Homogeneous continuous adsorption sewage treatment process and system

Abstract

This invention discloses a homogeneous continuous adsorption wastewater treatment process and system. The process includes the following steps: the water to be treated enters a pre-reactor for primary treatment, during which no new adsorbent is added; the water after primary treatment enters a post-reactor for secondary treatment, during which new adsorbent is continuously added to the reaction unit; the adsorbent in the pre-reactor is discharged; the pre-reactor and post-reactor are periodically and automatically switched, with the former pre-reactor becoming the post-reactor and the former post-reactor becoming the pre-reactor; the primary treatment, secondary treatment, discharge of adsorbent from the pre-reactor, and periodic switching are repeated. The two reactors are connected in series, enabling continuous operation under homogeneous adsorption conditions; the new and old adsorbents in the two reactors are not mixed, but rather reach adsorption saturation step by step and are regenerated in batches, thereby reducing the regeneration frequency and cost.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a homogeneous continuous adsorption wastewater treatment process and system. Background Technology

[0002] Wastewater adsorption treatment is a process that utilizes the physical and chemical adsorption properties of solid adsorbents to remove or reduce various pollutants in wastewater. Solid adsorbents can effectively remove a variety of pollutants from wastewater, especially highly toxic and recalcitrant pollutants that are difficult to treat effectively using other methods. The treated effluent has good and relatively stable quality. In addition, adsorption processes can recover substances such as fluoride, phosphorus, and heavy metals from water, achieving resource utilization of these substances while purifying the water.

[0003] Adsorption processes differ from other physicochemical reactions in that they require longer hydraulic retention times, and most adsorbents are expensive with high regeneration costs. For homogeneous adsorption systems, short hydraulic retention times result in insufficient utilization of the adsorbent's adsorption capacity, increasing the number of regeneration cycles, reducing adsorbent lifespan, and raising regeneration costs. However, extending the hydraulic retention time leads to excessively large reactor volumes, increasing civil engineering and equipment investment costs. Therefore, designing a rational adsorption process that fully utilizes the adsorbent's adsorption capacity, extends the regeneration cycle, reduces hydraulic retention time, simplifies operating procedures, and ultimately lowers overall operating costs will be crucial for the large-scale application of adsorption water treatment technology.

[0004] Patent CN103073088A, entitled "Continuous Adsorption System for Wastewater Treatment Process," describes a continuous adsorption treatment system for wastewater using two-stage adsorption units connected in series. However, this system is a fixed-bed adsorption system. Compared to a homogeneous, completely mixed reaction system, the adsorbent's contact with pollutants in the water is insufficient, resulting in low adsorption capacity utilization and increased adsorbent regeneration frequency and costs. Although transferring the adsorbent from the secondary adsorption unit to the primary adsorption unit via air stripping can increase the adsorbent capacity utilization to some extent, this also leads to the mixing of adsorbents with different remaining adsorption capacities in the two stages, making batch regeneration impossible. Fixed-bed adsorption systems impose significant limitations on the particle size and physical properties of the adsorbent. If the adsorbent particle size is small, suspended solids in the wastewater can easily clog the fixed bed. Conversely, if a larger particle size adsorbent is used, its specific surface area is often small, resulting in limited adsorption capacity and affecting the adsorption effect. Furthermore, if the density of the adsorbent used is low, it is prone to loss during backwashing.

[0005] Patent CN201910826316.9, entitled "A Water Treatment Method Based on Adsorption and Solid-Liquid Separation," uses powdered activated carbon to adsorb organic pollutants in water and a microfiltration membrane to separate the activated carbon adsorbent. This method employs a homogeneous, completely mixed reaction system, allowing for sufficient contact between the adsorbent and the organic pollutants in the water. However, to achieve stable effluent quality, fresh adsorbent needs to be continuously added to the reactor. The newly added adsorbent mixes with the old adsorbent in the same reactor. When using a microfiltration membrane for separation, some of the newly added adsorbent is also separated out. This prevents the graded utilization and batch regeneration of the new and old adsorbents. The newly added adsorbent is far from reaching adsorption saturation, its adsorption capacity is not fully utilized, and the regeneration frequency and cost are high. Summary of the Invention

[0006] Therefore, the present invention provides a homogeneous continuous adsorption wastewater treatment process and system. This process achieves continuous operation of the adsorption system under the condition of series operation of the front and rear reactors. Under the premise of ensuring that the effluent meets the standards, it increases the maximum adsorption capacity of the adsorbent during continuous operation, improves the utilization efficiency of the adsorbent, and extends the regeneration cycle, thereby solving the related technical problems in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A first aspect of the present invention provides a homogeneous continuous adsorption wastewater treatment process, comprising the following steps:

[0009] The water to be treated enters the pre-reactor for primary treatment; during the primary treatment, the water to be treated enters the reaction unit and is fully mixed with the old adsorbent in the reaction unit to carry out the adsorption reaction. No new adsorbent is added to the reaction unit (pre-reactor) during the primary treatment; the effluent from the reaction unit enters the recovery unit, which captures the old adsorbent that comes with the water and returns the old adsorbent to the reaction unit with part of the water.

[0010] The water treated in the first stage enters the post-reactor for secondary treatment. During the secondary treatment, new adsorbent is continuously added to the reaction unit (post-reactor). The water treated in the first stage enters the reaction unit and mixes thoroughly with the new adsorbent in the reaction unit to carry out the adsorption reaction. The effluent from the reaction unit enters the recovery unit, which captures the new adsorbent that comes with the water and returns the new adsorbent to the reaction unit with part of the water.

[0011] The saturated old adsorbent in the pre-reaction unit is discharged.

[0012] The pre-reactor and post-reactor are periodically and automatically switched, turning the previous pre-reactor into the post-reactor and the previous post-reactor into the pre-reactor.

[0013] The process involves continuous primary treatment, secondary treatment, adsorbent discharge, and periodic replacement.

[0014] Furthermore, the wastewater treatment process also includes the following steps:

[0015] The effluent from the recovery unit of the pre-reactor flows into the intermediate water tank for buffering and transfer;

[0016] The water in the intermediate pool is pumped into the reaction unit of the post-reactor for secondary treatment.

[0017] Furthermore, the wastewater treatment process also includes the following steps:

[0018] When the total amount of new adsorbent added to the reaction unit of the post-reactor is equal to the total amount of old adsorbent in the reaction unit of the pre-reactor, the addition of new adsorbent to the reaction unit of the post-reactor is stopped, and then the old adsorbent in the reaction unit of the pre-reactor is discharged; subsequently, the pre-reactor and post-reactor are switched.

[0019] Furthermore, the wastewater treatment process also includes the following steps:

[0020] During the adsorption reaction, the pH value of the liquid in the reaction unit is adjusted in real time to ensure that the pH value is maintained within a range that is favorable for the adsorption reaction.

[0021] Furthermore, the wastewater treatment process also includes the following steps:

[0022] During the process of adding new adsorbent to the reaction unit of the post-reactor, the pH value of the liquid in the reaction unit is adjusted in real time and kept within a range that is conducive to the adsorption reaction.

[0023] A second aspect of the present invention provides a homogeneous continuous adsorption wastewater treatment system, comprising a pre-reactor and a post-reactor;

[0024] The pre-reactor includes a first reaction unit and a first recovery unit. The first reaction unit and the first recovery unit are connected by a pipeline. The reflux port of the first recovery unit is connected to the first reaction unit by a pipeline so that the adsorbent captured by the first recovery unit is returned to the first reaction unit.

[0025] The post-reactor includes a second reaction unit and a second recovery unit. The second reaction unit and the second recovery unit are connected by a pipeline. The reflux port of the second recovery unit is connected to the second reaction unit by a pipeline so that the adsorbent captured by the second recovery unit is returned to the second reaction unit.

[0026] Each of the two reaction units is connected to the water inlet unit via a pipe with a valve; the first recovery unit is connected to the second reaction unit via a pipe with a valve, and the second recovery unit is connected to the first reaction unit via a pipe with a valve; each of the two recovery units is connected to the water outlet unit via a pipe with a valve.

[0027] Furthermore, the wastewater treatment system also includes a dispensing unit, which is connected to two reaction units via two pipelines equipped with valves.

[0028] Furthermore, the wastewater treatment system also includes a pH adjustment unit, which is connected to the two reaction units respectively through two pipelines with valves.

[0029] Furthermore, the wastewater treatment system also includes an intermediate water tank, which is connected in series in the pipeline connecting the first recovery unit and the second reaction unit, and in series in the pipeline connecting the second recovery unit and the first reaction unit. Valves are provided on both pipelines at the sections flowing into and out of the intermediate water tank.

[0030] Furthermore, the two reaction units are connected to the temporary storage unit via pipelines equipped with valves.

[0031] The present invention has the following advantages:

[0032] Through innovative process design, the wastewater to be treated is sequentially passed through two reactors connected in series, a pre-reactor and a post-reactor, for adsorption treatment. The two reactors can be periodically (the period is adjustable) switched according to the residence time of the adsorbent. On the one hand, fresh adsorbent is always added to the post-reactor to ensure that the effluent meets the standards. On the other hand, the adsorption capacity of the adsorbent is maximized in the pre-reactor, thereby reducing the frequency of adsorbent regeneration and lowering regeneration costs. Attached Figure Description

[0033] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0034] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0035] Figure 1 This is a schematic diagram of a homogeneous continuous adsorption wastewater treatment system provided in an embodiment of the present invention.

[0036] In the diagram: 1-Inlet unit, 2-Outlet pump, 3-First pipeline, 4-First electric valve, 5-First reaction unit, 6-Third pipeline, 7-First recovery unit, 8-Fifth pipeline, 9-First circulation pump, 10-Seventh pipeline, 11-Third electric valve, 12-Intermediate water tank, 13-Tenth pipeline, 14-Sixth electric valve, 15-Second lift pump, 16-Second reaction unit, 17-Fourth pipeline, 18-Second recovery unit, 19-Sixth pipeline, 20-Second circulation pump, 21-Twelfth pipeline, 22-Eighth electric valve, 23-Outlet unit, 24-Dispensing unit, 25-Sixteenth pipeline, 2 6-Twelfth electric valve, 27-pH adjustment unit, 28-Seventeenth pipeline, 29-Thirteenth electric valve, 30-Eighteenth pipeline, 31-Fourteenth electric valve, 32-Thirteenth pipeline, 33-Ninth electric valve, 34-External discharge pump, 35-Temporary storage unit, 36-Second pipeline, 37-Second electric valve, 38-Eighth pipeline, 39-Fourth electric valve, 40-Ninth pipeline, 41-Fifth electric valve, 42-First booster pump, 43-Eleventh pipeline, 44-Seventh electric valve, 45-Fifteenth pipeline, 46-Eleventh electric valve, 47-Fourteenth pipeline, 48-Tenth electric valve. Detailed Implementation

[0037] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0039] This invention provides a homogeneous continuous adsorption wastewater treatment process and system, which enables the wastewater treatment process to be implemented. In fact, other systems modified from this wastewater treatment system can also implement this wastewater treatment process; similarly, slight modifications to this wastewater treatment process can also be used for wastewater treatment. Therefore, improvements made to the homogeneous continuous adsorption wastewater treatment process and system provided by this invention should also be protected by this invention.

[0040] The process mainly includes the following:

[0041] (1) The water to be treated enters the reaction unit of the pre-reactor and mixes thoroughly with the old adsorbent in the reaction unit to carry out the adsorption reaction. At the same time, the pH value in the reaction unit is adjusted in real time to ensure that the adsorption reaction takes place at a pH that is conducive to adsorption. No fresh adsorbent is added to the reaction unit of the pre-reactor. The actual adsorption amount of the adsorbent is controlled by controlling the residence time of the adsorbent. When the adsorbent is close to adsorption saturation, it is discharged for regeneration.

[0042] (2) The effluent from the pre-reactor's reaction unit enters the recovery unit, which can employ different separation and recovery technologies or a combination of multiple separation technologies depending on the properties of the adsorbent. For example, if the adsorbent used has good free settling performance in water, a bottom-in, top-out sedimentation device or inclined tube sedimentation technology can be used; if the adsorbent is a magnetic adsorbent, magnetic separation can be used. The adsorbent captured by the recovery unit is returned to the reaction unit for sufficient adsorption, ensuring a short hydraulic residence time in the reaction unit while achieving a longer adsorbent residence time.

[0043] (3) An intermediate water tank is set up as a buffer and transfer unit. The intermediate water tank is equipped with a submersible pump or other type of lifting device, which can lift the effluent from the recovery unit of the pre-reactor to the reaction unit of the post-reactor.

[0044] (4) The structure of the post-reactor is the same as that of the pre-reactor. The difference is that fresh adsorbent is continuously added to the reaction unit of the post-reactor and pH is adjusted. The post-reactor is used to control the effluent quality to meet the standards.

[0045] (5) The pre-reactor and post-reactor can be automatically switched periodically. This process is achieved by switching two sets of automatic valves, and the inlet positions of the two reactors are replaced once in each cycle. On the one hand, this ensures that the reactors can continuously receive and discharge water, and on the other hand, it allows the adsorbent in the two reactors to be used in stages, with intervals approaching adsorption saturation and discharged in stages, maximizing the utilization rate of the adsorbent's adsorption capacity. Preferably, before each switchover, the adsorbent in the pre-reactor is discharged for regeneration.

[0046] (6) The dosing unit only quantitatively replenishes fresh adsorbent to the post-reactor to ensure that the final effluent meets the standards.

[0047] (7) Each switching of the dual reactor process is a reaction stage. The duration of each stage can be adjusted according to the adsorption saturation of the adsorbent and the effluent requirements. The switching cycle is generally 6-12 hours.

[0048] (8) Preferably, when the total amount of adsorbent added to the downstream reactor is the same as the total amount of adsorbent in the upstream reactor, the adsorbent in the upstream reactor is discharged for regeneration, and the two reactors are switched.

[0049] (9) When the adsorbent in the pre-reactor is discharged for regeneration (the time is short), the post-reactor can be used alone for wastewater treatment to ensure continuous inflow and outflow of water.

[0050] like Figure 1 As shown, the homogeneous continuous adsorption wastewater treatment system includes a pre-reactor, a post-reactor, a dosing unit 24, a pH adjustment unit 27, an intermediate water tank 12, as well as multiple pipelines, multiple valves, and multiple pumps. Both the pre-reactor and the post-reactor include a reaction unit and a recovery unit. For ease of explanation, the pre-reactor is referred to as the first reaction unit 5 and the first recovery unit 7, and the post-reactor is referred to as the second reaction unit 16 and the second recovery unit 18.

[0051] The outlet of the inlet unit 1 (also known as the inlet pipe, sewage source, or sewage tank) is equipped with an outlet pump 2, which is connected to the first reaction unit 5 via a first pipe 3 and to the second reaction unit 16 via a second pipe 36. The first reaction unit 5 is connected to the first recovery unit 7 via a third pipe 6. The second reaction unit 16 is connected to the second recovery unit 18 via a fourth pipe 17. The return port of the first recovery unit 7 (where the captured adsorbent is discharged) is connected to the first reaction unit 5 via a fifth pipe 8, and a first circulation pump 9 is connected in series on the fifth pipe 8. The return port of the second recovery unit 18 is connected to the second reaction unit 16 via a sixth pipe 19, and a second circulation pump 20 is connected in series on the sixth pipe 19. The intermediate water tank 12 is connected to the first recovery unit 7 via a seventh pipe 10, to the second recovery unit 18 via an eighth pipe 38, and to the second recovery unit 16 via a ninth pipe 40. A reaction unit 5 is connected to a second reaction unit 16 via a tenth pipe 13. A first booster pump 42 is connected in series on a ninth pipe 40, and a second booster pump 15 is connected in series on a tenth pipe 13. A water outlet unit 23 (water outlet pipe, water purification tank, etc.) is connected to a first recovery unit 7 via an eleventh pipe 43 and to a second recovery unit 18 via a twelfth pipe 21. A temporary storage unit 35 (storing saturated adsorbent discharged from the system) has an outlet pump 34 at its inlet, which is connected to the first reaction unit 5 via a thirteenth pipe 32 and to the second reaction unit 16 via a fourteenth pipe 47. A dispensing unit 24 is connected to the first reaction unit 5 via a fifteenth pipe 45 and to the second reaction unit 16 via a sixteenth pipe 25. A pH adjustment unit 27 is connected to the first reaction unit 5 via a seventeenth pipe 28 and to the second reaction unit 16 via an eighteenth pipe 30.

[0052] The first electric valve 4 is installed on the first pipeline 3; the second electric valve 37 is installed on the second pipeline 36; the third electric valve 11 is installed on the seventh pipeline 10; the fourth electric valve 39 is installed on the eighth pipeline 38; the fifth electric valve 41 is installed on the ninth pipeline 40; the sixth electric valve 14 is installed on the tenth pipeline 13; the seventh electric valve 44 is installed on the eleventh pipeline 43; the eighth electric valve 22 is installed on the twelfth pipeline 21; the ninth electric valve 33 is installed on the thirteenth pipeline 32; the tenth electric valve 48 is installed on the fourteenth pipeline 47; the eleventh electric valve 46 is installed on the fifteenth pipeline 45; the twelfth electric valve 26 is installed on the sixteenth pipeline 25; the thirteenth electric valve 29 is installed on the seventeenth pipeline 28; and the fourteenth electric valve 31 is installed on the eighteenth pipeline 30.

[0053] according to Figure 1 The wastewater treatment system shown has the following wastewater treatment process:

[0054] Phase 1:

[0055] (1) The first set of automatic valves (first electric valve 4, third electric valve 11, sixth electric valve 14, eighth electric valve 22, twelfth electric valve 26) are opened, and the second set of automatic valves (second electric valve 37, fourth electric valve 39, fifth electric valve 41, seventh electric valve 44, eleventh electric valve 46) are closed. The water to be treated first enters the first reaction unit 5 for adsorption reaction. The adsorbent can be stirred and mixed by a stirrer or other mixing method, and the pH is controlled by the pH adjustment unit 27.

[0056] (2) The effluent from the first reaction unit 5 enters the first recovery unit 7. The adsorbent in the first recovery unit 7 is separated and recovered along with the effluent from the first reaction unit 5, and then circulated back to the first reaction unit 5 by the first circulation pump 9. The recovery unit can use different methods for separation and recovery according to the physicochemical properties of the adsorbent, such as magnetic separation, precipitation separation, membrane separation, etc.

[0057] (3) The effluent from the first recovery unit 7 enters the intermediate water tank 12, and is then further lifted from the intermediate water tank 12 to the second reaction unit 16. Fresh adsorbent is added to the second reaction unit 16 through the delivery unit 24, and pH is controlled by the pH adjustment unit 27.

[0058] (4) The effluent from the second reaction unit 16 enters the second recovery unit 18. The adsorbent in the second recovery unit 18 is periodically recovered and circulated back to the second reaction unit 16 through the second circulation pump 20.

[0059] (5) When the adsorption reaction has been carried out for a certain period of time, the adsorbent in the first reaction unit 5 approaches adsorption saturation, and the adsorbent in the first reaction unit 5 is discharged for regeneration treatment. When the adsorbent in the first reaction unit 5 is discharged, the second electric valve 37 and the eighth electric valve 22 are opened, and the other automatic valves are closed. At this time, the second reaction unit 16 and the second recovery unit 18 are operated independently to ensure the continued inflow and outflow of water.

[0060] Phase Two:

[0061] (6) The first set of automatic valves (first electric valve 4, third electric valve 11, sixth electric valve 14, eighth electric valve 22, twelfth electric valve 26) are closed, and the second set of automatic valves (second electric valve 37, fourth electric valve 39, fifth electric valve 41, seventh electric valve 44, eleventh electric valve 46) are opened. The water to be treated enters the second reaction unit 16 for adsorption reaction. The adsorbent can be stirred and mixed by a stirrer or other mixing method, and the pH is controlled by the pH adjustment unit 27.

[0062] (7) The effluent from the second reaction unit 16 enters the second recovery unit 18, and the adsorbent in the second recovery unit 18 is periodically recovered and circulated back to the second reaction unit 16 through the second circulation pump 20.

[0063] (8) The effluent from the second recovery unit 18 enters the intermediate water tank 12 and is then further lifted from the intermediate water tank 12 to the first reaction unit 5. Fresh adsorbent is added to the first reaction unit 5 through the delivery unit 24 and pH is controlled by the pH adjustment unit 27.

[0064] (9) The effluent from the first reaction unit 5 enters the first recovery unit 7, and the adsorbent in the first recovery unit 7 is periodically recovered and circulated back to the first reaction unit 5 through the first circulation pump 9.

[0065] (10) When the adsorption reaction has been carried out for a certain period of time, the adsorbent in the second reaction unit 16 approaches adsorption saturation, and the adsorbent in the second reaction unit 16 is discharged for regeneration treatment. When the adsorbent in the second reaction unit 16 is discharged, the first electric valve 4 and the seventh electric valve 44 can be opened, and other automatic valves can be closed. At this time, the first reaction unit 5 and the first recovery unit 7 are operated separately to ensure the continued inflow and outflow of water.

[0066] (11) The two sets of valves switch open and close states again and repeat the first stage process. The two stages run alternately to ensure continuous operation of the system. The two sets of automatic valves can be linked and controlled by PLC settings. One set is closed and the other is open. They can be interchanged when switching cycles.

[0067] Example 1

[0068] use Figure 1 The wastewater treatment system shown utilizes a corresponding wastewater treatment process to continuously remove fluoride and phosphorus from wastewater from the power battery recycling industry. The influent pH is 6.6, fluoride ion concentration is 84 mg / L, dissolved phosphorus concentration is 14 mg / L, oil content is 22 mg / L, and the influent flow rate is 40 L / h. Both reaction units have an effective volume of 20 L, and both recovery units have an effective volume of 2 L. The adsorbent used is a ZrO2 / Fe3O4 magnetic composite material. The initial adsorbent concentration in the first reaction unit is 24 g / L. Fresh adsorbent slurry (400 g (dry weight of adsorbent) / L (water)) is added to the second reaction unit at a rate of 0.2 L / h. The two reaction units are switched every 6 hours, and the adsorbent in the first reaction unit is simultaneously discharged for regeneration.

[0069] In terms of the recycling unit design, due to the adsorbent's excellent ferromagnetism, electromagnets are installed in both recycling units, each linked to its corresponding circulation pump. When the circulation pump is off, the electromagnet remains energized, creating a magnetic separation effect on the adsorbent and preventing it from entering the intermediate water tank 12 from either the first recycling unit 7 or the second recycling unit 18. When the circulation pump is on, the electromagnet is de-energized, eliminating its magnetic attraction to the adsorbent, thus allowing the adsorbent to return to either the first reaction unit 5 or the second reaction unit 16. The circulation pump operates at 20-minute intervals, with an operating time of 15 seconds.

[0070] In terms of system operation, an automatic control system is used to control the valves in a coordinated manner, according to... Figure 1 The process shown is for the adsorption and removal of fluoride and phosphorus from water:

[0071] Phase 1:

[0072] (1) The first electric valve 4, the third electric valve 11, the sixth electric valve 14, the eighth electric valve 22, and the twelfth electric valve 26 are opened, and the second electric valve 37, the fourth electric valve 39, the fifth electric valve 41, the seventh electric valve 44, and the eleventh electric valve 46 are closed. The water to be treated enters the first reaction unit 5 for adsorption reaction. The stirrer stirs and mixes the water, and the pH is controlled at 5.5 by the pH adjustment unit 27.

[0073] (2) The effluent from the first reaction unit 5 enters the first recovery unit 7. The adsorbent in the first recovery unit 7 is separated by electromagnetic separation and circulated back to the first reaction unit 5 by the first circulation pump 9. The residence time of the adsorbent in the reactor is 6 hours.

[0074] (3) The effluent from the first recovery unit 7 enters the intermediate water tank 12. The water in the intermediate water tank 12 is further raised to the second reaction unit 16 to continue the adsorption reaction. At the same time, fresh adsorbent slurry is added to the second reaction unit 16 through the delivery unit 24, and the reaction pH is adjusted to 5.5 through the pH adjustment unit 27.

[0075] (4) The effluent from the second reaction unit 16 enters the second recovery unit 18. The adsorbent in the second recovery unit 18 is separated by electromagnetic separation and circulated back to the second reaction unit 16 by the second circulation pump 20. The effluent from the second recovery unit 18 is the final effluent.

[0076] (5) After the adsorption reaction has been going on for 6 hours, the second electric valve 37, the eighth electric valve 22, and the ninth electric valve 33 are opened, and the other automatic valves are closed. At this time, the adsorbent in the first reaction unit 5 is discharged for regeneration treatment, while the second reaction unit 16 and the second recovery unit 18 are operated separately to ensure the continued inflow and outflow of water.

[0077] Phase Two:

[0078] (6) The first electric valve 4, the third electric valve 11, the sixth electric valve 14, the eighth electric valve 22, and the twelfth electric valve 26 are closed, and the second electric valve 37, the fourth electric valve 39, the fifth electric valve 41, the seventh electric valve 44, and the eleventh electric valve 46 are opened. The water to be treated enters the second reaction unit 16 for adsorption reaction. The stirrer stirs and mixes the water, and the pH is controlled at 5.5 by the pH adjustment unit 27.

[0079] (7) The effluent from the second reaction unit 16 enters the second recovery unit 18. The adsorbent in the second recovery unit 18 is separated by electromagnetic separation and circulated back to the second reaction unit 16 by the second circulation pump 20. The residence time of the adsorbent in the reactor is 6 hours.

[0080] (8) The effluent from the second recovery unit 18 enters the intermediate water tank 12. The water in the intermediate water tank 12 is further raised to the first reaction unit 5 to continue the adsorption reaction. At the same time, fresh adsorbent slurry is added to the first reaction unit 5 through the delivery unit 24, and the reaction pH is adjusted to 5.5 through the pH adjustment unit 27.

[0081] (9) The effluent from the first reaction unit 5 enters the first recovery unit 7. The adsorbent in the first recovery unit 7 is separated by electromagnetic separation and circulated back to the first reaction unit 5 by the first circulation pump 9. The effluent from the first recovery unit 7 is the final effluent.

[0082] (10) After the adsorption reaction has been going on for 6 hours, the first electric valve 4, the seventh electric valve 44, and the tenth electric valve 48 are opened, and the other automatic valves are closed. At this time, the adsorbent in the second reaction unit 16 is discharged for regeneration treatment, while the first reaction unit 5 and the first recovery unit 7 are operated separately to ensure the continued inflow and outflow of water.

[0083] (11) Then, the process of the first stage is repeated again, and the two stages are constantly alternating.

[0084] Under these conditions, the fluoride ion concentration decreased from 84 mg / L to below 5 mg / L and remained stable, while the dissolved phosphorus concentration decreased from 14 mg / L to below 0.5 mg / L and remained stable. Calculations showed that the adsorbent used for effluent regeneration adsorbed over 40 mg / g for fluoride ions and over 6.5 mg / g for soluble phosphorus. This demonstrates that this process effectively removes fluoride ions from wastewater, while ensuring a high utilization rate of the adsorbent's adsorption capacity during continuous operation, thus reducing the number of regeneration cycles and lowering regeneration costs.

[0085] Example 2

[0086] use Figure 1 The wastewater treatment system shown treats Cd-containing wastewater using a corresponding wastewater treatment process. The influent Cd concentration is 2.8 mg / L, suspended solids are 15 mg / L, and the influent flow rate is 3 L / h. Both the pre-reactor and post-reactor have an effective volume of 2 L, and the recovery unit has an effective volume of 0.2 L. The adsorbent is a binary composite material of manganese oxide and iron oxide. The initial adsorbent concentration in the pre-reactor is 0.8 g / L. Fresh adsorbent is added to the post-reactor at a rate of 0.2 g / h. The two reactors are switched every 8 hours, and the adsorbent in the pre-reactor is discharged for regeneration. In the recovery unit design, due to the high density and good settling performance of the adsorbent, the separation unit uses a bottom-in, top-out inlet configuration, separating the adsorbent and wastewater through free settling. The circulation pump is turned on every 10 minutes for a duration of 5 seconds. Using the same implementation method and process flow as in Example 1, the system was continuously operated for 200 hours, and the Cd concentration in the effluent remained stably below 0.1 mg / L. Under these conditions, the adsorbent regenerated by external discharge can adsorb more than 40 mg / g of Cd.

[0087] Example 3

[0088] use Figure 1 The wastewater treatment system shown utilizes a corresponding wastewater treatment process to treat wastewater extracted from spent power batteries. The influent oil content is 95 mg / L, suspended solids are 4 mg / L, and the influent flow rate is 200 L / h. Both the pre-reactor and post-reactor have an effective volume of 100 L, and the recovery unit has an effective volume of 10 L. The adsorbent used is ORZ type oil removal resin. The initial adsorbent concentration in the pre-reactor is 1 g / L. Fresh adsorbent is added to the post-reactor at a rate of 10 g / h. The two reactors are switched every 10 hours, and the adsorbent in the pre-reactor is simultaneously discharged for regeneration. The recovery unit reactor uses a bottom-in, top-out influent configuration and is equipped with inclined tube sedimentation. A circulating pump is used for intermittent adsorbent recovery, with an opening interval of 15 min and an opening duration of 10 s. The system operates continuously using the process flow described in the above implementation method and Example 1, and the oil content in the effluent is consistently maintained below 5 mg / L. Under these conditions, the oil adsorption capacity of the discharged regenerated adsorbent reaches over 1.8 g / g.

[0089] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A homogeneous continuous adsorptive sewage treatment process, characterized by, The process comprises the following steps: The water to be treated enters the pre-reactor for primary treatment; during the primary treatment, the water to be treated enters the first reaction unit and mixes with the old adsorbent in the first reaction unit for adsorption reaction, and no new adsorbent is added to the reaction unit during the primary treatment; the effluent from the first reaction unit enters the first recovery unit, which traps the old adsorbent coming with the water and makes the old adsorbent backflow with part of the water to the first reaction unit; The water treated in the primary treatment enters the post-reactor for secondary treatment; during the secondary treatment, new adsorbent is continuously added to the second reaction unit, and the water treated in the primary treatment enters the second reaction unit and mixes with the new adsorbent in the second reaction unit for adsorption reaction; the effluent from the second reaction unit enters the second recovery unit, which traps the new adsorbent coming with the water and makes the new adsorbent backflow with part of the water to the second reaction unit; The saturated old adsorbent in the pre-reactor is discharged; The pre-reactor and the post-reactor are periodically and automatically switched, so that the previous pre-reactor becomes the post-reactor, and the previous post-reactor becomes the pre-reactor; The primary treatment, the secondary treatment, the adsorbent discharge, and the periodic switching are continuously repeated; When the total amount of the new adsorbent added to the reaction unit of the post-reactor is equal to the total amount of the old adsorbent in the reaction unit of the pre-reactor, the addition of the new adsorbent to the reaction unit of the post-reactor is stopped; then the old adsorbent in the reaction unit of the pre-reactor is discharged; Subsequently, the switching of the pre-reactor and the post-reactor is performed.

2. The homogeneous continuous adsorptive sewage treatment process according to claim 1, characterized in that, The sewage treatment process further comprises the following steps: The effluent from the first recovery unit of the pre-reactor flows into the intermediate pool for buffering and transfer; The water in the intermediate pool is lifted and sent into the second reaction unit of the post-reactor for secondary treatment.

3. The homogeneous continuous adsorptive sewage treatment process according to claim 1, characterized in that, The sewage treatment process further comprises the following steps: During the process that the water to be treated fully mixes with the old adsorbent in the reaction unit for adsorption reaction, the pH value of the liquid in the reaction unit is adjusted in real time, and the pH value is kept in a range that is favorable for the adsorption reaction.

4. The homogeneous continuous adsorptive sewage treatment process according to claim 1, characterized in that, During the process that the new adsorbent is added to the reaction unit of the post-reactor, the pH value of the liquid in the reaction unit is adjusted in real time, and the pH value is kept in a range that is favorable for the adsorption reaction. The process comprises the following steps:

5. A homogeneous continuous adsorptive sewage treatment system for implementing the homogeneous continuous adsorptive sewage treatment process according to any one of claims 1 to 4, characterized in that The pre-reactor comprises a first reaction unit and a first recovery unit, the first reaction unit is connected with the first recovery unit through a pipeline, and a backflow port of the first recovery unit is connected with the first reaction unit through a pipeline to make the adsorbent trapped by the first recovery unit backflow to the first reaction unit; The post-reactor comprises a second reaction unit and a second recovery unit, the second reaction unit is connected with the second recovery unit through a pipeline, and a backflow port of the second recovery unit is connected with the second reaction unit through a pipeline to make the adsorbent trapped by the second recovery unit backflow to the second reaction unit; ​ The two reaction units are respectively connected with the water inlet unit through pipes with valves; the first recovery unit is connected with the second reaction unit through a pipe with a valve, and the second recovery unit is connected with the first reaction unit through a pipe with a valve; the two recovery units are respectively connected with the water outlet unit through pipes with valves. The two reaction units are respectively provided with pipes with valves for discharging the adsorbent.

6. The homogeneous continuous adsorptive sewage treatment system according to claim 5, characterized in that, The sewage treatment system further comprises a dosing unit, which is connected with the two reaction units through two pipes with valves.

7. The homogeneous continuous adsorptive sewage treatment system according to claim 5, characterized in that, The sewage treatment system further comprises a pH adjusting unit, which is connected with the two reaction units through two pipes with valves.

8. The homogeneous continuous adsorptive sewage treatment system according to claim 5, characterized in that, The sewage treatment system further comprises an intermediate water pool, which is connected in series with the pipe connecting the first recovery unit with the second reaction unit and with the pipe connecting the second recovery unit with the first reaction unit, and valves are arranged on the pipe sections flowing into and out of the intermediate water pool.

9. The homogeneous continuous adsorptive sewage treatment system according to claim 5, wherein, The two reaction units are respectively connected with the temporary storage unit through pipes with valves.

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