Optimization technology innovation integration of brine salt production system before drying of periodic drought and flood alternation type salt lake ecological management

Abstract

The invention provides a brine salt production system optimization technology innovation integration before drying of periodic drought and flood alternation type salt lake ecological management, belongs to the technical field of salt lake ecological management and resource comprehensive utilization, and particularly relates to a brine salt production system optimization technology innovation integration before drying of periodic drought and flood alternation type salt lakes by taking ecological management as a primary task and in a window period before drying of the periodic drought and flood alternation type salt lakes. Through digital regulation and control and multi-technology system optimization integration, the integrated system and method for reducing the source of salt-alkali dust storm, recovering high-value salt resources, realizing zero emission of old brine and quickly recovering an ecological base are realized. The integrated system has the following remarkable benefits: the ecological benefits are excellent: white tornado type salt-alkali dust storm formed after the periodic drought and flood alternating type salt lake is dried up is effectively eradicated, the discharge flux of the salt-alkali dust is reduced to be less than or equal to 5 mu gms, and the dust source reduction rate is gt; 92%; after treatment, the vegetation coverage rate of the lake basin is not less than 40% in one year and not less than 70% in three years. The recovery rate of NaSOis is not less than 90%, and the recovery rate of NaCl is not less than 85%.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of salt lake ecological management and resource comprehensive utilization, and specifically relates to an integrated system and method for reducing salt and alkali dust sources, recycling high-value salt resources, zero-discharging old brine, and rapidly recovering ecological base, by digital control and multi-technology system optimization integration in the window period before the dry-up of a periodic drought-flood alternating salt lake, with ecological management as the primary task. BACKGROUND

[0002] Periodic drought-flood alternating salt lakes such as the dry-up lake basins of An'gurili Naohu and Chahanmohor in Hebei, China, and the Aral Sea in Central Asia are super sources of regional and even global salt and alkali dust storms. The salt and alkali particulate matter released by them can be transported 500-2000 kilometers, and is an important culprit of air pollution, soil alkalization, and ecological degradation in downwind areas such as Beijing-Tianjin-Hebei, contributing >90% of the salt material. The existing technologies such as traditional salt field drying method only focus on brine mineral extraction, and have three fundamental defects: 1. Ignoring "prevention": failing to effectively manage the source, lacking intervention means before dry-up, and the dust emission rate after lake basin exposure is >70%, causing great environmental pollution; 2. Extensive resource utilization: low salt recovery rate, low product purity, and very low comprehensive recovery rate of valuable elements such as magnesium, potassium, lithium, and boron; 3. Pollution transfer and deterioration: the generated high-concentration old brine cannot be effectively treated, and is mostly discharged or stored locally, leading to pollution of groundwater resources and ecological vicious cycle in the lake area and surrounding areas.

[0003] Therefore, there is an urgent need in the field for a revolutionary and innovative, systematic solution to change the core goal of periodic drought-flood alternating salt lakes from "resource development" to "ecological management first, resource utilization second", and to use the key window period before dry-up to achieve the simultaneous goals of dust suppression, yield increase, emission reduction, and green recovery through technology innovation integration. SUMMARY

[0004] The primary purpose of the present application is to provide a systematic technical solution to preferentially and proactively reduce the salt and alkali dust sources of periodic drought-flood alternating salt lakes (reduction rate >90%), and fundamentally solve the ecological hazard problem. On this basis, high-value salt products (sodium sulfate ≥98%, table salt ≥99%) are produced, and zero liquid discharge of terminal old brine and rapid natural recovery of lake basin ecological base are achieved.

[0005] To achieve the above-mentioned primary goal of ecological management, the present application provides a solution named "periodic drought-flood alternating salt lake ecological management brine desalination system optimization technology innovation integration before dry-up", the core of which is the following modular system composition and collaborative workflow.

[0006] System composition (modular) The key technologies, features, core functions, and performance indicators of each module are as follows: M1: Dust Source Risk Perception Network, buoy-type multi-parameter cabin + multi-source remote sensing collaboration, monitoring grid ≤ 1km×1km, real-time generation and output of dust source risk index (DRI) distribution map, prediction accuracy R²≥0.90; M2: A digital twin decision-making platform that couples a multi-physics model of "hydrology-meteorology-dust source-process-ecology" to achieve three-level forecasting and early warning (72h-7d-1y), automatically generate the optimal brine extraction-crystallization-coating strategy, and has a human intervention rate of ≤5%. M3: Ecological brine extraction system, directly driven by solar / wind power, floating design, brine extraction capacity Qmax=k×(A×H_crit) / T_pump(k=0.8-0.95), dynamically extracting brine according to strategy, the core function is to maintain the lake surface area ≥15%, thereby reducing the risk of dust pollution by ≥90% from the source; M4: Five-stage fractional salt field, HDPE+clay composite seepage prevention (leakage <0.05mm / d), solar heating system laid at the bottom of the ②④⑤ stages (heating up 4-6℃), extending the annual effective evaporation period by 30-45 days, realizing the tandem and efficient fractional crystallization of gypsum, mirabilite (purity ≥98%), salt, magnesium potassium, lithium boron; M5:ZLD terminal treatment system, photovoltaic direct drive-MVR (mechanical vapor recompression) integrated process, treats terminal old brine, achieves zero liquid discharge, evaporation energy consumption ≤45kWh / t water, and condensate (TDS≤500mg / L) is reused; M6: Skin-Carbon Sequestration Accelerator. Old brine and lake silt are sprayed at a ratio of 1:3 (3-8mm thick) and inoculated with compound halophilic microbial agents to quickly form a wind-erosion resistant skin (compressive strength ≥0.2MPa) and generate additional carbon sequestration (≥0.8tCO2-eq / ha•yr). M7: A blockchain dual-certificate platform that uses blockchain's immutable notarization and smart contracts to issue tradable Dust Reduction Certificates (DRC) and Green Salt Certificates (GSC), providing a market-based financing path for ecological governance activities.

[0007] The method of this invention follows the process described below to form a closed-loop intelligent optimization system: Sensing and Monitoring (DRI) → Prediction, Early Warning and Decision Generation → Ecological Brine Extraction (Water Conservation and Dust Suppression) → Five-Level Fractional Crystallization (Resource Utilization) → ZLD Treatment (Zero Emission) → Skin Spraying and Microbial Carbon Sequestration (Ecological Restoration) → "Planting in Suitable Locations" Technology Support for Vegetation Restoration → Monitoring-Feedback-Optimization.

[0008] Due to the adoption of the above technical solution, the integrated system of the present invention has the following significant advantages: 1. Outstanding ecological benefits: Effectively eradicates the "white tornado" type saline-alkali dust storms formed after the periodic drought and flood alternation of salt lakes, reducing the saline-alkali dust emission flux to ≤5μgm⁻²s⁻¹, with a dust source reduction rate of >92%; after treatment, the vegetation coverage rate of the lake basin is ≥40% after 1 year and ≥70% after 3 years; 2. High efficiency in resource recovery: Na2SO4 recovery rate ≥90%, NaCl ≥85%, and comprehensive recovery rate of elements such as Mg, K, B, and Li ≥80%; 3. Zero environmental emissions: Achieves zero liquid discharge from the old brine, and the resulting solid salts have a moisture content of ≤3%; 4. Significant energy saving and carbon reduction: The comprehensive energy consumption per unit of salt product is ≤0.35tce / t, which is more than 55% lower than that of the traditional process (0.78tce / t); the carbon sink of the crusting system is ≥0.8tCO2-eq / ha•yr; 5. Economic Model Innovation: The dual certification of blockchain DRC and GSC gives environmental value, and green salt products gain a market premium (approximately 12%). Detailed Implementation

[0009] The present invention will now be described in detail using Anguli Lake (approximately 8 km²) in Zhangbei County, Hebei Province, China as an example case.

[0010] 1. System Deployment: An M1 sensing network (50 monitoring points) was deployed, achieving a DRI prediction model accuracy of R² of 0.91. The M2-M3 systems worked in tandem, initiating ecological brine extraction based on prediction results to maintain the lake surface at 18%, reducing the measured dust source release potential by 92%.

[0011] 2. Resource-based production: After the M4 Level 5 salt field was put into operation, it produced 12,000 tons of mirabilite in the first year with a purity of 98.7% and a carbon footprint of 0.18tCO2 / t.

[0012] 3. Zero emissions achieved: The M5ZLD terminal treats all the old brine, with condensate TDS=420mg / L, and all of it is recycled into the process, achieving zero external discharge.

[0013] 4. Ecological restoration: M6 technology was used for spraying and crust formation. After wind tunnel testing (28m / s wind speed erosion for 30 minutes), the mass loss was <1g / m², and the annual carbon sequestration was calculated to be 0.83tCO2-eq / ha.

[0014] 5. Value Realization: Through the M7 platform, each ton of green sodium sulfate comes with 150kg DRC and 80kg GSC certificates, and is acquired by the Green Fund at a 12% premium.

[0015] 6. The system prioritizes ecological governance and includes the following modules: a) A real-time dust source risk index (DRI) sensing network with a monitoring grid resolution of no more than 1km×1km and a DRI output accuracy R²≥0.90; b) A digital twin decision-making platform, coupled with multi-physics models of brine, meteorology, dust sources, and ecology, can automatically generate brine extraction-crystallization-coating optimization strategies with a human intervention rate of ≤5%; c) The ecological brine extraction system is driven directly by solar or wind power. Its maximum brine extraction capacity is designed according to the formula Qmax=k×(A×H_crit) / T_pump, where k is the safety factor, which takes a value of 0.8-0.95. Its core function is to maintain the lake surface area at no less than 15% to suppress dust sources. d) Five-stage tandem seepage-proof salt fields, whose ponds adopt a composite seepage-proof structure of HDPE membrane and clay, with a leakage rate of <0.05mm / d. The bottom of the second, fourth and fifth stage salt ponds is equipped with solar heating devices, which can extend the annual evaporation period by 30-45 days. e) Zero Liquid Discharge (ZLD) terminal, using photovoltaic-MVR integrated technology, with evaporation energy consumption ≤45kWh / t water, and the generated condensate can be reused; f) Crust-microbial carbon fixation accelerator: By spraying the mixed salts produced by the ZLD terminal and the lake silt at a ratio of 1:3 and inoculating them with microorganisms, a crust layer with a compressive strength ≥0.2MPa is formed, and its carbon sequestration capacity ≥0.8tCO2-eq / ha•yr is formed. g) A blockchain dual-certificate management platform for issuing, managing, and trading Dust Reduction Certificates (DRC) and Green Salt Certificates (GSC). The modules a) to g) are coupled and linked through data flow, energy flow and material flow to ultimately achieve the synergistic goals of reducing the salt and alkali dust storm source by >90%, recovering the main components of brine (Na2SO4≥90%, NaCl≥85%), and achieving zero liquid discharge of the terminal old brine.

[0016] 7. The five-stage series salt fields are, in order: a pre-precipitation pool for precipitating gypsum and carbonates, a nitrate precipitation pool for freezing and precipitating mirabilite, a salt precipitation pool for precipitating salt by sun evaporation, a concentration pool for enriching magnesium and potassium elements, and a deep concentration pool for concentrating lithium and boron elements.

[0017] 8. The nitrate precipitation tank utilizes the low temperature in winter (-5℃ to -20℃) to crystallize sodium sulfate (Na2SO4•10H2O), and the purity of the sodium sulfate product is ≥98%, and the recovery rate of Na2SO4 is ≥90%.

[0018] 9. The photovoltaic system of the ZLD terminal adopts a DC bus direct-drive MVR compressor, which does not require a grid-connected inverter, and the final condensate water quality meets the reuse standard of TDS≤500mg / L.

[0019] 10. A method for the ecological management and resource utilization of salt lakes with periodic drought and flood alternation, characterized in that the method includes the following steps: S1. Sensing and Prediction: The lake basin DRI and ecological water level data are acquired in real time through the sensing network and input into the digital twin platform to generate the optimal brine extraction-crystallization-covering integrated strategy; S2. Ecological brine extraction: Based on the strategy generated in S1, the ecological brine extraction system is activated to extract brine. The core control objective is to always maintain the lake surface area ratio at no less than 15%. S3. Five-stage fractional crystallization: The extracted brine is sequentially introduced into the five-stage salt fields to crystallize and precipitate gypsum, mirabilite, and salt, respectively, and magnesium-potassium enriched solution and lithium-boron enriched solution are obtained. S4. Zero liquid discharge treatment: All the terminal brine generated in S3 is sent to the ZLD terminal treatment to achieve zero liquid discharge; S5. Crust formation and ecological restoration: Mix the mixed salts produced in S4 with the lake silt and spray them, and inoculate them with microorganisms to accelerate the formation of wind-erosion resistant crusts and promote the natural restoration of vegetation; S6. Monitoring and Market Feedback: Continuously monitor dust source flux, carbon sink rate and ecological indicators, and upload the data to the blockchain platform to generate tradable DRC and GSC certificates, realizing the market value of environmental benefits.

[0020] 11. In S3, the freeze crystallization operation of Glauber's salt is carried out in a temperature range of -5°C to -20°C, and the freezing cycle is controlled within 72 hours.

[0021] 12. In S5, the thickness of the sprayed crust is 3-8 mm, and a stable crust with a compressive strength of not less than 0.2 MPa is formed within 3 months, so that the secondary dust reduction rate of the treated lake basin is >90%.

[0022] 13. In S6, for every ton of green salt product produced, 100-200 kg of DRC certificate and 50-80 kg of GSC certificate can be obtained.

[0023] 14. This invention clearly establishes ecological governance as the primary task and fundamental starting point for addressing the cyclical drought-flood alternation problem of salt lakes. It innovatively integrates the technology of "salt production from brine before drying up" into the system solution, making it serve the core objective of "dust suppression." Through the full-chain, multi-technology optimization and integration of "DRI sensing - digital twin decision-making - ecological brine extraction - five-level quality classification - ZLD zero discharge - crust carbon sequestration - blockchain empowerment," it successfully solves the dilemma of conflict between resource development and environmental protection, achieving a unity of ecological, resource, and economic benefits.

Claims

1. An integrated optimization technology for a brine salt production system before drying up in a periodically alternating drought and flood salt lake ecological management system, characterized in that: The system prioritizes ecological governance and includes the following modules: a) A real-time dust source risk index (DRI) sensing network with a monitoring grid resolution of no more than 1km×1km and a DRI output accuracy R²≥0.90; b) A digital twin decision-making platform, coupled with multi-physics models of brine, meteorology, dust sources, and ecology, can automatically generate brine extraction-crystallization-coating optimization strategies with a human intervention rate of ≤5%; c) The ecological brine extraction system is driven by solar or wind power. Its maximum brine extraction capacity is designed according to the formula Qmax=k×(A×H_crit) / T_pump, where k is the safety factor, which takes a value of 0.8~0.

95. Its core function is to maintain the lake surface area at no less than 15% to suppress dust sources. d) Five-stage tandem seepage-proof salt fields, whose ponds adopt a composite seepage-proof structure of HDPE membrane and clay, with a leakage rate of <0.05mm / d. The bottom of the second, fourth and fifth stage salt ponds is equipped with solar heating devices, which can extend the annual evaporation period by 30-45 days. e) Zero Liquid Discharge (ZLD) terminal, using photovoltaic-MVR integrated technology, with evaporation energy consumption ≤45kWh / t water, and the generated condensate can be reused; f) Crust-microbial carbon fixation accelerator: By spraying the mixed salts produced by the ZLD terminal and the lake silt at a ratio of 1:3 and inoculating them with microorganisms, a crust layer with a compressive strength ≥0.2MPa is formed, and its carbon sequestration capacity ≥0.8tCO2-eq / ha•yr is formed. g) A blockchain dual-certificate management platform for issuing, managing, and trading Dust Reduction Certificates (DRC) and Green Salt Certificates (GSC). The modules a) to g) are coupled and linked through data flow, energy flow and material flow to ultimately achieve the synergistic goals of reducing the salt and alkali dust storm source by >90%, recovering the main components of brine (Na2SO4≥90%, NaCl≥85%), and achieving zero liquid discharge of the terminal old brine.

2. The system according to claim 1, characterized in that, The five-stage series salt fields are, in order: a pre-precipitation pool for precipitating gypsum and carbonates, a nitrate precipitation pool for freezing and precipitating mirabilite, a salt precipitation pool for precipitating salt by sun evaporation, a concentration pool for enriching magnesium and potassium elements, and a deep concentration pool for concentrating lithium and boron elements.

3. The system according to claim 2, characterized in that, The nitrate precipitation tank utilizes the low winter temperature (-5℃ to -20℃) to crystallize sodium sulfate (Na2SO4•10H2O), with a sodium sulfate product purity ≥98% and Na2SO4 recovery rate ≥90%.

4. The system according to claim 1, characterized in that, The photovoltaic system of the ZLD terminal adopts a DC bus direct-drive MVR compressor, which does not require a grid-connected inverter, and the final condensate water quality meets the reuse standard of TDS≤500mg / L.

5. A method for ecological restoration and resource utilization of a periodically alternating drought and flood salt lake using the system described in any one of claims 1 to 4, characterized in that, The method includes the following steps: S1. Sensing and Prediction: The lake basin DRI and ecological water level data are acquired in real time through the sensing network and input into the digital twin platform to generate the optimal brine extraction-crystallization-covering integrated strategy; S2. Ecological brine extraction: Based on the strategy generated in S1, the ecological brine extraction system is activated to extract brine. The core control objective is to always maintain the lake surface area ratio at no less than 15%. S3. Five-stage fractional crystallization: The extracted brine is sequentially introduced into the five-stage salt fields to crystallize and precipitate gypsum, mirabilite, and salt, respectively, and magnesium-potassium enriched solution and lithium-boron enriched solution are obtained. S4. Zero liquid discharge treatment: All the terminal brine generated in S3 is sent to the ZLD terminal treatment to achieve zero liquid discharge; S5. Crust formation and ecological restoration: Mix the mixed salts produced in S4 with the lake silt and spray them, and inoculate them with microorganisms to accelerate the formation of wind-erosion resistant crusts and promote the natural restoration of vegetation; S6. Monitoring and Market Feedback: Continuously monitor dust source flux, carbon sink rate and ecological indicators, and upload the data to the blockchain platform to generate tradable DRC and GSC certificates, realizing the market value of environmental benefits.

6. The method according to claim 5, characterized in that, In S3, the freeze crystallization of sodium sulfate is carried out in a temperature range of -5°C to -20°C, and the freezing cycle is controlled within 72 hours.

7. The method according to claim 5 or 6, characterized in that, In S5, the thickness of the sprayed crust is 3-8 mm, and a stable crust with a compressive strength of not less than 0.2 MPa is formed within 3 months, resulting in a secondary dust reduction rate of >90% in the treated lake basin.

8. The method according to claim 5, characterized in that, In S6, for every ton of green salt produced, 100-200 kg of DRC certificates and 50-80 kg of GSC certificates can be obtained.