WO2021036406A1

WO2021036406A1 - Zero liquid discharge systems and processes for high-salinity wastewater treatment

Info

Publication number: WO2021036406A1
Application number: PCT/CN2020/095282
Authority: WO
Inventors: Shuaifei ZHAO; Yang Zhang; Juan Du; Lian DU
Original assignee: Nanjing Bidun Environmental Protection Technology Co.
Priority date: 2019-08-28
Filing date: 2020-06-10
Publication date: 2021-03-04
Also published as: CN110550802A

Abstract

Disclosed are zero liquid discharge systems and processes for high-salinity solution treatment, the system comprises an electrodialysis treatment module, a membrane filtration concentration treatment module and a thermal concentration treatment module, wherein the electrodialysis treatment module comprises a plurality of treatment units between a cathode and an anode, each unit comprises a first diluting chamber, a first concentrate chamber, a feed solution chamber and a second concentrate chamber which are spaced by an exchange membrane, the membrane filtration concentration treatment module includes a first and a second membrane filtration concentrating device, which have inlets communicated correspondingly with the high-concentration solution outlets of the first and the second concentrate chamber, the thermal concentration treatment module includes a first and a second thermal concentrating device, which have inlets communicated correspondingly with the high-concentration solution outlets of the first and the second membrane filtration concentrating device. The present application well combines an electrodialysis device, a membrane filtration concentrating device and a thermal concentrating device to treat the high-salinity solution with the advantages of: simplified process, less or avoided use of chemical reagents and therefore more environmental friendliness; capability of deep concentration to achieve zero liquid discharge or near zero liquid discharge; capability of separate recovery of water and salt; and capability of effective utilization of waste heat and reducing the energy consumption.

Description

ZERO LIQUID DISCHARGE SYSTEMS AND PROCESSES FOR HIGH-SALINITY WASTEWATER TREATMENT

Technical field

The present application belongs to the fields of water treatment, chemical engineering and environmental engineering, and relates to zero liquid discharge systems and processes for high-salinity wastewater treatment.

Background

With the increasingly serious water pollution and water shortages, high-quality drinking water resources, such as qualified groundwater as well as the water from rivers and lakes are getting fewer. In order to address this issue, we have developed an environment-friendly and energy-saving zero liquid discharge technology and equipment for high-salinity brine. As a common industrial wastewater, high-salinity wastewater can be found in many industries and has huge quantity. The high-salinity wastewater comes mainly from, for example: printing and dyeing wastewater, electroplating wastewater, coal chemical and petrochemical wastewater, oil and gas (such as shale gas) produced water, reverse osmosis desalination brine, desulfurization wastewater, etc.

Seawater, the most abundant water resource on earth, is the dominant means to solve the shortage of drinking water in the future. However, at present, seawater desalination mainly relies on reverse osmosis technology, which has the disadvantages of serious membrane fouling and relatively low water recovery (～50%) . In addition, brackish water is the main source of drinking water in certain areas (e.g. some islands) , but it cannot be consumed directly. Desalination methods therefor primarily include distillation and membrane filtration, with the drawbacks of high costs, low water recovery, and high salinity brine discharge issues.

In the present application, high-salinity solutions relates to all of high-salinity wastewater, seawater, brackish water, and desalination brine. At present, the treatment processes for high-salinity solutions comprise the thermal method, membrane method and electrosorption method. The processes above generally further require pretreatment processes to remove suspended solids, part of organics, and petroleum contaminants from the wastewater. Pretreatment methods, such as air flotation, coagulation, precipitation, filtration, intend mainly to meet the water intake conditions of processes such as the membrane process, the thermal process and the electrosorption process. Any of the three processes above alone may has different disadvantages, for example, a lower water recovery of under 60%for the membrane process alone; a higher running cost for the thermal method alone and for the electrosorption; the produced water is difficult to meet the recycling standard. It is therefore necessary to provide an integrated process to effectively treat high-salinity solutions.

Electrodialysis, as a new technology developed in the 1950s originally for seawater desalination, is now widely used in chemical engineering, light industry, metallurgy, papermaking, and pharmaceutical industries, especially favored in the production of pure water and the treatment of the three types of wastes (i.e. waste gas, waste water and waste residue) in environmental protection. In the existing integrated process for treating high-salinity solution, an electrodialysis treatment step has been included. Chinese patent CN201310310857.9 disclosed a near-zero liquid discharge process for salt-containing wastewater, which includes steps of ultrafiltration, reverse osmosis, electrodialysis and heat treatment (evaporation crystallization) , wherein the electrodialysis is used for treating the high-concentration solution after the steps of ultrafiltration and reverse osmosis, which has high total salt solubility and is prone to block the electrodialysis membrane, resulting in high maintenance cost in practical application. Chinese application patent CN201110123654. X disclosed a new process for separation and recovery of salty wastewater with combined membrane, which comprises the steps of pretreatment, preliminary treatment, electrodialysis and reverse osmosis. Electrodialysis is before the reverse osmosis step in order to treat the brine after pretreatment and preliminary treatment, so that the probability of blocking the electrodialysis membrane is reduced. However, the high-concentration solution produced by the electrodialysis step is not effectively treated and cannot achieve zero liquid discharge or near zero liquid discharge.

Summary

The technical issue to be addressed by the present application is to provide zero liquid discharge systems and processes for high-salinity solution treatment, intending to overcome the defects of the prior art, such as high energy consumption, low efficiency and incapability of zero liquid discharge or near zero liquid discharge, when the high-salinity wastewater and seawater are desalted.

The present application addresses the above technical issues by the following technical solutions: a zero liquid discharge system for high-salinity solution treatment. It comprises an electrodialysis treatment module, a membrane filtration concentration treatment module and a thermal concentration treatment module; wherein the electrodialysis treatment module comprises a plurality of treatment units between a cathode and an anode, each treatment unit comprises a first diluting chamber, a first concentrate chamber, a feed solution chamber and a second concentrate chamber which are sequentially spaced by anion and cation exchange membranes, wherein the feed solution chamber is provided with an inlet for intaking a high-salinity solution and an outlet for discharging a first low-concentration solution; the first diluting chamber has an inlet for intaking a low-concentration brine and an outlet for discharging a low-concentration solution, and the outlet of the first diluting chamber is configured to output a second low-concentration solution; both of the first concentrate chamber and the second concentrate chamber individually have an inlet for intaking a low-concentration solution and an outlet for discharging high-concentration solution, wherein the outlets of the first and the second concentrate chamber are configured to output a first and a second high-concentration solution, respectively. The membrane filtration concentration treatment module is an ion fractionation module by filtration and includes a first membrane filtration concentrating device and a second membrane filtration concentrating device, which have inlets communicated correspondingly with the outlets of the first and the second concentrate chamber respectively. The first membrane filtration concentrating device has two outlets, one for discharging a first low-concentration brine or a third low-concentration solution and the other one for discharging a third high-concentration solution. The second membrane filtration concentrating device also has two outlets, one for discharging a second low-concentration brine or a fourth low-concentration solution and the other for discharging a fourth high-concentration solution. The thermal concentration treatment module includes a first thermal concentrating device and a second thermal concentrating device, which have inlets communicated correspondingly with the outlets of the first and the second membrane filtration concentrating device for discharging the third and the fourth high-concentration solution respectively. The first thermal concentrating device has two outlets, one for discharging a fifth low-concentration solution and the other one for discharging a first super concentrated brine or a first solid salt; the second thermal concentrating device also has two outlets, one for discharging a sixth low-concentration solution, and the other one for discharging a second super concentrated brine or a second solid salt.

Based on the above technical solutions, the present application may further have the following specific selections.

Specifically, when the corresponding outlets of the first and the second membrane filtration concentrating device both output low-concentration brine, and the ions contained in the low-concentration brine are not easy to react with the counter ions in the first or the second concentrate chamber to form a salt easy to precipitate, the inlet of the first diluting chamber for intaking the low-concentration brine is communicated with the corresponding outlet of the first or the second membrane filtration concentrating device for discharging the first or the second low-concentration brine. Herein, "the ions contained in the low-concentration brine are not easy to react with the counter ions in the first or the second concentrate chamber to form a salt easy to precipitate" means that all of the salts formed by the ions contained in the low-concentration brine and the counter ions in the first concentrate chamber or the second concentrate chamber have a high solubility.

Specifically, the first and the second membrane filtration concentrating device are respectively selected from one of the group consisting of an ultrafiltration concentrating device, a nanofiltration concentrating device and a reverse osmosis concentrating device, or a combination of at least two thereof.

Specifically, the first and the second thermal concentration treatment device are respectively selected from one of the group consisting of a distillation concentrating device, a membrane distillation concentrating device, a flash concentrating device, an evaporation concentrating device, and a multi-stage flash concentrating device, or a combination of at least two thereof.

Specifically, the total dissolved solid concentrations of both the first and the second low-concentration brine discharged from the first and the second membrane filtration concentrating device range from 50-50,000 mg/L.

Specifically, the total dissolved solid (TDS) concentration of the high-salinity solution that enters the feed solution chamber via the high-salinity solution inlet ranges from 2,000-50,000 mg/L, and the TDS concentrations of the first and the second super concentrated brine range above 200,000 mg/L respectively.

In addition, the present application also provides a zero liquid discharge process for high-salinity solution treatment, which is processed by using the above-mentioned treatment system, and includes the following steps:

S1. Initially, after the pretreatment the high-salinity solution is infused into the corresponding feed solution chamber of the electrodialysis treatment module via the high-salinity solution inlet, a low-concentration brine is infused into the first diluting chamber of the electrodialysis treatment module, a low-concentration solution is infused into the first and the second concentrate chamber respectively, and electrodialysis treatment is then conducted, wherein the anions in the high-salinity solution within the feed solution chamber migrate to the first concentrate chamber and the cations migrate to the second concentrate chamber, and the cations in the first diluting chamber migrate to the first concentrate chamber and the anions migrate to the second concentrate chamber;

S2. After the electrodialysis treatment, the first low-concentration solution obtained from the feed solution chamber is outputted via the first low-concentration solution outlet, and the first and the second high-concentration solution obtained from the first and the second concentrate chamber are respectively outputted to the first and the second membrane filtration concentrating device for membrane filtration concentrating treatment, and after that, one outlet of the first membrane filtration concentrating device outputs the first low-concentration brine or the third low-concentration solution, and the other outlet thereof outputs the third high-concentration solution, one outlet of the second membrane filtration concentrating device outputs the second low-concentration brine or the fourth low-concentration solution, and the other outlet thereof outputs the fourth high-concentration solution;

S3. The third and the fourth high-concentration solution are respectively outputted into the first and the second thermal concentrating device for thermal concentration treatment, after that, one outlet of the first thermal concentrating device outputs the fifth low-concentration solution, and the other outlet thereof outputs the first super concentrated brine or the first solid salt, and one outlet of the second thermal concentrating device outputs the sixth low-concentration solution, and the other outlet thereof outputs the second super concentrated brine or the second solid salt.

Based on the above process, the present application may also have the following specific options.

Specifically, in S2, when the corresponding outlets of the first and the second membrane filtration concentrating device output the first and the second low-concentration brine, and the ions contained in the low-concentration brine are not easy to react with the counter ions in the first or the second concentrate chamber to form a salt easy to precipitate, the first or the second low-concentration brine is outputted into the first diluting chamber to replenish ions to the electrodialysis process.

Specifically, the pre-treated high-salinity solution in S1 contains cations including one or more selected from the group consisting of sodium, potassium, silver, calcium, magnesium, copper, nickel, barium, aluminum, zinc, manganese, iron, ferrous and ammonium ions, and contains anions including one or more selected from the group consisting of chlorine, sulfate, carbonate, nitrate, phosphate, oxalate, and benzoate ions.

Specifically, the heat source for the thermal concentration treatment in S3 is terrestrial heat, solar energy, coal combustion heat, gasoline combustion heat, diesel combustion heat, natural gas combustion heat, hydrogen combustion heat, electric heating, steam afterheat or flue afterheat, and the temperature therefor is 40-300 ℃.

As compared to the prior art, the present application has the following beneficial effects:

The present application well combines an electrodialysis device, a membrane filtration concentrating device (ultrafiltration, nanofiltration, reverse osmosis device, etc. ) and a thermal concentrating device (membrane distillation, flash, evaporation device, etc. ) to deeply concentrate the high-salinity solution. Thus the present application has the following advantages: process is simplified; use of chemical reagents (such as scale inhibitors) are less or even avoid and therefore the process is more clean and eco-friendly; deep concentration can be performed to achieve zero liquid discharge or near zero liquid discharge and high water recovery rate (up to 99%) ; the separation and recovery of water and salt can be simultaneously achieved; and the waste heat can be effectively utilized so that the energy consumption throughout the process is reduced.

Brief Description of the Drawings

Fig. 1 is a schematic diagram of a zero liquid discharge system for high-salinity solution treatment according to an specific embodiment of the present application.

Detailed Description

The principles and features of the present application are described in combination with the accompanying drawings and specific embodiments. The examples are for illustrative purposes only and are not intended to limit the scope of the present application.

In the following examples, the devices used are conventional devices in the art, and the methods used are conventional methods in the art, unless otherwise specified.

As shown in Fig. 1, the present application provides a zero liquid discharge system for high-salinity solution treatment, which comprises an electrodialysis treatment module, a membrane filtration concentration treatment module and a thermal concentration treatment module, wherein the electrodialysis treatment module comprises a plurality of treatment units between a cathode and an anode, each treatment unit comprises a first diluting chamber, a first concentrate chamber, a feed solution chamber and a second concentrate chamber which are sequentially spaced by an exchange membrane, wherein the feed solution chamber is provided with an inlet for intaking a high-salinity solution and an outlet for discharging a first low-concentration solution, the first diluting chamber has an inlet for intaking a low-concentration brine and an outlet for discharging a low-concentration solution, and the outlet of the first diluting chamber is configured to output a second low-concentration solution; both of the first concentrate chamber and the second concentrate chamber individually have an inlet for intaking a low-concentration solution and an outlet for discharging high-concentration solution, wherein the outlets of the first and the second concentrate chamber are configured to output a firstand a second high-concentration solution, respectively. The membrane filtration concentration treatment module includes a first membrane filtration concentrating device and a second membrane filtration concentrating device, which have inlets communicated correspondingly with the outlets of the first and the second concentrate chamber respectively. The first membrane filtration concentrating device has two outlets, one for discharging a first low-concentration brine or a third low-concentration solution and the other one for discharging a third high-concentration solution; the second membrane filtration concentrating device also has two outlets, one for discharging a second low-concentration brine or a fourth low-concentration solution and the other for discharging a fourth high-concentration solution. The thermal concentration treatment module includes a first thermal concentrating device and a second thermal concentrating device, which have inlets communicated correspondingly with the outlets of the first and the second membrane filtration concentrating device for discharging the third and the fourth high-concentration solution respectively. The first thermal concentrating device has two outlets, one for discharging a fifth low-concentration solution and the other one for discharging a first super concentrated brine or a first solid salt; the second thermal concentrating device also has two outlets, one for discharging a sixth low-concentration solution, and the other one for discharging a second super concentrated brine or a second solid salt.

It should be noted that the high-concentration solutions produced by the first and the second concentrate chamber during the electrodialysis have relatively high solubility, thus the concentration process generally does not have a negative impact on the concentration devices due to scale formation. The plurality of treatment units may be divided into a plurality of groups, and all of them may share one membrane filtration concentration treatment module and thermal concentration treatment module, or each or several of them may correspond to one membrane filtration concentration treatment module and thermal concentration treatment module, which may be selected flexibly according to actual needs. The liquids in the first diluting chamber, the first concentrate chamber, the feed solution chamber and the second concentrate chamber may be one-way or cyclic, that is, the liquids in the first diluting chamber, the first concentrate chamber, the feed solution chamber and the second concentrate chamber, after the electrodialysis treatment, can directly enter a next device or be reused or discharged, or can be returned to the first diluting chamber, the first concentrate chamber, the feed solution chamber and the second concentrate chamber for retreatment, and then enter a next device or are reused or discharged until they meet the requirements. The concentrations of the first and the second super concentrated brine are very high, and can be saturated or even evaporated to a corresponding first or a second solid salt by afterheat.

Specifically, when the corresponding outlets of the first and the second membrane filtration concentrating device both outputs low-concentration brine, and the ions contained in the low-concentration brine are not easy to react with the counter ions in the first or the second concentrate chamber to form a salt easy to precipitate, in this case, the inlet of the first diluting chamber for intaking the low-concentration brine is communicated with the corresponding outlet of the first or the second membrane filtration concentrating device for discharging the first low-concentration brine or the second low-concentration brine. On one hand, the discharged low-concentration brine can be desalinized again, and on the other hand, it is an ion supplement for the electrodialysis treatment process to avoid separately collecting or arranging the low-concentration brine supplied for the normal running of the electrodialysis treatment.

Specifically, the first and the second membrane filtration concentrating device may be respectively one of an ultrafiltration concentrating device, a nanofiltration concentrating device and a reverse osmosis concentrating device, or a combination of at least two thereof.

It should be noted that when the specific devices and types of the membrane filtration concentrating device mentioned above are different, and the ion concentration in the permeate is correspondingly different, so that it is possible to produce low-concentration brine or low-concentration solution that can be directly used and meets the corresponding standards.

Specifically, the first and the second thermal concentration treatment device can be respectively one selected from the group consisting of a distillation concentrating device, a membrane distillation concentrating device, a flash concentrating device, an evaporation concentrating device, and a multi-stage flash concentrating device, or a combination of at least two thereof.

Example 1

In this example, in the above-mentioned zero liquid discharge system for high-salinity solution treatment, the first and the second membrane filtration concentrating device are respectively a nanofiltration concentrating device, the first and the second thermal concentration treatment device are respectively a membrane distillation concentrating device, and the heat source during heat concentration is a flue afterheat.

Example 2

In this example, in the above-mentioned zero liquid discharge system for high-salinity solution treatment, the first and the second membrane filtration concentrating device are respectively a reverse osmosis concentrating device, the first and the second thermal concentration treatment device are respectively a distillation concentrating device, and the heat source during heat concentration is electric heating.

Example 3

In this example, in the above-mentioned zero liquid discharge system for high-salinity solution treatment, the first membrane filtration concentrating device is a reverse osmosis device, the second membrane filtration concentrating device is a nanofiltration concentrating device, the first thermal concentration treatment device is a membrane distillation concentrating device, the second thermal concentration treatment device is a evaporation concentrating device, and the heat source during heat concentration is electric heating.

Example 4

In this example, when the oil recovery wastewater was purified by the treatment system corresponding to Example 1, the following steps were specifically included:

S1. Initially, the oil recovery wastewater (with the TDS of 2,430 mg/L and the ions contained are of the following concentrations: sodium ions at 520 mg/L, magnesium ions at 90 mg/L, calcium ions at 200 mg/L, chloride ions at 580 mg/L, sulfate ions at 1,060 mg/L) was pretreated and then infused into the corresponding feed solution chamber of the electrodialysis treatment module via the high-salinity solution inlet, a low-concentration brine (a sodium chloride solution with the TDS of 42,710 mg/L) was infused into the first diluting chamber of the electrodialysis treatment module, a low-concentration solution was infused into the first concentrate chamber and the second concentrate chamber respectively, and electrodialysis treatment was conducted, wherein the anions in the high-salinity solution within the feed solution chamber migrated to the first concentrate chamber and the cations migrated to the second concentrate chamber, and the cations in the first diluting chamber migrated to the first concentrate chamber and the anions migrated to the second concentrate chamber;

S2. After the electrodialysis treatment, the first low-concentration solution obtained from the feed solution chamber was outputted via the first low-concentration solution outlet, and the first high-concentration solution (with the TDS of 54,770 mg/L and the ions contained are of the following concentrations: sodium ions at 22,460 mg/L, magnesium ions at 0 mg/L, calcium ions at 0 mg/L, chloride ions at 13,730 mg/L, sulfate ions at 18,580 mg/L) and the second high-concentration solution (with the TDS of 42,800 mg/L and the ions contained are of the following concentrations: sodium ions at 12,200 mg/L, magnesium ions at 2,300 mg/L, calcium ions at 2,260 mg/L, chloride ions at 24,870 mg/L, sulfate ions at 1,170 mg/L) obtained from the first and the second concentrate chamber were respectively outputted to the first membrane filtration concentrating device (nanofiltration) and the second membrane filtration concentrating device (nanofiltration) for nanofiltration concentrating treatment respectively, and after nanofiltration concentrating treatment, one outlet of the first membrane filtration concentrating device output the first low-concentration brine (with the TDS of 54,320 mg/L and the ions contained are of the following concentrations: sodium ions at 22,520 mg/L, magnesium ions at 0 mg/L, calcium ions at 0 mg/L, chloride ions at 31,800 mg/L, sulfate ions at 4 mg/L) , and the other outlet thereof output the third high-concentration solution (with the TDS of 79,390 mg/L and the ions contained are of the following concentrations: sodium ions at 27,180 mg/L, magnesium ions at 0 mg/L, calcium ions at 0 mg/L, chloride ions at 33,010 mg/L, sulfate ions at 19,200 mg/L) , one outlet of the second membrane filtration concentrating device output the second low-concentration brine (with the TDS of 31,100 mg/L and the ions contained are of the following concentrations: sodium ions at 12,290 mg/L, magnesium ions at 30 mg/L, calcium ions at 20 mg/L, chloride ions at 18,770 mg/L, sulfate ions at 0 mg/L) , and the other outlet thereof output the fourth high-concentration solution (with the TDS of 61,450 mg/L and the ions contained are of the following concentrations: sodium ions at 13,920 mg/L, magnesium ions at 4,040 mg/L, calcium ions at 3,120 mg/L, chloride ions at 38,520 mg/L, sulfate ions at 1,880 mg/L) ;

S3. The third and the fourth high-concentration solution were respectively outputted into the first thermal concentrating device (membrane distillation) and the second thermal concentrating device (membrane distillation) , for thermal concentration treatment, wherein the heat source used was hot steam after the thermal concentration treatment, one outlet of the first thermal concentrating device output the fifth low-concentration solution, and the other outlet thereof output the first super concentrated brine (with the TDS of 306,180 mg/L and the ions contained are of the following concentrations: sodium ions at 120,650 mg/L, magnesium ions at 0 mg/L, calcium ions at 0 mg/L, chloride ions at 132,060 mg/L, sulfate ions at 53,470 mg/L) , and one outlet of the second thermal concentrating device output the sixth low-concentration solution, and the other outlet thereof output the second super concentrated brine (with the TDS of 310,700 mg/L and the ions contained are of the following concentrations: sodium ions at 62,290 mg/L, magnesium ions at 21,080 mg/L, calcium ions at 16,300 mg/L, chloride ions at 201,230 mg/L, sulfate ions at 9,800 mg/L) .

It should be noted that the first low-concentration solution produced in this example contained some organics, which can enter a biochemical tank for further treatment; in the operation process of the treatment system, the first and the second low-concentration brine generated were mixed and then entered the first diluting chamber of the electrodialysis separation module; the second low-concentration solution generated had the TDS of less than 200 mg/L, and can be used as water supplement for the first and second electrodialysis concentrate chamber, and can also be directly used for other applications of an industrial park such as irrigation. The fifth and the sixth low-concentration solution generated were pure water, and part of the pure water was supplemented into the first or the second concentrate chamber of the electrodialysis treatment module, and can also be used as other industrial water.

From the above examples, by treating high-salinity solution using the treatment system and process provided by the present application, the total dissolved solid concentration of the obtained super concentrated brine reaches above 300,000mg/L, which is very close to the solubility limit of the solution at the thermal concentration treatment temperature, in other words, it is very concentrated, when the temperature is reduced to room temperature, the solubility is reduced, the salt is separated out, a small amount of water is essentially evaporated by the afterheat during cooling to room temperature, with only solid salt left, and zero liquid or near zero liquid output can be essentially achieved. Throughout the process, the water recovery rate in the high-salinity solution can be improved to more than 80%, even close to 100%, and the water recovery rate is greatly improved. The salt produced throughout the process can be directly or indirectly used as an industrial raw material (such as the printing and dyeing industry) , and the produced low-concentration solution (with the total dissolved solid concentration reaching the drinking water standard of WHO 500 mg/L) can be used as drinking water after further post-treatment such as disinfection and the like, and can also be directly used as industrial water.

The above are only preferred examples of the present application and should not be taken as limiting the present application, and any modification, equivalent substitution or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

A zero liquid discharge system for high-salinity solution treatment, comprising an electrodialysis treatment module, a membrane filtration concentration treatment module and a thermal concentration treatment module, wherein the electrodialysis treatment module comprises a plurality of treatment units between a cathode and an anode, each treatment unit comprises a first diluting chamber, a first concentrate chamber, a feed solution chamber and a second concentrate chamber which are sequentially spaced by anion and cation exchange membranes, wherein the feed solution chamber is provided with an inlet for intaking a high-salinity solution and an outlet for discharging a first low-concentration solution; the first diluting chamber has an inlet for intaking a low-concentration brine and an outlet for discharging a low-concentration solution, and the outlet of the first diluting chamber is configured to output a second low-concentration solution; both of the first concentrate chamber and the second concentrate chamber individually have an inlet for intaking a low-concentration solution and an outlet for discharging high-concentration solution, wherein the outlets of the first and the second concentrate chamber are configured to output a first and a second high-concentration solution, respectively. The membrane filtration concentration treatment module includes a first membrane filtration concentrating device and a second membrane filtration concentrating device, which have inlets communicated correspondingly with the outlets of the first and the second concentrate chamber respectively. The first membrane filtration concentrating device has two outlets, one for discharging a first low-concentration brine or a third low-concentration solution and the other one for discharging a third high-concentration solution; the second membrane filtration concentrating device also has two outlets, one for discharging a second low-concentration brine or a fourth low-concentration solution and the other one for discharging a fourth high-concentration solution. The thermal concentration treatment module includes a first thermal concentrating device and a second thermal concentrating device, which have inlets communicated correspondingly with the outlets of the first and the second membrane filtration concentrating device for discharging the third and the fourth high-concentration solution respectively. The first thermal concentrating device has two outlets, one for discharging a fifth low-concentration solution and the other one for discharging a first super concentrated brine or a first solid salt; the second thermal concentrating device also has two outlets, one for discharging a sixth low-concentration solution, and the other one for discharging a second super concentrated brine or a second solid salt.
The zero liquid discharge system for high-salinity solution treatment according to claim 1, wherein when the corresponding outlets of the first or the second membrane filtration concentrating device output low-concentration brine, and the ions contained in the low-concentration brine are not easy to react with the counter ions in the first or the second concentrate chamber to form a salt easy to precipitate, the inlet of the first diluting chamber is communicated with the corresponding outlet of the first or the second membrane filtration concentrating device for discharging the first or the second low-concentration brine.
The zero liquid discharge system for high-salinity solution treatment according to claim 1, wherein the first and the second membrane filtration concentrating device are respectively selected from one of the group consisting of an ultrafiltration concentrating device, a nanofiltration concentrating device and a reverse osmosis concentrating device, or a combination of at least two thereof.
The zero liquid discharge system for high-salinity solution treatment according to claim 1, wherein the first and the second thermal concentration treatment device are respectively selected from one of the group consisting of a distillation concentrating device, a membrane distillation concentrating device, a flash concentrating device, an evaporation concentrating device, and a multi-stage flash concentrating device, or a combination of at least two thereof.
The zero liquid discharge system for high-salinity solution treatment according to claim 1, wherein the total dissolved solid concentrations of both the first and the second low-concentration brine discharged from the first and the second membrane filtration concentrating device range from 50-50,000 mg/L.
The zero liquid discharge system for high-salinity solution treatment according to any one of claims 1 to 5, wherein the total dissolved solid concentration of the high-salinity solution that enters the feed solution chamber via the high-salinity solution inlet ranges from 2000-50,000 mg/L, and the total dissolved solid concentrations of the first and the second super concentrated brine range above 200,000 mg/L, respectively.
A zero liquid discharge process for high-salinity solution treatment by using the treatment system according to any one of claims 1 to 6, comprising the following steps:

S1. Initially, after the pretreatment, the high-salinity solution is infused into the corresponding feed solution chamber of the electrodialysis treatment module via the high-salinity solution inlet, a low-concentration brine is infused into the first diluting chamber of the electrodialysis treatment module, a low-concentration solution is infused into the first and the second concentrate chamber respectively, and electrodialysis treatment is then conducted, wherein the anions in the high-salinity solution within the feed solution chamber migrate to the first concentrate chamber and the cations migrate to the second concentrate chamber, and the cations in the first diluting chamber migrate to the first concentrate chamber and the anions migrate to the second concentrate chamber;

S2. After the electrodialysis treatment, the first low-concentration solution obtained from the feed solution chamber is outputted via the first low-concentration solution outlet, and the first and the second high-concentration solution obtained from the first and the second concentrate chamber are respectively outputted to the first and the second membrane filtration concentrating device for membrane filtration concentrating treatment, and after that, one outlet of the first membrane filtration concentrating device outputs the first low-concentration brine or the third low-concentration solution, and the other outlet thereof outputs the third high-concentration solution, one outlet of the second membrane filtration concentrating device outputs the second low-concentration brine or the fourth low-concentration solution, and the other outlet thereof outputs the fourth high-concentration solution;

S3. The third and the fourth high-concentration solution are respectively outputted into the first and the second thermal concentrating device, for thermal concentration treatment, after that, one outlet of the first thermal concentrating device outputs the fifth low-concentration solution, and the other outlet thereof outputs the first super concentrated brine or the first solid salt, and one outlet of the second thermal concentrating device outputs the sixth low-concentration solution, and the other outlet thereof outputs the second super concentrated brine or the second solid salt.
The zero liquid discharge process for high-salinity solution treatment according to claim 7, wherein in S2, when the corresponding outlets of the first and the second membrane filtration concentrating device output the first and the second low-concentration brine, the first or the second low-concentration brine is outputted into the first diluting chamber to replenish ions to the electrodialysis process.
The zero liquid discharge process for high-salinity solution treatment according to claim 7, wherein the pre-treated high-salinity solution in S1 contains cations including one or more selected from the group consisting of sodium, potassium, silver, calcium, magnesium, copper, nickel, barium, aluminum, zinc, manganese, iron, ferrous and ammonium ions, and contains anions including one or more selected from the group consisting of chlorine, sulfate, carbonate, nitrate, phosphate, oxalate, and benzoate ions.
The zero liquid discharge process for high-salinity solution treatment according to claim 7, wherein the heat source for the thermal concentration treatment in S3 is terrestrial heat, solar energy, coal combustion heat, gasoline combustion heat, diesel combustion heat, natural gas combustion heat, hydrogen combustion heat, electric heating, steam afterheat or flue afterheat, and the temperature therefor is 40-300 ℃.