CN111960515A - Chemical-adding-free acid pickling device and method for desulfurization wastewater concentration electrodialysis system - Google Patents
Chemical-adding-free acid pickling device and method for desulfurization wastewater concentration electrodialysis system Download PDFInfo
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Abstract
The invention relates to a dosing-free acid washing device of a desulfurization wastewater concentration electrodialysis system, which comprises a bipolar membrane electrodialysis system and a main electrodialysis system; the bipolar membrane electrodialysis system mainly comprises a bipolar membrane electrodialysis reactor, an acid chamber, an acid circulating pump, an alkali chamber, an alkali circulating pump, a polar chamber, a polar circulating pump, a brine circulating pump and a meter valve pipeline matched with the brine circulating pump; the bipolar membrane electrodialysis reactor consists of an anode, a membrane stack and a cathode, wherein the membrane stack comprises a bipolar membrane BM, a selective anion exchange membrane A, a selective cation exchange membrane C and a supporting clapboard; the membrane stack arrangement order is: (BM-A-C)n-BM, the acid solution channel, the salt solution channel and the alkali solution channel are distributed at intervals; the outermost layers on both sides of the membrane stack are bipolar membranes. The invention has the beneficial effects that: the bipolar membrane electrodialysis system can be used for pickling the electrodialysis system for treating the desulfurization wastewater without additionally using a pickling agent, so that the cost of the pickling agent can be saved, the pickling step can be simplified, and the safety risk of using acid can be reduced.
Description
Technical Field
The invention belongs to the technical field of environment-friendly water treatment, and particularly relates to a dosing-free acid washing device and a dosing-free acid washing method for a desulfurization wastewater concentration electrodialysis system.
Background
The electrodialysis technology has the advantages of high efficiency, cleanness, energy conservation and low cost, and has wide development potential and application prospect. Different types of electrodialysis systems have different scales and characteristics in the industries such as chemical metallurgy, light industry, paper making, pharmaceutical industry and the like. The electrodialysis system in the process route of the concentration treatment of the desulfurization wastewater of the coal-fired power plant has certain specificity, and a monovalent selective exchange membrane is used for replacing an anion exchange membrane without selectivity. And (3) treating the desulfurization wastewater by an electrodialysis reactor, and transferring ions on the fresh water side to the concentrated water side under the driving of an electric field force to finally divide the desulfurization wastewater into concentrated water and fresh water. The concentrated water has the characteristics of small water quantity, high chloride ion concentration, low sulfate ion concentration, low divalent cation concentration and deep treatment, and the fresh water has the characteristics of large water content, low chloride ion concentration, high sulfate ion concentration, high divalent cation concentration and direct recycling. The schematic diagram of the electrodialysis reactor for the concentration treatment of the desulfurization waste water is shown in figure 3.
For the electrodialysis system for concentrating the desulfurization wastewater, the initial polar water is a sodium chloride solution with the mass fraction of 2%. With the treatment of the system on the desulfurization wastewater, a small amount of divalent cations in the concentrated water channel can penetrate through the monovalent cation selective exchange membrane to enter the cathode side polar water channel (the monovalent cation selective membrane cannot realize 100% separation, and the separation effect of the membrane is represented by the selective permeability coefficient or the permeability of multivalent ions. Moreover, the surface of the ion exchange membrane on the fresh water side can be scaled after the system is operated for a long time. Calcium and magnesium scaling on the surfaces of the electrode plate and the ion exchange membrane can cause the problems of membrane surface structure damage, membrane channel blockage, membrane resistance increase, electrode corrosion, current efficiency reduction, ion migration capacity reduction and the like, and the electrode plate and the membrane surface must be periodically pickled to maintain the normal operation of equipment. Because the hardness of the desulfurization wastewater is higher and the scaling rate is faster, the acid washing frequency of the electrodialysis equipment for concentrating the desulfurization wastewater is higher than that of the electrodialysis equipment for treating other wastewater.
The common electrodialysis pickling mode is to prepare hydrochloric acid with the mass fraction of 0.1-0.5% and carry out circular pickling on the electrodialysis membrane stack and the electrode plate. The hydrochloric acid has the defects of large medicament demand, high medicament cost, environmental pollution caused by pickling waste water, complex operation, poor safety and the like. There is a need to develop a novel electrodialysis pickling system, which can carry out comprehensive pickling on the electrode plates and the membrane stack without adding a pickling agent additionally.
Disclosure of Invention
The invention aims to provide a chemical-free pickling device and a chemical-free pickling method aiming at the problem that the existing electrodialysis pickling agent for concentrating desulfurization wastewater is high in demand.
The chemical-adding-free acid washing device of the desulfurization wastewater concentration electrodialysis system comprises a bipolar membrane electrodialysis system and a main electrodialysis system; the bipolar membrane electrodialysis system mainly comprises a bipolar membrane electrodialysis reactor, an acid chamber, an acid circulating pump, an alkali chamber, an alkali circulating pump, a polar chamber, a polar circulating pump, a brine circulating pump and a meter valve pipeline matched with the brine circulating pump; the bipolar membrane electrodialysis reactor consists of an anode, a membrane stack and a cathode, wherein the membrane stack comprises a bipolar membrane BM, a selective anion exchange membrane A, a selective cation exchange membrane C and a supporting clapboard; the membrane stack arrangement order is: (BM-A-C)n-BM, wherein n is a natural number of 1-500, forming n acid solution channels, n salt solution channels, n alkali solution channels and 2 outermost polar water channels, the acid solution channels, the salt solution channels and the alkali solution channels being distributed at intervals; the outermost layers on the two sides of the membrane stack are bipolar membranes; brine tank and bypass valve of main electrodialysis system, brine circulating pump and bipolar membrane electrodialysis reactorForming brine internal circulation; an acid chamber, an acid circulating pump and an acid channel of the bipolar membrane electrodialysis reactor form internal acid circulation; an alkali chamber, an alkali circulating pump and an alkali channel of the bipolar membrane electrodialysis reactor form alkali internal circulation; the polar chamber, the polar water circulating pump and the polar water channel of the bipolar membrane electrodialysis reactor form polar water internal circulation; the bipolar membrane electrodialysis system is communicated with a concentrated water tank of the main electrodialysis system through a bypass valve 1 and a bypass valve 2, an acid chamber is communicated to a cleaning water tank of the main electrodialysis system through an acid circulating pump and an acid adding valve in sequence, and an alkali chamber is communicated to a cleaning water tank of the main electrodialysis system through an alkali circulating pump and a neutralization valve in sequence.
Preferably, the method comprises the following steps: an outlet of the concentrated water tank is communicated to an inlet of a saline passage of the bipolar membrane electrodialysis reactor through a bypass valve 1 and a saline circulating pump in sequence, and an outlet of the saline passage of the bipolar membrane electrodialysis reactor is communicated to an inlet of the concentrated water tank through a bypass valve 2.
Preferably, the method comprises the following steps: the anode and the membrane stack are adjacently arranged on one side close to the selective anion exchange membrane, and the cathode and the membrane stack are adjacently arranged on one side close to the selective cation exchange membrane.
Preferably, the method comprises the following steps: the cathode membrane of the bipolar membrane faces the cathode side, and the anode membrane of the bipolar membrane faces the anode side.
Preferably, the method comprises the following steps: supporting partition boards are arranged on two sides of each layer of membrane, and water flow holes and communication holes are respectively formed in the upper end and the lower end of each partition board.
Preferably, the method comprises the following steps: and the switches of all the electric valves are connected into a remote control system.
Preferably, the method comprises the following steps: all the devices are connected through PE pipes, and the outlets of the water pumps are provided with check valves.
Preferably, the method comprises the following steps: a turbidity meter, a pH meter, a conductivity meter and a thermometer are arranged at a high-salt concentrated water inlet of the bipolar membrane electrodialysis system, the pH meter and the conductivity meter are arranged in an acid chamber and an alkali chamber, liquid level meters are arranged in all water tanks, and signals of all the meters are accessed into a remote control system.
According to the acid making method of the dosing-free acid washing device of the desulfurization wastewater concentration electrodialysis system, when the concentration of a hydrochloric acid solution in an acid chamber is insufficient or the volume of the hydrochloric acid solution in the acid chamber is insufficient and a main electrodialysis system normally and continuously operates, an acid making program is started by the bipolar membrane electrodialysis system, and the method comprises the following steps:
s1, applying the sodium sulfate solution to polar water of the bipolar membrane electrodialysis system to enable the volume of the solution to be not less than 60% of the volume of the polar chamber;
s2, taking the desalted water as initial water for acid solution circulation and alkali solution circulation, and respectively supplementing the desalted water into the acid chamber and the alkali chamber to a specified volume;
s3, opening a bypass valve 1 and a bypass valve 2, and communicating a concentrated water tank of the main electrodialysis system with the bipolar membrane electrodialysis system;
s4, simultaneously starting an acid circulating pump, an alkali circulating pump, an extreme water circulating pump and a brine circulating pump, and controlling the pressure and the flow of the four pumps to be at the same level;
s5, after the circulation is stable, starting the bipolar membrane electrodialysis reactor, adjusting the electrode voltage and the membrane stack current to proper values, and monitoring the H of the acid solution in the acid chamber+Concentration and OH of alkaline solution in alkaline chamber-Concentration;
s6, when the concentration of hydrochloric acid in the acid solution in the acid chamber is higher than a set value, closing the bipolar membrane electrodialysis reactor; simultaneously turning off the acid circulating pump, the alkali circulating pump, the polar water circulating pump and the brine circulating pump;
s7, closing the bypass valve 1 and the bypass valve 2;
s8, temporarily storing the prepared acid solution in an acid chamber, and temporarily storing the prepared alkali solution in an alkali chamber.
According to the acid washing method of the chemical-adding-free acid washing device of the desulfurization wastewater concentration electrodialysis system, when the main electrodialysis system needs acid washing, the bipolar membrane electrodialysis system starts an acid washing program, and the acid washing method comprises the following steps:
s1, firstly, adding a certain volume of demineralized water into the cleaning water tank;
s2, opening an acid adding valve, switching the valve, pumping acid solution in an acid chamber into a cleaning water tank of the main electrodialysis system by using an acid circulating pump as concentrated acid, and adjusting the concentration of the hydrochloric acid in the cleaning water tank to be 0.1-0.5%;
s3, carrying out circulating acid washing on the homogeneous membrane electrodialysis reactor by using an acid washing pump;
s4, after the acid washing is finished, the pH value of the acid washing liquid in the washing water tank is still at a lower level; at the moment, a neutralization valve is opened, an alkali solution in an alkali chamber is pumped into a cleaning water tank by an alkali circulating pump for neutralization, and the pH value of the cleaning water tank is adjusted to 6-9 and then discharged to the outside.
The invention has the beneficial effects that:
1. the bipolar membrane electrodialysis system provided by the invention can be used for pickling the electrodialysis system for treating the desulfurization wastewater without additionally using a pickling agent, so that the cost of the pickling agent can be saved, the pickling step can be simplified, and the safety risk of using acid can be reduced.
2. The pickling device provided by the invention utilizes the high-salinity concentrated water obtained by the operation of the main electrodialysis system, and realizes the resource utilization of byproducts.
3. The byproduct alkaline solution of the pickling device is reasonably utilized and is used for neutralizing the low-pH wastewater after pickling.
4. The pickling device has the advantages of low operation cost (compared with the method of directly purchasing hydrochloric acid), reliable, safe and easy maintenance of equipment, and automatic operation can be realized by subsequently configuring an automatic control program.
Drawings
FIG. 1 is a process flow diagram of a chemical-addition-free acid washing device of a desulfurization wastewater concentration electrodialysis system;
FIG. 2 is a schematic diagram of a bipolar membrane electrodialysis reactor for producing acid;
fig. 3 is a schematic view of an electrodialysis reactor for concentrating desulfurization waste water in the prior art.
Detailed Description
The present invention will be further described with reference to the following examples. The following examples are set forth merely to aid in the understanding of the invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
The concentrated electrodialysis system of desulfurization waste water exempts from to add medicine acid dip pickle, acid dip pickle main body equipment are one set of bipolar membrane electrodialysis system, and this system comprises bipolar membrane electrodialysis reactor, acid chamber, acid circulating pump, alkali chamber, alkali circulating pump, utmost point room, utmost point circulating pump, salt solution circulating pump and supporting table meter valve pipeline. A concentrated water tank of an electrodialysis system for treating desulfurization wastewater, a bypass valve, a brine circulating pump and a brine channel of a bipolar membrane electrodialysis reactor form brine internal circulation; an acid chamber, an acid circulating pump and an acid channel of the bipolar membrane electrodialysis reactor form internal acid circulation; an alkali chamber, an alkali circulating pump and an alkali channel of the bipolar membrane electrodialysis reactor form alkali internal circulation; the polar chamber, the polar water circulating pump and the polar water channel of the bipolar membrane electrodialysis reactor form polar water internal circulation.
As shown in figure 1, the bipolar membrane electrodialysis system is a bypass system of an electrodialysis system originally used for concentration treatment of desulfurization wastewater, and is communicated with a main system through a bypass valve 1, a bypass valve 2, an acid adding valve and a neutralization valve. Electric valves are arranged among the devices, and the switches of all the electric valves are connected to a remote control system; all the devices are connected by PE pipes with strong corrosion resistance, and the outlets of the water pumps are provided with check valves; a turbidity meter, a pH meter, a conductivity meter and a thermometer are arranged at a high-salt concentrated water inlet of the bypass pickling system, the pH meter and the conductivity meter are respectively arranged in the acid chamber and the alkali chamber, liquid level meters are arranged in all water tanks, and signals of all the meters are accessed into a remote control system.
As shown in fig. 2, the bipolar membrane electrodialysis reactor consists of an anode plate, a membrane stack and a cathode plate. Wherein, the membrane stack part comprises a Bipolar Membrane (BM), a selective anion exchange membrane (A), a selective cation exchange membrane (C) and a supporting clapboard. The membrane stack arrangement order is: (BM-A-C)n-BMs, wherein n is a natural number of 1 to 500, the n acid solution passages, the n salt solution passages, the n alkali solution passages, and the outermost 2 polar water passages are formed at intervals. The outermost layers of the two sides of the membrane stack are bipolar membranes, the anode of the electrode and one side of the membrane stack close to the selective anion exchange membrane are adjacently arranged, and the cathode of the electrode and one side of the membrane stack close to the selective cation exchange membrane are adjacently arranged. The cathode membrane of the bipolar membrane faces the cathode side, and the anode membrane of the bipolar membrane faces the anode side. And supporting clapboards are arranged on two sides of each layer of film, so that the effects of supporting protection and shunting are mainly achieved. The upper end and the lower end of the clapboard are respectively provided with a water flow hole and a communicating holeThe water flow direction can be fixed.
In the normal operation process of the main electrodialysis system, the bypass valve 1, the bypass valve 2, the acid adding valve and the neutralizing valve are in a long-closed state, and the bipolar membrane electrodialysis system is also in a standby state.
The working process of the chemical-adding-free acid washing device of the desulfurization wastewater concentration electrodialysis system is divided into two steps of acid preparation and acid washing.
When the concentration of the hydrochloric acid solution in the acid chamber is insufficient (for example, the mass fraction of hydrochloric acid is less than 5g/L) or the volume of the hydrochloric acid solution in the acid chamber is insufficient (for example, less than 10% of the total volume of the acid chamber), and the main electrodialysis system is normally and continuously operated, the acid-making program can be started by the acid-washing system, and the steps are as follows:
s1, applying 0.5mol/L sodium sulfate solution to polar water of the bipolar membrane electrodialysis system, and ensuring that the volume of the solution is not less than 60% of the volume of the polar chamber. If the volume of the polar water in the polar chamber is insufficient, the polar water needs to be prepared for supplement.
S2, adding demineralized water to the acid chamber and the alkali chamber to a predetermined volume (for example, 80% of the volume of the acid chamber and the alkali chamber) as initial water for circulating the acid solution and the alkali solution.
And S3, opening the bypass valve 1 and the bypass valve 2, and communicating the main system concentrated water tank with the bypass pickling system.
And S4, simultaneously starting the acid circulating pump, the alkali circulating pump, the polar water circulating pump and the brine circulating pump, and controlling the pressure and the flow of the four pumps to the same level (for example, 0.06MPa and 4 t/h).
S5, after the circulation is stable, starting the bipolar membrane electrodialysis reactor, adjusting the electrode voltage and the membrane stack current to proper values, and monitoring the H of the acid solution in the acid chamber+Concentration and OH of alkaline solution in alkaline chamber-And (4) concentration.
And S6, the hydrochloric acid concentration in the acid solution in the acid waiting chamber is higher than a set value (for example, 25g/L), and the bipolar membrane electrodialysis reactor is closed (the electrode voltage and the membrane stack current are both zero). And simultaneously turning off the acid circulating pump, the alkali circulating pump, the polar water circulating pump and the brine circulating pump.
S7, closing the bypass valve 1 and the bypass valve 2.
As the concentrated water tank of the main electrodialysis system is mainly high-concentration sodium chloride wastewater, the prepared acid is mainly hydrochloric acid, and the prepared alkali is mainly sodium hydroxide. The prepared acid solution (i.e., pickling agent) is temporarily stored in the acid chamber, and the prepared alkali solution (by-product) is temporarily stored in the alkali chamber.
When the main electrodialysis system needs acid washing, the acid washing system starts an acid washing program, and the steps are as follows:
s1, a volume of demineralized water (e.g., 50% wash tank level) is first added to the wash tank.
S2, opening the acid adding valve, switching the valve, pumping the solution in the acid chamber into the cleaning water tank of the main system as concentrated acid by using the acid circulating pump, and adjusting the concentration of hydrochloric acid in the cleaning water tank to 0.1-0.5%.
S3, carrying out circulating acid washing on the electrodialysis reactor in the main equipment by using an acid washing pump (the acid washing pump is positioned between the cleaning water tank and the homogeneous membrane electrodialysis reactor, belongs to the original system and is not shown in the figure), wherein the acid washing duration can be flexibly adjusted according to the actual situation (for example, 30 minutes). The hydrochloric acid solution with higher concentration can completely react with the calcium and magnesium scales on the surfaces of the main equipment electrode and the homogeneous membrane.
And S4, after the acid washing is finished, the pH value of the acid washing liquid in the washing water tank is still at a lower level. And opening a neutralization valve, pumping the byproduct alkali liquor in the acid preparation step into a cleaning water tank by using an alkali circulating pump for neutralization, adjusting the pH value of the cleaning water tank to 6-9, and discharging to the outside so as to reduce the pollution of the acidic wastewater to the environment.
Example (b):
a power plant adopts a homogeneous membrane electrodialysis system as a key step in a desulfurization wastewater concentration and reduction treatment process, and the fresh water quality is as follows: the pH value is 8.34, the conductivity is 8.38mS/cm, the chloride ion concentration is 2168mg/L, the sulfate ion concentration is 1232mg/L, the sodium ion concentration is 2048mg/L, the calcium ion concentration is 5mg/L, the magnesium ion concentration is 3mg/L, and the concentrated water quality is as follows: the pH value is 7.72, the conductivity is 64.2mS/cm, the chloride ion concentration is 30449mg/L, the sulfate ion concentration is 60mg/L, the sodium ion concentration is 21293mg/L, the calcium ion concentration is 54mg/L and the magnesium ion concentration is 22 mg/L.
The frequency of the acid washing of the homogeneous membrane electrodialysis system is 2 times/month, and the system acid washing is carried out by adding hydrochloric acid from an acid storage tank to an acid washing water tank. And discharging the acid wastewater after cleaning to an industrial wastewater treatment system of the plant, adding liquid alkali to adjust the pH to be neutral, and then sending the acid wastewater to a tail end treatment system for advanced treatment.
A bypass chemical-free pickling device is arranged at present, and is shown in figure 1. Treating concentrated water of an original system by using a bipolar membrane electrodialysis system to prepare acid and alkali, pickling the original system by using the prepared acid, and neutralizing pickling wastewater by using the prepared alkali.
The chemical-free acid washing system has obvious effect after 2 months of operation, and can realize chemical-free acid preparation and acid washing. The acid preparation system can prepare acid with the purity of 87 percent, store the acid in the acid chamber and can be used for acid washing of the original homogeneous membrane electrodialysis system; the alkali making system can make the alkali with the purity of 84 percent and can be used for neutralizing the pickling wastewater.
When the original system is seriously scaled, the acid making and adding amount can be increased, and the concentration of the hydrochloric acid solution in the cleaning water tank is improved, so that the thorough scale removal of the original electrodialysis system is ensured, and the safe and stable operation of the desulfurization wastewater concentration and reduction system is ensured.
After the chemical-adding-free acid washing system is put into operation, the original system operates normally, and the concentration efficiency of the desulfurization wastewater is basically kept unchanged. The application result shows that the system has better environmental benefit, economic benefit and social benefit and has potential to be popularized and applied in various coal-fired power plants.
Claims (10)
1. The utility model provides a concentrated electrodialysis system of desulfurization waste water exempts from to add medicine acid dip pickle which characterized in that: comprises a bipolar membrane electrodialysis system and a main electrodialysis system; the bipolar membrane electrodialysis system mainly comprises a bipolar membrane electrodialysis reactor, an acid chamber, an acid circulating pump, an alkali chamber, an alkali circulating pump, a polar chamber, a polar circulating pump, a brine circulating pump and a meter valve pipeline matched with the brine circulating pump; the bipolar membrane electrodialysis reactor consists of an anode, a membrane stack and a cathode, wherein the membrane stack comprises a bipolar membrane BM, a selective anion exchange membrane A, a selective cation exchange membrane C and a supporting clapboard; the membrane stack arrangement order is: (BM-A-C)n-BM, where n is a natural number from 1 to 500, forming n acid solution channels, n salt solution channels, n alkali solution channels and the outermost 2 polar watersThe acid solution channel, the salt solution channel and the alkali solution channel are distributed at intervals; the outermost layers on the two sides of the membrane stack are bipolar membranes; a concentrated water tank of the main electrodialysis system, a bypass valve, a brine circulating pump and a brine channel of the bipolar membrane electrodialysis reactor form brine internal circulation; an acid chamber, an acid circulating pump and an acid channel of the bipolar membrane electrodialysis reactor form internal acid circulation; an alkali chamber, an alkali circulating pump and an alkali channel of the bipolar membrane electrodialysis reactor form alkali internal circulation; the polar chamber, the polar water circulating pump and the polar water channel of the bipolar membrane electrodialysis reactor form polar water internal circulation; the bipolar membrane electrodialysis system is communicated with a concentrated water tank of the main electrodialysis system through a bypass valve 1 and a bypass valve 2, an acid chamber is communicated to a cleaning water tank of the main electrodialysis system through an acid circulating pump and an acid adding valve in sequence, and an alkali chamber is communicated to a cleaning water tank of the main electrodialysis system through an alkali circulating pump and a neutralization valve in sequence.
2. The chemical-free pickling device of the desulfurization wastewater concentration electrodialysis system according to claim 1, characterized in that: an outlet of the concentrated water tank is communicated to an inlet of a saline passage of the bipolar membrane electrodialysis reactor through a bypass valve 1 and a saline circulating pump in sequence, and an outlet of the saline passage of the bipolar membrane electrodialysis reactor is communicated to an inlet of the concentrated water tank through a bypass valve 2.
3. The chemical-free pickling device of the desulfurization wastewater concentration electrodialysis system according to claim 1, characterized in that: the anode and the membrane stack are adjacently arranged on one side close to the selective anion exchange membrane, and the cathode and the membrane stack are adjacently arranged on one side close to the selective cation exchange membrane.
4. The chemical-free pickling device of the desulfurization wastewater concentration electrodialysis system according to claim 1, characterized in that: the cathode membrane of the bipolar membrane faces the cathode side, and the anode membrane of the bipolar membrane faces the anode side.
5. The chemical-free pickling device of the desulfurization wastewater concentration electrodialysis system according to claim 1, characterized in that: supporting partition boards are arranged on two sides of each layer of membrane, and water flow holes and communication holes are respectively formed in the upper end and the lower end of each partition board.
6. The chemical-free pickling device of the desulfurization wastewater concentration electrodialysis system according to claim 1, characterized in that: and the switches of all the electric valves are connected into a remote control system.
7. The chemical-free pickling device of the desulfurization wastewater concentration electrodialysis system according to claim 1, characterized in that: all the devices are connected through PE pipes, and the outlets of the water pumps are provided with check valves.
8. The chemical-free pickling device of the desulfurization wastewater concentration electrodialysis system according to claim 1, characterized in that: a turbidity meter, a pH meter, a conductivity meter and a thermometer are arranged at a high-salt concentrated water inlet of the bipolar membrane electrodialysis system, the pH meter and the conductivity meter are arranged in an acid chamber and an alkali chamber, liquid level meters are arranged in all water tanks, and signals of all the meters are accessed into a remote control system.
9. The acid preparation method of the chemical-free acid washing device of the desulfurization wastewater concentration electrodialysis system according to claim 1, characterized in that: when the concentration of the hydrochloric acid solution in the acid chamber is insufficient or the volume of the hydrochloric acid solution in the acid chamber is insufficient and the main electrodialysis system normally and continuously operates, the bipolar membrane electrodialysis system starts an acid making program and comprises the following steps:
s1, applying the sodium sulfate solution to polar water of the bipolar membrane electrodialysis system to enable the volume of the solution to be not less than 60% of the volume of the polar chamber;
s2, taking the desalted water as initial water for acid solution circulation and alkali solution circulation, and respectively supplementing the desalted water into the acid chamber and the alkali chamber to a specified volume;
s3, opening a bypass valve 1 and a bypass valve 2, and communicating a concentrated water tank of the main electrodialysis system with the bipolar membrane electrodialysis system;
s4, simultaneously starting an acid circulating pump, an alkali circulating pump, an extreme water circulating pump and a brine circulating pump, and controlling the pressure and the flow of the four pumps to be at the same level;
s5, after the circulation is stable, the start is doubleAdjusting electrode voltage and membrane stack current to proper values, and monitoring H of acid solution in acid chamber+Concentration and OH of alkaline solution in alkaline chamber-Concentration;
s6, when the concentration of hydrochloric acid in the acid solution in the acid chamber is higher than a set value, closing the bipolar membrane electrodialysis reactor; simultaneously turning off the acid circulating pump, the alkali circulating pump, the polar water circulating pump and the brine circulating pump;
s7, closing the bypass valve 1 and the bypass valve 2;
s8, temporarily storing the prepared acid solution in an acid chamber, and temporarily storing the prepared alkali solution in an alkali chamber.
10. The acid cleaning method of the chemical-free acid cleaning device of the desulfurization wastewater concentration electrodialysis system as claimed in claim 1, characterized in that: when the main electrodialysis system needs acid washing, the bipolar membrane electrodialysis system starts an acid washing program and comprises the following steps:
s1, firstly, adding a certain volume of demineralized water into the cleaning water tank;
s2, opening an acid adding valve, switching the valve, pumping acid solution in an acid chamber into a cleaning water tank of the main electrodialysis system by using an acid circulating pump as concentrated acid, and adjusting the concentration of the hydrochloric acid in the cleaning water tank to be 0.1-0.5%;
s3, carrying out circulating acid washing on the homogeneous membrane electrodialysis reactor by using an acid washing pump;
s4, after the acid washing is finished, the pH value of the acid washing liquid in the washing water tank is still at a lower level; at the moment, a neutralization valve is opened, an alkali solution in an alkali chamber is pumped into a cleaning water tank by an alkali circulating pump for neutralization, and the pH value of the cleaning water tank is adjusted to 6-9 and then discharged to the outside.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7001882B1 (en) * | 2021-07-22 | 2022-01-20 | 生態環境部華南環境科学研究所 | Copper pyrophosphate plating Electrodialysis device for highly efficient desalination of wastewater |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06262172A (en) * | 1993-03-12 | 1994-09-20 | Asahi Glass Co Ltd | Fresh water process |
| CN106241972A (en) * | 2016-08-23 | 2016-12-21 | 盛发环保科技（厦门）有限公司 | Based on electrodialytic zero emission treatment of desulfured waste water and system |
| CN110065958A (en) * | 2019-03-27 | 2019-07-30 | 浙江工业大学 | A kind of method that integrated selection electrodialysis and selective bipolar membrane electrodialysis treatment salt lake bittern prepare lithium hydroxide |
| CN110102188A (en) * | 2018-04-27 | 2019-08-09 | 轻工业环境保护研究所 | Concentrated water electrocatalytic oxidation permeates cleaning reverse osmosis/nanofiltration membrane method and device online |
| CN111517533A (en) * | 2020-04-15 | 2020-08-11 | 国电安徽电力有限公司 | Thermal power plant desulfurization wastewater resource utilization system and method with low reagent consumption |
| CN212356665U (en) * | 2020-08-28 | 2021-01-15 | 浙江浙能技术研究院有限公司 | Chemical-adding-free acid washing device of desulfurization wastewater concentration electrodialysis system |
-
2020
- 2020-08-28 CN CN202010884906.XA patent/CN111960515A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06262172A (en) * | 1993-03-12 | 1994-09-20 | Asahi Glass Co Ltd | Fresh water process |
| CN106241972A (en) * | 2016-08-23 | 2016-12-21 | 盛发环保科技（厦门）有限公司 | Based on electrodialytic zero emission treatment of desulfured waste water and system |
| CN110102188A (en) * | 2018-04-27 | 2019-08-09 | 轻工业环境保护研究所 | Concentrated water electrocatalytic oxidation permeates cleaning reverse osmosis/nanofiltration membrane method and device online |
| CN110065958A (en) * | 2019-03-27 | 2019-07-30 | 浙江工业大学 | A kind of method that integrated selection electrodialysis and selective bipolar membrane electrodialysis treatment salt lake bittern prepare lithium hydroxide |
| CN111517533A (en) * | 2020-04-15 | 2020-08-11 | 国电安徽电力有限公司 | Thermal power plant desulfurization wastewater resource utilization system and method with low reagent consumption |
| CN212356665U (en) * | 2020-08-28 | 2021-01-15 | 浙江浙能技术研究院有限公司 | Chemical-adding-free acid washing device of desulfurization wastewater concentration electrodialysis system |
Non-Patent Citations (1)
| Title |
|---|
| 陈观文等: "《膜技术新进展与工程应用》", 中国科学技术大学出版社, pages: 315 - 316 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7001882B1 (en) * | 2021-07-22 | 2022-01-20 | 生態環境部華南環境科学研究所 | Copper pyrophosphate plating Electrodialysis device for highly efficient desalination of wastewater |
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