Method and device for recycling high-turbidity seawater resource

Abstract

The invention relates to the technical field of seawater resource utilization, and provides a method and a device for recycling high-turbidity seawater resources. According to the invention, high-turbidity seawater is treated by means of filtration, calcium and magnesium removal, boron removal, reverse osmosis and the like, high-salinity seawater, desalted and mineralized water and salinized soil can be recovered, the desalted and mineralized water can be used as irrigation water, and the high-salinity seawater can be used as aquaculture water; the nutrient soil can be obtained after the aquaculture nutrient-containing waste and the salinized soil are further treated. According to the invention, an agriculture-aquatic product-ecology coupling model for multistage utilization of seawater resources is created for the first time, an agricultural recycling type desalinated water mineralization regulation and control process based on a membrane separation technology is developed, and a closed-loop circulation system for gradient utilization of aquaculture tail water is established; a systematic solution covering water resource utilization, saline-alkali soil biological improvement and aquaculture is provided for coastal ecologically vulnerable areas, and the method has important theoretical value and practical guiding significance for constructing a sustainable agricultural-ecological compound system.

Description

Technical Field

[0001] The present invention relates to the technical field of seawater resource utilization, and in particular to a method and device for recovering high-turbidity seawater resources. Background Art

[0002] As climate change drives increasing soil degradation and desalinated water scarcity, the development and utilization of seawater resources has become a key approach to alleviating water stress. Highly turbid seawater, prevalent in estuaries and coastal areas, represents a vast potential reservoir of water. Utilizing this turbidity can effectively alleviate water stress in coastal and even inland areas, reducing reliance on desalinated water.

[0003] Currently, common methods for utilizing seawater as a resource include desalination, chemical extraction, and seawater irrigation. Desalination involves removing salt from seawater through methods such as distillation or reverse osmosis to produce desalinated water. Chemical extraction is most commonly achieved through seawater salt production, which involves evaporating seawater to crystallize salt and then further processing it into refined salt. Seawater irrigation typically involves irrigating salt-tolerant crops with seawater, selecting and cultivating salt-tolerant plant varieties, and irrigating them directly with seawater or diluted seawater. However, both the desalination and salt production industries partially utilize seawater, limiting the extent of resource utilization. Seawater irrigation is only suitable for salt-tolerant crops, and the current number of salt-tolerant crops is relatively small, resulting in relatively low yields and economic benefits. Furthermore, seawater irrigation can lead to increased soil salinization and other issues. Therefore, existing methods for utilizing seawater as a resource have significant limitations, making it difficult to achieve comprehensive utilization of seawater resources. Furthermore, existing seawater treatment technologies are mostly designed for conventional seawater and are not suitable for treating highly turbid seawater.

[0004] In summary, there is an urgent need to provide a method for efficient resource utilization of high turbidity seawater. Summary of the Invention

[0005] In view of this, the present invention provides a method and device for recovering high turbidity seawater resources. The method provided by the present invention can recover and utilize high turbidity seawater resources, with a high comprehensive utilization rate.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] A method for recovering high turbidity seawater resources comprises the following steps:

[0008] Filtering the highly turbid seawater to obtain filtered seawater and saline soil; the highly turbid seawater has a salinity of greater than 10,000 mg / L and a turbidity of greater than 100 NTU;

[0009] The filtered seawater is subjected to a calcium-magnesium removal treatment using an ion exchange resin to obtain calcium-magnesium-removed seawater and a calcium-magnesium adsorbing resin; the calcium-magnesium adsorbing resin is regenerated using an acetic acid solution to obtain a calcium-magnesium-containing solution; the calcium-magnesium-containing solution is mixed with a KOH solution to obtain a calcium-magnesium-potassium-containing solution;

[0010] performing a deboronization treatment on the decalcified and magnesium-depleted seawater using an ion exchange resin to obtain deboronized seawater;

[0011] The deboronized seawater is subjected to reverse osmosis treatment to obtain desalinated water and high-salinity seawater; the salinity of the high-salinity seawater is 45,000 to 50,000 mg / L;

[0012] The desalinated water and the calcium, magnesium and potassium-containing solution are mixed to obtain desalinated mineralized water.

[0013] Preferably, the soil recovery tank used for the filtration comprises a coarse solid material layer and a secondary filtration layer arranged at the bottom of the coarse solid material layer; the particle size of the coarse solid material in the coarse solid material layer is 0.05 to 2 mm; the pore size of the secondary filtration layer is 0.05 to 0.1 mm;

[0014] The highly turbid seawater is passed into the coarse-grained solid material layer of the soil recovery tank, and the solid particles in the seawater are intercepted by the coarse-grained solid material layer. Then, flushing water is passed into the top of the soil recovery tank for flushing. The intercepted solid particles pass through the secondary filtration layer under the action of the flushing water to collect saline soil.

[0015] Preferably, the ion exchange resin used in the decalcification and magnesium treatment is Purolite C100H IND type cation exchange resin; and the endpoint pH value of the mixture of the calcium-magnesium solution and the KOH solution is 6.8-7.2.

[0016] Preferably, the ion exchange resin used in the deboronation treatment is a chelated ion exchange resin functionalized with an N-methylglucamine group.

[0017] Preferably, the salinity of the desalinated water is less than 200 mg / L.

[0018] Preferably, the high-salinity seawater is used for aquaculture; the desalinated mineralized water is used for agricultural irrigation;

[0019] The nutrient-containing waste generated by the aquaculture is mixed with the saline soil and subjected to sedimentation treatment to obtain nutrient soil and nutrient water; the nutrient water and the residual runoff water after the agricultural irrigation are mixed and treated.

[0020] The present invention also provides a device for recovering high turbidity seawater resources, comprising:

[0021] A soil recovery tank comprising a coarse solid material layer and a secondary filtration layer disposed at the bottom of the coarse solid material layer;

[0022] a decalcification magnesium ion exchange system; the inlet of the decalcification magnesium ion exchange system is connected to the water outlet of the soil recovery tank;

[0023] regeneration tank; the inlet of the regeneration tank is connected to the resin outlet of the decalcification magnesium ion exchange system;

[0024] A mixing tank; the inlet of the mixing tank is connected to the water outlet of the regeneration tank;

[0025] a deboronation ion exchange system; the inlet of the deboronation ion exchange system is connected to the outlet of the decalcification and magnesium ion exchange system;

[0026] Reverse osmosis system; the inlet of the reverse osmosis system is connected to the outlet of the deboronation ion exchange system;

[0027] Remineralization tank; the inlet of the remineralization tank is connected to the water outlet of the mixing tank and the water outlet of the reverse osmosis system.

[0028] Preferably, the decalcified magnesium ion exchange system includes two ion exchange columns, which are switched for use.

[0029] Preferably, it also includes a sedimentation tank; the sedimentation tank is used to precipitate the saline soil produced in the soil recovery tank and the nutrient-containing waste produced by aquaculture.

[0030] Preferably, it also includes a sewage mixing tank; the sewage mixing tank is used to mix the runoff water remaining after agricultural irrigation and the nutrient water produced by the sedimentation tank.

[0031] The invention provides a method for recovering high-turbidity seawater resources, comprising the following steps: filtering high-turbidity seawater to obtain filtered seawater and saline soil, wherein the salinity of the high-turbidity seawater is greater than 10,000 mg / L and the turbidity is greater than 100 NTU; performing calcium-magnesium removal treatment on the filtered seawater by using an ion exchange resin to obtain calcium-magnesium-removed seawater and a calcium-magnesium-adsorbing resin; regenerating the calcium-magnesium-adsorbing resin by using an acetic acid solution to obtain a calcium-magnesium-containing solution; mixing the calcium-magnesium-containing solution with a KOH solution to obtain a calcium-magnesium-potassium-containing solution; performing boron removal treatment on the calcium-magnesium-removed seawater by using an ion exchange resin to obtain boron-removed seawater; performing reverse osmosis treatment on the boron-removed seawater to obtain desalinated water and high-salinity seawater, wherein the salinity of the high-salinity seawater is 45,000-50,000 mg / L; and mixing the desalinated water and the calcium-magnesium-potassium-containing solution to obtain desalinated mineralized water. In the traditional method, seawater is directly treated by reverse osmosis to prepare desalinated water. Both monovalent and divalent salts are removed in the reverse osmosis process. However, the Ca in the divalent salt is2+ and Mg 2+ It is a beneficial ion required for plant growth; the present invention uses acetic acid solution to treat the adsorbed calcium magnesium resin, thereby recovering calcium magnesium salts, and adding KOH to the resulting calcium magnesium solution for the mineralization of desalinated water. The resulting desalinated mineralized water contains calcium, magnesium, and potassium ions, which can be used for agricultural irrigation, supplementing essential nutrients for plant growth, and providing the mineral components required for healthy and sustainable agricultural productivity. In addition, the present invention controls the salinity level of high-salinity seawater to 45,000 to 50,000 mg / L, and the resulting high-salinity seawater can be used for aquaculture, achieving further resource utilization of seawater. Furthermore, the present invention precipitates the nutrient-containing waste generated by aquaculture and the saline soil generated by filtration to obtain nutrient soil. The porous structure of the saline soil can effectively retain and stabilize the nutrient-rich waste generated by aquaculture. The resulting nutrient soil can be used as a nutrient matrix for salt-tolerant crops and has high application potential in sustainable agriculture.

[0032] In summary, the present invention pioneered an agriculture-aquaculture-ecology (AAE) coupling model for multi-stage utilization of seawater resources, developed an agricultural reuse-type desalinated water mineralization control process based on membrane separation technology, and established a closed-loop circulation system for cascade utilization of aquaculture tailwater. This integrated solution provides a systematic solution for fragile coastal ecological areas covering water resource recycling, saline-alkali land biological improvement and low-carbon aquaculture through a multi-dimensional resource collaborative utilization strategy, which has important theoretical value and practical guiding significance for building the sustainability of agricultural-ecological complex systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the device for recovering high turbidity seawater resources provided by the present invention, wherein: 1-soil recovery tank, 2-decalcification and magnesium ion exchange system, 3-mixing tank, 4-deboration ion exchange system, 5-reverse osmosis system, 6-remineralization tank, 7-sedimentation tank, 8-sewage mixing tank, 9-regeneration tank. DETAILED DESCRIPTION

[0034] The present invention provides a method for recovering high turbidity seawater resources, comprising the following steps:

[0035] Filtering the highly turbid seawater to obtain filtered seawater and saline soil; the highly turbid seawater has a salinity of greater than 10,000 mg / L and a turbidity of greater than 100 NTU;

[0036] The filtered seawater is subjected to a calcium-magnesium removal treatment using an ion exchange resin to obtain calcium-magnesium-removed seawater and a calcium-magnesium adsorbing resin; the calcium-magnesium adsorbing resin is regenerated using an acetic acid solution to obtain a calcium-magnesium-containing solution; the calcium-magnesium-containing solution is mixed with a KOH solution to obtain a calcium-magnesium-potassium-containing solution;

[0037] performing a deboronization treatment on the decalcified and magnesium-depleted seawater using an ion exchange resin to obtain deboronized seawater;

[0038] The deboronized seawater is subjected to reverse osmosis treatment to obtain desalinated water and high-salinity seawater; the salinity of the high-salinity seawater is 45,000 to 50,000 mg / L;

[0039] The desalinated water and the calcium, magnesium and potassium-containing solution are mixed to obtain desalinated mineralized water.

[0040] The present invention filters high turbidity seawater to obtain filtered seawater and saline soil; the salinity of the high turbidity seawater is above 10,000 mg / L, preferably 10,000-35,000 mg / L, and the turbidity of the high turbidity seawater is preferably above 100 NTU, more preferably 100-300 NTU; in a specific embodiment of the present invention, the high turbidity seawater is specifically low-salinity, high-turbidity seawater. In the present invention, the filtration is preferably carried out using a soil recovery tank; the soil recovery tank preferably includes a coarse-grained solid material layer and a secondary filtration layer arranged at the bottom of the coarse-grained solid material layer; the particle size of the coarse-grained solid material in the coarse-grained solid material layer is preferably 0.05-2 mm, more preferably 0.1-1.5 mm; the coarse-grained solid material is preferably one or both of filter sand and activated carbon; the pore size of the secondary filtration layer is preferably 0.05-0.1 mm, more preferably 0.05-0.06 mm; the secondary filtration layer can specifically be filter screen; the soil recovery tank is provided with a water inlet, a water outlet, a flushing water outlet on the top, and a saline soil collection port on the bottom; during filtration, the present invention passes the high-turbidity seawater into the coarse-grained solid material layer of the soil recovery tank, and the solid particles in the seawater are intercepted by the coarse-grained solid material layer. Thereafter, flushing water is passed into the top of the soil recovery tank for flushing, and the intercepted solid particles pass through the secondary filtration layer under the action of the flushing water to collect the saline soil; the saline soil is specifically in a muddy state; the turbidity of the filtered seawater is preferably 0.1 to 1 NTU.

[0041] The present invention provides a coarse solid material layer that can intercept solid particles in highly turbid seawater, allowing them to accumulate between the coarse solid material. The resistance created by the coarse solid material also slows the flow of seawater, making solid particle collection more efficient. Furthermore, by controlling the particle size of the coarse solid material within the aforementioned range, the present invention also increases the proportion of silt and clay in the intercepted material and reduces the proportion of sand, resulting in a better quality nutrient soil. The present invention also provides a secondary filtration layer at the bottom of the coarse solid material layer. This secondary filtration layer only allows the passage of smaller particles suspended in the water. This design allows water to be introduced through the top of the soil recovery tank to control the flushing of accumulated solid particles, thereby collecting saline soil at the bottom of the secondary filtration layer. Furthermore, by controlling the pore size of the secondary filtration layer within the aforementioned range, the present invention allows only silt and clay particles suspended in the water to pass through the secondary filtration layer, while retaining the majority of sand particles, resulting in saline soil with a high proportion of silt and clay.

[0042] After obtaining filtered seawater, the present invention uses an ion exchange resin to decalcify and magnesium-deionize the filtered seawater to obtain decalcified and magnesium-deionized seawater and a calcium-magnesium-adsorbed resin. The ion exchange resin used for the decalcification and magnesium-deionization treatment is preferably Purolite C100H IND type cation exchange resin. The Purolite C100H IND type cation exchange resin has a dynamic color indication function. Through the pH-responsive ligand (-SO3H) in its molecular structure, the resin produces a reversible chromatographic migration (from amber to dark brown) during the calcium and magnesium ion exchange process, forming a dynamic saturation threshold monitoring system based on visual recognition, which is significantly different from the static exchange process of traditional gel-type resins. Its color development kinetic characteristics conform to the Langmuir adsorption isotherm model, which can achieve real-time visual control of the resin's working exchange capacity and control the regeneration cycle determination error within a reasonable range.

[0043] In the present invention, the ion exchange reaction of the ion exchange resin in the decalcification and magnesium treatment is as follows:

[0044] 2R-SO3H+Ca 2+ →(R-SO3)2Ca+2H + ;

[0045] 2R-SO3H+Mg 2+ →(R-SO 3)2 Mg+2H + .

[0046] In the present invention, the calcium ion content in the decalcified magnesium seawater is preferably less than 0.1 mg / L, and the magnesium ion content is preferably less than 0.1 mg / L.

[0047] After obtaining the calcium-magnesium adsorbing resin, the present invention uses an acetic acid solution to regenerate the calcium-magnesium adsorbing resin to obtain a calcium-magnesium solution. During the regeneration process, the acetic acid solution is preferably passed through an ion exchange column, and the effluent is collected, which is the calcium-magnesium solution. The regenerated resin is repeatedly used in the decalcification and magnesium treatment. In the present invention, the concentration of the acetic acid solution is preferably 1 to 1.5 mol / L. During the regeneration process, the calcium-magnesium adsorbing resin and acetic acid react as follows:

[0048] (R-SO3)2Ca+2CH3COOH→2R-SO3H+Ca(CH3COO)2;

[0049] (R-SO3)2Mg+2CH3COOH→2R-SO3H+Mg(CH3COO)2.

[0050] The present invention uses acetic acid solution with weak protonation characteristics (pKa = 4.76) as the regeneration agent. Compared with the commonly used hydrochloric acid and sulfuric acid regeneration agents, it has the following advantages: the acetic acid solution can be completely mineralized into CO2 and H2O through the microbial mediated β-oxidation pathway; it avoids the Cl - Risk of soil conductivity surge caused by migration; elimination of SO4 caused by sulfuric acid regeneration 2- -Ca 2+ The problem of increased membrane fouling index caused by co-precipitation. In summary, the present invention uses acetic acid solution as a regeneration agent to reduce the emission equivalent of secondary pollutants.

[0051] After obtaining the calcium-magnesium solution, the present invention mixes the calcium-magnesium solution with a KOH solution to obtain a calcium-magnesium-potassium solution; the concentration of the KOH solution is preferably 1 to 1.5 mol / L; the endpoint pH value of the mixture of the calcium-magnesium solution and the KOH solution is preferably 6.8 to 7.2. The present invention uses KOH solution to mix with the calcium-magnesium solution and controls the inflection point of the acid-base titration curve (pH 6.8 to 7.2) to simultaneously achieve dual goals: 1) based on K + -H + Ion exchange reaction neutralizes excess acetic acid; 2) forms plant-available potassium (K + ) slow-release mechanism. Compared with the traditional NaOH neutralization method, the present invention can increase the exchangeable potassium content of the soil while avoiding Na + The exchangeable sodium percentage exceeds the limit due to accumulation. The reaction between the KOH solution and the acetic acid in the calcium and magnesium solution is as follows:

[0052] KOH+CH3COOH→CH3COOK+H2O.

[0053] After obtaining the decalcified magnesium seawater, the present invention uses an ion exchange resin to perform a deboronization treatment on the decalcified magnesium seawater to obtain deboronized seawater. In order to improve the efficiency of deboronization, the pH value of the decalcified magnesium seawater needs to be adjusted to 8.6 to 9.5. In the present invention, the ion exchange resin used in the deboronization treatment is preferably a chelated ion exchange resin functionalized with an N-methylglucamine group (NMDG), specifically a Purolite S108 type ion exchange resin; the boron content in the deboronized seawater is preferably 0.2 to 0.3 mg / L. In the present invention, the boron in the decalcified magnesium seawater exists in the form of boron hydroxide, and the reaction between boron hydroxide and the ion exchange resin is as follows:

[0054]

[0055] After the deboronation treatment, an adsorbed boron resin is also obtained. The present invention preferably uses a regeneration agent to regenerate the adsorbed boron resin. The regeneration agent is preferably a hydrochloric acid solution or a sodium hydroxide solution. The concentration of the hydrochloric acid solution is preferably 0.1-0.5 mol / L, and the concentration of the sodium hydroxide solution is preferably 0.1-0.5 mol / L. The effluent is collected during the regeneration process to obtain a boron-containing effluent. When a hydrochloric acid solution is used as the regeneration agent, the boron in the boron-containing effluent exists in the form of boric acid. When a sodium hydroxide solution is used as the regeneration agent, the boron in the boron-containing effluent exists in the form of borate. After obtaining the boron-containing effluent, the boron in the boron-containing effluent is preferably recovered. The present invention has no special requirements for the recovery method, and a method well known to those skilled in the art can be used. For example, when the boron in the boron-containing effluent exists in the form of boric acid, boric acid crystals can be obtained by cooling.

[0056] In the present invention, the boron content in the high turbidity seawater is 4.5-5 mg / L. Although boron is a trace element necessary for plant growth, its concentration in seawater exceeds the tolerance threshold of many crops, especially varieties that are sensitive to boron, such as citrus, grapes and beans. Excessive absorption of boron can lead to plant toxicity, including chlorophyll deficiency, leaf edge necrosis, stunted root development and a decrease in overall yield. In addition, due to the limited mobility of boron, it will accumulate in the soil, so long-term irrigation with boron-rich water will become increasingly harmful. Standard seawater desalination technology (such as reverse osmosis) is generally not enough to reduce boron to agronomically safe levels. Therefore, the present invention uses ion exchange resins for deboronization, which can achieve effective removal of boron, which is crucial for seawater desalination used in agriculture, ensuring crop safety, maintaining soil health and supporting sustainable irrigation.

[0057] After obtaining the deboronized seawater, the present invention performs reverse osmosis treatment on the deboronized seawater to obtain desalinated water and high-salinity seawater; the salinity of the desalinated water is preferably less than 200 mg / L, and the salinity of the high-salinity seawater is 45,000 to 50,000 mg / L; in the present invention, the concentrated water produced by the reverse osmosis is preferably returned to the water inlet end of the reverse osmosis treatment and circulated for reverse osmosis treatment until the salinity of the concentrated water reaches 45,000 to 50,000 mg / L; the recovery rate of the reverse osmosis treatment is preferably 50 to 80%; during the reverse osmosis treatment process, high pressure is used to push water molecules through the semipermeable membrane to effectively remove dissolved salts, microorganisms and other impurities.

[0058] In the present invention, the high-salinity seawater is preferably used for aquaculture, preferably for bio-bait farming. The bio-bait can be one or more of Artemia, Dunaliella salina, and Spirulina, which are tolerant to high salinity conditions. The farm receives the high-salinity seawater and adds nutrients required for the bio-bait before using it for bio-bait farming.

[0059] After obtaining desalinated water, the present invention mixes the desalinated water with the calcium, magnesium, and potassium-containing solution to obtain desalinated mineralized water. In the present invention, the desalinated mineralized water preferably has a calcium ion content of 32 to 48 mg / L, a magnesium ion content of 48 to 65 mg / L, and a potassium ion content of 15 to 250 mg / L. The desalinated mineralized water is preferably used for agricultural irrigation to supplement essential nutrients for plant growth and provide the mineral components required for healthy and sustainable agricultural productivity.

[0060] In the present invention, the nutrient-containing waste generated by aquaculture and the saline soil are preferably mixed and subjected to sedimentation treatment to obtain nutrient soil and nutrient water; the nutrient-containing waste generated by aquaculture is specifically sludge, which contains metabolic waste of biological bait during the aquaculture process and nutrients that are not completely digested; in the present invention, the porous structure of the saline soil can effectively retain and stabilize the nutrient-rich waste generated by aquaculture, and the obtained nutrient soil can be used as a nutrient matrix for salt-tolerant crops, and has high application potential in sustainable agriculture.

[0061] In the present invention, the nutrient water and residual runoff water from agricultural irrigation are preferably mixed. Runoff water specifically refers to water that, after irrigation, is not absorbed by the soil, utilized by plants, or evaporates within the irrigated area, but instead flows out of the irrigated area via surface runoff or subsurface runoff. The mixed water can be discharged. The TDS of the discharged water is preferably 10,000-15,000 mg / L, and the turbidity is preferably <25 NTU.

[0062] The present invention mixes nutrient water with the residual runoff water after irrigation, which can adjust the salinity level of sewage and balance the composition of the final effluent, thereby minimizing the potential impact of directly discharging high-salinity seawater on the environment and ensuring the stability and health of the surrounding marine ecosystem.

[0063] The present invention also provides a device for recovering high turbidity seawater resources, comprising:

[0064] A soil recovery tank 1 comprising a coarse solid material layer and a secondary filtration layer disposed at the bottom of the coarse solid material layer;

[0065] decalcification magnesium ion exchange system 2; the inlet of the decalcification magnesium ion exchange system 2 is connected to the water outlet of the soil recovery tank 1;

[0066] Regeneration tank 9; the inlet of the regeneration tank 9 is connected to the resin outlet of the decalcification magnesium ion exchange system 2;

[0067] A mixing tank 3; the inlet of the mixing tank 3 is connected to the water outlet of the decalcification magnesium ion exchange system 2;

[0068] Deboronization ion exchange system 4; the inlet of the deboronization ion exchange system 4 is connected to the outlet of the decalcification magnesium ion exchange system 3;

[0069] Reverse osmosis system 5; the inlet of the reverse osmosis system 5 is connected to the outlet of the deboronation ion exchange system 4;

[0070] Remineralization tank 6; the inlet of the remineralization tank 6 is connected to the water outlet of the mixing tank 3 and the water outlet of the reverse osmosis system 5.

[0071] In the present invention, the soil recovery tank 1 preferably includes a coarse-grained solid material layer and a secondary filtration layer arranged at the bottom of the coarse-grained solid material layer. The type and particle size of the coarse solid material are the same as those in the above-mentioned scheme and will not be repeated here. The pore size of the secondary filtration layer is consistent with that in the above-mentioned scheme and will not be repeated here. The soil recovery tank 1 is specifically a water tank, which is filled with coarse-grained solid material and has a secondary filtration layer arranged at the bottom of the water tank.

[0072] In the present invention, the type of ion exchange resin used in the decalcified magnesium ion exchange system 2 is the same as that in the above-mentioned scheme, and will not be repeated here; the decalcified magnesium ion exchange system 2 preferably includes two ion exchange columns, and the two ion exchange columns are switched for use; specifically, the two ion exchange columns are preferably arranged in parallel, and after one ion exchange column is saturated with adsorption, the other ion exchange column is switched for adsorption, and the saturated ion exchange column enters the regeneration tank 9 for regeneration, and the regenerated resin is reused, and the calcium-magnesium solution generated during the regeneration process enters the mixing tank 3 and is mixed with the KOH solution.

[0073] The present invention has no special requirements for the regeneration tank 9, the mixing tank 3, the deboronation ion exchange system 4, and the remineralization tank 6, and those known to those skilled in the art can be used.

[0074] In the present invention, the reverse osmosis system 5 preferably includes a water inlet, a produced water outlet and a concentrated water outlet, and the concentrated water outlet is connected to the water inlet of the reverse osmosis system; when performing reverse osmosis treatment, the concentrated water is preferably returned to the water inlet end of the reverse osmosis system for circulation for reverse osmosis treatment. When the salinity of the concentrated water reaches 45,000 to 50,000 mg / L, the valve automatically opens to discharge the concentrated water (i.e., high-salinity seawater).

[0075] In the present invention, the reverse osmosis system 5 preferably also includes a brine return control mechanism, which adjusts the reverse osmosis recovery rate by balancing flow rate, pressure, and salinity level to increase the water production. Specifically, the brine return control mechanism preferably includes a valve, a pressure sensor, and a flow meter. The valve is disposed at the brine outlet, and the pressure sensor is disposed on a pipe connected to the reverse osmosis system water inlet. The valve, pressure sensor, and flow meter are preferably electrically connected to a programmable logic controller, which is preferably a PLC system or a SCADA system. The programmable logic controller continuously monitors the conductivity of the brine. When the conductivity of the brine exceeds a set threshold, the brine is directly discharged. When the conductivity of the brine is less than the set threshold, the brine is returned to the inlet side of the reverse osmosis membrane to continue reverse osmosis treatment.

[0076] In the present invention, the reverse osmosis system 5 preferably further includes a flushing system, which is used to regularly flush the reverse osmosis membrane with chemical agents to maintain stable membrane performance; the chemical agents may specifically be scale inhibitors.

[0077] In the present invention, the device preferably further comprises a sedimentation tank 7 ; the sedimentation tank 7 is used to perform sedimentation treatment on the saline soil produced in the soil recovery tank 1 and the nutrient-containing waste produced by aquaculture.

[0078] In the present invention, the device preferably further includes a sewage mixing tank 8; the sewage mixing tank 8 is used to mix the runoff water remaining after agricultural irrigation and the nutrient water produced by the sedimentation tank.

[0079] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0080] Example 1

[0081] use Figure 1 The device shown recovers resources from highly turbid seawater. The specific process is as follows: highly turbid seawater (salinity of 25,000 mg / L, turbidity of 200 NTU, and boron content of 5 mg / L) is passed into a soil recovery tank 1. Solid particles in the seawater are trapped in the gaps between the coarse solid materials in the soil recovery tank 1. Flushing water is introduced from the top of the soil recovery tank 1 for flushing, and muddy saline soil is collected at the bottom of the secondary filtration layer.

[0082] The filtered seawater from the soil recovery tank 1 enters the decalcified magnesium ion exchange system 2 (the resin used is Purolite C100H IND type cation exchange resin) for decalcified magnesium treatment to obtain adsorbed calcium magnesium resin and decalcified magnesium seawater (wherein the calcium ion content is less than 0.1 mg / L and the magnesium ion content is less than 0.1 mg / L). The adsorbed calcium magnesium resin is regenerated with acetic acid solution in the regeneration tank 9 to obtain a calcium-magnesium solution. The calcium-magnesium solution is passed into the mixing tank 3 and mixed with the KOH solution to obtain a calcium-magnesium-potassium solution.

[0083] The decalcified magnesium seawater is passed into the deboronized ion exchange system 4 (the resin used is a chelated ion exchange resin functionalized with N-methylglucosamine groups, model Purolite The deboronized seawater is deborated in step S108 to obtain deboronized seawater (boron content of 0.2-0.3 mg / L); the deboronized seawater enters the reverse osmosis system 5 for circulating reverse osmosis treatment to obtain high-salinity seawater (salinity of 45,000-50,000 mg / L) and desalinated water (salinity <100 mg / L); the desalinated water and the calcium, magnesium and potassium solution are passed into the remineralization tank 6 for mixing to obtain desalinated mineralized water; the recovery rate of the reverse osmosis system 5 is 50.1%; the desalinated mineralized water is used as agricultural irrigation water; the high-salinity seawater is sent to the aquaculture farm as water for biological bait breeding, and nutrients are added to the high-salinity seawater during breeding; the muddy saline soil produced in the soil recovery tank 1 and the nutrient-containing waste produced by aquaculture are passed into the sedimentation tank 7 for sedimentation treatment to obtain nutrient soil and nutrient water; the nutrient water and the runoff water remaining after irrigation are passed into the sewage mixing tank 8 for mixing treatment before discharge.

[0084] In response to the soil degradation and desalination water scarcity caused by climate change, this invention proposes a sustainable solution based on the comprehensive utilization of seawater resources. It is the first to create an agriculture-aquaculture-ecology (AAE) coupling model for multi-level utilization of seawater resources. Through a multi-dimensional resource collaborative utilization strategy, it provides coastal ecologically fragile areas with a systematic solution covering water resource recycling, saline-alkali land biological improvement and low-carbon aquaculture. It has important theoretical value and practical guiding significance for building the sustainability of agricultural-ecological complex systems.

[0085] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for recovering high turbidity seawater resources, characterized in that: The following steps are involved: Filtering the highly turbid seawater to obtain filtered seawater and saline soil; the highly turbid seawater has a salinity of greater than 10,000 mg / L and a turbidity of greater than 100 NTU; The filtered seawater is subjected to a calcium-magnesium removal treatment using an ion exchange resin to obtain calcium-magnesium-removed seawater and a calcium-magnesium adsorbing resin; the calcium-magnesium adsorbing resin is regenerated using an acetic acid solution to obtain a calcium-magnesium-containing solution; the calcium-magnesium-containing solution is mixed with a KOH solution to obtain a calcium-magnesium-potassium-containing solution; performing a deboronization treatment on the decalcified and magnesium-depleted seawater using an ion exchange resin to obtain deboronized seawater; The deboronized seawater is subjected to reverse osmosis treatment to obtain desalinated water and high-salinity seawater; the salinity of the high-salinity seawater is 45,000 to 50,000 mg / L; The desalinated water and the calcium, magnesium and potassium-containing solution are mixed to obtain desalinated mineralized water.

2. The method according to claim 1, characterized in that The filtration is performed using a soil recovery tank; the soil recovery tank comprises a coarse solid material layer and a secondary filtration layer disposed at the bottom of the coarse solid material layer; the particle size of the coarse solid material in the coarse solid material layer is 0.05 to 2 mm; the pore size of the secondary filtration layer is 0.05 to 0.1 mm; The highly turbid seawater is passed into the coarse-grained solid material layer of the soil recovery tank, and the solid particles in the seawater are intercepted by the coarse-grained solid material layer. Then, flushing water is passed into the top of the soil recovery tank for flushing. The intercepted solid particles pass through the secondary filtration layer under the action of the flushing water to collect saline soil.

3. The method according to claim 1, characterized in that The ion exchange resin used in the decalcification and magnesium treatment is Purolite C100H IND type cation exchange resin; the endpoint pH value of the mixture of the calcium-magnesium solution and the KOH solution is 6.8-7.

2.

4. The method according to claim 1, wherein The ion exchange resin used in the deboronation treatment is a chelated ion exchange resin functionalized with an N-methylglucamine group.

5. The method according to claim 1, wherein The salinity of the desalinated water is less than 200 mg / L.

6. The method according to claim 1, characterized in that The high-salinity seawater is used for aquaculture; the desalinated mineralized water is used for agricultural irrigation; The nutrient-containing waste generated by the aquaculture is mixed with the saline soil and subjected to sedimentation treatment to obtain nutrient soil and nutrient water; the nutrient water and the residual runoff water after the agricultural irrigation are mixed and treated.

7. A device for recovering high turbidity seawater resources, characterized in that: include: soil recovery tanks; The soil recovery tank includes a coarse solid material layer and a secondary filtration layer arranged at the bottom of the coarse solid material layer; decalcification magnesium ion exchange system; The inlet of the decalcification magnesium ion exchange system is connected to the water outlet of the soil recovery tank; regeneration tank; the inlet of the regeneration tank is connected to the resin outlet of the decalcification magnesium ion exchange system; A mixing tank; the inlet of the mixing tank is connected to the water outlet of the regeneration tank; a deboronation ion exchange system; the inlet of the deboronation ion exchange system is connected to the outlet of the decalcification and magnesium ion exchange system; Reverse osmosis system; the inlet of the reverse osmosis system is connected to the outlet of the deboronation ion exchange system; Remineralization tank; the inlet of the remineralization tank is connected to the water outlet of the mixing tank and the water outlet of the reverse osmosis system.

8. The device according to claim 7, characterized in that The decalcified magnesium ion exchange system comprises two ion exchange columns, which are switched for use.

9. The device according to claim 7, characterized in that It also includes a sedimentation tank; the sedimentation tank is used to precipitate the saline soil produced in the soil recovery tank and the nutrient-containing waste produced by aquaculture.

10. The device according to claim 9, characterized in that It also includes a sewage mixing tank; the sewage mixing tank is used to mix the runoff water remaining after agricultural irrigation and the nutrient water produced by the sedimentation tank.

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