Sulfide-containing wastewater desulfurization and sulfur recovery device and method

Abstract

The invention discloses a device and a method for desulfurizing sulfide-containing wastewater and recovering sulfur, the device and the method utilize efficient reaction of iron oxyhydroxide and sulfide, excessive iron oxyhydroxide reacts to generate ferrous oxide and sulfur, and a small part of ferrous sulfide exists; the surfaces of ferrous sulfide and sulfur in a reaction product are provided with negative charges, and the surface of the residual unreacted iron oxyhydroxide is provided with positive charges, so that floc is formed through the electric neutralization flocculation action of several compounds and can be quickly precipitated; after precipitation, overlying water is treated desulfurized water, ferrous sulfide and ferrous oxide generated in the precipitate are aerated and oxidized in an iron regeneration device, iron oxyhydroxide can be regenerated, and residual sulfide in the ferrous sulfide is converted into elemental sulfur; and the generated iron oxyhydroxide can be used for treating the sulfide-containing water again, so that the sulfide-containing water is treated through reciprocating circulation, and the elemental sulfur and the iron oxyhydroxide are mixed together for continuous accumulation.

Description

Technical Field

[0001] The present invention belongs to the field of wastewater treatment, and specifically relates to the desulfurization treatment of wastewater containing sulfides and the recovery of sulfur. Background Art

[0002] Industrial wastewater containing sulfides is diverse, such as pulp and paper industry, food processing, animal husbandry, tanneries, rubber processing, acid mine drainage (AMD), petrochemical plant wastewater, coal smelting wastewater, and natural gas production wastewater. Sulfides in the wastewater will volatilize to form a large amount of hydrogen sulfide, leading to serious safety problems. The direct discharge of sulfides will also cause toxic death of aquatic organisms. The national discharge standard requires that the sulfide in water be less than 1 mg / L. Therefore, the treatment of sulfide-containing water is essential for many industrial sectors.

[0003] The chemical precipitation method is to add metal ions (Fe2+, Ca2+) to the sulfur-containing wastewater to form precipitable metal sulfides with sulfides. Since this method has high removal efficiency and simple operation, it has been widely applied. (Chinese Patent CN217230409U; Levent, and Hanife Sulfide removal in petroleum refinery wastewater by chemical precipitation, Journal of hazardous materials, 2008, 153(1-2): 462-469; Si Guangyuan et al., Experimental study on the pretreatment of high-sulfur organic wastewater by anaerobic reverse sulfide precipitation method [J], Journal of Light Industry, 2016, 31(05): 25-29.). However, the above ordinary chemical precipitation methods cannot recover sulfur. The iron cycle variable valence conversion method similar to the chemical precipitation method removes sulfides by recycling iron hydroxide, which greatly saves the input of chemical reagents and can convert sulfides into sulfur (Chinese Patent CN117466360A).

[0004] However, this method has the following disadvantages: (1) The selectivity of converting sulfides into sulfur is not high, and some sulfides are over-oxidized to form sulfates; (2) The treatment efficiency of this method is low. In wastewater treatment, it is necessary to aerate first and then precipitate before draining, which reduces the wastewater treatment efficiency. Summary of the Invention

[0005] To overcome the above problems, the present inventor has conducted intensive research and designed a device and method for desulfurizing sulfide-containing wastewater and recovering sulfur. The device and method utilize the efficient reaction between iron oxyhydroxide and sulfide. The reaction between iron oxyhydroxide and sulfide will be completed within a few seconds. The reaction of excessive iron oxyhydroxide will generate iron oxide and sulfur, as well as a small amount of iron sulfide. The selectivity of generating elemental sulfur during the reaction is close to 100%. The surfaces of iron sulfide and sulfur in the reaction products carry negative charges, while the surface of the remaining unreacted iron oxyhydroxide carries a positive charge. Therefore, through the electro-neutralization and flocculation of several compounds, flocs can be formed and quickly precipitate. After precipitation, the overlying water is the treated desulfurized water, and the iron sulfide and iron oxide generated in the precipitate can enter the iron regeneration device, and through aeration oxidation, iron oxyhydroxide can be regenerated again, and the remaining sulfide in the iron sulfide can be converted into elemental sulfur. The generated iron oxyhydroxide can be put into the desulfurization device again, and when mixed with the newly pumped sulfide-containing water, it can treat the sulfide-containing water again, thus reciprocating to treat the sulfide-containing water. The elemental sulfur accumulates continuously in a mixture with iron oxyhydroxide, thus completing the present invention.

[0006] Specifically, the object of the present invention is to provide a device for desulfurizing sulfide-containing wastewater and recovering sulfur, including a water inlet device 1, an iron regeneration device 2, and a plurality of desulfurization devices.

[0007] The water inlet device 1 is used to store sulfide-containing wastewater, and the water inlet device 1 is connected to each desulfurization device through a pipeline, so as to be able to pump the sulfide-containing wastewater into the desulfurization device.

[0008] The iron regeneration device 2 is used to store and generate iron salt materials, and the iron regeneration device 2 is connected to each desulfurization device through a pipeline, so as to be able to pump the iron salt materials into the desulfurization device.

[0009] The bottom of the desulfurization device is connected to the iron regeneration device 2 through a pipeline, so as to be able to discharge the precipitate at the bottom of the desulfurization device into the iron regeneration device 2; realizing the recycling of iron salt materials and the accumulation of elemental sulfur.

[0010] Among them, a regeneration stirring mechanism 7 is arranged in the iron regeneration device 2.

[0011] The iron regeneration device 2 is also connected to an external aeration device 3 through an air pipe, and the iron regeneration device 2 is aerated through the aeration device 3 to oxidize divalent iron to trivalent iron.

[0012] Among them, an independent valve is arranged on each pipeline flowing from the water inlet device 1 to the desulfurization device.

[0013] An independent valve is arranged on each pipeline flowing from the iron regeneration device 2 to the desulfurization device.

[0014] An independent valve is provided on each pipeline flowing from the desulfurization device to the iron regeneration device 2, so that each desulfurization device can work independently.

[0015] Further, it includes a water outlet device 6 for collecting the sulfide-free water after treatment.

[0016] An independent valve is provided on each pipeline flowing from the desulfurization device to the water outlet device 6.

[0017] Preferably, the pipeline connected to the water outlet device 6 is connected to the middle and lower part of the desulfurization device. When the reaction in the desulfurization device is completed and precipitation occurs, the liquid above the sediment interface can just flow out through this pipeline.

[0018] Wherein, a desulfurization stirring mechanism is provided in the desulfurization device.

[0019] The lower part of the desulfurization device is set as a cone to facilitate the efficient discharge of sediment through the bottom.

[0020] Wherein, at least two desulfurization devices are provided.

[0021] When two desulfurization devices are provided, the two desulfurization devices are the first desulfurization device 4 and the second desulfurization device 5 respectively.

[0022] The valve on the pipeline flowing from the water inlet device 1 to the first desulfurization device 4 is the first valve 11.

[0023] The valve on the pipeline flowing from the iron regeneration device 2 to the first desulfurization device 4 is the second valve 12.

[0024] The valve on the pipeline pointing from the first desulfurization device 4 to the iron regeneration device 2 is the third valve 13.

[0025] The valve on the pipeline pointing from the first desulfurization device 4 to the water outlet device 6 is the fourth valve 14.

[0026] The valve on the pipeline flowing from the water inlet device 1 to the second desulfurization device 5 is the fifth valve 15.

[0027] The valve on the pipeline flowing from the iron regeneration device 2 to the second desulfurization device 5 is the sixth valve 16.

[0028] The valve on the pipeline pointing from the second desulfurization device 5 to the iron regeneration device 2 is the seventh valve 17.

[0029] The valve on the pipeline pointing from the second desulfurization device 5 to the water outlet device 6 is the eighth valve 18.

[0030] The desulfurization stirring mechanism in the first desulfurization device 4 is the first desulfurization stirring mechanism 8.

[0031] The desulfurization stirring mechanism in the second desulfurization device 5 is the second desulfurization stirring mechanism 9;

[0032] Preferably, at least three such desulfurization devices are provided.

[0033] The present invention also provides a method for desulfurizing sulfide-containing wastewater and recovering sulfur, characterized in that this method is carried out using the sulfide-containing wastewater desulfurization and sulfur recovery device described above.

[0034] Among them, the method includes the following steps:

[0035] Step 1, put an iron salt material into the iron regeneration device 2; the iron salt includes one or more of iron oxyhydroxide, ferrous chloride and its solution, ferric chloride and its solution, siderite, hematite, magnetite, limonite; preferably iron oxyhydroxide;

[0036] Step 2, open the first valve 11 to input sulfide-containing wastewater into the first desulfurization device 4, and the sulfide includes one or more of sodium sulfide, potassium sulfide, zinc sulfide, ferrous sulfide, calcium sulfide, thiol, thioether; at the same time, open the second valve 12 to input the iron salt material into the first desulfurization device 4, and at the same time start the first desulfurization stirring mechanism 8; in the mixed liquid input into the first desulfurization device 4, the molar ratio of iron element to sulfur element in the sulfide is greater than 2:1. Preferably, the molar ratio of iron element to sulfur element in the sulfide is between 5:1 and 7:1;

[0037] Step 3, after the first desulfurization device 4 is full, close the first valve 11 and the second valve 12, continue to stir for a certain time and then close the first desulfurization stirring mechanism 8; preferably, the continuous stirring time is less than 30 min, and more preferably, less than 1 min;

[0038] Step 4, close the first desulfurization stirring mechanism 8 and let it stand and precipitate for a certain time. Preferably, the precipitation time is not less than 30 min;

[0039] Step 5, after the precipitation is completed, open the fourth valve 14 to discharge the sulfide-free water after treatment to the effluent device 6;

[0040] Step 6, after the drainage is completed, open the third valve 13 to discharge the precipitate at the bottom of the first desulfurization device 4 into the iron regeneration device 2;

[0041] Step 7, following step 2, after the first desulfurization device 4 is filled, open the fifth valve 15 to input sulfide-containing wastewater into the second desulfurization device 5, and at the same time open the sixth valve 16 to input iron salt material into the second desulfurization device 5, and start the second desulfurization stirring mechanism 9 at the same time; in the mixed liquid input into the second desulfurization device 5, the molar ratio of iron element to sulfur element in sulfide is greater than 2:1. Preferably, the molar ratio of iron element to sulfur element in sulfide is between 5:1 and 7:1;

[0042] Step 8, after the second desulfurization device 5 is filled, close the fifth valve 15 and the sixth valve 16, continue stirring for a certain period of time and then close the second desulfurization stirring mechanism 9; preferably, the continuous stirring time is less than 30 min, and more preferably, less than 1 min;

[0043] Step 9, close the second desulfurization stirring mechanism 9, and let it stand and precipitate for a certain period of time. Preferably, the precipitation time is not less than 30 min;

[0044] Step 10, after the precipitation is completed, open the eighth valve 18 to discharge the sulfide-free water after treatment to the effluent device 6;

[0045] Step 11, after the drainage is completed, open the seventh valve 17 to discharge the precipitate at the bottom of the second desulfurization device 5 into the iron regeneration device 2;

[0046] Step 12, following step 7, after the second desulfurization device 5 is filled, open the first valve 11 and the second valve 12 again, and repeat steps 2 to 11; preferably, replace the iron salt material in the iron regeneration device 2 after repeating steps 2 to 11 for a total of 5 - 100 cycles. Preferably, replace the iron salt material in the iron regeneration device 2 after repeating 15 - 25 cycles.

[0047] Among them, in step 1, the concentration of the input iron salt material is set according to the concentration of the sulfide-containing wastewater to be treated,

[0048] Preferably, when the iron regeneration device 2 is filled with iron salt material, the number of moles of iron in all the iron salt materials is M, and when all the desulfurization devices are filled with the sulfide-containing wastewater to be treated, the number of moles of sulfur element in all the sulfide-containing wastewater is N. By setting the concentration of the input iron salt material, M:N is greater than 12:1.

[0049] Among them, during the whole process of implementing this method, the regeneration stirring mechanism 7 and the aeration device 3 are continuously turned on.

[0050] The beneficial effects of the present invention include:

[0051] (1) The device and method for desulfurizing sulfide-containing wastewater and recovering sulfur provided by the present invention first solve the problem of low conversion rate of elemental sulfur in the desulfurization process of the iron cycle variable valence conversion method, and convert sulfides in sulfide-containing wastewater into elemental sulfur for recovery with a selectivity close to 99%;

[0052] (2) The device and method for desulfurizing sulfide-containing wastewater and recovering sulfur provided by the present invention separate the generated elemental sulfur and ferrous compounds in a direct flocculation precipitation manner after adding an excessive amount of iron hydroxide, and then discharge the precipitate into the iron regeneration device for regeneration. The precipitation time is significantly reduced and controlled within 1 hour. In addition, the aeration time of the sewage is also reduced, thereby greatly improving the treatment efficiency;

[0053] (3) The device and method for desulfurizing sulfide-containing wastewater and recovering sulfur provided by the present invention greatly improve the treatment efficiency of sulfide-containing wastewater through a simple precipitation and aeration regeneration process, and greatly reduce the chemical cost, which is of great significance for the treatment of industrial sulfide-containing wastewater; in addition, the present invention recovers elemental sulfur in wastewater with higher selectivity, which is of great significance for the market supply of sulfur;

[0054] (4) The device and method for desulfurizing sulfide-containing wastewater and recovering sulfur provided by the present invention greatly improve the utilization rate of chemical reagents through a recycling method compared with the traditional chemical precipitation method, and have a greater cost advantage; compared with the iron cycle variable valence method, the two have similar cost inputs, but the efficiency and sulfur recovery selectivity are stronger than the iron cycle variable valence method;

[0055] (5) The device and method for desulfurizing sulfide-containing wastewater and recovering sulfur provided by the present invention are different from Chinese Patent CN117466360A in the process sequence and the newly established iron regeneration device. In the present application, an excessive amount of iron hydroxide is first used to form a flocculation effect. After the sulfide-containing water reacts with the iron hydroxide, there is no need to aerate the wastewater, and the treatment of sulfur-containing wastewater can be completed through simple static precipitation. In addition, an iron regeneration device is set up for the regeneration of the iron-based desulfurizer, which greatly improves the treatment efficiency; in addition, the selectivity of the reaction between iron hydroxide and sulfide to generate elemental sulfur is higher than the oxidation of ferrous sulfide, so the selectivity is also greatly improved. Description of the Drawings

[0056] Figure 1 It is a schematic diagram of the overall structure of the device for desulfurizing sulfide-containing wastewater and recovering sulfur provided by the present invention;

[0057] Figure 2 It is the recovery rate of elemental sulfur and desulfurization efficiency under the conditions of various iron-sulfur molar ratios in Example 1 of the present invention;

[0058] Figure 3 Schematic diagram of the change in sulfide content in the influent and effluent in Example 2 and Comparative Example 2 of the present invention;

[0059] Figure 4 XRD pattern after long-term accumulation of sediments in Example 2.

[0060] Explanation of the reference numerals in the attached drawings:

[0061] 1 - influent device

[0062] 2 - iron regeneration device

[0063] 3 - aeration device

[0064] 4 - first desulfurization device

[0065] 5 - second desulfurization device

[0066] 6 - effluent device

[0067] 7 - regeneration stirring mechanism

[0068] 8 - first desulfurization stirring mechanism

[0069] 9 - second desulfurization stirring mechanism

[0070] 11 - first valve

[0071] 12 - second valve

[0072] 13 - third valve

[0073] 14 - fourth valve

[0074] 15 - fifth valve

[0075] 16 - sixth valve

[0076] 17 - seventh valve

[0077] 18 - eighth valve Detailed implementation manners

[0078] The present invention will be further described in detail below with reference to the drawings and embodiments. Through these descriptions, the features and advantages of the present invention will become clearer and more definite. Among them, although various aspects of the embodiments are shown in the drawings, the drawings do not have to be drawn to scale unless otherwise specified.

[0079] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0080] The present invention provides a device for desulfurizing sulfide-containing wastewater and recovering sulfur, as Figure 1 shown in the figure, which includes a water inlet device 1, an iron regeneration device 2, and a plurality of desulfurization devices.

[0081] The water inlet device 1 is used to store sulfide-containing wastewater. The water inlet device 1 is connected to each desulfurization device through a pipeline, so as to be able to pump the sulfide-containing wastewater into the desulfurization device. In this application, this sulfide-containing wastewater is the wastewater to be treated.

[0082] The iron regeneration device 2 is used to store and generate iron salt materials. The iron regeneration device 2 is connected to each desulfurization device through a pipeline, so as to be able to pump the iron salt materials into the desulfurization device. In this application, the sulfide is converted into elemental sulfur through this iron salt material.

[0083] The bottom of the desulfurization device is connected to the iron regeneration device 2 through a pipeline, so as to be able to discharge the sediment at the bottom of the desulfurization device into the iron regeneration device 2; realizing the recycling of iron salt materials and the accumulation of elemental sulfur.

[0084] In a preferred embodiment, a regeneration stirring mechanism 7 is provided in the iron regeneration device 2.

[0085] The iron regeneration device 2 is also connected to an external aeration device 3 through an air pipe. The aeration device 3 aerates the iron regeneration device 2, so as to oxidize divalent iron to trivalent iron, so that the iron element in the iron regeneration device 2 mainly exists in the form of trivalent iron.

[0086] In a preferred embodiment, an independent valve is provided on each pipeline flowing from the water inlet device 1 to the desulfurization device.

[0087] An independent valve is provided on each pipeline flowing from the iron regeneration device 2 to the desulfurization device.

[0088] An independent valve is provided on each pipeline flowing from the desulfurization device to the iron regeneration device 2, so that each desulfurization device can work independently and can be independently controlled, and there is no interference between two desulfurization devices.

[0089] In a preferred embodiment, the sulfide-containing wastewater desulfurization and sulfur recovery device further includes an effluent device 6, which is used to collect the sulfide-free water after treatment. This sulfide-free water after treatment meets the national discharge standards and can be directly discharged or reused secondarily;

[0090] An independent valve is provided on each pipeline flowing from the desulfurization device to the effluent device 6; preferably, the pipeline connected to the effluent device 6 is connected to the middle and lower part of the desulfurization device. When the reaction of the fully loaded desulfurization device is completed and precipitation occurs, there is just liquid above the sediment interface that can flow out through this pipeline; such a setting makes the drainage control more convenient. The valve can be opened for drainage when the sediment settles below the pipeline interface, and the drainage volume control is convenient, and there is basically no situation of over-drainage or under-drainage.

[0091] In a preferred embodiment, a desulfurization stirring mechanism is provided in the desulfurization device,

[0092] The lower part of the desulfurization device is set as a cone to facilitate the efficient discharge of sediment through the bottom. Preferably, the volume of the cone just accounts for one-fourth of the total volume of the desulfurization device. After injecting water into the effluent device 6, the remaining mixture in the desulfurization device is concentrated in this cone.

[0093] Preferably, at least two desulfurization devices are provided,

[0094] When two desulfurization devices are provided, the volumes of the two desulfurization devices are the same. As Figure 1 shown, the two desulfurization devices are the first desulfurization device 4 and the second desulfurization device 5 respectively;

[0095] The valve on the pipeline flowing from the inlet device 1 to the first desulfurization device 4 is the first valve 11;

[0096] The valve on the pipeline flowing from the iron regeneration device 2 to the first desulfurization device 4 is the second valve 12,

[0097] The valve on the pipeline pointing from the first desulfurization device 4 to the iron regeneration device 2 is the third valve 13,

[0098] The valve on the pipeline pointing from the first desulfurization device 4 to the effluent device 6 is the fourth valve 14;

[0099] The valve on the pipeline flowing from the inlet device 1 to the second desulfurization device 5 is the fifth valve 15;

[0100] The valve on the pipeline flowing from the iron regeneration device 2 to the second desulfurization device 5 is the sixth valve 16,

[0101] The valve on the pipeline pointing from the second desulfurization device 5 to the iron regeneration device 2 is the seventh valve 17,

[0102] The valve on the pipeline pointing from the second desulfurization device 5 to the water outlet device 6 is the eighth valve 18;

[0103] The desulfurization stirring mechanism in the first desulfurization device 4 is the first desulfurization stirring mechanism 8,

[0104] The desulfurization stirring mechanism in the second desulfurization device 5 is the second desulfurization stirring mechanism 9;

[0105] Preferably, at least three desulfurization devices are provided. When there are three or more desulfurization devices, the desulfurization devices are divided into two groups or three groups. When adding sulfide-containing wastewater and iron salt materials to one group or two groups of desulfurization devices, the other group or two groups of desulfurization devices perform sedimentation, discharging of sulfide-free water and discharging of precipitates, so as to realize the alternation of the two types of work, thereby improving work efficiency.

[0106] The present invention also provides a method for desulfurizing sulfide-containing wastewater and recovering sulfur, and this method is carried out by using the sulfide-containing wastewater desulfurization and sulfur recovery device described above.

[0107] In a preferred embodiment, when two desulfurization devices are provided in the sulfide-containing wastewater desulfurization and sulfur recovery device and the volume sizes of the two desulfurization devices are the same, as Figure 1 shown in, the method includes the following steps:

[0108] Step 1, put iron salt materials into the iron regeneration device 2, and the volume of the iron regeneration device is 3.5L; the iron salts include one or more of iron oxyhydroxide, ferrous chloride and its solution, ferric chloride and its solution, siderite, hematite, magnetite, limonite; preferably iron oxyhydroxide; in this application, when the main component of the iron salt material put into the iron regeneration device 2 is iron oxyhydroxide, the preparation process of the iron oxyhydroxide is as follows: first add primary iron salt materials, and the primary iron salt materials are selected from one or more of water-soluble or acid-soluble iron salts, water-soluble or acid-soluble iron ores, preferably one or more of ferrous chloride, ferric chloride, limonite, siderite and ferrous nitrate; more preferably, ferric chloride; adjust the PH to above 7 at a temperature of 75 degrees Celsius, and then cool it to room temperature at room temperature, thereby generating the iron salt material with the active ingredient of iron oxyhydroxide used in this application.

[0109] Step 2: Open the first valve 11 to input sulfide-containing wastewater into the first desulfurization device 4. The sulfides include one or more of sodium sulfide, potassium sulfide, zinc sulfide, ferrous sulfide, calcium sulfide, mercaptan, and thioether. At the same time, open the second valve 12 to input an iron salt material into the first desulfurization device 4, and start the first desulfurization stirring mechanism 8 simultaneously. In the mixed liquid input into the first desulfurization device 4, the molar ratio of iron element to sulfur element in the sulfide is greater than 2:1. Preferably, the molar ratio of iron element to sulfur element in the sulfide is between 5:1 and 7:1. The volume of the first desulfurization device 4 is 3.5 L. In the water inlet device, the sulfide concentration in the sulfide-containing wastewater is 400 mg S / L, the alkalinity is 2000 mgCaCO3 / L, and the pH is 7.

[0110] Step 3: After the first desulfurization device 4 is full, close the first valve 11 and the second valve 12, continue stirring for a certain period of time, and then close the first desulfurization stirring mechanism 8. Preferably, the continuous stirring time is less than 30 min, more preferably, less than 1 min. The minimum value of this continuous stirring time can be 0.

[0111] Step 4: Close the first desulfurization stirring mechanism 8 and let it stand and precipitate for a certain period of time. Preferably, the precipitation time is not less than 30 min.

[0112] Step 5: After precipitation is completed, open the fourth valve 14 to discharge the sulfide-free water after treatment to the water outlet device 6. Preferably, three-quarters of the supernatant liquid in the first desulfurization device 4 is discharged as the sulfide-free water after treatment.

[0113] Step 6: After draining, open the third valve 13 to discharge the precipitate at the bottom of the first desulfurization device 4 into the iron regeneration device 2.

[0114] Step 7: Synchronously follow Step 2. After the first desulfurization device 4 is full, close the first valve 11 and the second valve 12, open the fifth valve 15 to input sulfide-containing wastewater into the second desulfurization device 5, open the sixth valve 16 to input an iron salt material into the second desulfurization device 5, and start the second desulfurization stirring mechanism 9 simultaneously. In the mixed liquid input into the second desulfurization device 5, the molar ratio of iron element to sulfur element in the sulfide is greater than 3:1. Preferably, the molar ratio of iron element to sulfur element in the sulfide is between 5:1 and 7:1. The volume of the second desulfurization device 5 is 3.5 L.

[0115] Step 8: After the second desulfurization device 5 is full, close the fifth valve 15 and the sixth valve 16, continue stirring for a certain period of time, and then close the second desulfurization stirring mechanism 9. Preferably, the continuous stirring time is less than 30 min, more preferably, less than 1 min. The minimum value of this continuous stirring time can be 0.

[0116] Step 9: Turn off the second desulfurization stirring mechanism 9 and let it stand and precipitate for a certain period of time. Preferably, the precipitation time is not less than 30 minutes.

[0117] Step 10: After the precipitation is completed, open the eighth valve 18 to discharge the sulfide-free water after treatment to the water outlet device 6. Preferably, three-quarters of the supernatant in the second desulfurization device 5 is discharged as the sulfide-free water after treatment.

[0118] Step 11: After the drainage is completed, open the seventh valve 17 to discharge the sediment at the bottom of the second desulfurization device 5 into the iron regeneration device 2.

[0119] Step 12: Synchronously follow Step 7. After the second desulfurization device 5 is filled, open the first valve 11 and the second valve 12 again, and repeat Steps 2 to 11. Preferably, after repeating Steps 2 to 11 for a total of 5 - 100 cycles, replace the iron salt material in the iron regeneration device 2 and recover the sulfur therein. Preferably, replace the iron salt-containing material in the iron regeneration device 2 after repeating 15 - 25 cycles.

[0120] Preferably, in Step 1, set the concentration of the iron salt material input according to the concentration of the sulfide-containing wastewater to be treated.

[0121] Preferably, when the iron regeneration device 2 is filled with the iron salt material, the number of moles of iron in all the iron salt materials is M, and when all the desulfurization devices are filled with the sulfide-containing wastewater to be treated, the number of moles of sulfur element in all the sulfide-containing wastewaters is N. Set the concentration of the input iron salt material so that M:N is greater than or equal to 12:1.

[0122] Preferably, during the whole process of implementing this method, the regeneration stirring mechanism 7 and the aeration device 3 are continuously turned on; the aeration rate of the aeration device 3 is 2 L / min.

[0123] Example 1:

[0124] In this Example 1, the removal efficiency and selectivity under different iron-sulfur molar ratios were tested through a single dosing experiment.

[0125] Prepare ferric chloride solutions with concentrations of 4.2 g Fe / L, 8.4 g Fe / L, 12.6 g Fe / L, and 16.8 g Fe / L respectively, adjust the pH to 7 at a temperature of 75 degrees Celsius, and then let it cool to room temperature at room temperature to obtain the iron salt material, in which the iron exists in the form of iron hydroxide.

[0126] Use the sulfide-containing wastewater desulfurization and sulfur recovery device as Figure 1 shown to perform the following operations:

[0127] Step 1: Charge 1.5 L of an iron salt material with a concentration of 4.2 g Fe / L into the iron regeneration device 2, where the iron exists in the form of iron oxyhydroxide.

[0128] Step 2: Open the first valve 11 to input sulfide-containing wastewater into the first desulfurization device 4, and at the same time open the second valve 12 to input the iron salt material into the first desulfurization device 4. At the same time, start the first desulfurization stirring mechanism 8 and input it into the mixed liquid in the first desulfurization device 4. The molar ratio of iron element to sulfur element in zinc sulfide is 3:1.

[0129] Step 3: After pumping in 3 L, close the first valve 11, the second valve 12, and the first desulfurization stirring mechanism 8.

[0130] Step 4: Precipitate for 40 minutes, and the interface between the precipitate and water is below the 0.75 L scale line of the first desulfurization device.

[0131] Step 5: Open the fourth valve 14 to discharge 2.25 L of sulfide-free water after treatment to the water outlet device 6.

[0132] Step 6: After draining the water, open the third valve 13 to discharge 0.75 L of the precipitate at the bottom of the first desulfurization device 4 into the iron regeneration device 2.

[0133] Step 7: Open the regeneration stirring mechanism 7 and the aeration device 3, stop aeration after 40 minutes of aeration; test the concentrations of sulfide and iron element in the water outlet device 6, and test the concentration of elemental sulfur in the iron regeneration device 2.

[0134] Step 8: After completing the above operations, clean all the reagents in the sulfide-containing wastewater desulfurization and sulfur recovery device, and then successively charge 1.5 L of iron salt materials with concentrations of 8.4 g Fe / L, 12.6 g Fe / L, and 16.8 g Fe / L into the iron regeneration device 2 again, and repeat the above steps 1 to 7 three times.

[0135] Measure the desulfurization efficiency and elemental sulfur recovery rate under different iron-sulfur ratios.

[0136] Example 2:

[0137] This example conducts long-term operation of the process system under the condition that the molar ratio of iron element to sulfur element in sulfide is 5:1.

[0138] Prepare ferric chloride solutions with concentrations of 10.5 g Fe / L respectively, adjust the pH to 7 at a temperature of 75 °C, and then cool it to room temperature at room temperature to obtain an iron salt material, where the iron exists in the form of iron oxyhydroxide.

[0139] Use the sulfide-containing wastewater desulfurization and sulfur recovery device as shown in Figure 1 to perform the following operations:

[0140] Step 1: Put 3 L of iron-containing salt material with a concentration of 10.5 g Fe / L into the iron regeneration device 2, where the iron exists in the form of iron oxyhydroxide.

[0141] Step 2: Open the first valve 11 to input sulfide-containing wastewater into the first desulfurization device 4, and at the same time open the second valve 12 to input the iron-containing salt material into the first desulfurization device 4. At the same time, start the first desulfurization stirring mechanism 8 and input it into the mixed liquid in the first desulfurization device 4. The molar ratio of iron element to sulfur element in zinc sulfide is 5:1. It takes 45 minutes to input the sulfide-containing wastewater and the iron-containing salt material.

[0142] Step 3: The volume of the first desulfurization device 4 is 3 L. After 45 minutes of starting to input the sulfide-containing wastewater and the iron-containing salt material, the first desulfurization device 4 is full. Close the first valve 11, the second valve 12 and the first desulfurization stirring mechanism 8.

[0143] Step 4: Precipitate for 40 minutes, and the interface between the precipitate and the water is lower than the 0.75 L scale line of the first desulfurization device.

[0144] Step 5: Open the fourth valve 14 and it takes 2 minutes to discharge 2.25 L of sulfide-free water after treatment to the water outlet device 6.

[0145] Step 6: After the drainage is completed, open the third valve 13 and it takes 2 minutes to discharge 0.75 L of precipitate at the bottom of the first desulfurization device 4 into the iron regeneration device 2.

[0146] Step 7: Synchronously follow Step 2. After the first desulfurization device 4 is full, open the fifth valve 15 to input sulfide-containing wastewater into the second desulfurization device 5, and at the same time open the sixth valve 16 to input the iron-containing salt material into the second desulfurization device 5. At the same time, start the second desulfurization stirring mechanism 9. In the mixed liquid input into the second desulfurization device 5, the molar ratio of iron element to sulfur element in the sulfide is 5:1. It takes 45 minutes to input the zinc sulfide-containing wastewater and the iron-containing salt material.

[0147] Step 8: The volume of the second desulfurization device 5 is 3 L. After 45 minutes of starting to input the sulfide-containing wastewater and the iron-containing salt material, the first desulfurization device 4 is full. Close the fifth valve 15, the sixth valve 16 and the second desulfurization stirring mechanism 9.

[0148] Step 9: Precipitate for 40 minutes, and the interface between the precipitate and the water is lower than the 0.75 L scale line of the second desulfurization device.

[0149] Step 10: Open the eighth valve 18 and it takes 2 minutes to discharge 2.25 L of sulfide-free water after treatment to the water outlet device 6.

[0150] Step 11: After the drainage is completed, open the seventh valve 17 for 2 minutes to discharge the sediment at the bottom of the second desulfurization device 5 into the iron regeneration device 2;

[0151] Step 12: Synchronously follow Step 7. After the second desulfurization device 5 is filled, open the first valve 11 and the second valve 12 again, and repeat Steps 2 to 11 at the same rate; stop after repeating Steps 2 to 11 a total of 12 times. During the execution of all the above operations, the regeneration stirring mechanism 7 in the iron regeneration device 2 continuously stirs and works, and the aeration device 3 is continuously turned on to aerate air into the iron regeneration device 2 at an efficiency of 2 L / min. Comparative Example 1:

[0152] This Comparative Example 1 tests the addition of ferric chloride for desulfurization under a single condition.

[0153] Specifically, the operations are as follows:

[0154] Step 1: Add ferric chloride reagent to a 3 L container with a stirring mechanism;

[0155] Step 2: Add zinc sulfide-containing wastewater to the container until it is full. At this time, in the container, based on the mass of the iron element contained, the iron concentration is 700 mg / L, and based on the mass of the sulfur element contained, the sulfur element concentration in zinc sulfide is 400 mg / L;

[0156] Step 3: Stir for 5 min, then let it stand and precipitate for 40 min, and discharge 2.25 L of the supernatant. This water is the treated water without sulfide, and test the concentrations of sulfide and iron element in it; then take the remaining precipitate and test the elemental sulfur concentration in it.

[0157] Comparative Example 2:

[0158] This Comparative Example 2 tests the desulfurization effect of the iron cycle variable valence desulfurization method.

[0159] Specifically, the operations are as follows:

[0160] Step 1: At room temperature, add ferrous chloride reagent to a 3 L container with a stirring mechanism;

[0161] Step 2: Add zinc sulfide-containing wastewater to the container until it is full. At this time, in the container, based on the mass of the iron element contained, the ferrous concentration is 700 mg / L, and based on the mass of the sulfur element contained, the sulfur element concentration in the sulfide is 400 mg / L;

[0162] Step 3: Stir for 20 min to mix it evenly;

[0163] Step 4: Turn on the aeration equipment and aerate air into the container at a rate of 2 L / min for 3 hours. The liquid in the container turns completely golden yellow, indicating that the oxidation is completed;

[0164] Step 5: Let it stand and precipitate for 30 min, then drain 3 / 4 of the supernatant. This is the treated water without sulfide.

[0165] Step 6: Add 3 / 4 of the volume of sulfide-containing wastewater to the container and stir for 5 min to mix evenly.

[0166] Step 7: Turn on the aeration equipment and aerate air into the container at a rate of 2 L / min for 40 minutes. The liquid in the container turns completely golden yellow, indicating that the oxidation is complete.

[0167] Step 8: Let it stand and precipitate for 30 min, then drain 3 / 4 of the supernatant. This is the treated water without sulfide.

[0168] Step 9: Repeat steps 6 - 8 again. Finally, stop after performing steps 6 - 8 eleven times.

[0169] As Figure 2 shown, the elemental sulfur recovery rate and desulfurization efficiency under various iron-sulfur molar ratio conditions in Example 1 are similar, fully indicating that as long as there is an excessive amount of iron oxyhydroxide, the desulfurization efficiency and elemental sulfur recovery rate are similar.

[0170] As Figure 3 shown, the effluents in Example 2 and Comparative Example 2 both stably reached the national standard requirement of 1 mg S / L during long-term operation, indicating that the desulfurization effect of the sulfide-containing wastewater desulfurization and sulfur recovery device and method provided by the present invention is stable.

[0171] As described in Table 1 below, in Experimental Example 2, Comparative Example 1, and Comparative Example 2, the sulfide in the treated water without sulfide all reached the national standard requirement of 1 mg S / L. The desulfurization efficiency and elemental sulfur recovery rate in Experimental Example 2 and Comparative Example 1 are similar and both higher than those in Comparative Example 2; the iron loss rate in Experimental Example 2 and Comparative Example 2 is similar and both lower than that in Comparative Example 1. The above results fully illustrate that compared with the iron cycle variable valence desulfurization method, the sulfide-containing wastewater desulfurization and sulfur recovery device and method provided by the present invention have higher desulfurization efficiency and elemental sulfur recovery rate under the same iron loss rate and effluent sulfide.

[0172] Table 1

[0173]

[0174] Perform X-ray diffraction (XRD) detection on the dried precipitate of the iron regeneration device in Example 2. Its XRD pattern is as Figure 4 shown, indicating the generation of sulfur during this process, specifically α-S 0 .

[0175] The present invention has been described in conjunction with preferred embodiments, but these embodiments are merely exemplary and serve only an illustrative function. On this basis, various substitutions and improvements can be made to the present invention, and all of these fall within the protection scope of the present invention.

Claims

1. A device for desulfurizing sulfide-containing wastewater and recovering sulfur, characterized in that, Comprising a water inlet device (1), an iron regeneration device (2) and a plurality of desulfurization devices, The water inlet device (1) is used for storing sulfide-containing wastewater, and the water inlet device (1) is connected to each desulfurization device through a pipeline, so as to be able to pump the sulfide-containing wastewater into the desulfurization device; The iron regeneration device (2) is used for storing and generating iron salt materials, and the iron regeneration device (2) is connected to each desulfurization device through a pipeline, so as to be able to pump the iron salt materials into the desulfurization device; The bottom of the desulfurization device is connected to the iron regeneration device (2) through a pipeline, so as to be able to discharge the precipitate at the bottom of the desulfurization device into the iron regeneration device (2); Realize the recycling of iron salt materials and the accumulation of elemental sulfur.

2. The sulfide-containing wastewater desulfurization and sulfur recovery device according to claim 1, characterized in that, A regeneration stirring mechanism (7) is arranged in the iron regeneration device (2), The iron regeneration device (2) is also connected to an external aeration device (3) through an air pipe, and the iron regeneration device (2) is aerated through the aeration device (3) to oxidize ferrous iron to ferric iron.

3. The sulfide-containing wastewater desulfurization and sulfur recovery device according to claim 1, characterized in that, An independent valve is arranged on each pipeline flowing from the water inlet device (1) to the desulfurization device; An independent valve is arranged on each pipeline flowing from the iron regeneration device (2) to the desulfurization device, An independent valve is arranged on each pipeline flowing from the desulfurization device to the iron regeneration device (2), so that each desulfurization device can work independently.

4. The sulfide-containing wastewater desulfurization and sulfur recovery device according to claim 1, characterized in that, It further comprises a water outlet device (6), and the water outlet device (6) is used for collecting the sulfide-free water after treatment; An independent valve is arranged on each pipeline flowing from the desulfurization device to the water outlet device (6); Preferably, the pipeline connected to the water outlet device (6) is connected to the middle and lower part of the desulfurization device. When the desulfurization device finishes reacting and precipitating, there is just liquid above the precipitate interface that can flow out through this pipeline.

5. The sulfide-containing wastewater desulfurization and sulfur recovery device according to claim 1, characterized in that, A desulfurization stirring mechanism is arranged in the desulfurization device, The lower part of the desulfurization device is set as a cone to facilitate the efficient discharge of the precipitate through the bottom.

6. The sulfide-containing wastewater desulfurization and sulfur recovery device according to any one of claims 1 to 5, characterized in that, At least two desulfurization devices are provided, When two desulfurization devices are provided, the two desulfurization devices are respectively a first desulfurization device (4) and a second desulfurization device (5); The valve on the pipeline flowing from the water inlet device (1) to the first desulfurization device (4) is a first valve (11); The valve on the pipeline flowing from the iron regeneration device (2) to the first desulfurization device (4) is a second valve (12), The valve on the pipeline pointing from the first desulfurization device (4) to the iron regeneration device (2) is a third valve (13), The valve on the pipeline pointing from the first desulfurization device (4) to the water outlet device (6) is a fourth valve (14); The valve on the pipeline flowing from the water inlet device (1) to the second desulfurization device (5) is the fifth valve (15); The valve on the pipeline flowing from the iron regeneration device (2) to the second desulfurization device (5) is the sixth valve (16), The valve on the pipeline pointing from the second desulfurization device (5) to the iron regeneration device (2) is the seventh valve (17), The valve on the pipeline pointing from the second desulfurization device (5) to the water outlet device (6) is the eighth valve (18); The desulfurization stirring mechanism in the first desulfurization device (4) is the first desulfurization stirring mechanism (8), The desulfurization stirring mechanism in the second desulfurization device (5) is the second desulfurization stirring mechanism (9); Preferably, at least three desulfurization devices are provided.

7. A method for desulfurization of sulfide-containing wastewater and sulfur recovery, characterized in that, This method is carried out using the sulfide-containing wastewater desulfurization and sulfur recovery device described in claim 6.

8. According to the sulfide-containing wastewater desulfurization and sulfur recovery method described in claim 7, characterized in that This method includes the following steps: Step 1, put iron-containing salt materials into the iron regeneration device (2); the iron-containing salts include one or more of iron hydroxide, ferrous chloride and its solution, ferric chloride and its solution, siderite, hematite, magnetite, limonite; preferably iron hydroxide; Step 2, open the first valve (11) to input sulfide-containing wastewater into the first desulfurization device (4), the sulfides include one or more of sodium sulfide, potassium sulfide, zinc sulfide, ferrous sulfide, calcium sulfide, mercaptan, thioether, and at the same time open the second valve (12) to input iron-containing salt materials into the first desulfurization device (4), and at the same time start the first desulfurization stirring mechanism (8); in the mixed solution input into the first desulfurization device (4), the molar ratio of iron element to sulfur element in the sulfide is greater than 2:1, preferably, the molar ratio of iron to sulfide is between 5:1 - 7:1; Step 3, after the first desulfurization device (4) is full, close the first valve (11) and the second valve (12), continue to stir for a certain time and then close the first desulfurization stirring mechanism (8); preferably, the continuous stirring time is less than 30 min, more preferably less than 1 min; Step 4, close the first desulfurization stirring mechanism (8), stand and precipitate for a certain time, preferably, the precipitation time is not less than 30 min; Step 5, after the precipitation is completed, open the fourth valve (14) to discharge the sulfide-free water after treatment to the water outlet device (6); Step 6, after the drainage is completed, open the third valve (13) to discharge the precipitate at the bottom of the first desulfurization device (4) into the iron regeneration device (2); Step 7, synchronously following step 2, after the first desulfurization device (4) is full, open the fifth valve (15) to input sulfide-containing wastewater into the second desulfurization device (5), and at the same time open the sixth valve (16) to input iron-containing salt materials into the second desulfurization device (5), and at the same time start the second desulfurization stirring mechanism (9); in the mixed solution input into the second desulfurization device (5), the molar ratio of iron element to sulfur element in the sulfide is greater than 2:1, preferably, the molar ratio of iron element to sulfur element in the sulfide is between 5:1 - 7:1; Step 8, after the second desulfurization device (5) is full, close the fifth valve (15) and the sixth valve (16), continue stirring for a certain period of time and then close the second desulfurization stirring mechanism (9); preferably, the time for continuous stirring is less than 30 min, and more preferably, less than 1 min; Step 9, close the second desulfurization stirring mechanism (9), let it stand and precipitate for a certain period of time, preferably, the precipitation time is not less than 30 min; Step 10, after the precipitation is completed, open the eighth valve (18) to discharge the sulfide-free water after treatment to the water outlet device (6); Step 11, after the drainage is completed, open the seventh valve (17) to discharge the precipitate at the bottom of the second desulfurization device (5) into the iron regeneration device (2); Step 12, synchronously following Step 7, after the second desulfurization device (5) is full, open the first valve (11) and the second valve (12) again, and repeat Steps 2 to 11; preferably, replace the iron salt material in the iron regeneration device (2) after repeating Steps 2 to 11 for a total of 5 - 100 cycles, and preferably, replace the iron salt material containing iron in the iron regeneration device (2) after repeating 15 - 25 cycles.

9. The method for desulfurizing sulfide-containing wastewater and recovering sulfur according to claim 8, wherein in Step 1, set the concentration of the iron salt material input according to the concentration of the sulfide-containing wastewater to be treated, preferably, when the iron regeneration device (2) is filled with the iron salt material, the number of moles of iron in all the iron salt materials is M, and when all the desulfurization devices are filled with the sulfide-containing wastewater to be treated, the number of moles of sulfur element in all the sulfide-containing wastewaters is N. Set the concentration of the iron salt material input so that M:N is greater than 12:

1.

10. The method for desulfurizing sulfide-containing wastewater and recovering sulfur according to claim 8, wherein during the whole process of implementing this method, the regeneration stirring mechanism (7) and the aeration device (3) are continuously turned on.

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