In-situ coupling synergistic hardness removal and resource utilization process

Abstract

The invention discloses an in-situ coupling synergistic hardness removal and resource utilization process. The process comprises a hardness removal process section and a concentration and salt separation process section, the hardness removal process section comprises a hardness adsorption module, an analysis module and a calcium recovery module; the hardness adsorption module is composed of hardness adsorption assemblies and is filled with a functional adsorbent, the analysis module is used for recovering the performance of the adsorbent of the hardness adsorption module, and the calcium recovery module is used for treating analysis waste liquid generated by the analysis module and the hardness adsorption module; salt extracted in the concentration and salt separation process section is used as a resolving agent in the hardness removal process section; the method comprises the following steps: extracting alkalinity ions from raw water, using the alkalinity ions as a precipitating agent, treating the hardness extracted by a hardness adsorption module through a calcium recovery device, recycling calcium ions, further treating the hardness in the raw water by using ions in the raw water, and realizing the purpose of no addition of chemicals, and the method is a mutual coupling and cooperative treatment process, which couples an adsorption technology and a salt separation purification technology for the first time; and by cooperating with a particle membrane filtration technology, the technological process is shortened, and waste resource utilization is realized.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to an in-situ coupled synergistic hardness removal and resource utilization process. Background Art

[0002] With the increasingly stringent requirements of the national environmental protection industry policy, zero discharge of wastewater is imperative, especially the zero discharge of coal chemical wastewater has been the first to implement environmental protection design requirements; zero discharge of wastewater generally adopts a high-density pool to remove hardness, and then adopts a multi-stage membrane concentration process, and finally achieves zero discharge through evaporation and crystallization. The technical pain points of the industry are the high consumption of chemicals for hardness removal in high-density pools, large amounts of sludge, high operating costs, and easy contamination and clogging of membranes, which in turn affects the stable operation of the system, and has always plagued the development of the industry. Exploring short processes, low energy consumption, no drug addition, and stable operation processes is a public relations topic for the water treatment industry.

[0003] In particular, coal chemical wastewater has the characteristics of complex composition, high suspended matter content, high hardness and easy scaling. Among them, system scaling caused by high hardness has always been a problem in the industry. How to effectively reduce the hardness and turbidity of coal chemical wastewater and realize the recycling of wastewater has become a hot topic in water treatment research.

[0004] At present, the hardness removal processes mainly include the following two types: 1. Chemical hardness removal: that is, by adding drugs to the reaction tank, the calcium and magnesium in the water are discharged in the form of precipitation, and then concentrated and filtered with a filter press. However, this method has problems such as large acid and alkali consumption, the need to adjust the pH value, large amount of slag, large equipment footprint, high energy consumption, and unstable operation. It has the common pain points of adding alkali at the front end, adding acid at the back end, and steaming salt at the end; 2. Ion exchange technology, mainly tank equipment, its disadvantages include large size, large footprint, difficult maintenance, large amount of adsorbent used, large amount of analytical agent and high concentration, and difficult treatment of analytical waste liquid. Summary of the invention

[0005] In response to the technical pain points of zero wastewater discharge, the present invention has developed a new process that does not require the addition of drugs, has a short process and low energy consumption, which can effectively solve problems such as membrane concentration and membrane pollution, improve the stability of the system, effectively solve the user cost problem, and has good economy.

[0006] To achieve the above-mentioned purpose, the technical solution of the present application is: an in-situ coupled synergistic hardness removal and resource utilization process, including a hardness removal process section and a concentration and salt separation process section; the hardness removal process section is used to remove the hardness in the water, and the concentration and salt separation process section is used to extract and purify the salt and alkalinity ions in the water.

[0007] The hardness removal process section includes a hardness adsorption module, an analysis module, and a calcium recovery module. The hardness adsorption module is used to extract the hardness in the incoming water; the analysis module is used to analyze the hardness adsorption module to restore the adsorption function of the adsorbent of the hardness adsorption module; the calcium recovery module is used to process the analysis waste liquid generated by the analysis module and the hardness adsorption module.

[0008] The hardness adsorption module includes a hardness adsorption component, and the hardness adsorption component includes but is not limited to a column structure, a tank structure, a trough structure, etc., and the component is filled with a hardness removal adsorbent. The hardness adsorption component can be filled with different functional adsorbents according to the water inlet conditions to achieve the function of subsequent process synergistic treatment;

[0009] The analysis module includes an analysis liquid tank, an analysis liquid pump and an analysis liquid filter connected in sequence. The operation mode of the analysis module includes continuous analysis, group analysis or complete analysis.

[0010] The calcium recovery module includes but is not limited to one or more equipment such as an ultra-gravity reactor, a high-efficiency separator, a connected precipitant pump and precipitant tank, a high-density tank, a reaction tank, etc. The waste liquid of the calcium recovery module can be processed into products, such as producing calcium sulfate, defluoridation agent, etc.

[0011] The concentration and salt separation process section is used to extract salt, alkalinity and other ions from purified water, including but not limited to extracting inorganic salts such as sodium chloride, potassium chloride, sodium nitrate, potassium sulfate, carbonate, sulfate, silicate, hydroxide ion, fluoride ion and the like from water, and the salt separation methods include but are not limited to membrane concentration, evaporation and the like.

[0012] The salt extracted in the concentration and salt separation process section includes but is not limited to one or several inorganic salts such as sodium chloride, potassium chloride, sodium nitrate, potassium sulfate, etc., which are used as analytical agents in the hardness removal process section; the extracted one or several inorganic salts such as carbonates, sulfates, silicates, hydroxide ions, fluoride ions, etc. are used as precipitants, and the hardness extracted by the hardness adsorption module is processed by the calcium recovery module to achieve calcium ion recovery and utilization, thereby achieving the purpose of treating the hardness in the raw water with ions in the raw water without adding drugs.

[0013] In one of the embodiments, it also includes a turbidity removal process section, which is used to remove turbidity in the incoming water to ensure stable operation of the hardness removal process section; this process section is realized by a skid-type structure formed by a particle membrane high-speed filtration component, and the particle membrane high-speed filtration component includes but is not limited to a column structure, a tank structure, a trough structure, etc.

[0014] The in-situ coupled synergistic hardness removal and resource utilization process of the present invention is a mutually coupled and synergistic processing process, that is, the concentration and salt separation process section is the hardness removal process section for extracting raw materials, and the hardness removal process section is the concentration and salt separation process section for removing hardness to ensure the stable operation of the concentration and salt separation process section. The two are mutually conditional and complementary.

[0015] The present invention adopts the above technical solution, and can achieve the following technical effects:

[0016] 1) Column adsorption technology is used to extract the hardness in water, effectively solving the membrane fouling problem caused by the hardness in water. Compared with conventional processes, the reaction tank, dosing, concentration tank, filtration and other devices are eliminated, which has the advantages of low pressure and no dosing, and effectively solves the scaling problem of concentrated salt separation;

[0017] 2) The concentration and salt separation process can effectively concentrate and purify the salt in the wastewater, and can be used as an analytical agent for the adsorption and hardness removal unit. Compared with the conventional process, it has the advantages of not adding drugs, no need to adjust the pH value, and greatly reduces the amount of sludge;

[0018] 3) Adsorption and hardness removal and concentration and salt separation are coupled and mutually guaranteed, which improves the stability of system operation and has low pretreatment requirements. Compared with membrane technology, it has the advantages of short process, low operating pressure, stable process operation, and good anti-pollution performance;

[0019] 4) The innovation of the present invention is to use ions in water to treat pollutants in water, and to achieve the recovery and valuable utilization of pollutants. It is a new process that is both simple and stable, and can guide and promote industry innovation;

[0020] 5) Compared with conventional processes, it greatly reduces the amount of hazardous waste and solid slag, saves floor space, reduces operating costs, and has certain environmental and economic benefits;

[0021] 6) The effective combination of this technology and particle membrane high-speed filtration technology can shorten the process flow and improve operating economy.

[0022] 7) The present invention couples the adsorption technology with the salt separation and purification technology for the first time to construct a new zero-emission coupling process, which cleverly solves the contradiction between concentration and scaling in the current zero-emission process, realizes the resource utilization of waste, and transforms the contradictory technologies into a mutually coupled process. It is advanced and innovative, and can effectively solve the problems of high pressure and high pretreatment requirements in membrane concentration technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is the process principle diagram of in-situ coupling synergistic hardness removal and resource utilization;

[0025] Figure 2 This is the principle diagram of the combination of in-situ coupled synergistic hardness removal technology and particle film technology;

[0026] Figure 3 This is a process flow chart of Example 1;

[0027] Figure 4 This is a process flow chart of Example 2;

[0028] Figure 5 This is a process flow chart of Example 3. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] like Figure 1 As shown, this embodiment provides an in-situ coupled synergistic hardness removal and resource utilization process, including a hardness removal process section and a concentration and salt separation process section;

[0032] The hardness removal process section includes a hardness adsorption module, an analysis module, and a calcium recovery module;

[0033] The hardness adsorption module is composed of a hardness adsorption component, and the hardness adsorption component is in the form of, but not limited to, a column structure, a tank structure, a trough structure, etc. The component is filled with a hardness removal adsorbent to extract the hardness in the incoming water;

[0034] The hardness adsorption component can be filled with different functional adsorbents according to the water inlet conditions to achieve the collaborative processing function of the subsequent process;

[0035] The analysis module includes an analysis liquid tank, an analysis liquid pump, and an analysis liquid filter connected in sequence. The operation mode of the analysis module includes continuous analysis, group analysis, or complete analysis, which is used to analyze the hardness adsorption module and restore the adsorption function of the adsorbent;

[0036] The calcium recovery module includes but is not limited to one or more equipment such as an ultra-gravity reactor, a high-efficiency separator, a connected precipitant pump and precipitant tank, a high-density tank, a reaction tank, etc. This module is mainly used to treat the analytical waste liquid generated by the analytical module and the hardness adsorption module. The waste liquid of the calcium recovery module can be processed into products, such as producing calcium sulfate, defluoridation agent, etc.;

[0037] The concentration and salt separation process section is used to extract salt, alkalinity and other ions from purified water, including but not limited to extracting sodium chloride, potassium chloride, sodium nitrate, potassium sulfate, carbonate, sulfate, silicate, hydroxide ion, fluoride ion and other inorganic salts from water, and its salt separation process includes but is not limited to membrane concentration, evaporation and other methods;

[0038] The salt extracted in the concentration and salt separation process section includes but is not limited to one or several inorganic salts such as sodium chloride, potassium chloride, sodium nitrate, potassium sulfate, etc., which are used as analytical agents in the hardness removal process section; the extracted carbonates, sulfates, silicates, hydroxide ions, fluoride ions, etc., one or several inorganic salts are used as precipitants, and the hardness extracted by the hardness adsorption module is treated by the calcium recovery module to achieve calcium ion recovery and utilization, thereby achieving the purpose of treating the hardness in the raw water with the ions in the raw water without adding drugs;

[0039] The present invention is combined with particle membrane technology to shorten the zero-emission process and solve problems such as turbidity, hardness, and salt concentration. The specific embodiments are as follows:

[0040] like Figure 2 As shown, the process flow also includes a turbidity removal process section for removing turbidity in the incoming water to ensure stable operation of the hardness removal process section, which is implemented by a skid-type structure formed by a particle membrane high-speed filtration component, and the particle membrane high-speed filtration component includes but is not limited to a column structure, a tank structure, a trough structure, etc.;

[0041] In this embodiment, 1) the particle membrane high-speed filtration component of the turbidity removal process section has a columnar appearance, small footprint, small backwash flow, short backwash time, and excellent effluent quality. 2) The in-situ coupled synergistic hardness removal process section does not require the addition of external agents and no analytical waste liquid is generated, and the analytical waste liquid is directly used as a product raw material. 3) The concentrated salt separation process section produces water for reuse, and the by-product sodium sulfate can be widely used in the textile and papermaking industries.

[0042] Example 1

[0043] like Figure 3As shown, the raw water is low-sodium sulfate and high-sodium chloride brine, which is sent to the turbidity removal process section. The turbidity removal process section adopts a particle membrane high-speed filtration component and is a skid-mounted structure for removing turbidity, suspended matter, and colloids in the incoming water. The raw water is then sent to the in-situ coupled synergistic hardness removal process section, which is used to remove hardness in the water. The produced water after hardness removal enters the reverse osmosis device. The reverse osmosis produced water is desalted water and can be used for production; the reverse osmosis concentrate is a high-concentration brine containing sodium sulfate, which enters the nanofiltration device. The nanofiltration produced water is a brine containing sodium chloride and is used as an analytical agent in the in-situ coupled synergistic hardness removal process section; the concentrate from the nanofiltration device is a brine containing sodium sulfate and can be used in the papermaking and textile industries.

[0044] Example 2

[0045] like Figure 4 As shown, the raw water is mine water, and the water quality characteristics are high sodium sulfate and low sodium chloride brine, water hardness 650mg / L, sodium sulfate content 3350mg / L, sodium chloride content 661mg / L, suspended solids content 118mg / L, turbidity 122NTU, and the process adopts "particle membrane + in-situ coupling synergistic hardness removal technology". The raw water is first sent to the turbidity removal process section, which adopts a particle membrane high-speed filtration component and a skid-mounted structure to remove turbidity, suspended matter, and colloids in the incoming water, and the turbidity of the produced water is <1NTU; then it is sent to the in-situ coupling collaborative hardness removal process section, which is used to extract the hardness in the water, and the hardness of the produced water is <5mg / L; the produced water is sent to the nanofiltration device, and the nanofiltration produced water enters the reverse osmosis. The reverse osmosis fresh water is desalted water and can be used for production; the reverse osmosis concentrated water is high-concentration brine with a sodium chloride content of >2440mg / L. The high-concentration brine is sent to the in-situ coupling device and used as the analytical agent of the in-situ coupling device. The analytical waste liquid of the in-situ coupling device reacts with the nanofiltration concentrated water in an ultra-gravity reactor to generate calcium sulfate.

[0046] Example 3

[0047] like Figure 5 As shown, the raw water is coal gasification ash water with a flow rate of 106t / h, a hardness of 1620mg / L, a suspended solids content of 138mg / L and a turbidity of 141NTU. The process adopts "particle membrane + in-situ coupling synergistic hardness removal technology". After being sent into the particle membrane to remove turbidity, suspended solids and colloids, the turbidity of the produced water is less than 1.2NTU, and it enters the in-situ coupling to extract the hardness of the water. The produced water after hardness removal enters the ash water tank and is pressurized by a pump and sent to the vaporization furnace for recycling and reuse; the coal gasification ash water tank is sent to the reverse osmosis device after sewage discharge, and the fresh water of the reverse osmosis device can be recycled for production, and the reverse osmosis concentrated water is a highly concentrated brine, which enters the evaporation and crystallization device, and the concentrated solution produced by evaporation and crystallization is sent to the in-situ coupling device for use as the analytical agent of the in-situ coupling device. The analytical waste liquid produced by the in-situ coupling device is calcium chloride, which can be used as a defluorination agent.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An in-situ coupled synergistic hardness removal and resource utilization process, characterized in that: It includes a hardness removal process section and a concentration and salt separation process section. The hardness removal process section is used to remove the hardness in the water, and the concentration and salt separation process section is used to extract and purify the salt and alkalinity ions in the water.

2. According to claim 1, the in-situ coupled synergistic hardness removal and resource utilization process is characterized in that: The hardness removal process section includes a hardness adsorption module, an analysis module, and a calcium recovery module. The hardness adsorption module is used to extract the hardness in the incoming water; the analysis module is used to analyze the hardness adsorption module to restore the adsorption function of the adsorbent of the hardness adsorption module; the calcium recovery module is used to process the analysis waste liquid generated by the analysis module and the hardness adsorption module.

3. According to claim 2, an in-situ coupled synergistic hardness removal and resource utilization process is characterized in that: The hardness adsorption module includes a hardness adsorption component. The hardness adsorption component includes a column structure, a tank structure, and a trough structure. The component is filled with a hardness removal adsorbent.

4. According to claim 3, the in-situ coupled synergistic hardness removal and resource utilization process is characterized in that: The hardness adsorption component is filled with different functional adsorbents according to the water inlet conditions to achieve the collaborative processing function of the subsequent process.

5. According to claim 2, the in-situ coupled synergistic hardness removal and resource utilization process is characterized in that: The analysis module includes an analysis liquid tank, an analysis liquid pump and an analysis liquid filter which are connected in sequence. The operation mode of the analysis module includes continuous analysis, group analysis or complete analysis.

6. According to claim 2, the in-situ coupled synergistic hardness removal and resource utilization process is characterized in that: The calcium recovery module comprises one or more of a supergravity reactor, a high-efficiency separator, a connected precipitant pump and precipitant tank, a high-density tank, and a reaction tank; the waste liquid generated by the calcium recovery module is processed into products.

7. According to claim 1, the in-situ coupled synergistic hardness removal and resource utilization process is characterized in that: The concentration and salt separation process section is used to extract inorganic salts from purified water, including sodium chloride, potassium chloride, sodium nitrate, potassium sulfate, carbonate, sulfate, silicate, hydroxide ion, and fluoride ion, and the salt separation method includes membrane concentration and evaporation.

8. According to claim 7, the in-situ coupled synergistic hardness removal and resource utilization process is characterized in that: The salt extracted in the concentration and salt separation process section includes one or several inorganic salts such as sodium chloride, potassium chloride, sodium nitrate and potassium sulfate, which are used as analytical agents in the hardness removal process section; the extracted one or several inorganic salts such as carbonate, sulfate, silicate, hydroxide ion and fluoride ion are used as precipitants, and the hardness extracted by the hardness adsorption module is processed by the calcium recovery module to realize the recovery and utilization of calcium ions, thereby realizing the purpose of treating the hardness in the raw water with ions in the raw water without adding drugs.

9. The in-situ coupled synergistic hardness removal and resource utilization process according to claim 1, characterized in that: It also includes a turbidity removal process section, which is used to remove turbidity in the incoming water to ensure stable operation of the hardness removal process section; this process section is realized by a skid-type structure formed by a particle membrane high-speed filtration component, and the particle membrane high-speed filtration component is a column structure, a tank structure, and a trough structure.

10. The in-situ coupled synergistic hardness removal and resource utilization process according to claim 1, characterized in that: The concentration and salt separation process section is a hardness removal process section for extracting raw materials, and the hardness removal process section is a concentration and salt separation process section for removing hardness to ensure stable operation of the concentration and salt separation process section. The two process sections are mutually conditional and complementary.

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