A device for advanced treatment and full resource recovery of molybdenum-iron polluted water

Abstract

This invention discloses a device for the advanced treatment and full resource recovery of molybdenum-iron contaminated water, comprising: a pretreatment and advanced molybdenum removal unit consisting of a homogeneous adsorption-flocculation synergistic sedimentation chamber and a two-stage molybdenum removal separator; a molybdenum desorption and enrichment unit consisting of a molybdenum desorption reaction chamber and a molybdenum enrichment chamber; and an iron conversion and regeneration unit consisting of an iron conversion chamber and an iron salt regenerator. This invention achieves advanced purification of molybdenum-iron contaminated water to drinking water standards, while simultaneously and efficiently recovering molybdenum and iron resources, forming a zero-emission recycling system for iron salts and solid products, significantly reducing treatment costs and creating economic benefits.

Description

Technical Field

[0001] This utility model belongs to the field of wastewater recycling and treatment technology, specifically relating to a device for the deep treatment and full resource utilization of molybdenum and iron polluted water. It is a device that achieves efficient separation and recovery of molybdenum and iron and purification of wastewater through adsorption-flocculation, precipitation analysis and iron salt recycling. Background Technology

[0002] The discharge of molybdenum-containing wastewater has become a serious environmental problem in industries such as metallurgy, molybdenum mining, chemical catalysis, and electronic materials production. As a heavy metal, molybdenum, when its ionic form (such as molybdate) exceeds the discharge standard of 0.5 mg / L in water bodies, can have toxic effects on aquatic organisms (inhibiting algal photosynthesis and damaging the respiratory system of fish), and may accumulate in human organs such as the liver and kidneys through the food chain, leading to chronic poisoning. Statistics show that global industrial production generates over ten million tons of molybdenum-containing wastewater annually, with molybdenum concentrations typically ranging from 10 to 100 mg / L. Direct discharge of such wastewater not only incurs hefty environmental fines (e.g., the EU imposes fines of up to 5% of annual output value on companies exceeding emission standards) but also results in a severe waste of molybdenum resources. Molybdenum, as a strategically scarce metal, is irreplaceable in fields such as alloy steel, catalysts, and semiconductor thin films. However, primary molybdenum mining faces challenges such as declining ore grade, high energy consumption, and heavy pollution. In contrast, the cost of recovering molybdenum from wastewater is only one-third to one-half that of ore refining, resulting in significant economic benefits. Traditional treatment technologies such as sulfide precipitation easily generate toxic H2S gas, lime precipitation generates a large amount of sludge and has a molybdenum recovery rate of less than 60%, and ion exchange has low adsorption efficiency for low concentrations of molybdenum. None of these technologies can meet the current dual requirements of "zero emissions" and "resource utilization". There is an urgent need to develop an efficient and low-cost integrated adsorption-recovery technology.

[0003] There are many methods for adsorption and recovery of molybdenum-containing wastewater. For example, Chinese patent CN118561396A, "A method for treating molybdenum-containing wastewater and a coagulant for removing molybdenum from wastewater," utilizes a combination of neutralization, calcium salts, compound coagulants, and organic flocculants to treat molybdenum-containing wastewater. This method significantly solves the problem of treating highly alkaline, high-salt, and high-concentration molybdenum-containing wastewater, achieving both preliminary molybdenum recovery and deep molybdenum removal. While this method can achieve a molybdenum removal rate of over 99.9%, most of the calcium salts, compound coagulants, and organic flocculants are converted into precipitates or dissolved in the wastewater after the reaction, making them difficult to recover and reuse through simple physical or chemical methods. This not only increases the cost of reagents but also consumes a large amount of resources, which is inconsistent with the requirements of a circular economy. Chinese patent CN114735846A, "A Method for Deep Removal of Molybdenum from Molybdenum-Containing Wastewater," utilizes D318 resin for adsorption and pre-removal of molybdenum, followed by pH adjustment and deep removal of molybdenum using iron salts. The process involves filtration, collection and recycling of the filter residue, and treatment of the filtrate, achieving deep removal of molybdenum from molybdenum smelting wastewater. While this method can achieve deep molybdenum removal, the adsorption of D318 resin is affected by the wastewater composition and pH, easily adsorbing impurities that make it difficult to guarantee molybdenum purity. Regeneration is required after adsorption saturation, and frequent regeneration reduces resin performance and lifespan, increasing molybdenum recovery costs and instability risks. In patent TW109115778, "Method and Apparatus for Treating and Recovering Ferrous Molybdate Crystals from Molybdenum-Containing Wastewater," the molybdenum-containing wastewater is first introduced into a first reaction tank, where ferric ion reagent and acid are added to adjust the pH. Then, the wastewater is diverted to a second reaction tank where an alkali is added, causing molybdenum and iron ions to react and form ferrous molybdate crystals that adhere to the crystalline substrate. The treated water overflows from the top, and a portion of the treated water is diverted as circulating water and reinjected into the second reaction tank, allowing the residual ferrous molybdate crystals to continue to adhere and accumulate. Once the ferrous molybdate crystals on the surface of the crystalline substrate reach a certain particle size, the substrate particles are removed, thus achieving the treatment of molybdenum-containing wastewater and the recovery and reuse of molybdenum metal resources. However, this method and apparatus mainly focus on the removal of molybdenum and do not effectively recover iron ions, which are discarded with iron slag, resulting in resource waste. Furthermore, it does not mention the recovery of other potentially valuable components in the wastewater. In Chinese patent "CN103755003A", a composite molybdenum removal agent is prepared by oxidizing ferrous salt and stirring it with ferrous salt under a protective atmosphere with temperature control, adding a catalyst and an alkaline regulator, aging it at a higher temperature, and then adding high-valent iron salt and a dispersant. Although this method can remove molybdenum by preparing a composite molybdenum removal agent through a simple synthesis step, it does not recycle the adsorbed molybdenum or the iron-based agent after molybdenum adsorption, which easily generates molybdenum-containing solid waste and fails to achieve resource recycling.

[0004] In summary, existing technologies cannot simultaneously meet the multiple demands of "deep purification," "efficient separation and high-value recovery of molybdenum and ferromolybdenum," "recycling of treatment reagents," and "economical and environmentally friendly processes" for molybdenum-containing wastewater. Therefore, there is an urgent need to develop an integrated treatment technology and equipment that can achieve deep removal of molybdenum and ferromolybdenum, separate enrichment and recovery, internal recycling of reagents, and high-quality water production. Utility Model Content

[0005] Addressing the shortcomings of existing technologies and aiming to solve the challenges of deep purification and resource recovery of molybdenum-iron-containing wastewater, this invention provides a device for the deep treatment and full resource recovery of molybdenum-iron-contaminated water. This invention not only achieves efficient deep removal and enrichment recovery of molybdenum from wastewater, but also enables the recycling of iron salt reagents, purifying the treated water to a high quality (e.g., molybdenum-iron content reaching drinking water standards), ultimately achieving near-zero wastewater discharge and full recovery of valuable resources.

[0006] The technical solution of this utility model is as follows:

[0007] A device for the advanced treatment and full resource utilization of molybdenum-iron polluted water includes a pretreatment and advanced molybdenum removal unit, a molybdenum analysis and enrichment unit, and an iron conversion and regeneration unit.

[0008] The pretreatment and deep molybdenum removal unit includes:

[0009] Homogeneous adsorption-flocculation synergistic sedimentation chamber: The middle part is equipped with a wastewater inlet pipe and an iron salt dosing port; the upper part is equipped with an outlet pipe connected to the secondary molybdenum separator; the bottom is equipped with a mud pump pipe, through which mud is pumped into the molybdenum desorption reaction chamber; a pH sensor is equipped to measure the pH value of the system, and an intelligent dosing controller is equipped to control the dosing amount.

[0010] Two-stage molybdenum removal separator: its interior is filled with modified shell powder adsorption filler and quartz sand; the upper part is equipped with a water inlet, which is connected to the water outlet pipe of the homogeneous adsorption-flocculation co-sedimentation chamber; the lower part is equipped with a water outlet; and it is equipped with a pH sensor and an intelligent dosing controller.

[0011] The aforementioned two-stage molybdenum separator has a lower layer packing material with a size of 40-100 mm and an upper layer packing material with a size of 10-25 mm. Quartz sand is placed beneath the packing material for deep molybdenum removal. The upper packing material has a height of 700-800 cm, and the lower quartz sand layer has a height of 800-1000 cm. The treated effluent has a molybdenum content of <0.07 mg / L.

[0012] The molybdenum analysis and enrichment unit includes:

[0013] The molybdenum reaction chamber is equipped with an eluent dosing port and a sludge inlet at the top. The sludge inlet is connected to the sludge pump in the homogeneous adsorption-flocculation co-sedimentation chamber. It is equipped with a pH sensor, an intelligent dosing controller, and an ultrasonic transducer to promote the reaction. The upper effluent end is equipped with an ultrafiltration membrane module and a molybdenum-containing eluent effluent pipe, which is connected to the molybdenum enrichment chamber. The bottom is equipped with a sludge pump connector, through which sludge is pumped into the iron conversion chamber.

[0014] Molybdenum enrichment chamber: Equipped with an alanine dosing port, a molybdenum-containing eluent inlet, and an enrichment solution outlet. The molybdenum-containing eluent inlet is connected to the molybdenum-containing eluent outlet pipe of the molybdenum eluent reaction chamber. The molybdenum-rich solution produced by the molybdenum enrichment chamber has a molybdenum content of 50 mg / L or higher.

[0015] The iron conversion and regeneration unit includes:

[0016] Iron conversion chamber: The upper part is equipped with an inlet for iron-containing precipitate, an outlet for the supernatant of the conversion liquid, an outlet for FeOOH-containing solids after conversion, and a dosing port for the conversion liquid. The inlet for iron-containing precipitate is connected to the mud pump at the bottom of the molybdenum desorption reaction chamber. The outlet for FeOOH-containing solids after conversion is connected to the homogeneous adsorption-flocculation synergistic sedimentation chamber through the mud pump. The crystallinity is 10-30%. The outlet for the supernatant of the conversion liquid is connected to the iron salt regenerator. It is equipped with a pH sensor, an intelligent dosing controller, and an agitator.

[0017] Iron salt regenerator: It is equipped with an inlet for the supernatant of the iron conversion chamber, a return port for filter residue, and an outlet for the regenerated iron salt enriched liquid. It is equipped with a filtration device inside. The inlet for the supernatant of the iron conversion chamber is connected to the outlet for the supernatant of the iron conversion chamber, and the return port for filter residue is connected to the iron conversion chamber through a mud pump.

[0018] In each unit, the intelligent dosing controller is connected to the pH monitoring device and automatically controls the dosage of the corresponding agent in the unit based on the monitored pH value.

[0019] The above-mentioned device is used for the advanced treatment and full resource recovery of molybdenum-iron contaminated water. The specific method is as follows: First, the molybdenum-iron contaminated water is introduced into a homogeneous adsorption-flocculation synergistic sedimentation chamber unit. Iron salt is added as a coagulant, and the pH of the reaction system is controlled within the range of 4-6.5 for homogeneous adsorption-flocculation synergistic sedimentation. The resulting supernatant is introduced into a secondary molybdenum removal unit for advanced molybdenum removal treatment, and the pH of the effluent is adjusted to the range of 6.5-8.5. Then, a disinfectant is added to ensure the treated water meets drinking water standards. The precipitates generated in the homogeneous adsorption-flocculation synergistic sedimentation chamber unit and the secondary molybdenum removal unit are combined and then... The molybdenum is analyzed in the molybdenum unit, where an analytical solution is added to perform the molybdenum analysis reaction. The pH of the reaction system is controlled at 9-11. The resulting liquid is then introduced into the molybdenum enrichment unit to enrich molybdenum, resulting in a high-concentration molybdenum solution, which is used as a corrosion inhibitor for the coolant. The precipitate generated after the analytical reaction is introduced into the iron conversion unit, where a conversion solution is added and the pH is controlled at 2-4 to perform the iron speciation conversion reaction. The resulting solid material is returned to the homogeneous adsorption-flocculation co-sedimentation chamber unit. The liquid from the conversion reaction is introduced into the iron salt regeneration unit to obtain a regenerated solution rich in iron salts. The precipitate generated in the iron salt regeneration unit is returned to the iron conversion unit for further conversion.

[0020] The specific steps are as follows:

[0021] Step (1), Homogeneous Adsorption-Flocculation Co-sedimentation and Primary Molybdenum Removal: The molybdenum-containing ferric wastewater is introduced into the homogeneous adsorption-flocculation co-sedimentation chamber, where ferric salt is added as an adsorbent. The pH of the reaction system is monitored and controlled at 4-6.5 using a pH intelligent controller, allowing the ferric salt to fully react with the molybdate ions in the wastewater to form ferric molybdate precipitate. After the reaction is complete, solid-liquid separation is performed: the supernatant is diverted to a secondary molybdenum separator for deep molybdenum removal; the ferric molybdate sludge generated during sedimentation is pumped to the molybdenum desorption reaction chamber.

[0022] The iron salt is one or a mixture of two or more of ferric sulfate, ferric chloride, and polyferric sulfate, and is used to treat water contaminated with molybdenum and ferric iron.

[0023] Step (2), Secondary Deep Molybdenum Removal and Water Purification: The supernatant from step (1) enters the secondary molybdenum separator, which is filled with modified shell powder and quartz sand adsorbent material. The supernatant flows through the molybdenum removal packing, where residual molybdenum is further adsorbed and removed. The pH of the treated effluent is controlled within the range of 6.5-8.5, and then disinfectant is added to ensure that the final effluent molybdenum-iron content meets drinking water standards. The molybdenum-containing saturated adsorbent and precipitated sludge generated in the secondary molybdenum separator are transported to the molybdenum desorption reaction chamber via a sludge pump.

[0024] The modified shell powder is composed of CaO, shell powder and sodium alginate, with quartz sand below the modified shell powder. The mass ratio of CaO, shell powder, sodium alginate and quartz sand is (1-2):(20-25):(0.1-0.2):(78.9-72.8).

[0025] Step (3), Molybdenum Desorption and Enrichment: The molybdenum-containing sludge and adsorbent from steps (1) and (2) are placed in the molybdenum desorption reaction chamber, and an alkaline desorption solution is added. Under the control of a pH intelligent controller, the pH of the reaction system is maintained within the range of 9-11, and the desorption reaction is carried out under ultrasonic assistance, so that molybdenum is transferred from the solid phase to the liquid phase. After the desorption is completed, solid-liquid separation is performed: the molybdenum-containing desorption solution is diverted to the molybdenum enrichment chamber for concentration treatment to obtain a high-concentration molybdate solution, which can be used as a corrosion inhibitor for a coolant and other high-value-added products; the iron-containing precipitate remaining after desorption is transported to the iron conversion chamber by a mud pump.

[0026] The alkaline eluent is formed by mixing water, NaOH, and triethanolamine, with a NaOH concentration of 30–36 g / L and a triethanolamine concentration of 12–15 g / L. The molybdenum content in the high-concentration molybdate solution is above 50 mg / L.

[0027] Step (4), iron precipitation conversion and iron salt regeneration cycle:

[0028] Conversion: Add acidic conversion solution to the iron conversion chamber. The acidic conversion solution is hydrochloric acid or sulfuric acid with a volume concentration of 5-12% (v / v). Under stirring and pH intelligent control (pH 2.0-4.0), solid-liquid separation occurs after the reaction: the amorphous iron precipitate is converted into iron hydroxyl oxide (FeOOH). The FeOOH solid is returned to the homogeneous adsorption-flocculation co-sedimentation chamber by a mud pump, and participates in the sedimentation reaction of step (1) as a crystal nucleus or flocculant, so as to realize the recycling of iron salt form.

[0029] Regeneration: The supernatant (containing soluble iron salts) produced by the conversion is diverted to the iron salt regenerator, and the filter residue can be returned to the iron conversion chamber for reprocessing. The purified iron salt enriched liquid can be collected and used as a coagulant to participate in the sedimentation reaction in step (1) to realize the recovery of iron resources.

[0030] The beneficial effects of this utility model are:

[0031] (1) This utility model achieves efficient deep removal of molybdenum from molybdenum-containing wastewater through a combination of iron salt flocculation sedimentation and modified shell powder adsorption secondary treatment; the final treated water has a molybdenum iron content that is significantly lower than the discharge standard and can meet the drinking water quality standard, thus realizing the high-value reuse of wastewater.

[0032] (2) This utility model adopts an alkaline desorption-enrichment process to efficiently recover molybdenum from molybdenum-containing sludge / adsorbent, and obtain a high-concentration molybdate solution, which can be used as a corrosion inhibitor for coolant and other products, thus realizing the effective recycling and utilization of molybdenum resources.

[0033] (3) This utility model converts the iron-containing precipitate generated by molybdenum removal into iron hydroxyl oxide (FeOOH) through acid conversion, which is directly recycled to the front-end homogeneous adsorption-flocculation synergistic sedimentation step. The soluble iron salt solution generated during the conversion process is regenerated and purified to obtain iron salt enriched liquid, which can be used as a high-efficiency coagulant for recycling in this system or external water treatment, realizing the closed-loop recovery and resource utilization of iron elements.

[0034] (4) The key reaction units of this utility model device (homogeneous adsorption-flocculation synergistic sedimentation chamber, secondary molybdenum removal separator, molybdenum desorption reaction chamber, and iron conversion chamber) are all equipped with pH sensors and intelligent dosing controllers to achieve accurate real-time monitoring of reaction pH and automatic optimization control of reagent dosage, ensuring efficient and stable reaction, improving resource recovery efficiency, and reducing reagent waste and operating costs.

[0035] (5) In order to improve equipment efficiency and product qualification rate, an intelligent pH control system is adopted. pH sensors and intelligent dosing controllers are installed in the homogeneous adsorption-flocculation synergistic sedimentation chamber, the secondary molybdenum removal separator, the molybdenum desorption reaction chamber and the iron conversion chamber to detect pH changes in real time and better control the amount of reagent added.

[0036] (6) This utility model recovers valuable metal resources (molybdenum and iron) to the greatest extent, achieves "near-zero discharge" of wastewater and "near-zero generation" of waste residue, and significantly reduces operating costs through reagent recycling, thus having significant environmental and economic benefits. Attached Figure Description

[0037] Figure 1 The process flow diagram for the advanced treatment and full resource utilization of molybdenum-iron polluted water using this utility model is shown below.

[0038] Figure 2 This is a diagram of the homogeneous adsorption-flocculation synergistic sedimentation chamber and the two-stage molybdenum removal separator of this utility model;

[0039] Figure 3 This is a diagram of the apparatus for analyzing the molybdenum reaction chamber and the molybdenum enrichment chamber of this utility model;

[0040] Figure 4 This is a diagram of the iron conversion chamber and iron salt regenerator of this utility model.

[0041] Figure 5 Infrared image of the iron-based adsorbent-A prepared for recycling according to this utility model.

[0042] Figure 6 The XRD pattern of the iron-based adsorbent-A prepared by recycling according to this invention.

[0043] Figure 7 Infrared spectrum of the iron-based adsorbent-B prepared by recycling according to this invention.

[0044] Figure 8 The XRD pattern of the iron-based adsorbent-B prepared by recycling according to this invention. Detailed Implementation

[0045] The present invention will be further described below with reference to implementation examples and accompanying drawings.

[0046] This utility model discloses a device for the advanced treatment and full resource utilization of molybdenum-iron polluted water, comprising a pretreatment and advanced molybdenum removal unit, a molybdenum desorption and enrichment unit, and an iron conversion and regeneration unit. The pretreatment and advanced molybdenum removal unit includes a homogeneous adsorption-flocculation synergistic sedimentation chamber and a two-stage molybdenum separator, such as... Figure 2 As shown; molybdenum analysis and enrichment unit analyzes the molybdenum reaction chamber and molybdenum enrichment chamber, as shown. Figure 3 As shown; the iron conversion and regeneration unit includes an iron conversion chamber and an iron salt regenerator, such as Figure 4 As shown. The basic process of using the device of this invention for the advanced treatment and full resource recovery of molybdenum-iron polluted water is as follows. Figure 1 As shown.

[0047] Example 1:

[0048] Take a sample of molybdenum-iron wastewater containing approximately 40 mg / L of molybdenum and approximately 15 mg / L of iron.

[0049] Wastewater was introduced into a homogeneous adsorption-flocculation synergistic sedimentation chamber, and iron-based adsorbent-A (recovered and prepared) was slowly added while stirring. The infrared and XRD patterns of iron-based adsorbent-A are shown below. Figure 5 and 6 As shown, from Figure 5 It can be seen that there are obvious hydroxyl peaks and ferrite bond peaks. Figure 6 (As can be seen from the image, the prepared ferric hydroxide has low crystallinity.) FeCl3 solution was then added sequentially to form an adsorption-coagulation synergistic technology. A pH intelligent controller monitored the pH in real time, automatically stopping the addition of FeCl3 solution when the pH dropped to 4.0±0.2. The reaction continued for 30 minutes. After the reaction, the molybdenum concentration in the water decreased to 0.07 mg / L. The supernatant was drained through the effluent pipe to the secondary molybdenum removal separator; the bottom ferric molybdate sludge was pumped into the molybdenum removal reaction chamber via a sludge pump.

[0050] The supernatant flows through a two-stage molybdenum separator with a filter bed packing height of 1.0-1.5 meters. The filter media consists of modified shell powder and quartz sand (with a mass ratio of CaO, shell powder, sodium alginate, and quartz sand of 1:20:0.1:78.9). After treatment, the molybdenum concentration in the effluent is further reduced to 0.04 mg / L, the iron concentration to 0.05 mg / L, and the pH rises to 6.5±0.2. The final effluent molybdenum and iron content meets drinking water standards.

[0051] Eluent: Composed of NaOH and triethanolamine. 12g of triethanolamine and 30g of NaOH are added sequentially to 1000ml of water and stirred until completely dissolved to obtain the eluent.

[0052] Eluent was added to the sludge in the molybdenum reaction chamber. A pH intelligent controller controlled the dosage, maintaining the pH at 9, and an ultrasonic transducer assisted the reaction for 60 minutes. After eluent removal, the molybdenum-containing eluent was filtered through an ultrafiltration membrane and then concentrated in a molybdenum enrichment chamber to obtain a high-concentration sodium molybdate solution (molybdenum concentration approximately 200 mg / L). 3% alanine was added as a corrosion inhibitor for the coolant. The corrosion inhibition rate of A3 steel in 25% calcium chloride was tested.

[0053] The formula for calculating the corrosion inhibition rate (η) is: η = (1 - v 空 / v 缓 )×100%

[0054] Among them, v 空 Corrosion rate (in mm / a) of the blank system (without corrosion inhibitor); v 缓 Corrosion rate of the system after adding corrosion inhibitor (unit: mm / a).

[0055] The corrosion inhibition rate was 99.9%. The residual iron-containing precipitate after analysis was pumped into the iron conversion chamber via a mud pump.

[0056] A conversion solution consisting of 5% hydrochloric acid (by volume) is added to the iron conversion chamber. A pH intelligent controller controls the dosage, maintaining the pH at 2.0 ± 0.2. The reaction is stirred for 12 hours and then allowed to stand. The generated FeOOH solid is pumped back to the homogeneous adsorption-flocculation co-sedimentation chamber, where it can be used as an iron-based adsorbent in the next round of wastewater treatment. The supernatant from the conversion process is introduced into the iron salt regenerator for filtration. The filter residue is returned to the iron conversion chamber. The filtrate, a regenerated iron salt enriched solution, is collected and used as a coagulant for later use.

[0057] Example 2:

[0058] A sample of molybdenum-iron wastewater with a molybdenum content of approximately 15 mg / L and an iron content of approximately 8 mg / L was taken. The operating procedures were the same as in Example 1. The wastewater was introduced into a homogeneous adsorption-flocculation synergistic sedimentation chamber, and iron-based adsorbent-A (recovered and prepared; the infrared and XRD patterns of iron-based adsorbent-A are shown below) was slowly added while stirring. Figure 5 and 6 As shown, from Figure 5 It can be seen that there are obvious hydroxyl peaks and ferrite bond peaks. Figure 6 As can be seen from the above, the prepared ferric hydroxide has low crystallinity. FeSO4-2 (recycled preparation) solution is then added sequentially to form an adsorption-coagulation synergistic technology. A pH intelligent controller monitors the pH in real time; when the pH drops to 6.5±0.2, the addition of FeSO4-2 (recycled preparation) solution is automatically stopped. The reaction continues for 30 minutes. After the reaction, the molybdenum concentration in the water drops to 0.06 mg / L. The supernatant is drained through the effluent pipe to the secondary molybdenum removal separator; the bottom ferric molybdate sludge is pumped into the molybdenum removal reaction chamber via a sludge pump.

[0059] The supernatant flows through a two-stage molybdenum separator with a filter bed packing height of 1.0-1.5 meters. The filter media consists of modified shell powder and quartz sand (with a mass ratio of CaO, shell powder, sodium alginate, and quartz sand of 2:25:0.2:72.8). After treatment, the molybdenum concentration in the effluent is further reduced to 0.03 mg / L, the iron concentration to 0.04 mg / L, and the pH rises to 8.5±0.2. The final effluent molybdenum and iron content meets drinking water standards.

[0060] Eluent: Composed of NaOH and triethanolamine. 15g of triethanolamine and 36g of NaOH are added sequentially to 1000ml of water and stirred until completely dissolved to obtain the eluent.

[0061] The eluent was added to the sludge / adsorbent in the molybdenum reaction chamber. A pH intelligent controller controlled the dosage, maintaining the pH at 11, and the ultrasonic transducer assisted the reaction for 60 minutes. After eluent removal, the molybdenum-containing eluent was filtered through an ultrafiltration membrane and then concentrated in a molybdenum enrichment chamber to obtain a high-concentration sodium molybdate solution (molybdenum concentration approximately 50 mg / L). 3% alanine was added as a corrosion inhibitor for the coolant. The corrosion inhibition rate for A3 steel in 25% calcium chloride solution was 79%.

[0062] The residual iron-containing precipitate after analysis is pumped into the iron conversion chamber via a mud pump.

[0063] A conversion solution consisting of 5% sulfuric acid (by volume) is added to the iron conversion chamber. A pH intelligent controller controls the dosage, maintaining the pH at 4.0 ± 0.2. The reaction is stirred for 12 hours and then allowed to stand. The generated FeOOH solid is pumped back to the homogeneous adsorption-flocculation co-sedimentation chamber, where it can be used as an iron-based adsorbent in the next round of wastewater treatment. The supernatant from the conversion process is introduced into the iron salt regenerator for filtration. The filter residue is returned to the iron conversion chamber. The filtrate, a regenerated iron salt enriched solution, is collected and used as a coagulant for later use.

[0064] Example 3:

[0065] A sample of molybdenum-iron wastewater containing approximately 25 mg / L of molybdenum and 10 mg / L of iron was taken. The operating procedure was the same as in Example 1. The wastewater was introduced into a homogeneous adsorption-flocculation synergistic sedimentation chamber, and iron-based adsorbent-B (recovered and prepared; the infrared and XRD patterns of iron-based adsorbent-B are shown below) was slowly added while stirring. Figure 7 and 8 As shown, from Figure 7 The peaks show both hydroxyl and ferrite bond peaks. Figure 8 The prepared ferric hydroxide showed high crystallinity. FeCl3-2 (recycled preparation) solution was then added sequentially, forming an adsorption-coagulation synergistic technology. A pH intelligent controller monitored the pH in real time, automatically stopping the addition of FeCl3-2 (recycled preparation) solution when the pH dropped to 5±0.2. The reaction continued for 30 minutes. After the reaction, the molybdenum concentration in the water dropped to 0.07 mg / L. The supernatant was drained through the effluent pipe to the secondary molybdenum separator; the bottom ferric molybdate sludge was pumped into the molybdenum removal reaction chamber via a sludge pump.

[0066] The supernatant flows through a two-stage molybdenum separator with a filter bed packing height of 1.0-1.5 meters. The filter media consists of modified shell powder and quartz sand (with a mass ratio of CaO, shell powder, sodium alginate, and quartz sand of 1.5:22.5:0.15:75.85). After treatment, the molybdenum concentration in the effluent is further reduced to 0.04 mg / L, the iron concentration to 0.05 mg / L, and the pH rises to 7.5 ± 0.2. The final effluent molybdenum and iron content meets drinking water standards.

[0067] Eluent: Composed of NaOH and triethanolamine. 13.5g of triethanolamine and 33g of NaOH are added sequentially to 1000ml of water and stirred until completely dissolved to obtain the eluent.

[0068] Add the eluent to the sludge / adsorbent in the molybdenum reaction chamber. A pH intelligent controller controls the dosage, maintaining the pH at 10, and the ultrasonic transducer assists the reaction for 60 minutes. After eluent removal, the molybdenum-containing eluent is filtered through an ultrafiltration membrane and then diverted to a molybdenum enrichment chamber for concentration, yielding a high-concentration sodium molybdate solution (approximately 100 mg / L molybdenum). Add 3% alanine as a corrosion inhibitor for the coolant; the corrosion inhibition rate for A3 steel in 25% calcium chloride solution is 96%.

[0069] The residual iron-containing precipitate after analysis is pumped into the iron conversion chamber via a mud pump.

[0070] A conversion solution consisting of hydrochloric acid (12% by volume) is added to the iron conversion chamber. A pH intelligent controller controls the dosage, maintaining the pH at 3 ± 0.2. The reaction is stirred for 12 hours and then allowed to stand. The generated FeOOH solid is pumped back to the homogeneous adsorption-flocculation co-sedimentation chamber, where it can be used as an iron-based adsorbent in the next round of wastewater treatment. The supernatant from the conversion process is introduced into the iron salt regenerator for filtration. The filter residue is returned to the iron conversion chamber. The filtrate, a regenerated iron salt enriched solution, is collected and used as a coagulant for later use.

[0071] Example 4:

[0072] A sample of molybdenum-iron wastewater containing approximately 25 mg / L of molybdenum and 10 mg / L of iron was taken. The operating procedure was the same as in Example 1. The wastewater was introduced into a homogeneous adsorption-flocculation synergistic sedimentation chamber, and iron-based adsorbent-B (recovered and prepared; the infrared and XRD patterns of iron-based adsorbent-B are shown below) was slowly added while stirring. Figure 7 and 8 As shown, from Figure 7 The peaks show both hydroxyl and ferrite bond peaks. Figure 8 As can be seen from the above, the prepared ferric hydroxide has a high degree of crystallinity. FeSO4 solution is then added sequentially to form an adsorption-coagulation synergistic technology. A pH intelligent controller monitors the pH in real time, and automatically stops adding FeSO4 solution when the pH drops to 5±0.2. The reaction continues for 30 minutes. After the reaction, the molybdenum concentration in the water drops to 0.07 mg / L. The supernatant is drained through the effluent pipe to the secondary molybdenum removal separator; the bottom ferric molybdate sludge is pumped into the molybdenum removal reaction chamber via a sludge pump.

[0073] The supernatant flows through a two-stage molybdenum separator with a filter bed packing height of 1.0-1.5 meters. The filter media consists of modified shell powder and quartz sand (with a mass ratio of CaO, shell powder, sodium alginate, and quartz sand of 1.5:22.5:0.15:75.85). After treatment, the molybdenum concentration in the effluent is further reduced to 0.04 mg / L, the iron concentration to 0.05 mg / L, and the pH rises to 7.5 ± 0.2. The final effluent molybdenum and iron content meets drinking water standards.

[0074] Eluent: Composed of NaOH and triethanolamine. 13.5g of triethanolamine and 33g of NaOH are added sequentially to 1000ml of water and stirred until completely dissolved to obtain the eluent.

[0075] Add the eluent to the sludge / adsorbent in the molybdenum reaction chamber. A pH intelligent controller controls the dosage, maintaining the pH at 10, and the ultrasonic transducer assists the reaction for 60 minutes. After eluent removal, the molybdenum-containing eluent is filtered through an ultrafiltration membrane and then diverted to a molybdenum enrichment chamber for concentration, yielding a high-concentration sodium molybdate solution (approximately 100 mg / L molybdenum). Add 3% alanine as a corrosion inhibitor for the coolant; the corrosion inhibition rate for A3 steel in 25% calcium chloride solution is 96%.

[0076] The residual iron-containing precipitate after analysis is pumped into the iron conversion chamber via a mud pump.

[0077] A conversion solution composed of sulfuric acid (12% by volume) is added to the iron conversion chamber. A pH intelligent controller controls the dosage, maintaining the pH at 3 ± 0.2. The reaction is stirred for 12 hours and then allowed to stand. The generated FeOOH solid is pumped back to the homogeneous adsorption-flocculation co-sedimentation chamber, where it can be used as an iron-based adsorbent in the next round of wastewater treatment. The supernatant from the conversion process is introduced into the iron salt regenerator for filtration. The filter residue is returned to the iron conversion chamber. The filtrate, a regenerated iron salt enriched solution, is collected and used as a coagulant for later use.

Claims

1. A device for advanced treatment and full resource utilization of molybdenum-iron contaminated water, characterized in that, The device includes a pretreatment and deep molybdenum removal unit, a molybdenum analysis and enrichment unit, and an iron conversion and regeneration unit; The pretreatment and deep molybdenum removal unit includes: Homogeneous adsorption-flocculation synergistic sedimentation chamber: The middle part is equipped with a wastewater inlet pipe and an iron salt dosing port; the upper part is equipped with an outlet pipe connected to the secondary molybdenum removal separator; the bottom is equipped with a mud pump pipe, through which mud is pumped into the molybdenum desorption reaction chamber; a pH sensor is equipped to measure the pH value of the system, and an intelligent dosing controller is equipped to control the dosing amount; Two-stage molybdenum removal separator: its interior is filled with modified shell powder adsorption packing and quartz sand; the upper part is equipped with a water inlet, which is connected to the water outlet pipe of the homogeneous adsorption-flocculation co-sedimentation chamber; the lower part is equipped with a water outlet; it is equipped with a pH sensor and an intelligent dosing controller; The molybdenum analysis and enrichment unit includes: The molybdenum reaction chamber is equipped with an eluent dosing port and a sludge inlet at the top. The sludge inlet is connected to the sludge pump in the homogeneous adsorption-flocculation co-sedimentation chamber. It is equipped with a pH sensor, an intelligent dosing controller, and an ultrasonic transducer to promote the reaction. The upper effluent end is equipped with an ultrafiltration membrane module and a molybdenum-containing eluent effluent pipe, which is connected to the molybdenum enrichment chamber. The bottom is equipped with a sludge pump connector, through which sludge is pumped into the iron conversion chamber. Molybdenum enrichment chamber: It is equipped with an alanine dosing port, a molybdenum-containing eluent inlet, and an enrichment solution outlet. The molybdenum-containing eluent inlet is connected to the molybdenum-containing eluent outlet pipe of the molybdenum eluent reaction chamber. The iron conversion and regeneration unit includes: Iron conversion chamber: The upper part is equipped with an inlet for iron-containing precipitate, an outlet for the supernatant of the conversion liquid, an outlet for FeOOH-containing solids after conversion, and a dosing port for the conversion liquid. The inlet for iron-containing precipitate is connected to the mud pump at the bottom of the molybdenum desorption reaction chamber. The outlet for FeOOH-containing solids after conversion is connected to the homogeneous adsorption-flocculation co-sedimentation chamber through the mud pump. The outlet for the supernatant of the conversion liquid is connected to the iron salt regenerator. It is equipped with a pH sensor, an intelligent dosing controller, and an agitator. Iron salt regenerator: It is equipped with an inlet for the supernatant of the iron conversion chamber, a return port for filter residue, and an outlet for the regenerated iron salt enriched liquid. It is equipped with a filtration device inside. The inlet for the supernatant of the iron conversion chamber is connected to the outlet for the supernatant of the iron conversion chamber, and the return port for filter residue is connected to the iron conversion chamber through a mud pump. In each unit, the intelligent dosing controller is connected to the pH monitoring device and automatically controls the dosage of the corresponding agent in the unit based on the monitored pH value.

2. The device for advanced treatment and full resource utilization of molybdenum-iron contaminated water according to claim 1, characterized in that, The aforementioned two-stage molybdenum removal separator has a lower layer packing material with a size of 40-100mm and an upper layer packing material with a size of 10-25mm. Quartz sand is placed under the packing material for deep molybdenum removal. The upper packing material has a height of 700-800cm, and the lower quartz sand has a height of 800-1000cm. The molybdenum content in the treated effluent is <0.07mg / L.

3. The advanced treatment and full resource recovery device for molybdenum-iron polluted water according to claim 1, characterized in that, The modified shell powder is composed of CaO, shell powder and sodium alginate, with quartz sand below the modified shell powder. The mass ratio of CaO, shell powder, sodium alginate and quartz sand is (1-2):(20-25):(0.1-0.2):(78.9-72.8).

4. The device for advanced treatment and full resource utilization of molybdenum-iron contaminated water according to claim 1, characterized in that, The iron salt is one or a mixture of two or more of ferric sulfate, ferric chloride, and polyferric sulfate.

5. The device for advanced treatment and full resource utilization of molybdenum-iron contaminated water according to claim 1, characterized in that, The alkaline eluent is formed by mixing water, NaOH and triethanolamine, with the concentration of NaOH being 30-36 g / L and the concentration of triethanolamine being 12-15 g / L.

6. The device for advanced treatment and full resource utilization of molybdenum-iron contaminated water according to claim 1, characterized in that, The acidic conversion solution is hydrochloric acid or sulfuric acid with a volume concentration of 5-12%.

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