A method and apparatus for recovering high turbidity seawater resources

Abstract

The present application relates to seawater resource utilization technical field, provide a kind of high turbidity seawater resource recovery method and device.The present application is treated to high turbidity seawater by filtering, decalcification magnesium, boron removal, reverse osmosis etc., high salinity seawater, desalination mineralized water and saline soil can be recovered, wherein desalination mineralized water can be used as irrigation water, high salinity seawater can be used as aquaculture water;Aquaculture contains nutrient waste and saline soil can be obtained after further processing nutrient soil.The present application initiates seawater resource multi-level utilization agricultural-aquaculture-ecological coupling model, develops agricultural reuse type desalination water mineralization regulation process based on membrane separation technology, establishes the closed loop circulation system of aquaculture tail water cascade utilization, provides the systematic solution for coastal ecological fragile zone, which covers water resource utilization, saline-alkali soil biological improvement and aquaculture, and has important theoretical value and practical guiding significance for building sustainable agricultural-ecological complex system.

Description

Technical Field

[0001] This invention relates to the field of seawater resource utilization technology, and in particular to a method and apparatus for recovering highly turbid seawater resources. Background Technology

[0002] As climate change exacerbates soil degradation and desalination scarcity, the development and utilization of seawater resources is gradually becoming an important direction for alleviating water resource pressure. Highly turbid seawater is widely found in estuaries and nearshore areas, representing a potentially vast water resource reservoir. Utilizing this resource can effectively alleviate water pressure in coastal areas and even parts of inland regions, reducing dependence on desalination.

[0003] Currently, common methods for utilizing seawater resources include seawater desalination, seawater chemical resource extraction, and seawater irrigation. Seawater desalination removes salt from seawater through methods such as distillation or reverse osmosis to produce desalinated water. Seawater chemical resource extraction most commonly involves seawater salt production, which uses seawater to evaporate salt crystals, which are then further processed into refined salt. Seawater irrigation typically involves irrigating salt-tolerant crops with seawater, selecting and cultivating salt-tolerant plant varieties, and directly irrigating with seawater or diluted seawater. However, both seawater desalination and seawater salt production industries only partially utilize seawater, resulting in limited resource utilization. Seawater irrigation is only suitable for salt-tolerant crops, but the current variety of salt-tolerant crops is limited, leading to relatively low yields and economic benefits. Furthermore, seawater irrigation may exacerbate soil salinization. Therefore, existing methods for utilizing seawater resources have significant limitations, making it difficult to achieve comprehensive utilization of seawater resources. Moreover, most existing seawater treatment technologies are designed for conventional seawater and are not suitable for treating highly turbid seawater.

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

[0005] In view of this, the present invention provides a method and apparatus for recycling highly turbid seawater resources. The method provided by the present invention can recycle and utilize highly turbid seawater resources with a high comprehensive utilization rate.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] A method for recovering highly turbid seawater resources includes the following steps:

[0008] Highly turbid seawater is filtered to obtain filtered seawater and saline soil; the salinity of the highly turbid seawater is above 10000 mg / L and the turbidity is above 100 NTU.

[0009] The filtered seawater is treated with ion exchange resin to remove calcium and magnesium, resulting in decalcified and magnesium-containing seawater and calcium- and magnesium-adsorbing resin. The calcium- and magnesium-adsorbing resin is regenerated with acetic acid solution to obtain a calcium- and magnesium-containing solution. The calcium- and magnesium-containing solution is then mixed with KOH solution to obtain a calcium-, magnesium-, and potassium-containing solution.

[0010] The demineralized and magnesium-treated seawater was treated with ion exchange resin to remove boron, resulting in deboron-treated seawater.

[0011] The deboron-removed 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 filtration includes a coarse solid material layer and a secondary filter 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 0.05-2 mm; the pore size of the secondary filter layer is 0.05-0.1 mm.

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

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

[0016] Preferably, the ion exchange resin used in the boron removal treatment is an N-methylglucosamine functionalized chelated ion exchange resin.

[0017] Preferably, the salinity of the desalinated water is <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 from aquaculture is mixed with the saline soil and subjected to sedimentation treatment to obtain nutrient soil and nutrient water; the nutrient water is then mixed with the residual runoff from agricultural irrigation.

[0020] The present invention also provides an apparatus for recovering high-turbidity seawater resources, comprising:

[0021] Soil recovery tank; the soil recovery tank includes a coarse solid material layer and a secondary filter layer disposed at the bottom of the coarse solid material layer;

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

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

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

[0025] A boron removal ion exchange system; the inlet of the boron removal ion exchange system is connected to the outlet of the calcium and magnesium removal ion exchange system.

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

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

[0028] Preferably, the decalcification and magnesium ion exchange system includes two ion exchange columns, which are used interchangeably.

[0029] Preferably, it also includes a sedimentation tank; the sedimentation tank is used to settle saline soil generated in the soil recycling tank and nutrient-containing waste generated from aquaculture.

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

[0031] This invention provides a method for recovering highly turbid seawater resources, comprising the following steps: filtering highly turbid seawater to obtain filtered seawater and saline soil; the salinity of the highly turbid seawater is above 10000 mg / L and the turbidity is above 100 NTU; treating the filtered seawater with ion exchange resin to remove calcium and magnesium, obtaining decalcified magnesium seawater and calcium-magnesium adsorbent resin; regenerating the calcium-magnesium adsorbent resin with acetic acid solution to obtain a calcium-magnesium-containing solution; mixing the calcium-magnesium-containing solution with KOH solution to obtain a calcium-magnesium-potassium-containing solution; treating the decalcified magnesium seawater with ion exchange resin to remove boron, obtaining boron-removed seawater; treating the boron-removed seawater with reverse osmosis to obtain desalinated water and highly saline seawater; the salinity of the highly saline seawater is 45000–50000 mg / L; mixing the desalinated water and the calcium-magnesium-potassium-containing solution to obtain desalinated mineralized water. Traditional methods involve directly treating seawater using reverse osmosis to produce desalinated water. During reverse osmosis, both monovalent and divalent salts are removed; however, the calcium in the divalent salts...2+ and Mg 2+ These are beneficial ions required for plant growth. This invention uses acetic acid solution to treat the adsorbed calcium-magnesium resin, thereby recovering the calcium-magnesium salts. KOH is added to the resulting calcium-magnesium-containing solution for mineralization of desalinated water. The resulting desalinated mineralized water contains calcium, magnesium, and potassium ions and can be used for agricultural irrigation, supplementing essential nutrients for plant growth and providing the necessary mineral components for healthy and sustainable agricultural productivity. Furthermore, this invention controls the salinity level of high-salinity seawater at 45,000–50,000 mg / L, allowing the high-salinity seawater to be used for aquaculture, achieving further resource utilization of seawater. Further, this invention precipitates nutrient-rich waste from aquaculture and saline soil from filtration to obtain nutrient soil. The porous structure of the saline soil effectively retains and stabilizes the nutrient-rich waste from aquaculture. The resulting nutrient soil can serve as a nutrient substrate for salt-tolerant crops and has high application potential in sustainable agriculture.

[0032] In summary, this invention pioneered an agriculture-aquaculture-ecology (AAE) coupling model for multi-level utilization of seawater resources, developed an agricultural reuse-type desalination water mineralization regulation process based on membrane separation technology, and established a closed-loop recycling system for the cascade utilization of aquaculture tailwater. This integrated solution, through a multi-dimensional resource synergistic utilization strategy, provides a systematic solution for ecologically fragile coastal areas, encompassing water resource recycling, saline-alkali land biological improvement, and low-carbon aquaculture. It has significant theoretical value and practical guiding significance for building a sustainable agriculture-ecology composite system. Attached Figure Description

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

[0034] This invention provides a method for recovering highly turbid seawater resources, comprising the following steps:

[0035] Highly turbid seawater is filtered to obtain filtered seawater and saline soil; the salinity of the highly turbid seawater is above 10000 mg / L and the turbidity is above 100 NTU.

[0036] The filtered seawater is treated with ion exchange resin to remove calcium and magnesium, resulting in decalcified and magnesium-containing seawater and calcium- and magnesium-adsorbing resin. The calcium- and magnesium-adsorbing resin is regenerated with acetic acid solution to obtain a calcium- and magnesium-containing solution. The calcium- and magnesium-containing solution is then mixed with KOH solution to obtain a calcium-, magnesium-, and potassium-containing solution.

[0037] The demineralized and magnesium-treated seawater was treated with ion exchange resin to remove boron, resulting in deboron-treated seawater.

[0038] The deboron-removed 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] This invention filters highly turbid seawater to obtain filtered seawater and saline soil. The salinity of the highly turbid seawater is above 10,000 mg / L, preferably 10,000–35,000 mg / L, and the turbidity is preferably above 100 NTU, more preferably 100–300 NTU. In a specific embodiment of this invention, the highly turbid seawater is specifically low-salinity, highly turbid seawater. In this 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 disposed 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… The soil recovery tank is equipped with an inlet, an outlet, a flushing water outlet at the top, and a saline soil collection outlet at the bottom. During filtration, the highly turbid seawater is introduced into the coarse-grained solid material layer of the soil recovery tank. The solid particles in the seawater are trapped by the coarse-grained solid material layer. Then, flushing water is introduced into the top of the soil recovery tank for rinsing. The trapped solid particles pass through a secondary filtration layer under the action of the flushing water, and saline soil is collected. The saline soil is specifically in the form of mud. The turbidity of the filtered seawater is preferably 0.1 to 1 NTU.

[0041] This invention incorporates a coarse solid material layer that traps solid particles from highly turbid seawater, causing them to accumulate between the coarse particles. The resistance from the coarse solid material slows seawater flow, making particle collection more efficient. Furthermore, by controlling the particle size of the coarse solid material within the aforementioned range, this invention increases the proportion of silt and clay in the trapped material while reducing the proportion of sand, resulting in a better texture for the subsequent nutrient-rich soil. A secondary filtration layer is incorporated at the bottom of the coarse solid material layer. This secondary filtration layer allows only smaller suspended particles to pass through. This design allows water to be introduced from the top of the soil recovery tank to control and flush away accumulated solid particles, thereby collecting saline soil at the bottom of the secondary filtration layer. Simultaneously, by controlling the pore size of the secondary filtration layer within the aforementioned range, this invention allows only suspended silt and clay particles to pass through while retaining most sand particles, resulting in saline soil with a high proportion of silt and clay.

[0042] After obtaining filtered seawater, this invention uses ion exchange resin to treat the filtered seawater for calcium and magnesium removal, resulting in decalcified and magnesium-containing seawater and calcium and magnesium-adsorbed resin. The ion exchange resin used for the calcium and magnesium removal treatment is preferably Purolite C100H IND type cation exchange resin. The Purolite C100H IND type cation exchange resin has a dynamic colorimetric indication function. This resin, through pH-responsive coordinating groups (-SO3H) in its molecular structure, undergoes reversible chromatographic migration (changing from amber to dark brown) during calcium and magnesium ion exchange, forming a dynamic saturation threshold monitoring system based on visual recognition, significantly different from the static exchange process of traditional gel-type resins. Its colorimetric kinetics conform to the Langmuir adsorption isotherm model, enabling real-time visual control of the resin's working exchange capacity and keeping the regeneration cycle determination error within a reasonable range.

[0043] In this invention, the ion exchange reaction of the ion exchange resin in the decalcification and magnesium removal 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 this invention, the calcium ion content in the decalcified and magnesium-rich 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 adsorbed calcium-magnesium resin, the present invention regenerates the adsorbed calcium-magnesium resin with acetic acid solution to obtain a calcium-magnesium-containing solution. During the regeneration process, it is preferable to pass the acetic acid solution into an ion exchange column and collect the effluent, which is the calcium-magnesium-containing solution. The regenerated resin is reused in the decalcification and demagnesification treatment. In the present invention, the concentration of the acetic acid solution is preferably 1–1.5 mol / L. During the regeneration process, the adsorbed calcium-magnesium resin and acetic acid undergo the following reaction:

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

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

[0050] This invention uses acetic acid solution with weak protonation characteristics (pKa = 4.76) as a regenerator. Compared with commonly used hydrochloric acid and sulfuric acid regenerators, it has the following advantages: acetic acid solution radicals can be completely mineralized into CO2 and H2O through a microbial-mediated β-oxidation pathway; and it avoids the Cl- content in the hydrochloric acid regeneration process. - 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 coprecipitation. In summary, this invention uses acetic acid solution as a regenerator, which can reduce the emission equivalent of secondary pollutants.

[0051] After obtaining the calcium-magnesium-containing solution, this invention mixes the calcium-magnesium-containing solution with a KOH solution to obtain a calcium-magnesium-potassium solution; the concentration of the KOH solution is preferably 1–1.5 mol / L; the final pH value of the mixture of the calcium-magnesium-containing solution and the KOH solution is preferably 6.8–7.2. This invention uses the mixing of KOH solution and the calcium-magnesium-containing solution, and controls the pH value through the inflection point of the acid-base titration curve (pH 6.8–7.2), simultaneously achieving two objectives: 1) based on K... + -H + 1) Neutralize excess acetic acid through ion exchange reaction; 2) Form plant-available potassium (K) + The invention utilizes a slow-release mechanism. Compared to the traditional NaOH neutralization method, this invention can increase the exchangeable potassium content in the soil while avoiding the release of NaOH. + The accumulation resulted in an excessive percentage of exchangeable sodium. The reaction between the KOH solution and the acetic acid in the calcium-magnesium-containing solution is as follows:

[0052] KOH + CH3COOH → CH3COOK + H2O.

[0053] After obtaining decalcified and magnesium-treated seawater, this invention uses an ion exchange resin to treat the seawater for boron removal, resulting in boron-degraded seawater. To improve the boron removal efficiency, the pH value of the decalcified and magnesium-treated seawater needs to be adjusted to 8.6–9.5. In this invention, the ion exchange resin used for the boron removal treatment is preferably an N-methylglucosamine (NMDG) functionalized chelating ion exchange resin, specifically Purolite S108 type ion exchange resin; the boron content in the boron-degraded seawater is preferably 0.2–0.3 mg / L. In this invention, the boron in the decalcified and magnesium-treated 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 deboration treatment, boron-adsorbed resin is obtained. Preferably, the boron-adsorbed resin is regenerated using a regenerator, 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. During the regeneration process, the effluent is collected to obtain a boron-containing effluent. When using hydrochloric acid solution as the regenerator, the boron in the boron-containing effluent exists in the form of boric acid; when using sodium hydroxide solution as the regenerator, the boron in the boron-containing effluent exists in the form of borate. After obtaining the boron-containing effluent, it is preferable to recover the boron from the boron-containing effluent. The present invention does not have special requirements for the recovery method; any 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 this invention, the boron content in the highly turbid seawater is 4.5–5 mg / L. Although boron is an essential micronutrient for plant growth, its concentration in seawater exceeds the tolerance threshold for many crops, especially boron-sensitive varieties such as citrus, grapes, and legumes. Excessive boron absorption can lead to phytotoxicity, including chlorophyll deficiency, leaf margin necrosis, stunted root development, and reduced overall yield. Furthermore, due to the limited mobility of boron, it accumulates in the soil, making long-term irrigation with boron-rich water increasingly harmful. Standard seawater desalination technologies (such as reverse osmosis) are often insufficient to reduce boron to agronomically safe levels. Therefore, this invention employs ion exchange resins for boron removal, achieving effective boron removal, which is crucial for seawater desalination used in agriculture, ensuring crop safety, maintaining soil health, and supporting sustainable irrigation.

[0057] After obtaining boron-degraded seawater, the present invention performs reverse osmosis treatment on the boron-degraded seawater to obtain desalinated water and high-salinity seawater; the salinity of the desalinated water is preferably <200 mg / L, and the salinity of the high-salinity seawater is 45000-50000 mg / L; in the present invention, the concentrate produced by reverse osmosis is preferably returned to the inlet of the reverse osmosis treatment and circulated for reverse osmosis treatment until the salinity of the concentrate reaches 45000-50000 mg / L; the recovery rate of the reverse osmosis treatment is preferably 50-80%; during the reverse osmosis treatment process, high pressure is used to push water molecules through a semi-permeable membrane to effectively remove dissolved salts, microorganisms and other impurities.

[0058] In this invention, the high-salinity seawater is preferably used for aquaculture, and the aquaculture is preferably biological feed culture. Specifically, the biological feed can be one or more of Artemia salina, Dunaliella salina, and Spirulina, all of which are tolerant of high salinity conditions. The aquaculture farm receives the high-salinity seawater and adds the nutrients required for the biological feed before using it for biological feed culture.

[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 calcium ion content in the desalinated mineralized water is preferably 32–48 mg / L, the magnesium ion content is preferably 48–65 mg / L, and the potassium ion content is preferably 15–250 mg / L. The desalinated mineralized water is preferably used for agricultural irrigation to supplement the essential nutrients required for plant growth and provide the necessary mineral components for healthy and sustainable agricultural productivity.

[0060] In this invention, the nutrient-containing waste generated from 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 from aquaculture is specifically silt, which contains metabolic waste from biological feed during the aquaculture process and undigested nutrients. In this invention, the porous structure of the saline soil can effectively retain and stabilize the nutrient-rich waste generated from aquaculture, and the resulting nutrient soil can be used as a nutrient substrate for salt-tolerant crops, showing high application potential in sustainable agriculture.

[0061] In this invention, the nutrient water and the residual runoff after agricultural irrigation are preferably mixed. Specifically, the runoff refers to water that, after irrigation, is not absorbed by the soil, utilized by plants, or evaporated within the irrigation area, but flows out of the irrigation area through surface runoff or groundwater runoff. The mixed-treated water can be discharged, and the TDS of the discharged water is preferably 10,000–15,000 mg / L, and the turbidity is preferably <25 NTU.

[0062] This invention mixes nutrient water with residual runoff after irrigation, which can regulate the salinity level of the wastewater and balance the composition of the final effluent, thereby minimizing the potential environmental impact of direct discharge of high-salinity seawater and ensuring the stability and health of the surrounding marine ecosystem.

[0063] The present invention also provides an apparatus for recovering high-turbidity seawater resources, comprising:

[0064] Soil recycling tank 1; the soil recycling tank 1 includes a coarse solid material layer and a secondary filter layer disposed at the bottom of the coarse solid material layer;

[0065] Decalcification and magnesium ion exchange system 2; the inlet of the decalcification and magnesium ion exchange system 2 is connected to the 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 decalcified magnesium ion exchange system 2;

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

[0068] Boron removal ion exchange system 4; the inlet of the boron removal ion exchange system 4 is connected to the outlet of the calcium and magnesium removal ion exchange system 3;

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

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

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

[0072] In this invention, the type of ion exchange resin used in the calcium-magnesium decalcification ion exchange system 2 is the same as that in the above scheme, and will not be repeated here; the calcium-magnesium decalcification ion exchange system 2 preferably includes two ion exchange columns, which are used alternately; 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 to adsorption, and the saturated ion exchange column enters the regeneration tank 9 for regeneration. The regenerated resin is reused, and the calcium-magnesium-containing solution generated during the regeneration process enters the mixing tank 3 and is mixed with KOH solution.

[0073] The present invention does not have any special requirements for the regeneration tank 9, mixing tank 3, boron removal ion exchange system 4, and remineralization tank 6; any components well known to those skilled in the art can be used.

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

[0075] In this invention, the reverse osmosis system 5 preferably further includes a concentrate recirculation control mechanism. This mechanism adjusts the reverse osmosis recovery rate by balancing flow rate, pressure, and salinity levels, thereby increasing permeate production. Specifically, the concentrate recirculation control mechanism preferably includes a valve, a pressure sensor, and a flow meter. The valve is located at the concentrate outlet, and the pressure sensor and flow meter are located on the pipe connected to the reverse osmosis system inlet. The valve, pressure sensor, and flow meter are all preferably electrically connected to a programmable logic controller (PLC) system or a SCADA system. The PLC continuously monitors the conductivity of the concentrate. When the concentrate conductivity exceeds a set threshold, the concentrate is directly discharged. When the concentrate conductivity is less than the set threshold, the concentrate is recirculated to the reverse osmosis membrane feed side for continued reverse osmosis treatment.

[0076] In this invention, the reverse osmosis system 5 preferably further includes a flushing system, which uses chemical agents to periodically flush the reverse osmosis membrane in order to maintain stable membrane performance; the chemical agents may specifically be scale inhibitors.

[0077] In this invention, the device preferably further includes a sedimentation tank 7; the sedimentation tank 7 is used to sediment the saline soil generated in the soil recycling tank 1 and the nutrient-containing waste generated from aquaculture.

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

[0079] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0080] Example 1

[0081] use Figure 1 The device shown is used for resource recovery from highly turbid seawater. The specific process is as follows: Highly turbid seawater (salinity of 25000 mg / L, turbidity of 200 NTU, boron content of 5 mg / L) is introduced into soil recovery tank 1. Solid particles in the seawater are trapped in the gaps between the coarse solid materials in soil recovery tank 1. Rinsing water is introduced from the top of soil recovery tank 1 for rinsing. Muddy saline soil is collected at the bottom of the secondary filtration layer.

[0082] Seawater filtered through soil recovery tank 1 enters calcium and magnesium removal ion exchange system 2 (using Purolite C100H IND type cation exchange resin) for calcium and magnesium removal treatment, resulting in calcium and magnesium adsorbed resin and calcium and magnesium removed seawater (where calcium ion content is less than 0.1 mg / L and magnesium ion content is less than 0.1 mg / L). The calcium and magnesium adsorbed resin is regenerated in regeneration tank 9 with acetic acid solution to obtain calcium and magnesium-containing solution. The calcium and magnesium-containing solution is passed into mixing tank 3 and mixed with KOH solution to obtain calcium, magnesium and potassium-containing solution.

[0083] Decalcified and magnesium-treated seawater is introduced into the deboronization ion exchange system 4 (the resin used is an N-methylglucosamine functionalized chelating ion exchange resin, model Purolite). Boron removal treatment is carried out in S108 to obtain boron-degraded seawater (boron content of 0.2-0.3 mg / L); the boron-degraded seawater enters the reverse osmosis system 5 for circulating reverse osmosis treatment to obtain high-salinity seawater (salinity of 45000-50000 mg / L) and desalinated water (salinity <100 mg / L). The desalinated water and calcium, magnesium and potassium-containing solution are mixed in the remineralization tank 6 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 biological feed water, and nutrients are added to the high-salinity seawater during aquaculture; the muddy saline soil generated in the soil recovery tank 1 and the nutrient-containing waste generated from aquaculture are fed into the sedimentation tank 7 for sedimentation treatment to obtain nutrient soil and nutrient water; the nutrient water and the remaining runoff after irrigation are fed into the sewage mixing tank 8 for mixing treatment before discharge.

[0084] This invention addresses the soil degradation and desalination water scarcity caused by climate change, proposing a sustainable solution based on the comprehensive utilization of seawater resources. It pioneers an agriculture-aquaculture-ecology (AAE) coupling model for multi-level utilization of seawater resources. Through multi-dimensional resource synergistic utilization strategies, it provides a systematic solution for ecologically fragile coastal areas, encompassing water resource recycling, biological improvement of saline-alkali land, and low-carbon aquaculture. This has significant theoretical value and practical guiding significance for building a sustainable agriculture-ecology complex system.

[0085] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for recovering highly turbid seawater resources, characterized in that, Includes the following steps: Highly turbid seawater is filtered to obtain filtered seawater and saline soil. The salinity of the highly turbid seawater is above 10,000 mg / L, and the turbidity is above 100 NTU. The filtration is carried out using a soil recovery tank. The soil recovery tank includes a coarse-grained solid material layer and a secondary filtration layer disposed 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 0.05~2 mm. The pore size of the secondary filtration layer is 0.05~0.1 mm. The highly turbid seawater is introduced into the coarse-grained solid material layer of the soil recovery tank. The solid particles in the seawater are intercepted by the coarse-grained solid material layer. Then, flushing water is introduced into the top of the soil recovery tank for rinsing. The intercepted solid particles pass through the secondary filtration layer under the action of the flushing water, and the saline soil is collected. The filtered seawater is treated with ion exchange resin to remove calcium and magnesium, resulting in decalcified and magnesium-containing seawater and calcium- and magnesium-adsorbing resin. The calcium- and magnesium-adsorbing resin is regenerated with acetic acid solution to obtain a calcium- and magnesium-containing solution. The calcium- and magnesium-containing solution is then mixed with KOH solution to obtain a calcium-, magnesium-, and potassium-containing solution. The demineralized and magnesium-treated seawater was treated with ion exchange resin to remove boron, resulting in deboron-treated seawater. The deboron-removed seawater is subjected to reverse osmosis treatment to obtain desalinated water and high-salinity seawater; the salinity of the high-salinity seawater is 45,000~50,000 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 ion exchange resin used in the decalcification and magnesium removal treatment is Purolite C100H IND type cation exchange resin; the final pH value of the mixture of calcium-magnesium-containing solution and KOH solution is 6.8~7.

2.

3. The method according to claim 1, characterized in that, The ion exchange resin used in the boron removal treatment is an N-methylglucosamine functionalized chelated ion exchange resin.

4. The method according to claim 1, characterized in that, The salinity of the desalinated water is <200 mg / L.

5. 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 from aquaculture is mixed with the saline soil and subjected to sedimentation treatment to obtain nutrient soil and nutrient water; the nutrient water is then mixed with the residual runoff from agricultural irrigation.

6. The method according to claim 1, characterized in that, The apparatus used includes: Soil recycling tanks; A decalcification and magnesium ion exchange system; the inlet of the decalcification and magnesium ion exchange system is connected to the outlet of the soil recovery tank; A regeneration tank; the inlet of the regeneration tank is connected to the resin outlet of the decalcified magnesium ion exchange system; A mixing tank; the inlet of the mixing tank is connected to the outlet of the regeneration tank; A boron removal ion exchange system; the inlet of the boron removal ion exchange system is connected to the outlet of the calcium and magnesium removal ion exchange system. Reverse osmosis system; the inlet of the reverse osmosis system is connected to the outlet of the boron removal ion exchange system; A remineralization tank; the inlet of the remineralization tank is connected to the outlet of the mixing tank and the product water outlet of the reverse osmosis system.

7. The method according to claim 6, characterized in that, The decalcification and magnesium ion exchange system includes two ion exchange columns, which can be switched between each other.

8. The method according to claim 6, characterized in that, It also includes a sedimentation tank; the sedimentation tank is used to settle saline soil generated in the soil recycling tank and nutrient-containing waste generated from aquaculture.

9. The method according to claim 8, characterized in that, It also includes a wastewater mixing tank; the wastewater mixing tank is used to mix the runoff remaining after agricultural irrigation with the nutrient water generated from the sedimentation tank.

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