High-salt wastewater resource utilization device
Patent Information
- Application Number
- CN202521991822.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-16
- Publication Date
- 2026-09-29
- Estimated Expiration
- 2035-09-16
AI Technical Summary
然而，由于高盐废水中难降解有机物、钙、硅等杂质含量高，会对纳滤分盐和蒸发结晶等过程造成较大的影响，导致纳滤分盐和蒸发结晶过程运行不稳定，因此实现零排放和资源化利用难度大
[0011]本实用新型高盐废水资源化利用装置，包括通过管道依次连接的预处理装置、有机物处理装置、纳滤分盐装置、蒸发结晶装置，且有机物处理装置和纳滤分盐装置的底部分别通过管路与预处理装置连通，形成循环。本实用新型将高盐废水经过沉积过滤预处理后，进入有机物处理装置，通过有机物的絮凝剂与臭氧催化剂协调作用，实现废水中有机物的选择性分离与高效去除，后进入纳滤分盐装置，采用多膜系统耦合的MCR-纳滤-反渗透技术，实现氯化钠和硫酸钠的稳定高效分离；最后筛通过高温灼烧及分步结晶方法对结晶盐产物做到了有效纯化。
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Figure CN224812390U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of chemical technology and relates to wastewater treatment, specifically to a device for the resource utilization of high-salt wastewater. Background Technology
[0002] Coking wastewater mainly originates from the primary cooling of coke oven gas, production water used in the coking process, and steam condensate wastewater. Valuable resources within this wastewater primarily include sodium chloride, sodium sulfate, and reusable water. Sodium chloride is one of the most basic raw materials in the chemical industry, with a wide range of industrial applications, often referred to as the "mother of the chemical industry." Sodium sulfate is mainly used in the pulp, detergent, glass, dye, and textile industries, and is also used as a raw material for water glass, ultramarine, and other chemical products. This saline wastewater was once utilized as quenching water, but current processes, limited by membrane recovery rates such as reverse osmosis, generate approximately 30% membrane-concentrated high-salt wastewater. This wastewater is characterized by high levels of recalcitrant organic matter and impurities such as silicon, leading to unstable crystallization and salt separation processes, making zero discharge and resource utilization difficult.
[0003] The main approach to zero discharge of high-salinity wastewater currently involves separating and crystallizing the impurities in the wastewater to obtain high-value-added industrial salt products while simultaneously reusing the water. Existing salt separation and crystallization processes primarily include thermal separation and nanofiltration separation. Thermal separation relies on the principle that sodium chloride and sodium sulfate have different solubilities at different temperatures. However, this method has a narrow separation range, and the quality of the crystallized salt is difficult to stabilize when water quality fluctuates. Nanofiltration separation utilizes the Donnan effect of nanofiltration membranes to concentrate divalent salts to a higher concentration on the concentrate side, while monovalent salts pass through the nanofiltration membrane on the product water side, thus achieving separation. This method has a wider adaptability range for ion ratios, is more stable, and easier to control, making it more advantageous in the desalination and crystallization process of high-salinity coking wastewater. After nanofiltration separation, high-salinity wastewater yields a solution of inorganic salts with high concentrations of sodium chloride and sodium sulfate, which are then evaporated and crystallized to obtain the product salt. However, due to the high content of refractory organic matter, calcium, silicon and other impurities in high-salt wastewater, it will have a significant impact on processes such as nanofiltration desalination and evaporation crystallization, resulting in unstable operation of nanofiltration desalination and evaporation crystallization processes, making it difficult to achieve zero discharge and resource utilization.
[0004] Due to the high organic content of high-salinity wastewater, the raw COD is generally in the range of 5000-20000 mg / L, typically containing various recalcitrant organic compounds such as phenols, nitrogen-containing heterocyclic compounds, and polycyclic aromatic hydrocarbons (PAHs). Furthermore, processes such as gas washing, condensation, and purification introduce certain concentrations of inorganic ions such as Na+, Ca2+, Cl-, and SO42- into the wastewater. These factors contribute to the generally complex composition, poor biodegradability, and high treatment difficulty of coking wastewater. Therefore, achieving low-cost removal of organic matter and efficient concentration and crystallization of inorganic salts from high-salinity wastewater has become a key technological bottleneck restricting the zero discharge of coking wastewater.
[0005] To address the aforementioned problems in existing technologies, a device for the resource utilization of high-salinity wastewater was developed. Utility Model Content
[0006] The purpose of this invention is to provide a device for the resource utilization of high-salinity wastewater.
[0007] This utility model is achieved through the following technical solution: A device for the resource utilization of high-salt wastewater includes a pretreatment device, an organic matter treatment device, a nanofiltration desalination device, and an evaporation crystallization device connected in sequence by pipelines. The pretreatment device is used to treat high-salinity wastewater by sedimentation and filtration; The aforementioned organic matter treatment device is used for the selective separation and efficient removal of organic matter from high-salt wastewater; The nanofiltration desalination device achieves stable and efficient separation of sodium chloride and sodium sulfate in high-salt wastewater through multi-membrane system coupling. The evaporation crystallization device achieves effective purification of crystalline salt products through high-temperature calcination and stepwise crystallization.
[0008] The organic matter treatment device is a catalytic-biochemical treatment device; The nanofiltration salt separation device is a multi-membrane system coupling device, preferably an MCR-nanofiltration-reverse osmosis device.
[0009] The bottoms of the organic matter treatment device and the nanofiltration desalination device are connected to the pretreatment device through pipelines to form a cycle.
[0010] During operation, the steps are as follows: (1) Deep removal of organic matter in high-salt system: the selective separation and removal of organic matter in wastewater is achieved by using flocculant and catalyst in synergy; (2) Mixed salt separation and resource utilization: the stable separation of sodium chloride and sodium sulfate is achieved by using the design of MCR-nanofiltration-reverse osmosis multi-membrane coupling synergistic gradient coupling and reflux nesting; (3) Evaporation crystallization stabilization control of complex system: the scale inhibitor, humic acid and defoamer are used to achieve stepwise crystallization purification by high temperature calcination.
[0011] This utility model relates to a high-salinity wastewater resource utilization device, comprising a pretreatment device, an organic matter treatment device, a nanofiltration desalination device, and an evaporation crystallization device connected sequentially by pipelines. The bottoms of the organic matter treatment device and the nanofiltration desalination device are connected to the pretreatment device via pipelines, forming a circulation loop. After sedimentation filtration pretreatment, the high-salinity wastewater enters the organic matter treatment device. Through the synergistic action of organic matter flocculants and ozone catalysts, selective separation and efficient removal of organic matter in the wastewater are achieved. The wastewater then enters the nanofiltration desalination device, employing a multi-membrane system coupled with MCR-nanofiltration-reverse osmosis technology to achieve stable and efficient separation of sodium chloride and sodium sulfate. Finally, the crystallized salt products are effectively purified through high-temperature calcination and stepwise crystallization.
[0012] This invention can effectively solve the technical difficulties in the process of zero discharge of high-salt wastewater and resource utilization of inorganic salts in the coking industry, provide technical support for zero discharge of high-salt wastewater, save recycled water, recover a large amount of sodium chloride and sodium sulfate as by-products, and reduce COD and ammonia nitrogen emissions. The recovery rate of sodium sulfate and sodium chloride is greater than 85%, and the water reuse rate is greater than 95%. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the structure of the device of this utility model; In the diagram: 1-Pretreatment device, 2-Organic matter treatment device, 3-Nanofiltration salt separation device, 4-Evaporation crystallization device. Detailed Implementation
[0014] To make the objectives and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of this utility model and does not strictly limit the scope of protection specifically claimed by this utility model.
[0015] An apparatus for the resource utilization of high-salinity wastewater includes a pretreatment device 1, an organic matter treatment device 2, a nanofiltration desalination device 3, and an evaporation crystallization device 4, which are connected in sequence via pipelines. The pretreatment device 1 is used to treat high-salinity wastewater by sedimentation and filtration. The organic matter treatment device 2 is used to selectively separate and efficiently remove organic matter from the high-salinity wastewater. The nanofiltration desalination device 3 achieves stable and efficient separation of sodium chloride and sodium sulfate from the high-salinity wastewater through multi-membrane system coupling. The evaporation crystallization device 4 effectively purifies the crystallized salt products through high-temperature calcination and stepwise crystallization. The bottoms of the organic matter treatment device 2 and the nanofiltration desalination device 3 are respectively connected to the pretreatment device 1 through pipelines to form a circulation.
[0016] During operation, the steps are as follows: (1) The coking high-salt wastewater is precipitated and filtered through the pretreatment device 1 and input into the organic matter treatment device 2. The organic matter treatment device 2 is a catalytic-biochemical treatment device. During operation, epoxypropyl dodecyl dimethyl ammonium chloride flocculant and ozone catalyst are added to separate and remove organic matter in the wastewater. The quaternary ammonium group, epoxy group and long chain dodecyl group in the wastewater undergo charge neutralization with the ions in the wastewater and flocculate the organic matter through adsorption and cross-linking. (2) The wastewater after removing organic matter is input into the nanofiltration salt separation device 3. The nanofiltration salt separation device 3 is a membrane system. Through the design of MCR-nanofiltration-reverse osmosis multi-membrane coupling synergistic gradient coupling and reflux nesting, the stable separation of sodium chloride and sodium sulfate is achieved, and the wastewater is de-hardened, defluorinated and desilted. (3) The wastewater after being treated by the membrane system is input into the evaporation crystallization device 4. The scale inhibitor fulvic acid, humic acid and defoamer are used to achieve step-by-step crystallization purification through high temperature calcination.
[0017] The above description is merely a preferred embodiment of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model. Structures, devices, and operating methods not specifically described or explained in this utility model, unless otherwise specified or limited, shall be implemented using conventional methods in the field.
Claims
1. A device for the resource utilization of high-salinity wastewater, characterized in that, It includes a pretreatment unit, an organic matter treatment unit, a nanofiltration desalination unit, and an evaporation crystallization unit, which are connected in sequence by pipelines. The pretreatment device is used to treat high-salinity wastewater by sedimentation and filtration; The aforementioned organic matter treatment device is used for the selective separation and efficient removal of organic matter from high-salt wastewater; The nanofiltration desalination device achieves stable and efficient separation of sodium chloride and sodium sulfate in high-salt wastewater through multi-membrane system coupling. The evaporation crystallization device achieves effective purification of crystalline salt products through high-temperature calcination and stepwise crystallization.
2. The apparatus according to claim 1, characterized in that, The organic matter treatment device is a catalytic-biochemical treatment device.
3. The apparatus according to claim 2, characterized in that, The nanofiltration salt separation device is an MCR-nanofiltration-reverse osmosis device.
4. The apparatus according to claim 1, characterized in that, The bottoms of the organic matter treatment device and the nanofiltration desalination device are connected to the pretreatment device through pipelines to form a cycle.