A bromine-containing inorganic salt and organic acid (salt) wastewater treatment system and application method

Abstract

The present invention discloses a bromine-containing inorganic salt and organic acid (salt) wastewater treatment system and application method, belonging to the technical field of wastewater treatment. It includes a gas phase bromine-containing wastewater treatment system, a liquid phase bromine-containing wastewater treatment system, and other wastewater treatment systems. The gas phase bromine-containing wastewater treatment system includes a pretreatment unit, a concentration and desalination unit, a macromolecular organic separation unit, a carbon removal unit, and a bromine purification unit. The liquid phase bromine-containing wastewater treatment system includes a pretreatment unit, a macromolecular organic separation unit I, a concentration and desalination unit, a macromolecular organic separation unit II, a carbon removal unit, and a bromine purification unit. The other wastewater treatment systems include a biochemical unit, a pretreatment unit, a salt extraction unit, a concentration and desalination unit, and a wastewater treatment unit. The system of the present invention can not only extract resources from wastewater, but also reuse the wastewater after treatment.

Description

Technical Field

[0001] The present invention relates to a sewage treatment system and a treatment method, and in particular to a bromine-containing inorganic salt and organic acid (salt) wastewater treatment system and an application method. Background Art

[0002] Organic acids refer to some acidic organic compounds. The most common organic acid is carboxylic acid, whose acidity comes from the carboxyl group (-COOH). Sulfonic acid (-SO3H), sulfinic acid (RSOOH), thiocarboxylic acid (RCOSH) and the like are also organic acids. The organic acids contained in daily chemical wastewater are generally small molecular organic acids such as formic acid and acetic acid, long carbon chain fatty acids, citric acid, oxalic acid, aromatic carboxylic acids and dibasic acids.

[0003] Generally, organic acid wastewater does not contain only organic acids, but also other inorganic salts. Through relevant water treatment technologies, organic acids and inorganic salts in water can be separated, and high-value inorganic salts in water can be extracted. Small molecule organic acids such as formic acid and acetic acid have low boiling points of 100.6°C and 117.9°C respectively, and can be separated from the solution by heating methods such as evaporation and distillation. Large molecular organic acids such as terephthalic acid (TA), para-toluic acid (PT acid) and benzoic acid (BA) have very low solubility in aqueous solution and can be separated from the solution by adjusting the pH value of the wastewater. The residual large molecular organic matter and organic acids in the water can also be separated by material separation devices.

[0004] The wastewater produced in the PTA industry is mainly divided into gas-phase alkaline absorption wastewater, liquid-phase high-concentration organic acid wastewater, and wastewater generated by product and equipment flushing, which are referred to as other wastewater. The production of PTA generally uses paraxylene as raw material, cobalt and manganese as catalysts, and air oxidation in acetic acid medium to produce crude terephthalic acid (CTA), which is then hydrogenated and refined to remove impurities, and then crystallized, separated, and dried to obtain refined terephthalic acid products, namely PTA finished products. Inorganic bromides are used in the PTA production process, so the gas-phase wastewater and liquid-phase wastewater in the PTA production process will contain higher concentrations of bromide ions. The refined water used to flush products and the intermittent wastewater used to flush equipment contain less bromine.

[0005] Gas phase wastewater mainly consists of sodium formate, sodium acetate, sodium bromide, sodium carbonate, sodium bicarbonate and contains a small amount of oxidants and aromatic organic matter. Liquid phase wastewater mainly consists of sodium acetate, aromatic organic matter, sodium bromide and sodium bicarbonate. Other wastewater mainly contains macromolecular organic matter such as aromatic salts and small molecular organic matter such as sodium formate and sodium acetate, as well as concentrated water produced by tap water to make pure water, including inorganic salts such as chloride ions, calcium and magnesium ions.

[0006] At present, the main processes for treating this type of organic acid wastewater are physical and chemical methods, biochemical treatment methods, and membrane separation methods. The purpose of the biochemical treatment method is to discharge wastewater in compliance with standards, rather than to recycle valuable substances in the wastewater, resulting in a waste of resources. The most appropriate way to treat PTA wastewater is to use physical and chemical methods to recover organic acids, cobalt and manganese in the wastewater and then perform biochemical treatment. The membrane separation method can reuse wastewater resources, but the membrane has strict requirements on the influent, so the wastewater needs to be pretreated to achieve the water quality that meets the membrane.

[0007] How to reasonably design a perfect process that can both extract resources from wastewater and reuse the wastewater after treatment is currently an important research direction. Summary of the invention

[0008] The technical problems existing in the prior art have not been solved. The present invention provides a bromine-containing inorganic salt and organic acid (salt) wastewater treatment system and an application method. The system can be divided into three types of wastewater treatment systems: a gas phase bromine-containing wastewater treatment system, a liquid phase bromine-containing wastewater treatment system, and other wastewater treatment systems.

[0009] A bromine-containing inorganic salt and organic acid (salt) wastewater treatment system, including a gas phase bromine-containing wastewater treatment system, a liquid phase bromine-containing wastewater treatment system, and other wastewater treatment systems;

[0010] The gas phase bromine-containing wastewater treatment system comprises gas phase bromine-containing wastewater, a divalent and higher-valent metal ion removal device, an oxidant removal device, a concentration and desalination device I, a crystallization centrifugal device I, a material separation device I, a carbon removal unit, an evaporation device and a collection device connected in sequence;

[0011] The liquid phase bromine-containing wastewater treatment system comprises liquid phase bromine-containing wastewater, a filtering device I, a material separation device II, and a concentration and desalination device II which are connected in sequence, wherein the concentrated water end of the concentration and desalination device II is connected to the water inlet of the crystallization centrifugal device I;

[0012] The other wastewater treatment system includes other wastewater, an anaerobic device, an aerobic device, a filtering device II, and a concentrating and desalination device III which are connected in sequence. The water production end of the concentrating and desalination device III is connected to the concentrating and desalination device IV, the concentrated water end of the concentrating and desalination device III is connected to the crystallization centrifugal device II, and the concentrated water end of the concentrating and desalination device IV is connected to the water inlet of the concentrating and desalination device III; the water production end of the crystallization centrifugal device II is connected in sequence to the material separation device III, the nitrate removal device, the ammonia nitrogen removal device, the phosphorus removal device, the heavy metal removal device, and the external discharge unit.

[0013] Furthermore, the concentrating and desalination device I and the concentrating and desalination device II are both: the water production end produces water for reuse, and the concentrated water end is connected to the water inlet of the crystallization centrifuge device I; the water production end of the concentrating and desalination device IV produces water for reuse, and the concentrated water end is connected to the water inlet of the concentrating and desalination device III; the water production port of the concentrating and desalination device III is also connected to the feed port of the material separation device III; the concentrated water ends of the material separation device I, the material separation device II and the material separation device III are all connected to the anaerobic device, and the water production end of the material separation device I is connected to the carbon removal unit The water production end of the material separation device II is connected to the water inlet of the concentration and desalination device II, and the water production end of the material separation device III is connected to the nitrate removal device; the wastewater generated by the carbon removal unit is connected to the anaerobic device through a pipeline, and the water production end is connected to the evaporation device; the condensed water of the evaporation device is connected to the anaerobic device through a pipeline, and the evaporated sodium bromide is collected in the collection device; a filtering device is provided between the gas phase bromine-containing wastewater and the divalent and higher metal ion removal device; an advanced oxidation device is also provided at the water inlet of the anaerobic device.

[0014] Furthermore, the collecting device is connected to a hydrobromic acid preparation device, and the hydrobromic acid preparation device includes a bipolar membrane or an acidification device.

[0015] Furthermore, the carbon removal unit includes: an acidification device + an adsorption device, an acidification device + an evaporation device, an acidification device + an adsorption device + an evaporation device, an acidification device + a distillation device, an acidification device + a divalent metal ion carrying and separation device, an acidification device + a special separation membrane device, an acidification device + an extraction device, an acidification device + a stripping device + an evaporation device.

[0016] Furthermore, an oxidant removal device is provided at the water inlet or outlet of the acidification device.

[0017] Furthermore, a bromide ion enrichment device can be provided before the concentration and desalination device I and the concentration and desalination device II, and the bromide ion enrichment device uses an alkaline anion exchange resin; the specific implementation method is: the bromide ions in the water are selectively adsorbed by the bromide ion enrichment device, and the adsorbed water can directly enter other wastewater treatment systems, or enter the concentration and desalination device for concentration and then extracting sesquialkali.

[0018] After the bromide ion enrichment device is saturated with adsorption, the desorbent can be used for regeneration. The desorption liquid produced by the regeneration is a high-concentration bromine-containing inorganic wastewater. This wastewater can be treated by an acidification device and an evaporation device to obtain a high-concentration sodium bromide solution (solid) or hydrobromic acid;

[0019] Preferably, after acidification, the acidification device uses chlorine replacement and sulfuric acid distillation to extract bromine or hydrobromic acid; the desorption liquid includes but is not limited to alkaline compounds such as sodium hydroxide and a device for producing alkaline substances.

[0020] The chlorine replacement method is as follows: firstly, acid is added to adjust the wastewater to acidity, and then chlorine is introduced to distill to obtain bromine. The effluent (gas) is absorbed by sulfur dioxide and distilled again to obtain a high-purity hydrobromic acid solution. The sulfuric acid produced by the absorption liquid can be used for the acidification of the previous wastewater.

[0021] The sulfuric acid distillation method is as follows: first, sulfuric acid is added to acidify water, and then distillation is performed to obtain bromine. The effluent (gas) is absorbed by sulfur dioxide and distilled again to obtain a high-purity hydrobromic acid solution. The sulfuric acid produced by the absorption liquid can be used for the acidification of the wastewater.

[0022] Furthermore, the condensed water of the evaporation device is connected to the anaerobic device through a pipeline, the evaporated mother liquor is connected to one end of the neutralization device through a pipeline, the other end of the neutralization device is connected to the material separation device IV, the water outlet of the material separation device IV is connected to the sodium bromide solution collecting device, and the concentrated water outlet of the material separation device IV is connected to the anaerobic device.

[0023] Furthermore, the carbon removal unit includes an acidification device and an adsorption device connected in sequence, and the concentration and desalination device I is arranged between the acidification device and the adsorption device, and the crystallization centrifuge device I is removed; the water production end of the concentration and desalination device I is reused, and the concentrated water end of the concentration and desalination device I is connected to the adsorption device; the concentrated water end of the concentration and desalination device II is connected to one end of the acidification device II, and the other end of the acidification device II is connected to the adsorption device.

[0024] Furthermore, an oxidant removal device is provided at the water inlet or outlet of the acidification device; preferably, a bromide ion enrichment device can be provided before the acidification device and the concentration and desalination device II, and the bromide ion enrichment device uses an alkaline anion exchange resin; its specific implementation method is: the bromide ions in the water are selectively adsorbed by the bromide ion enrichment device, and the adsorbed water can directly enter other wastewater treatment systems, or enter the concentration and desalination device for concentration and then extraction of sesquialkali.

[0025] After the bromide ion enrichment device is saturated with adsorption, a desorbent can be used for regeneration. The desorption liquid produced by the regeneration is a high-concentration bromine-containing inorganic wastewater. This wastewater can be treated by an acidification device and an evaporation device to obtain a high-concentration sodium bromide solution (solid) or hydrobromic acid; preferably, after acidification by the acidification device, chlorine gas replacement and sulfuric acid distillation are used to extract bromine or hydrobromic acid; the desorption liquid includes but is not limited to alkaline compounds such as sodium hydroxide and a device for producing alkaline substances.

[0026] The chlorine replacement method is as follows: firstly, acid is added to adjust the wastewater to acidity, and then chlorine is introduced to distill to obtain bromine. The effluent (gas) is absorbed by sulfur dioxide and distilled again to obtain a high-purity hydrobromic acid solution. The sulfuric acid produced by the absorption liquid can be used for the acidification of the previous wastewater.

[0027] The sulfuric acid distillation method is as follows: first, sulfuric acid is added to acidify water, and then distillation is performed to obtain bromine. The effluent (gas) is absorbed by sulfur dioxide and distilled again to obtain a high-purity hydrobromic acid solution. The sulfuric acid produced by the absorption liquid can be used for the acidification of the wastewater.

[0028] An application method of a bromine-containing inorganic salt and organic acid (salt) wastewater treatment system comprises the following steps:

[0029] 1) After filtering, the gaseous bromine-containing wastewater enters the divalent and divalent metal ion removal device to remove the divalent and divalent metal ions in the wastewater, and the produced water enters the deoxidant removal device to remove the oxidant in the wastewater; the produced water enters the concentration and desalination device I to transfer the inorganic salts and organic matter in the wastewater to the concentrated water, and the fresh water is reused; the concentrated water enters the crystallization centrifugal device I to separate the sodium carbonate and sodium bicarbonate mixture into sesquialkali, and the produced mother liquor is diluted and enters the material separation device I. The concentrated water of the material separation device I enters the anaerobic device or enters after being treated by the advanced oxidation device Anaerobic device, water produced by material separation device I enters the carbon removal unit, wastewater discharged from the carbon removal unit enters the anaerobic device, water produced by the carbon removal unit enters the evaporation device to evaporate and remove small molecular organic acids that are not completely adsorbed, and obtain high-purity sodium bromide solid or liquid, and condensed water from the evaporation device enters the anaerobic device; sodium bromide solid or liquid enters the hydrobromic acid preparation device, and is treated with a bipolar membrane to obtain hydrobromic acid solution and sodium hydroxide solution, or an acidification device is used to transform sodium ions into hydrogen ions to obtain hydrobromic acid solution; the hydrobromic acid solution is concentrated to obtain a high-concentration hydrobromic acid solution;

[0030] 2) Liquid-phase bromine-containing wastewater enters the filtration device I to remove suspended solids in the wastewater, and the produced water is diluted and enters the material separation device II to separate the macromolecular organic matter in the wastewater into concentrated water. The concentrated water enters the anaerobic device, or enters the anaerobic device after being treated by the advanced oxidation device. The produced water enters the concentration and desalination device II to transfer the inorganic salts and organic matter in the wastewater to the concentrated water, and the fresh water is reused; the concentrated water enters the crystallization centrifuge device I of the gas-phase bromine-containing wastewater treatment system for further treatment;

[0031] 3) After other wastewater is treated by the anaerobic device and the aerobic device, the produced water enters the filtration device II to remove suspended solids in the wastewater, and the produced water enters the concentration and desalination device III to transfer sodium bicarbonate in the wastewater to the concentrated water. The produced water of the concentration and desalination device III is further treated by the concentration and desalination device IV, the produced water is reused, and the concentrated water is treated by the concentration and desalination device III again; the concentrated water of the concentration and desalination device III enters the crystallization centrifuge device II to extract sodium carbonate and sodium bicarbonate mixture-type sesquialkali, and the concentrated water enters the material separation device III after being diluted by the produced water of the concentration and desalination device III. The concentrated water of the material separation device III enters the anaerobic device, or enters the anaerobic device after being treated by the advanced oxidation device; the produced water of the material separation device III is successively treated by the nitrate removal device to remove nitrate, the ammonia nitrogen removal device to remove ammonia nitrogen, the phosphorus removal device to remove phosphorus, and the heavy metal removal device to remove heavy metals, and the wastewater is discharged when it meets the standards, or is further treated by evaporation to achieve zero discharge of the wastewater.

[0032] Furthermore, in the above technical scheme, when the wastewater of the gas phase bromine-containing wastewater treatment system contains a large amount of bromine, a small amount of carbonate and bicarbonate, or when the amount of water is small and there is no sesquialkali value to be recovered, after removing the oxidant in the wastewater in step 1), it first passes through the material separation device I, the concentrated water of the material separation device I enters the anaerobic device, the water produced by the material separation device I enters the acidification device, and after acidification, enters the concentration and desalination device I, the water produced by the concentration and desalination device I is reused, and the concentrated water of the concentration and desalination device I enters the adsorption device for adsorption;

[0033] Step 2) The concentrated water from the concentration and desalination device II is first acidified by the acidification device II and then directly enters the adsorption device for adsorption.

[0034] Furthermore, in the above technical solution, in step 1), the sodium bromide solid or liquid obtained by the evaporation device enters the neutralization device, is neutralized by adding alkali, and then enters the material separation device IV for separation, and the sodium bromide solid or liquid is separated, and the separated concentrated water enters the anaerobic device.

[0035] Furthermore, the material separation device I, material separation device II, and material separation device III all include devices or materials with material separation functions such as material separation membranes and nanofiltration membranes. Preferably, a nanofiltration membrane device is used, which can intercept various substances with a molecular weight greater than 200.

[0036] Furthermore, the divalent and higher-valent metal ion removal device can be an iron-manganese filter, ion exchange resin or other equipment that can remove divalent and higher-valent cations. It can be used alone or in combination to achieve the purpose of removing divalent and higher-valent cations in water.

[0037] Furthermore, the filter device I and the filter device II can both be microfiltration, sand filtration, precision filtration, bag filtration and other filtration devices that can intercept particulate matter in the water. There is no limit to the filtration form. They can be used alone or in combination. The purpose is to remove suspended matter in the water and protect the stable operation of the membrane system.

[0038] Furthermore, the purpose of the oxidant removal device is to remove oxidants from the water, which can be done by adding reducing agents such as sodium thiosulfate and sodium bisulfite, or by using resin adsorption to remove anionic oxidants.

[0039] Furthermore, the gas phase bromine-containing wastewater is connected to a divalent and higher-valent metal ion removal device to remove divalent and higher-valent metal ions in the water to protect the membrane element to work stably. The outlet water of the divalent and higher-valent metal ion removal device is connected to an oxidation removal device to remove strong oxidizing substances in the water and protect the membrane element to operate stably. The outlet water of the oxidation removal device is connected to a concentration and desalination device I. The concentration and desalination device I transfers most of the inorganic salts and organic matter in the water to the concentrated water of the concentration and desalination device I, and the fresh water is reused. The concentrated water outlet of the concentration and desalination device I is connected to a crystallization centrifugal device I, and a sodium carbonate and sodium bicarbonate mixture-type sesquialkali is obtained through the crystallization centrifugal device I. The mother liquor produced by the crystallization centrifugal device I is connected to the material separation device I. The connecting pipeline of the crystallization centrifugal device I and the material separation device I is provided with a tap water and a recycled water pipeline, and the concentrated water is diluted with tap water or recycled water to meet the conditions for entering the material separation device I. The concentrated water outlet of the material separation device I is connected to the anaerobic device in other wastewater treatment systems. The outlet water of the material separation device I is connected to the acidification device to remove carbonate and bicarbonate from the water, and convert small molecular organic matter such as sodium formate and sodium acetate in the water into small molecular organic acids such as formic acid and acetic acid. The acidification device is connected to the adsorption device to adsorb and remove small molecular organic acids such as formic acid and acetic acid from the water. After the adsorption device is saturated, it is desorbed with a desorbent, and the desorbed liquid is discharged to the anaerobic device. The outlet water of the adsorption device is connected to the evaporation device. Taking advantage of the low boiling point of small molecular organic acids, the small molecular organic acids that are not completely adsorbed by the adsorption device are evaporated and removed through the evaporation device, and high-purity sodium bromide solid or solution is obtained. The distilled water of the evaporation device is discharged to the anaerobic device or used as a carbon source.

[0040] Furthermore, the liquid phase bromine-containing wastewater is connected to the filter device I to remove suspended matter in the water, and the effluent of the filter device I is connected to the material separation device to separate the macromolecular organic matter in the water into concentrated water. The connecting pipeline of the filter device I and the material separation device II is provided with a tap water and a recycled water pipeline, which is diluted by adding tap water or recycled water to meet the conditions of entering the material separation device I. The concentrated water of the material separation device II is connected to the anaerobic device. The effluent of the material separation device II is connected to the concentration and desalination device II to concentrate and reduce the water, and the water produced by the concentration and desalination device II is used as recycled water or dilution water. The concentrated water of the concentration and desalination device II is connected to the water inlet of the crystallization centrifuge device I.

[0041] Furthermore, the other wastewater is connected to the anaerobic device and the aerobic device in sequence, and part or all of the water produced by the aerobic device is connected to the filtering device II. If there is any residual water produced by the aerobic device, it can be directly discharged in compliance with the standards or treated by evaporation to achieve zero discharge. The filtration device II removes the suspended matter in the water and the effluent is connected to the concentration and desalination device III, which transfers the salt mainly composed of sodium bicarbonate in the water to the concentrated water. The concentrated water of the concentration and desalination device III is connected to the crystallization centrifuge device II to extract the sodium bicarbonate in the water, and the remaining mother liquor is connected to the material separation device III to intercept the macromolecular organic matter in the water. Part of the water produced by the concentration and desalination device III is connected to the material separation device III as dilution water, and the rest of the water produced by the concentration and desalination device III is connected to the concentration and desalination device IV. The water produced by the concentration and desalination device IV is reused, and the concentrated water is connected to the water inlet of the concentration and desalination device III. The concentrated water of the material separation device III is connected to the water inlet of the anaerobic device, or is connected to the anaerobic device after advanced oxidation treatment. The effluent from the material separation device III is connected to the nitrate removal device, ammonia nitrogen removal device, phosphorus removal device, and heavy metal removal device in sequence to remove nitrate, ammonia nitrogen, total phosphorus, and residual cobalt, manganese and other metal ions in the water. Finally, the produced water meets the discharge standards or is treated by evaporation to achieve zero discharge.

[0042] Furthermore, if the total phosphorus or heavy metal content in the water is low and can meet the discharge conditions after being treated by the material separation device III, the phosphorus removal device or heavy metal removal device may not be required.

[0043] Furthermore, the concentration and desalination device includes all single devices or multiple devices used in combination with the concentration and desalination functions, such as pressure-driven membrane represented by reverse osmosis, electric-driven membrane represented by electrodialysis, and evaporation devices.

[0044] The main function of the concentration and desalination device I is to concentrate the inorganic salts in the water. The salt content of the inlet water is relatively high. The preferred method is electrodialysis + reverse osmosis, or direct electrodialysis.

[0045] The main function of the concentration and desalination device II is to concentrate the inorganic salts in the water and reuse the produced water. Reverse osmosis is preferably used, and a combination of electrodialysis and reverse osmosis can also be used.

[0046] The main function of the concentration and desalination device III is to concentrate the sodium bicarbonate in the water and then separate the sodium bicarbonate through a crystallization centrifugal device, preferably using electrodialysis.

[0047] The main function of the concentration and desalination device IV is to recycle the produced water, and reverse osmosis is preferably used.

[0048] Furthermore, in the wastewater treatment system containing bromine-containing inorganic salts and organic acids (salts), when the alkalinity content of the gas phase bromine is low, the sodium bromide content is high or the amount of water is small and there is no sesquialkali value to be recovered, sulfuric acid can be directly added to remove the alkalinity without using a crystallization centrifugal process. The specific implementation process is that the gas phase bromine-containing wastewater is connected to a divalent and above divalent metal ion removal device, and the divalent and above divalent metal ion removal device is connected to an oxidation removal device to remove strong oxidizing substances in the water and protect the membrane element for stable operation. The effluent of the oxidation removal device is connected to the material separation device I, and the macromolecular organic matter in the water is intercepted by the material separation device I, and the concentrated water is discharged to the anaerobic device. The effluent of the material separation device I is connected to the acidification device, and the sodium carbonate and sodium bicarbonate in the water are removed by the acidification device, and small molecular organic matter such as sodium formate and sodium acetate in the water are converted into small molecular organic acids such as formic acid and acetic acid. The effluent from the acidification device is connected to the concentration and desalination device I. The fresh water from the concentration and desalination device I is reused. The concentrated water from the concentration and desalination device I is connected to the adsorption device. The organic acid in the water is adsorbed and removed by the adsorption device. After the adsorption device is saturated, it is desorbed by a desorbent, and the desorbed liquid is discharged to the anaerobic device. The effluent from the desorption device is connected to the evaporation device. Taking advantage of the low boiling point of small molecule organic acids, the small molecule organic acids that are not completely adsorbed by the adsorption device are evaporated and removed by the evaporation device, and high-purity sodium bromide solid or solution is obtained. The distilled water from the evaporation device is discharged to the anaerobic device or used as a carbon source.

[0049] Furthermore, the carbon removal methods adopted by the carbon removal unit include "acidification + adsorption method", "acidification + evaporation method", "acidification + adsorption method + evaporation method", "acidification + distillation method", "acidification + divalent metal ion carrying and separation method", "acidification + special separation membrane method", "acidification + extraction method", and "acidification + stripping + evaporation method".

[0050] The acidification device can be a hydrogen-type ion exchange resin, which transforms cations in water into hydrogen ions through the resin.

[0051] The acidification device can also acidify the wastewater by adding hydrobromic acid.

[0052] The acidification device can also be acidified with other acids. If this method is used, it is necessary to separate the acid anion group from the water after the evaporation device according to its characteristics to ensure the purity of sodium bromide. For example, when sulfuric acid is used as an acidulant, a neutralization device needs to be added to the water outlet of the evaporation device, and the water is adjusted to neutrality by adding alkali, and then the sulfate radical in the water is separated by material separation, and the sulfate radical is separated and concentrated and discharged to the aerobic device, and the water produced is a high-purity sodium bromide solution, which can continue to evaporate to produce solid sodium bromide.

[0053] The "acidification + adsorption method" is to remove carbonate and bicarbonate in water through an acidification device, and then convert small molecular organic substances such as sodium formate and sodium acetate in water into small molecular organic acids such as formic acid and acetic acid, and then remove small molecular organic acids such as formic acid and acetic acid through an adsorption device to obtain a high-purity sodium bromide solution.

[0054] The adsorption device can be activated carbon, ion exchange resin, molecular sieve or the like, which has the function of adsorbing small molecular organic acids such as formic acid and acetic acid, and can be used alone or in combination with multiple devices.

[0055] The "acidification + evaporation method" is to remove carbonate and bicarbonate in water through an acidification device, and then convert small molecular organic substances such as sodium formate and sodium acetate in water into small molecular organic acids such as formic acid and acetic acid, and then use an evaporation device to evaporate and remove small molecular organic acids such as formic acid and acetic acid by utilizing the low boiling point of small molecular organic acids such as formic acid and acetic acid to obtain a high-purity sodium bromide solution.

[0056] The "acidification + adsorption method + evaporation method" combines the "acidification + adsorption method" and the "acidification + evaporation method" to ensure that small molecular organic acids such as formic acid and acetic acid in water are completely removed.

[0057] The "acidification + distillation method" is similar to the "acidification + evaporation method" except that the degree of acidification needs to be controlled more thoroughly. Sodium bromide needs to be converted into hydrobromic acid, and small molecular organic acids such as formic acid and acetic acid and hydrobromic acid are distilled out through distillation. Finally, a hydrobromic acid solution is obtained.

[0058] The "acidification + divalent metal ion carrying separation method" is to remove carbonate and bicarbonate in water through a peracidification device, and then convert small molecular organic substances such as sodium formate and sodium acetate in water into small molecular organic acids such as formic acid and acetic acid, and then add divalent or higher metal cations to form divalent organic acid salts, which are then separated through material separation to obtain a high-purity sodium bromide solution.

[0059] The "acidification + special separation membrane method" is to use a superacidification device to remove carbonate and bicarbonate in the water, and then convert small molecular organic matter such as sodium formate and sodium acetate in the water into small molecular organic acids such as formic acid and acetic acid, and then use membrane equipment of special materials, such as electric-driven membrane and pressure-driven membrane to separate the small molecular organic acids in the water to obtain a high-purity sodium bromide solution.

[0060] The "acidification + extraction method" is to acidify and remove sodium carbonate and sodium bicarbonate in the water, and then use an extractant to extract small molecular organic matter in the water, and the produced water enters the next process. The small molecular organic matter solution after extraction can be directly used as a carbon source or enter an anaerobic device. It can also be used as a carbon source or enter an anaerobic device after being analyzed by an analytical agent.

[0061] The "acidification + stripping + evaporation method" is to acidify and remove sodium carbonate and sodium bicarbonate in the water, then strip with air or other gases to strip out most of the formic acid and acetic acid in the water, and then use an evaporation device to evaporate and remove small molecular organic acids such as formic acid and acetic acid by utilizing the low boiling point of small molecular organic acids such as formic acid and acetic acid to obtain a high-purity sodium bromide solution.

[0062] Furthermore, the above carbon removal method of the present invention can directly produce bromine by adding an oxidant after removing sodium carbonate, sodium bicarbonate and small molecular organic matter such as sodium formate and sodium acetate in water, or produce bromine and then add a reducing agent to produce hydrobromic acid.

[0063] Furthermore, the crystallization centrifugal device can be "evaporation crystallization + centrifugal separation", "freezing (cooling) crystallization + centrifugal separation", or "eutectic freezing crystallization method". Its main purpose is to separate the salt from the water.

[0064] The "evaporation crystallization + centrifugal separation" is a method of increasing the concentration of salt in water to exceed its solubility in water by evaporation concentration, and then extracting the salt from the water. The specific implementation method is that the incoming water first enters the evaporator for evaporation, the distilled water is discharged to the anaerobic device or used as a carbon source, the solid-liquid mixture discharged from the evaporator is centrifuged to obtain solid salt, and the mother liquor enters the material separation device I.

[0065] The "freezing (cooling) crystallization + centrifugal separation" is a method of increasing the salt concentration in the water to exceed its solubility in water by a concentration and desalination device before a crystallization centrifugal device, and then reducing the solubility of the salt in water by lowering the temperature to extract the salt from the water. The specific implementation method is that the concentrated water from the concentration and desalination device enters the freezing (cooling) device, and after the salt is precipitated, it is separated by a centrifuge to obtain solid salt, and the centrifuge liquid returns to the concentration and desalination device to continue to concentrate or enter the next process.

[0066] The "eutectic freezing crystallization method" is to reduce the temperature of the solution to below the eutectic point by cooling, so that the water in the solution can be crystallized to form ice, so that the concentration of the salt solution increases, and the sodium carbonate and sodium bicarbonate in the water reach the saturation value and can be precipitated. Finally, the ice and sodium bicarbonate and sodium carbonate can be separated by gravity due to the different densities. The remaining solution of the reaction is returned to the concentration and desalination device for further concentration or enters the next process.

[0067] Furthermore, the crystallization centrifuge device I preferably adopts "evaporation + centrifugation".

[0068] Furthermore, the crystallization centrifuge device II preferably adopts "freezing (cooling) + centrifugation".

[0069] Furthermore, the solid salt extracted by the evaporation crystallization device is a mixed salt of sodium carbonate and sodium bicarbonate, called a sesquialkali. It can also be adjusted according to the desired salt type. If you want to obtain pure sodium carbonate solid, you can pass steam wet decomposition or add sodium hydroxide or other methods before the crystallization evaporation device to convert all the sodium bicarbonate in the water into sodium carbonate and then pass it through a crystallization centrifugal device to obtain sodium carbonate solid. If you want to obtain sodium bicarbonate solid, you can add carbon dioxide or other methods before the crystallization evaporation device to convert all the sodium carbonate in the water into sodium bicarbonate and then pass it through a crystallization centrifugal device to obtain sodium bicarbonate solid.

[0070] Furthermore, the high-purity sodium bromide solid or solution can be partially or completely treated with a bipolar membrane to obtain a hydrobromic acid solution and a sodium hydroxide solution. Alternatively, a hydrogen-type ion exchange resin can be used to transform sodium ions into hydrogen ions to obtain a hydrogen bromide solution. The obtained hydrobromic acid solution can be used as an acidifier in an acidification device to remove sodium carbonate and sodium bicarbonate in water and to transform small molecular organic substances such as sodium formate and sodium acetate in water into small molecular organic acids such as formic acid and acetic acid. Alternatively, the obtained hydrobromic acid solution is further concentrated to obtain a concentrated hydrobromic acid solution for self-use or sale.

[0071] Furthermore, if the liquid bromine-containing wastewater and other wastewaters contain oxidants, divalent or higher metal ions that may affect the operation of the subsequent membrane system, an oxidant removal device and a divalent metal ion removal device may be added after the filtration device.

[0072] Furthermore, if the oxidant content in the water is high or there is a lot of bromate in the water, an oxidant removal device can be added before or after the acidification device. The oxidant removal device can be a device that adds a reducing agent, including but not limited to sodium thiosulfate, sodium sulfite or other reducing substances and a device that can produce reducing agent substances.

[0073] Furthermore, the nitrate removal device may adopt a denitrification device, electrocatalytic reduction, ion exchange resin adsorption, etc.

[0074] Furthermore, the ammonia nitrogen removal device can adopt resin adsorption, activated carbon adsorption, electrocatalytic oxidation, etc.

[0075] Furthermore, the phosphorus removal device may adopt resin adsorption, activated carbon adsorption, chemical precipitation method, etc.

[0076] Furthermore, the heavy metal removal device can adopt resin adsorption, activated carbon adsorption, chemical precipitation method, etc.

[0077] Furthermore, the present invention is also applicable to the treatment of other inorganic salt-containing organic acid wastewater, such as the separation of nitrate and dibasic acid salt in adipic acid wastewater.

[0078] Furthermore, in the gas-phase bromine-containing wastewater treatment system, if the gas-phase bromine-containing wastewater contains suspended matter, it is necessary to add a filtering device before the divalent and higher-valent metal ion removal device to remove the suspended matter in the water.

[0079] Furthermore, other wastewater treatment systems of the present invention are also applicable to the treatment of other wastewater containing bicarbonate and carbonate.

[0080] Furthermore, in the other wastewater treatment systems described in the present invention, the aerobic produced water first enters the filter device II and is then processed by subsequent processes to obtain the recycled water. Alternatively, the anaerobic effluent first enters the filter device II and is then processed by subsequent processes to obtain the recycled water.

[0081] Furthermore, bromine-containing inorganic salts can also be extracted from water produced by aerobic devices or anaerobic devices, and then bromine and hydrobromic acid can be extracted. The specific extraction method is the same as the gas phase wastewater treatment system, that is, pretreatment unit + concentration and desalination single ring + macromolecular organic separation unit + carbon removal unit + bromine purification unit.

[0082] Furthermore, after the bromine purification unit, different process treatments can be selected according to the desired bromine product. If sodium bromide or a high-concentration sodium bromide solution is needed, it can be prepared by an evaporation device; if hydrobromic acid is needed, it can be prepared by a bipolar membrane device, and a sodium hydroxide solution can also be obtained at the same time, or it can be prepared by a hydrogen-type ion exchange resin, or bromine can be prepared and then a reducing agent can be added to prepare it; if bromine is desired, it can be prepared by adding an oxidant, or by sulfuric acid acid distillation, chlorine replacement, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 It is a schematic diagram of the bromine-containing inorganic salt and organic acid (salt) wastewater treatment system described in Example 1 of the present invention.

[0084] Figure 2 It is a schematic diagram of the bromine-containing inorganic salt and organic acid (salt) wastewater treatment system described in Example 2 of the present invention.

[0085] In the figure, 1-gas phase bromine-containing wastewater, 2-liquid phase bromine-containing wastewater, 3-other wastewater, 4-divalent and above divalent metal ion removal device, 5-oxidant removal device, 6-concentration and desalination device I, 7-crystallization centrifugal device I, 8-material separation device I, 9-acidification device, 10-adsorption device, 11-evaporation device, 12-filtration device I, 13-material separation device II, 14-concentration and desalination device II, 15-anaerobic device, 16-aerobic device, 17-filtration device II, 18-concentration and desalination device III, 19-concentration and desalination device IV, 20-crystallization centrifugal device II, 21-material separation device III, 22-nitrate removal device, 23-ammonia nitrogen removal device, 24-phosphorus removal device, 25-heavy metal removal device, 28-acidification device II. DETAILED DESCRIPTION

[0086] The following non-limiting embodiments may enable a person skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0087] Example 1

[0088] A bromine-containing organic wastewater, including gaseous bromine-containing wastewater generated by PTA tail gas absorption, liquid bromine-containing wastewater generated in the PTA production process, and other wastewater generated by flushing products and equipment.

[0089] like Figure 1 As shown, a bromine-containing inorganic salt and organic acid (salt) wastewater treatment system is provided. The whole system is divided into three water treatment systems, namely, a gas phase bromine-containing wastewater treatment system, a liquid phase bromine-containing wastewater treatment system, and other wastewater treatment systems.

[0090] The gas phase bromine-containing wastewater treatment system comprises a pretreatment unit, a concentration and desalination unit, a macromolecular organic separation unit, a carbon removal unit, and a bromine purification unit.

[0091] The liquid phase bromine-containing wastewater treatment system comprises a pretreatment unit, a macromolecular organic separation unit I, a concentration and desalination unit, a macromolecular organic separation unit II, a carbon removal unit, and a bromine purification unit.

[0092] The other wastewater treatment systems include a biochemical unit, a pretreatment unit, a salt extraction unit, a concentration and desalination unit, and a wastewater treatment unit.

[0093] The function of the pretreatment unit in the gas phase wastewater treatment system is to remove divalent and higher ions in the water (to protect the stable operation of the membrane elements), oxidants or strong oxidizing substances (to protect the stable operation of the membrane elements), including a divalent and higher metal ion removal device 4 and an oxidant removal device 5. The function of the concentration and desalination unit is to extract sesquialkali-like alkalis and desalination after concentrating the ions in the water, including a concentration and desalination device Ⅰ6 and a crystallization centrifuge device Ⅰ7. The function of the macromolecular organic separation unit is to separate the residual macromolecular organic matter in the water, including a material separation device Ⅰ8. The function of the carbon removal unit is to remove the remaining carbonate and bicarbonate in the water, and at the same time acidify the wastewater to form small molecular organic acids such as formic acid and acetic acid in the water. The formic acid and acetic acid in the water are removed by an adsorption device, including an acidification device 9 and an adsorption device 10. The function of the bromine purification unit is to remove the remaining small molecular organic matter in the water to obtain a high-purity sodium bromide solution, including an evaporation device 11. The acidifying agent added to the acidifying device 9 is hydrobromic acid or a hydrogen-type ion exchange resin is used as the acidifying device.

[0094] The function of the pretreatment unit in the liquid-phase bromine-containing wastewater treatment system is to remove suspended matter from the water, including a filtering device I12. The function of the macromolecular organic separation unit I is to separate macromolecular organic matter from the water, including a material separation device II13. The function of the concentration and desalination unit is to concentrate and reduce the water and reuse the produced water, including a concentration and desalination device II14. After the produced water of the concentration and desalination device II14 is reused, the concentrated water is further subjected to crystallization centrifugation. At this time, the crystallization centrifugation device can be used with the crystallization centrifugation device I7 shared with the gas-phase bromine-containing wastewater treatment system. The macromolecular organic separation unit II is the same as the macromolecular organic separation unit in the gas-phase bromine-containing wastewater treatment system, and shares a set of devices, including a material separation device I8. The carbon removal unit is the same as the carbon removal unit in the gas-phase bromine-containing wastewater treatment system, and shares a set of devices, including an acidification device 9 and an adsorption device 10. The bromine purification unit is the same as the bromine purification unit in the gas-phase bromine-containing wastewater treatment system and can share a set of devices, including an evaporation device 11.

[0095] The function of the biochemical unit in the other wastewater treatment systems is to decompose organic matter in the water, including an anaerobic device 15 and an aerobic device 16. The function of the pretreatment unit is to remove suspended matter in the water, including a filtration device II 17. The function of the salt extraction unit is to extract sodium bicarbonate from the water to reduce the salt content of the wastewater, including a concentration and desalination device III 18 and a crystallization centrifuge device II 20. The function of the concentration and desalination unit is to reuse the wastewater after treatment, including a concentration and desalination device IV 19. The function of the wastewater treatment unit is to treat the mother liquor produced by the sodium bicarbonate extraction unit and discharge it in compliance with the standards, including a material separation device III 21, a nitrate removal device 22, an ammonia nitrogen removal device 23, a phosphorus removal device 24, and a heavy metal removal device 25.

[0096] The bromine-containing inorganic salt and organic acid (salt) wastewater treatment system specifically includes: gas-phase bromine-containing wastewater 1 is sequentially connected to a divalent metal ion removal device 4, an oxidant removal device 5, and a concentration and desalination device I6, and the concentrated desalination device I6 produces water for reuse. The concentrated water of the concentrated desalination device I6 is connected to a crystallization centrifugal device I7, and the crystallization centrifugal device I7 extracts solid salt sodium carbonate, sodium bicarbonate, or sesquialkali. The effluent of the crystallization centrifugal device I7 is connected to a material separation device I8, and the concentrated water of the material separation device I8 is connected to an anaerobic device 15. The effluent of the material separation device I8 is connected to an acidification device 9, and the effluent of the acidification device 9 is connected to an adsorption device 10. After the adsorption device 10 is saturated, it is desorbed with a desorbent, and the desorbed liquid is discharged into the anaerobic device 15 or used as a carbon source. The effluent of the adsorption device 10 is connected to an evaporation device 11 to remove the remaining small molecular organic matter in the water to obtain high-purity solid sodium bromide or sodium bromide solution. The distilled water produced by the evaporation device 11 is discharged to the anaerobic device 15 or used as a carbon source.

[0097] The liquid phase bromine-containing wastewater 2 is connected to the filtering device Ⅰ12. The effluent is connected to the material separation device Ⅱ13, the concentrated water of the material separation device Ⅱ13 is connected to the anaerobic device 15, the water produced by the material separation device Ⅱ13 is connected to the concentration and desalination device Ⅱ14, the water produced by the concentration and desalination device Ⅱ14 is reused, and the concentrated water of the concentration and desalination device Ⅱ14 is connected to the crystallization centrifugal device Ⅰ7.

[0098] Other wastewater 3 is connected to anaerobic device 15, aerobic device 16, filtration device II 17, and concentration and desalination device III 18 in sequence. The water produced by concentration and desalination device III 18 is connected to material separation device III 21 for diluting the effluent of crystallization centrifuge device II 20 to ensure the water quality of material separation device III 21. The remaining effluent of concentration and desalination device III 18 is connected to concentration and desalination device IV 19, and the concentrated water of concentration and desalination device IV 19 is connected to the inlet of concentration and desalination device III 18 for circulation and production and reuse. The concentrated water of concentration and desalination device III 18 is connected to crystallization centrifuge device II 20 to separate sodium bicarbonate, and the mother liquor is connected to material separation device III 21. The effluent of material separation device III 21 is connected to nitrate removal device 22, ammonia nitrogen removal device 23, phosphorus removal device 24, heavy metal removal device 25 in sequence and finally discharged. The collected high-purity sodium bromide solid or solution or effluent of carbon removal unit can be treated by bipolar membrane to obtain hydrobromic acid solution and sodium hydroxide solution. Alternatively, an acidification device is used to convert sodium ions into hydrogen ions to obtain a hydrobromic acid solution. The obtained hydrobromic acid solution can be evaporated or concentrated by other devices to obtain a hydrobromic acid solution with a higher concentration for external sale or use as an acidifier in an acidification device.

[0099] A bromide ion enrichment device may be provided before the concentration and desalination device I6 and the concentration and desalination device II14 of the present embodiment. The bromide ion enrichment device adopts an alkaline anion exchange resin. The specific implementation method is as follows: the bromide ions in the water are selectively adsorbed by the bromide ion enrichment device, and the adsorbed water may directly enter other wastewater treatment systems, or enter the concentration and desalination device for concentration and then extraction of sesquialkali.

[0100] After the bromide ion enrichment device is saturated with adsorption, a desorbent can be used for regeneration. The desorption liquid produced by regeneration is a high-concentration bromine-containing inorganic wastewater. This wastewater can be treated by an acidification device 9 and an evaporation device 11 to obtain a high-concentration sodium bromide solution (solid) or hydrobromic acid; preferably, after acidification by the acidification device 9, chlorine gas replacement and sulfuric acid distillation are used to extract bromine or hydrobromic acid; the desorption liquid includes but is not limited to alkaline compounds such as sodium hydroxide and a device for producing alkaline substances.

[0101] The chlorine replacement method is as follows: firstly, acid is added to adjust the wastewater to acidity, and then chlorine is introduced to distill to obtain bromine. The effluent (gas) is absorbed by sulfur dioxide and distilled again to obtain a high-purity hydrobromic acid solution. The sulfuric acid produced by the absorption liquid can be used for the acidification of the previous wastewater.

[0102] The sulfuric acid distillation method is as follows: first, sulfuric acid is added to acidify water, and then distillation is performed to obtain bromine. The effluent (gas) is absorbed by sulfur dioxide and distilled again to obtain a high-purity hydrobromic acid solution. The sulfuric acid produced by the absorption liquid can be used for the acidification of the wastewater.

[0103] Example 2

[0104] like Figure 2 As shown, it is an embodiment of a system for treating wastewater containing bromine inorganic salts and organic acids (salts), in which the gas phase bromine-containing wastewater contains a large amount of bromine and a small amount of carbonate and bicarbonate.

[0105] The other wastewater treatment systems are the same as those in Example 1. In the gas phase bromine-containing wastewater treatment system, the crystallization centrifuge device I is removed, and the concentration and desalination device 1 is placed after the acidification device. In the liquid phase wastewater treatment system, an acidification device II 28 is added at the concentrated water outlet of the concentration and desalination device II. The acidifier added to the acidification device 9 is hydrobromic acid or a hydrogen-type ion exchange resin is used as the acidification device. The details are as follows:

[0106] The gas phase bromine-containing wastewater 1 is connected to the divalent metal ion removal device 4 to remove divalent metal ions in the water. The effluent of the divalent metal ion removal device 4 is connected to the deoxidant device 5 to remove strong oxidizing substances in the water and protect the stable operation of the rear membrane. The effluent of the deoxidant device 5 is connected to the material separation device Ⅰ8, which intercepts the macromolecular organic matter and carbonate in the water to the concentrated water side and discharges it to the anaerobic device 15. The effluent of the material separation device Ⅰ8 is connected to the acidification device 9 to remove carbonate and bicarbonate in the water, and acidifies the water to convert small molecular organic matter such as sodium formate and sodium acetate in the water into small molecular organic acids such as formic acid and acetic acid. The acidification device 9 is connected to the concentration and desalination device Ⅰ6 to transfer the salt in the water to the concentrated side and produce water for reuse. The concentrated water of the concentration and desalination device Ⅰ6 is connected to the adsorption device 10 to adsorb small molecular organic acids such as formic acid and acetic acid in the water. After the adsorption device 10 is saturated, it is desorbed with a desorbent, and the desorbed liquid is discharged into the anaerobic device 15 or used as a carbon source. The water outlet of the adsorption device 10 is connected to the evaporation device 11 to remove the remaining small molecular organic matter in the water to obtain high-purity solid sodium bromide or sodium bromide solution. The distilled water produced by the evaporation device 11 is discharged to the anaerobic device 15 or used as a carbon source.

[0107] The liquid phase bromine-containing wastewater 2 is connected to the filtering device Ⅰ12 to remove suspended matter in the water. The effluent is connected to the material separation device Ⅱ13 to separate the macromolecular organic matter in the water. The concentrated water of the material separation device Ⅱ13 is connected to the anaerobic device 15. The water produced by the material separation device Ⅱ13 is connected to the concentration and desalination device Ⅱ14. The water produced by the concentration and desalination device Ⅱ14 is reused. The concentrated water of the concentration and desalination device Ⅱ14 is connected to the acidification device Ⅱ28. The effluent of the acidification device Ⅱ28 is connected to the adsorption device 10.

[0108] Other wastewater 3 is connected to anaerobic device 15, aerobic device 16, filtration device II 17, and concentration and desalination device III 18 in sequence. The water produced by concentration and desalination device III 18 is connected to material separation device III 21 for diluting the effluent of crystallization centrifugal device II 20 to ensure the water quality of material separation device III 21. The remaining effluent of concentration and desalination device III 18 is connected to concentration and desalination device IV 19, and the concentrated water of concentration and desalination device IV 19 is connected to the inlet of concentration and desalination device III 18 for circulation and production and reuse. The concentrated water of concentration and desalination device III 18 is connected to crystallization centrifugal device II 20 to separate sodium bicarbonate or sesquialkali, and the mother liquor is connected to material separation device III 21. The effluent of material separation device III 21 is connected to nitrate removal device 22, ammonia nitrogen removal device 23, phosphorus removal device 24, heavy metal removal device 25 in sequence and finally discharged. The collected high-purity sodium bromide solid or solution or effluent of carbon removal unit can be treated with bipolar membrane to obtain hydrobromic acid solution and sodium hydroxide solution. Alternatively, an acidification device is used to convert sodium ions into hydrogen ions to obtain a hydrobromic acid solution. The obtained hydrobromic acid solution can be evaporated or concentrated by other devices to obtain a hydrobromic acid solution with a higher concentration for external sale or use as an acidifier in an acidification device.

[0109] In this embodiment, a bromide ion enrichment device can be set before the acidification device 9 and the concentration and desalination device II14, and the bromide ion enrichment device uses an alkaline anion exchange resin; its specific implementation method is: the wastewater passes through the bromide ion enrichment device to selectively adsorb bromide ions in the water, and the adsorbed water can directly enter other wastewater treatment systems, or enter the concentration and desalination device for concentration and then extract sesquialkali.

[0110] After the bromide ion enrichment device is saturated with adsorption, a desorbent can be used for regeneration. The desorption liquid produced by regeneration is a high-concentration bromine-containing inorganic wastewater. This wastewater can be treated by an acidification device 9 and an evaporation device 11 to obtain a high-concentration sodium bromide solution (solid) or hydrobromic acid; preferably, after acidification by the acidification device 9, chlorine gas replacement and sulfuric acid distillation are used to extract bromine or hydrobromic acid; the desorption liquid includes but is not limited to alkaline compounds such as sodium hydroxide and a device for producing alkaline substances.

[0111] The chlorine replacement method is as follows: firstly, acid is added to adjust the wastewater to acidity, and then chlorine is introduced to distill to obtain bromine. The effluent (gas) is absorbed by sulfur dioxide and distilled again to obtain a high-purity hydrobromic acid solution. The sulfuric acid produced by the absorption liquid can be used for the acidification of the previous wastewater.

[0112] The sulfuric acid distillation method is as follows: first, sulfuric acid is added to acidify water, and then distillation is performed to obtain bromine. The effluent (gas) is absorbed by sulfur dioxide and distilled again to obtain a high-purity hydrobromic acid solution. The sulfuric acid produced by the absorption liquid can be used for the acidification of the wastewater.

[0113] Example 3

[0114] This embodiment describes a specific implementation method of the present invention when the acidification device uses divalent or higher-valent acids such as sulfuric acid as an acidifier, and sulfuric acid is used for illustration in the embodiment.

[0115] In the specific implementation scheme, the liquid phase bromine-containing wastewater treatment system and other wastewater treatment systems are the same as those in Example 1, except that in the gas phase bromine-containing wastewater treatment system, a sulfate removal device is added after the evaporation device 11: a neutralization device and a material separation device IV. The specific implementation scheme is as follows.

[0116] The gas phase bromine-containing wastewater 1 is sequentially connected to a divalent metal ion removal device 4, an oxidant removal device 5, and a concentration and desalination device I6, and the concentrated and desalinated device I6 produces water for reuse. The concentrated water of the concentrated and desalinated device I6 is connected to a crystallization centrifuge device I7, and the crystallization centrifuge device I7 extracts solid salt sodium carbonate, sodium bicarbonate, or sesquialkali. The effluent of the crystallization centrifuge device I7 is connected to a material separation device I8, and the concentrated water of the material separation device I8 is connected to an anaerobic device 15. The effluent of the material separation device I8 is connected to an acidification device 9, sulfuric acid is added to remove sodium carbonate and sodium bicarbonate in the water, and small molecular organic matter such as sodium formate and sodium acetate in the water is transformed into small molecular organic acids such as formic acid and acetic acid. The effluent of the acidification device 9 is connected to an adsorption device 10. After the adsorption device 10 is saturated, it is desorbed with a desorbent, and the desorbed liquid is discharged into the anaerobic device 15 or used as a carbon source. The effluent of the adsorption device 10 is connected to an evaporation device 11 to remove the remaining small molecular organic matter in the water to obtain a sodium bromide solution containing sulfate. The distilled water produced by the evaporation device 11 is discharged to the anaerobic device 15 or used as a carbon source. The water output from the evaporation device 11 is connected to the neutralization device to adjust the water to neutrality by adding sodium hydroxide, and the neutralization device is connected to the material separation device IV to separate sodium sulfate and sodium bromide in the water. The concentrated water from the material separation device IV is connected to the anaerobic device 15, and the produced water is a high-purity sodium bromide solution. After evaporation, sodium bromide solid or a sodium bromide solution with a higher concentration can be obtained. This sodium bromide solution can also be used to produce hydrobromic acid.

[0117] The liquid phase bromine-containing wastewater 2 is connected to the filtering device Ⅰ12. The effluent is connected to the material separation device Ⅱ13, the concentrated water of the material separation device Ⅱ13 is connected to the anaerobic device 15, the water produced by the material separation device Ⅱ13 is connected to the concentration and desalination device Ⅱ14, the water produced by the concentration and desalination device Ⅱ14 is reused, and the concentrated water of the concentration and desalination device Ⅱ14 is connected to the crystallization centrifugal device Ⅰ7.

[0118] Other wastewater 3 is connected to anaerobic device 15, aerobic device 16, filtration device II 17, and concentration and desalination device III 18 in sequence. The water produced by concentration and desalination device III 18 is connected to material separation device III 21 for diluting the effluent of crystallization centrifuge device II 20 to ensure the water quality of material separation device III 21. The remaining effluent of concentration and desalination device III 18 is connected to concentration and desalination device IV 19, and the concentrated water of concentration and desalination device IV 19 is connected to the inlet of concentration and desalination device III 18 for circulation and production and reuse. The concentrated water of concentration and desalination device III 18 is connected to crystallization centrifuge device II 20 to separate sodium bicarbonate sesquialkali, and the mother liquor is connected to material separation device III 21. The effluent of material separation device III 21 is connected to nitrate removal device 22, ammonia nitrogen removal device 23, phosphorus removal device 24, heavy metal removal device 25 in sequence and finally discharged. The collected high-purity sodium bromide solid or solution or effluent of carbon removal unit can be treated by bipolar membrane to obtain hydrobromic acid solution and sodium hydroxide solution. Alternatively, an acidification device is used to convert sodium ions into hydrogen ions to obtain a hydrobromic acid solution. The obtained hydrobromic acid solution can be evaporated or concentrated by other devices to obtain a hydrobromic acid solution with a higher concentration for external sale or use as an acidifier in an acidification device.

[0119] A bromide ion enrichment device may be provided before the concentration and desalination device I6 and the concentration and desalination device II14 of the present embodiment. The bromide ion enrichment device adopts an alkaline anion exchange resin. The specific implementation method is as follows: the bromide ions in the water are selectively adsorbed by the bromide ion enrichment device, and the adsorbed water may directly enter other wastewater treatment systems, or enter the concentration and desalination device for concentration and then extraction of sesquialkali.

[0120] After the bromide ion enrichment device is saturated with adsorption, a desorbent can be used for regeneration. The desorption liquid produced by regeneration is a high-concentration bromine-containing inorganic wastewater. This wastewater can be treated by an acidification device 9 and an evaporation device 11 to obtain a high-concentration sodium bromide solution (solid) or hydrobromic acid; preferably, after acidification by the acidification device 9, chlorine gas replacement and sulfuric acid distillation are used to extract bromine or hydrobromic acid; the desorption liquid includes but is not limited to alkaline compounds such as sodium hydroxide and a device for producing alkaline substances.

[0121] The chlorine replacement method is as follows: firstly, acid is added to adjust the wastewater to acidity, and then chlorine is introduced to distill to obtain bromine. The effluent (gas) is absorbed by sulfur dioxide and distilled again to obtain a high-purity hydrobromic acid solution. The sulfuric acid produced by the absorption liquid can be used for the acidification of the previous wastewater.

[0122] The sulfuric acid distillation method is as follows: first, sulfuric acid is added to acidify water, and then distillation is performed to obtain bromine. The effluent (gas) is absorbed by sulfur dioxide and distilled again to obtain a high-purity hydrobromic acid solution. The sulfuric acid produced by the absorption liquid can be used for the acidification of the wastewater.

Claims

1. A system for treating wastewater containing bromine-containing inorganic salts and organic acids, characterized in that: Including gas phase bromine-containing wastewater treatment system, liquid phase bromine-containing wastewater treatment system, and other wastewater treatment systems; The gas phase bromine-containing wastewater treatment system comprises gas phase bromine-containing wastewater (1), a divalent and higher valent metal ion removal device (4), an oxidant removal device (5), a concentration and desalination device I (6), a crystallization centrifugal device I (7), a material separation device I (8), a carbon removal unit, an evaporation device (11) and a collection device connected in sequence; the carbon removal unit comprises an acidification device (9) and an adsorption device (10) connected in sequence; The liquid phase bromine-containing wastewater treatment system comprises liquid phase bromine-containing wastewater (2), a filtering device I (12), a material separation device II (13), and a concentration and desalination device II (14) which are connected in sequence, wherein the concentrated water end of the concentration and desalination device II (14) is connected to the water inlet of the crystallization centrifuge device I (7); The other wastewater treatment system comprises other wastewater (3), an anaerobic device (15), an aerobic device (16), a filtering device II (17), and a concentration and desalination device III (18) which are connected in sequence, wherein the water production end of the concentration and desalination device III (18) is connected to the concentration and desalination device IV (19), the concentrated water end of the concentration and desalination device III (18) is connected to the crystallization centrifugal device II (20), and the concentrated water end of the concentration and desalination device IV (19) is connected to the water inlet of the concentration and desalination device III (18); the water production end of the crystallization centrifugal device II (20) is connected in sequence to the material separation device III (21), the nitrate removal device (22), the ammonia nitrogen removal device (23), the phosphorus removal device (24), the heavy metal removal device (25), and the external discharge unit; The concentrating and desalinating device I (6) and the concentrating and desalinating device II (14) are both configured such that: the water produced at the water production end is recycled, and the concentrated water end is connected to the water inlet of the crystallization centrifuge device I (7); the water produced at the water production end of the concentrating and desalinating device IV (19) is recycled, and the concentrated water end is connected to the water inlet of the concentrating and desalinating device III (18); the water production port of the concentrating and desalinating device III (18) is also connected to the feed port of the material separation device III (21); the concentrated water ends of the material separation device I (8), the material separation device II (13) and the material separation device III (21) are all connected to the anaerobic device (15), the water production end of the material separation device I (8) is connected to the carbon removal unit, and the material separation device III (21) is connected to the anaerobic device (15). The water production end of the material separation device II (13) is connected to the water inlet of the concentration and desalination device II (14), and the water production end of the material separation device III (21) is connected to the nitrate removal device (22); the wastewater generated by the carbon removal unit is connected to the anaerobic device (15) through a pipeline, and the water production end is connected to the evaporation device (11); the condensed water of the evaporation device (11) is connected to the anaerobic device (15) through a pipeline, and the evaporated sodium bromide is collected in a collection device; a filtering device is provided between the gas phase bromine-containing wastewater (1) and the divalent and higher metal ion removal device (4); and an advanced oxidation device is also provided at the water inlet of the anaerobic device (15).

2. The bromine-containing inorganic salt and organic acid wastewater treatment system according to claim 1, characterized in that: The collecting device is connected to a hydrobromic acid preparation device, and the hydrobromic acid preparation device includes a bipolar membrane or an acidification device.

3. The bromine-containing inorganic salt and organic acid wastewater treatment system according to claim 1, characterized in that: The water inlet or outlet of the acidification device is provided with an oxidant removal device; a bromide ion enrichment device is provided before the concentration and desalination device I (6) and the concentration and desalination device II (14), and the bromide ion enrichment device uses an alkaline anion exchange resin; after the bromide ion enrichment device is adsorbed to saturation, a desorbent is used for regeneration, and the desorbed liquid generated by the regeneration is a high-concentration bromine-containing inorganic wastewater, and the wastewater is treated by the acidification device (9) and the evaporation device (11) to obtain a high-concentration sodium bromide solution and / or sodium bromide solid or hydrobromic acid; after the acidification device (9) is acidified, chlorine gas replacement and sulfuric acid distillation are used to extract bromine or hydrobromic acid; the desorbed liquid includes an alkaline compound of sodium hydroxide and a device for generating alkaline substances.

4. The bromine-containing inorganic salt and organic acid wastewater treatment system according to any one of claims 1 to 3, characterized in that: The condensed water of the evaporation device (11) is connected to the anaerobic device (15) through a pipeline, the evaporated mother liquor is connected to one end of the neutralization device through a pipeline, the other end of the neutralization device is connected to the material separation device IV, the water outlet of the material separation device IV is connected to the sodium bromide solution collection device, and the concentrated water outlet of the material separation device IV is connected to the anaerobic device (15).

5. The bromine-containing inorganic salt and organic acid wastewater treatment system according to any one of claims 1 to 2, characterized in that: The concentration and desalination device I (6) is arranged between the acidification device (9) and the adsorption device (10), and the crystallization centrifugal device I (7) is removed; the water produced by the water production end of the concentration and desalination device I (6) is reused, and the concentrated water end of the concentration and desalination device I (6) is connected to the adsorption device (10); the concentrated water end of the concentration and desalination device II (14) is connected to one end of the acidification device II (28), and the other end of the acidification device II (28) is connected to the adsorption device (10); an oxidant removal device is arranged at the water inlet or the water outlet of the acidification device; and a deoxidant removal device is arranged between the acidification device (9) and the concentration and desalination device. A bromide ion enrichment device is arranged before the device II (14), and the bromide ion enrichment device uses an alkaline anion exchange resin; after the bromide ion enrichment device is adsorbed to saturation, a desorbent is used for regeneration, and the desorption liquid generated by the regeneration is a high-concentration bromine-containing inorganic wastewater. After the wastewater is treated by an acidification device (9) and an evaporation device (11), a high-concentration sodium bromide solution and / or sodium bromide solid or hydrobromic acid is obtained; after the acidification device (9) is acidified, chlorine gas replacement and sulfuric acid distillation are used to extract bromine or hydrobromic acid; the desorption liquid includes an alkaline compound of sodium hydroxide and a device for generating alkaline substances.

6. The application method of the bromine-containing inorganic salt and organic acid wastewater treatment system according to any one of claims 1 to 3, characterized in that: The steps include: 1) After filtering, the gas-phase bromine-containing wastewater enters the divalent and higher-valent metal ion removal device to remove the divalent and higher-valent metal ions in the wastewater, and the produced water enters the deoxidant removal device to remove the oxidant in the wastewater; The produced water enters the concentration and desalination device I, and the inorganic salts and organic matter in the wastewater are transferred to the concentrated water, and the fresh water is reused; the concentrated water enters the crystallization centrifugal device I for separation to obtain sodium carbonate and sodium bicarbonate mixture-type sesquialkali, and the produced mother liquor is diluted and enters the material separation device I. The concentrated water of the material separation device I enters the anaerobic device or enters the anaerobic device after being treated by the advanced oxidation device. The produced water of the material separation device I enters the carbon removal unit, and the wastewater discharged from the carbon removal unit enters the anaerobic device. The produced water of the carbon removal unit enters the evaporation device to evaporate and remove the small molecular organic acid that is not completely adsorbed to obtain high-purity sodium bromide solid or liquid, and the condensed water of the evaporation device enters the anaerobic device; the sodium bromide solid or liquid enters the hydrobromic acid preparation device, and is treated by a bipolar membrane to obtain a hydrobromic acid solution and a sodium hydroxide solution, or an acidification device is used to transform sodium ions into hydrogen ions to obtain a hydrobromic acid solution; the hydrobromic acid solution is concentrated to obtain a high-concentration hydrobromic acid solution; 2) Liquid bromine-containing wastewater enters the filtration device I to remove suspended solids in the wastewater, and the produced water is diluted and enters the material separation device II to separate the macromolecular organic matter in the wastewater into concentrated water. The concentrated water enters the anaerobic device, or enters the anaerobic device after being treated by the advanced oxidation device; The produced water enters the concentration and desalination device II, where the inorganic salts and organic matter in the wastewater are transferred to the concentrated water, and the fresh water is reused; the concentrated water enters the crystallization centrifugal device I of the gas phase bromine-containing wastewater treatment system for further treatment; 3) After other wastewater is treated by the anaerobic device and the aerobic device, the produced water enters the filtration device II to remove suspended solids in the wastewater, and then enters the concentration and desalination device III to transfer sodium bicarbonate in the wastewater to the concentrated water. The produced water of the concentration and desalination device III is further treated by the concentration and desalination device IV, and the produced water is reused, and the concentrated water is treated by the concentration and desalination device III again; The concentrated water from the concentration and desalination device III enters the crystallization centrifuge device II to extract the sesquialkali of the mixture of sodium carbonate and sodium bicarbonate. The concentrated water is diluted by the produced water of the concentration and desalination device III and enters the material separation device III. The concentrated water of the material separation device III enters the anaerobic device, or enters the anaerobic device after being treated by the advanced oxidation device; the produced water of the material separation device III is successively treated by the nitrate removal device to remove nitrate, the ammonia nitrogen removal device to remove ammonia nitrogen, the phosphorus removal device to remove phosphorus, and the heavy metal removal device to remove heavy metals. The wastewater meets the standards and is discharged, or is further treated by evaporation to achieve zero discharge of the wastewater.

7. The application method of the bromine-containing inorganic salt and organic acid wastewater treatment system according to claim 6, characterized in that: When the wastewater of the gas phase bromine-containing wastewater treatment system contains a large amount of bromine, but a small amount of carbonate and bicarbonate, or the amount of treated water is small and there is no sesquialkali value to be recovered: after removing the oxidant in the wastewater in step 1), the wastewater first passes through the material separation device I, the concentrated water of the material separation device I enters the anaerobic device, the water produced by the material separation device I enters the acidification device, and after acidification, enters the concentration and desalination device I, the water produced by the concentration and desalination device I is reused, and the concentrated water of the concentration and desalination device I enters the adsorption device for adsorption; Step 2) The concentrated water from the concentration and desalination device II is first acidified by the acidification device II and then directly enters the adsorption device for adsorption.

8. The application method of the bromine-containing inorganic salt and organic acid wastewater treatment system according to claim 6, characterized in that: In step 1), the sodium bromide solid or liquid obtained from the evaporation device enters the neutralization device, is neutralized with alkali, and then enters the material separation device IV for separation to separate the sodium bromide solid or liquid, and the separated concentrated water enters the anaerobic device.

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