CN115611462A - Method for recovering and treating calcium ammonium nitrate and ammonium nitrate condensation wastewater - Google Patents

Abstract

The invention discloses a method for recycling and treating calcium ammonium nitrate and ammonium nitrate condensed wastewater, which belongs to the technical field of industrial wastewater treatment²⁺ Rear entryThe Ca in the water is further removed by entering a sodium ion exchanger²⁺ Then the mixture enters a neutralization tank and is subjected to pH regulation together with the ammonium nitrate wastewater; pumping the mixture into a storage tank A through a neutralization lifting pump; pumping the mixed wastewater of ammonium nitrate and calcium ammonium nitrate after the pH adjustment into a heat exchanger, conveying the wastewater after the heat exchange into a precision filter, and filtering suspended substances in the wastewater; the water is conveyed to a first-stage reverse osmosis device and a second-stage reverse osmosis device for advanced treatment, and the final effluent is discharged or recycled after being qualified.

Description

Method for recovering and treating calcium ammonium nitrate and ammonium nitrate condensation waste water

Technical Field

The invention belongs to the technical field of industrial wastewater treatment, and particularly relates to a method for recovering and treating calcium ammonium nitrate and ammonium nitrate condensation wastewater.

Background

Industrial wastewater, which is wastewater, sewage and waste liquid generated in an industrial production process, is inevitably generated in industrial production. The water loss-accompanied industrial production materials, intermediate products and pollutants generated in the production process are contained in the water loss-accompanied industrial production materials and intermediate products. Because many industrial waste water components are complex and properties are changeable, some technical problems are not completely solved so far, which is different from the treatment of the urban sewage with mature technology, and the prior art does not disclose how to recover and treat the waste water of calcium ammonium nitrate and ammonium nitrate.

Therefore, the technical personnel in the field need to solve the problem of how to provide a method for recovering and treating the calcium ammonium nitrate and the ammonium nitrate condensation wastewater.

Disclosure of Invention

In view of the above, the invention provides a method for recovering and treating calcium ammonium nitrate and ammonium nitrate condensation wastewater, which has the advantages of high recovery and treatment efficiency, zero emission, low investment cost, low energy consumption and simple process.

In order to achieve the purpose, the invention adopts the following technical scheme:

the method for recovering and treating the calcium ammonium nitrate and the ammonium nitrate condensation wastewater comprises the following steps:

s1: the ammonium nitrate wastewater forms a process condensate through a nitric acid device, and the process condensate and the evaporation condensate are mixed and input into a neutralization tank;

s2: step S1 is carried out, meanwhile, the process condensate in the calcium ammonium nitrate device is conveyed to a storage tank B, and then the process condensate is pumped into an intelligent ionization descaling device through a storage tank lifting pump to remove most of Ca in water²⁺ Then enters a sodium ion exchanger to further remove Ca in the water²⁺ Then the mixture enters a neutralization tank and is subjected to pH regulation together with the ammonium nitrate wastewater;

s3: pumping the calcium ammonium nitrate and the ammonium nitrate wastewater in the neutralization tank into a storage tank A through a neutralization lift pump;

s4: pumping the mixed liquid wastewater of ammonium nitrate and calcium ammonium nitrate which is subjected to P regulation into a heat exchanger by using a storage tank lift pump for heat exchange;

s5: conveying the wastewater subjected to heat exchange in the step S4 to a precision filter, and filtering suspended substances in the wastewater;

s6: and (4) sequentially conveying the wastewater without suspended substances to a first-stage reverse osmosis device and a second-stage reverse osmosis device for advanced treatment, and discharging or recycling the final effluent after the final effluent is qualified.

Further, the concentration of the nitric acid device process condensate is 500mg/L, the flow rate is 2.3t/h, the concentration of the evaporation condensate is 2g/L, the flow rate is 0.56t/h, and the flow rate of the nitric acid device process condensate and the evaporation condensate mixed liquid input into the storage tank A is 2.86t/h.

Further, the concentration of the calcium ammonium nitrate device process condensate is 1g/L, and Ca is generated after the calcium ammonium nitrate device process condensate is diluted in the storage tank B²⁺ The concentration is 185mg/L, ca is contained in the output solution after the descaling is carried out by the intelligent ionization descaling device²⁺ The concentration is 20mg/L, and the output water flows back to the storage tank and is used for diluting the process condensate of the calcium ammonium nitrate device.

Further, the flow rate of the solution output by the sodium ion exchanger to the neutralization tank is 2.86t/h.

Further, the pH value of the solution in the neutralization tank is 4.5-5.5 after being adjusted.

Further, the temperature of the heat exchanger is 23-35 ℃, and is preferably 25 ℃.

Furthermore, the primary reverse osmosis device comprises a primary reverse osmosis raw water tank, a primary reverse osmosis lift pump, a primary security filter, a primary high-pressure pump, a primary RO device and a primary reverse osmosis produced water tank, and the primary reverse osmosis raw water tank, the primary reverse osmosis lift pump, the primary security filter, the primary high-pressure pump, the primary RO device and the primary reverse osmosis produced water tank are sequentially connected.

Furthermore, the second-stage reverse osmosis device comprises a second-stage reverse osmosis lift pump, a second-stage security filter, a second-stage high-pressure pump, a second-stage RO device and a second-stage reverse osmosis water production tank, and the second-stage reverse osmosis lift pump, the second-stage security filter, the second-stage high-pressure pump, the second-stage RO device and the second-stage reverse osmosis water production tank are sequentially connected.

Further, the solution filtered in the precision filter is input into a first-stage reverse osmosis device for osmosis at the flow rate of 9.5t/h, wherein the mixed solution of 5g/L ammonium nitrate and calcium ammonium nitrate after osmosis is input into an ED membrane at the flow rate of 3.6t/h, the mixed solution of 500mg/L ammonium nitrate and calcium ammonium nitrate is input into a second-stage reverse osmosis device at the flow rate of 8.4t/h for osmosis, one part of the solution after osmosis reaches the standard and is discharged or recycled, and the other part of the solution after osmosis is conveyed to the first-stage reverse osmosis device at the flow rate of 2.5t/h for continuous osmosis after the concentration is increased.

Further, after receiving the solution output by the first-stage reverse osmosis device, the ED membrane carries out concentration and separation treatment, one part of the solution outputs a mixed solution of ammonium nitrate and calcium ammonium nitrate with the concentration of 50-100g/L at the flow rate of 0.1t/h, and the other part of the fresh water flows back to the storage tank A at the flow rate of 3.5t/h for continuous use.

The invention has the beneficial effects that:

the invention has simple process and convenient operation, and can obtain wastewater which can reach the standard and high-concentration calcium ammonium nitrate and ammonium nitrate solution which can be recycled by condensing and cooling calcium ammonium nitrate and ammonium nitrate wastewater, adjusting the pH value to reduce the temperature, then adopting a precise filter to filter surface suspended substances firstly and then treating the wastewater by a primary reverse osmosis device and a secondary reverse osmosis device, and various operations of the system can also work in a manual operation mode, wherein the manual operation can be carried out on a keyboard or an on-site pneumatic two-position valve box or a control device, so that the invention has the advantages of high recovery and treatment efficiency, zero discharge, low investment cost, low energy consumption and simple process.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic process flow diagram of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

Referring to the attached figure 1, the invention provides a method for recovering and treating calcium ammonium nitrate and ammonium nitrate condensation wastewater, which comprises the following steps:

s1: forming process condensate from the ammonium nitrate wastewater through a nitric acid device, mixing the process condensate with the evaporation condensate, and inputting the mixture into a neutralization tank;

s2: step S1 is carried out, meanwhile, the process condensate in the calcium ammonium nitrate device is conveyed to a storage tank B, and then the process condensate is pumped into an intelligent ionization descaling device through a storage tank lifting pump to remove most Ca in water²⁺ Then enters a sodium ion exchanger to further remove Ca in the water²⁺ Then the wastewater enters a neutralization tank to be subjected to PH regulation together with the ammonium nitrate wastewater;

s3: pumping the calcium ammonium nitrate and the ammonium nitrate wastewater in the neutralization tank into a storage tank A through a neutralization lift pump;

s4: pumping the waste water of the mixed liquid of ammonium nitrate and calcium ammonium nitrate which is subjected to P regulation into a heat exchanger by using a storage tank lifting pump for heat exchange;

s5: conveying the wastewater subjected to heat exchange in the step S4 into a precision filter, and filtering suspended substances in the wastewater;

s6: and (4) sequentially conveying the wastewater without suspended substances to a first-stage reverse osmosis device and a second-stage reverse osmosis device for advanced treatment, and discharging or recycling the final effluent after the final effluent is qualified.

The concentration of the nitric acid device process condensate is 500mg/L, the flow rate is 2.3t/h, the concentration of the evaporation condensate is 2g/L, the flow rate is 0.56t/h, the flow rate of the nitric acid device process condensate and the evaporation condensate mixed liquid input into the neutralization tank A is 2.86t/h, and the concentration of the calcium ammonium nitrate device process condensate is 1g/L. The neutralization tank is used for buffering, nitric acid or gas ammonia is used for neutralizing and adjusting the pH value, and the nitric acid or the gas ammonia is converted into ammonium nitrate, and the system is provided with 2 stations and 10m³ The material of the neutralization tank is 304 stainless steel.

After the process condensate of the calcium ammonium nitrate device is diluted in the storage tank B, ca²⁺ The concentration is 185mg/L, ca is in the output solution after the descaling of the intelligent ionization descaling device²⁺ The concentration is 20mg/L, the output water flows back to the storage tank and is used for diluting the process condensate of the calcium ammonium nitrate device, and when the amount of water flowing back by the intelligent ionization descaling device is insufficient, water can be supplemented from the outside. The intelligent ionization descaling device mainly comprises a control box, a reactor and a descaling and sludge squeezing system, wherein the reactor is directly arranged on a condensate liquid sewage discharge pipe of the calcium ammonium nitrate device process, which means that Ca in the calcium ammonium nitrate wastewater is reduced after the calcium ammonium nitrate wastewater is treated by the electrolytic water treatment descaling device²⁺ The concentration of the raw materials is treated by descaling and then enters the next procedure.

The speed of the sodium ion exchanger outputting the solution to the neutralization tank is 2.86t/h. Sodium ion exchange resin with a certain height is arranged in the sodium ion exchanger as an exchanger. Raw water passes through the exchanger layer from top to bottom, and sodium ions on the exchanger replace calcium and magnesium ions in the raw water to soften the water. The reaction is as follows:

Ca²⁺ +2NaR→CaR+2Na⁺

Mg²⁺ +2NaR→MgR+2Na⁺

the sodium ions on the exchanger are gradually replaced by calcium and magnesium ions, and after the exchanger is used for a period of time, the calcium and magnesium ions are leaked out, and when the hardness of the effluent reaches a specified value, the operation is stopped, and the regeneration is carried out. During regeneration, 5-8% of brine (or sodium nitrate) passes through the exchanger layer from bottom to top. The sodium ions in the salt solution replace the calcium and magnesium ions on the exchanger, so that the exchanger is regenerated and the exchange capacity is recovered. The reaction is as follows:

CaR+2Na⁺ →Ca²⁺ +2NaR

MgR+2Na⁺ →Mg²⁺ +2NaR

001X 7 strong acidic styrene cation resin is filled in an exchange column to soften raw water. The switching of the flowing direction and the size of the liquid is realized by closing the valve, thereby completing the softening of raw water and the loosening, regeneration, replacement and cleaning of the resin. The salt (industrial salt) solution stored in the salt tank is sucked into the resin tank through the negative pressure action of the ejector, diluted in the resin tank, and subjected to countercurrent regeneration through the resin, and the waste liquid is discharged through the water outlet, so that the resin is further regenerated by replacement, and the salt solution is fully utilized. In order to ensure that the renewable resource waste liquid is removed completely.

The pH value of the solution after being regulated in the neutralization tank is 4.5-5.5.

The temperature of the heat exchanger is 23-35 ℃, and preferably 25 ℃.

The primary reverse osmosis device comprises a primary reverse osmosis raw water tank, a primary reverse osmosis lifting pump, a primary security filter, a primary high-pressure pump, a primary RO device and a primary reverse osmosis produced water tank, and the primary reverse osmosis raw water tank, the primary reverse osmosis lifting pump, the primary security filter, the primary high-pressure pump, the primary RO device and the primary reverse osmosis produced water tank are sequentially connected; the second-stage reverse osmosis device comprises a second-stage reverse osmosis lift pump, a second-stage security filter, a second-stage high-pressure pump, a second-stage RO device and a second-stage reverse osmosis water production tank, and the second-stage reverse osmosis lift pump, the second-stage security filter, the second-stage high-pressure pump, the second-stage RO device and the second-stage reverse osmosis water production tank are sequentially connected.

The solution filtered in the precision filter is input into a first-stage reverse osmosis device for osmosis at the flow rate of 9.5t/h, wherein the mixed solution of 5g/L ammonium nitrate and calcium ammonium nitrate after osmosis is input into an ED membrane at the flow rate of 3.6t/h, the mixed solution of 500mg/L ammonium nitrate and calcium ammonium nitrate is input into a second-stage reverse osmosis device at the flow rate of 8.4t/h for osmosis, one part of the solution after osmosis reaches the standard and is discharged or recycled, the other part of the solution after osmosis is subjected to concentration increase and is conveyed to the first-stage reverse osmosis device at the flow rate of 2.5t/h for continuous osmosis, and a ceramic filter can be further used for enhancing the filtration effect after the precision filter. The precise filter is made of a cylinder shell and stainless steel, tubular filter elements such as PP melt-blown filter elements and wire-fired filter elements are adopted as filter elements inside the precise filter, and different filter elements are selected according to different filter media and design processes so as to meet the requirement of effluent quality.

Characteristics of performance

(1) High filtering precision and uniform filter element aperture

(2) Small filtration resistance, large flux, strong dirt intercepting capability and long service life.

(3) The filter element material has high cleanliness and no pollution to the filter medium.

(4) Acid-proof, alkali-proof chemical solvent.

(5) High strength, high-temp resistance and not deforming easily.

(6) Low cost, low operation cost, easy cleaning, replaceable filter core

And after receiving the solution output by the first-stage reverse osmosis device, the ED membrane is concentrated and separated, one part of the ED membrane outputs a mixed solution of ammonium nitrate and calcium ammonium nitrate with the concentration of 50-100g/L at the flow rate of 0.1t/h, and the other part of the fresh water flows back to the storage tank A at the flow rate of 3.5t/h for continuous use.

The ammonium nitrate and calcium ammonium nitrate wastewater treatment device adopts a PLC200 system to automatically control the operation and cleaning of equipment according to programs. The system is controlled and monitored by an operator station in a control room of the ammonium nitrate and calcium ammonium nitrate water treatment system, and various operations of the system can be manually intervened, wherein the manual operations can be carried out on a keyboard, an in-situ pneumatic two-position valve box or a control device. The PLC system for wastewater treatment is provided by a design unit.

Therefore, the invention has the advantages of high recovery and treatment efficiency, low investment cost, low energy consumption and simple process.

The embodiments in the present specification are described in a progressive manner, and for the method disclosed in the embodiments, since it corresponds to the apparatus disclosed in the embodiments, the description is relatively simple, and for the relevant points, refer to the description of the method part.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. The method for recycling and treating the calcium ammonium nitrate and the ammonium nitrate condensed wastewater is characterized by comprising the following steps of:

s1: performing pH adjustment on the ammonium nitrate wastewater through a nitric acid device to form process condensate, mixing the process condensate with the evaporation condensate, and inputting the mixture into a neutralization tank;

s2: step S1 is carried out, meanwhile, the process condensate in the calcium ammonium nitrate device is conveyed to a storage tank B, and then the process condensate is pumped into an intelligent ionization descaling device through a storage tank lifting pump to remove most of Ca in water²⁺ Then enters a sodium ion exchanger to further remove Ca in the water²⁺ Then the mixture enters a neutralization tank and is subjected to pH regulation together with the ammonium nitrate wastewater;

s3: pumping the calcium ammonium nitrate and the ammonium nitrate wastewater in the neutralization tank into a storage tank A through a neutralization lift pump;

s4: pumping the mixed solution wastewater of ammonium nitrate and calcium ammonium nitrate after the pH adjustment into a heat exchanger by using a storage tank lift pump for heat exchange;

s5: conveying the wastewater subjected to heat exchange in the step S4 to a precision filter, and filtering suspended substances in the wastewater;

s6: and (4) sequentially conveying the wastewater without suspended substances to a first-stage reverse osmosis device and a second-stage reverse osmosis device for advanced treatment, and discharging or recycling the final effluent after the final effluent is qualified.

2. The method for recovering and treating calcium ammonium nitrate and ammonium nitrate condensate wastewater as claimed in claim 1, wherein the concentration of the nitric acid device process condensate is 500mg/L, the flow rate is 2.3t/h, the concentration of the evaporation condensate concentrate is 2g/L, the flow rate is 0.56t/h, and the flow rate of the mixed solution of the nitric acid device process condensate and the evaporation condensate to the storage tank A is 2.86t/h.

3. The method for recycling and treating calcium ammonium nitrate and ammonium nitrate condensate wastewater as claimed in claim 1, wherein the concentration of the process condensate of the calcium ammonium nitrate device is 1g/L, and after the process condensate of the calcium ammonium nitrate device is diluted in the storage tank B, ca is added²⁺ The concentration is 185mg/L, ca is in the output solution after the descaling of the intelligent ionization descaling device²⁺ The concentration is 20mg/L, and the output water flows back to the storage tank and is used for diluting the process condensate of the calcium ammonium nitrate device.

4. The method for recovering and treating calcium ammonium nitrate and ammonium nitrate condensate wastewater as claimed in claim 1, wherein the flow rate of the solution output from the sodium ion exchanger to the neutralization tank is 2.86t/h.

5. The method for recovering and treating calcium ammonium nitrate and ammonium nitrate condensate wastewater as claimed in claim 1, wherein the pH value of the solution in the neutralization tank after adjustment is 4.5-5.5.

6. The method for recovering and treating calcium ammonium nitrate and ammonium nitrate condensate wastewater as claimed in claim 1, wherein the temperature of the heat exchanger is 23-35 ℃.

7. The method as claimed in claim 1, wherein the first stage reverse osmosis device comprises a first stage reverse osmosis raw water tank, a first stage reverse osmosis lift pump, a first stage cartridge filter, a first stage high pressure pump, a first stage RO device and a first stage reverse osmosis produced water tank, and the first stage reverse osmosis raw water tank, the first stage reverse osmosis lift pump, the first stage cartridge filter, the first stage high pressure pump, the first stage RO device and the first stage reverse osmosis produced water tank are sequentially connected.

8. The method for recycling and treating calcium ammonium nitrate and ammonium nitrate condensed wastewater as claimed in claim 1, wherein the secondary reverse osmosis device comprises a secondary reverse osmosis lift pump, a secondary safety filter, a secondary high-pressure pump, a secondary RO device and a secondary reverse osmosis water production tank, and the secondary reverse osmosis lift pump, the secondary safety filter, the secondary high-pressure pump, the secondary RO device and the secondary reverse osmosis water production tank are sequentially connected.

9. The method for recovering and treating calcium ammonium nitrate and ammonium nitrate condensate wastewater as claimed in claim 1, wherein the solution filtered in the precision filter is input into the primary reverse osmosis device for permeation at a flow rate of 9.5t/h, wherein the permeated mixed solution of ammonium nitrate and calcium ammonium nitrate with the concentration of 5g/L is input into Electrodialysis (ED) at a flow rate of 3.6t/h, the mixed solution of ammonium nitrate and calcium ammonium nitrate with the concentration of 500mg/L is input into the secondary reverse osmosis device at a flow rate of 8.4t/h for permeation, one part of the permeated solution reaches the standard and is discharged or recycled, and the other part of the permeated solution is increased in concentration and is transmitted to the primary reverse osmosis device at a flow rate of 2.5t/h for permeation.

10. The method for recovering and treating calcium ammonium nitrate and ammonium nitrate condensate wastewater as claimed in claim 9, wherein the ED membrane is used for concentrating and separating the solution output by the first-stage reverse osmosis device, wherein a part of the solution outputs a mixed solution of ammonium nitrate and calcium ammonium nitrate with the concentration of 50-100g/L at the flow rate of 0.1t/h, and the other part of the fresh water flows back to the storage tank A at the flow rate of 3.5t/h for continuous use.

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