the pretreated wastewater into a resin adsorption tower A tank by a pump, treating the wastewater by using LSI-010 type resin, and feeding the adsorbed effluent into a sewage treatment tank for subsequent treatment;

(3) when the concentration of ammonia nitrogen in the resin-adsorbed effluent of the tank A is increased, the tank B (LSI-010 type resin) is opened, the tank A and the tank B are connected in series for adsorption treatment, the adsorbed effluent is sent into a sewage treatment tank for subsequent treatment,

(4) when the ammonia nitrogen concentration of the effluent of the tank B in the step (3) begins to rise, opening a tank C (LSI-010 type resin), changing the pretreatment wastewater from the tank A into the tank B, namely adopting the tank B-C series adsorption treatment, and sequentially carrying out desorption regeneration on the resin in the tank A by using a 2% NaOH solution and a 5% HCl solution;

example 1	COD(mg/L)	Ammonia nitrogen (mg/L)
			Raw waste water	5500	3200
Adsorbed water	1550	120
			Ammonia distillation treatment of effluent	4000	330

Through the above embodiments, it can be seen that the process of the present application has a better treatment effect compared with the conventional ammonia distillation treatment, and each embodiment can realize continuous and stable water discharge, the process is uninterrupted, and the treatment efficiency is extremely high.

The above-mentioned embodiments only express the specific embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for those skilled in the art, without departing from the technical idea of the present application, several changes and modifications can be made, which are all within the protection scope of the present application.

Claims

1. A method for treating ammonia nitrogen in coking wastewater by a resin adsorption method comprises three steps of pretreatment, resin adsorption and desorption regeneration of resin, and is characterized in that:

the resin adsorption step and the desorption regeneration step are carried out in at least three adsorption tanks connected in series in a cycle, and the resin adsorption step is carried out in one or at least two adsorption tanks connected in series with each other.

2. The method for treating ammonia nitrogen in coking wastewater by using the resin adsorption method according to claim 1, wherein the resin adsorption step and the resin regeneration step are specifically as follows:

3. The method for treating ammonia nitrogen in coking wastewater by using the resin adsorption method according to claim 1 or 2, wherein the desorption regeneration of the resin specifically comprises the following steps:

4. The method for treating ammonia nitrogen in coking wastewater by using the resin adsorption method according to claim 3, which is characterized by comprising the following steps: the alkali solution in the step a is a NaOH solution with the mass fraction of 2-4%, and the acid solution in the step a is an HCl solution with the mass fraction of 5-8%.

5. The method for treating ammonia nitrogen in coking wastewater by using the resin adsorption method according to claim 1, which is characterized by comprising the following steps: the wastewater is coking wastewater with pH of 7.0-9.0 and ammonia nitrogen content of 2000-5000 mg/L.

6. The method for treating ammonia nitrogen in coking wastewater by using the resin adsorption method according to claim 1, which is characterized by comprising the following steps: the pretreatment process adopts a coagulation pretreatment method, the coagulation pretreatment adopts PAC and PAM coagulant, the PAC addition amount is 150-250mg/L, and the PAM addition amount is 20-40 mg/L.

7. An apparatus for the resin adsorption method for treating ammonia nitrogen in coking wastewater according to claim 1, which comprises a pretreatment tank (4) and an adsorption system, and is characterized in that: the adsorption system comprises at least adsorption tanks which are circularly connected in series, and each adsorption tank is provided with a pipeline for water inlet and water outlet.

8. The device for treating ammonia nitrogen in coking wastewater by using the resin adsorption method according to claim 7, is characterized in that: the adsorption system comprises a tank A (6), a tank B (8) and a tank C (10), a pipeline I (5) is arranged between the pretreatment tank (4) and the inlet of the tank A (6), a pipeline II (7) is arranged between the outlet of the tank A (6) and the inlet of the tank B (8), a pipeline III (9) is arranged between the outlet of the tank B (8) and the inlet of the tank C (10), and the outlet of the tank C (10) is connected with a pipeline IV (11); still include water treatment main line (21) and wash main line (19), water treatment main line (21) loops through branch pipeline and pipeline I (5), pipeline II (7), pipeline III (9) and pipeline IV (11) intercommunication respectively, wash main line (19) and loop through the export and the entry of branch pipeline and C jar (10), the export and the entry of B jar (8) and the export and the entry intercommunication of A jar (6) respectively, be provided with the valve on each branch pipeline.

9. The device for treating ammonia nitrogen in coking wastewater by using the resin adsorption method according to claim 8, is characterized in that:

the flushing main pipeline (19) is communicated with the pipeline I (5) through a branch pipe I (13), the pipeline I (5) is sequentially communicated with the pretreatment tank (4), the water treatment main pipeline (21), the branch pipe I (13) and an inlet of the tank A (6), and a valve is arranged between a communication point of the water treatment main pipeline (21) on the pipeline I (5) and a communication point of the branch pipe I (13);

two positions on the washing main pipeline (19) are respectively communicated with two positions on the pipeline II (7) through a branch pipe II (14) and a branch pipe III (15), the pipeline II (7) is sequentially communicated with an outlet of the tank A (6), the branch pipe II (14), the water treatment main pipeline (21), the branch pipe III (15) and an inlet of the tank B (8), a valve is arranged between a communication point of the branch pipe II (14) on the pipeline II (7) and a communication point of the water treatment main pipeline (21), and a valve is arranged between a communication point of the water treatment main pipeline (21) on the pipeline II (7) and a communication point of the branch pipe III (15);

two positions on the washing main pipeline (19) are respectively communicated with two positions on the pipeline III (9) through a branch pipe IV (16) and a branch pipe V (17), the pipeline III (9) is sequentially communicated with an outlet of the tank B (8), the branch pipe IV (16), a water treatment main pipeline (21), a branch pipe V (17) and an inlet of the tank C (10), a valve is arranged between a communication point of the branch pipe IV (16) on the pipeline III (9) and a communication point of the water treatment main pipeline (21), and a valve is arranged between a communication point of the water treatment main pipeline (21) on the pipeline III (9) and a communication point of the branch pipe V (17);

the flushing main pipeline (19) is communicated with a pipeline IV (11) through a branch pipe VI (18), the pipeline IV (11) is sequentially communicated with an outlet of the C tank (10), the branch pipe VI (18) and the water treatment main pipeline (21), and a valve is arranged between a communication point of an upper branch pipe VI (18) of the pipeline IV (11) and a communication point of the water treatment main pipeline (21);

the valve is arranged between a communication point of an upper branch pipe I (13) of the main pipeline (19) and a communication point of a branch pipe II (14), a valve is arranged between a communication point of an upper branch pipe III (15) of the main pipeline (19) and a communication point of a branch pipe IV (16), and a valve is arranged between a communication point of an upper branch pipe V (17) of the main pipeline (19) and a communication point of a branch pipe VI (18).

10. The device for treating ammonia nitrogen in coking wastewater by using the resin adsorption method according to any one of claims 8 or 9, characterized in that: a C water inlet pipe (23) is arranged between the pretreatment tank (4) and the inlet of the C tank (10), and a valve is arranged on the C water inlet pipe (23); the outlet of the tank A (6) is also provided with a water outlet pipe A (24).