Hexavalent chromium-containing wastewater treatment and chromium resource recovery system

Abstract

The utility model discloses a hexavalent chromium-containing wastewater treatment and chromium resource recovery system which comprises a flocculation impurity removal mechanism, a first filter pressing part, an acidification mechanism, an ion exchange mechanism and a crystallization mechanism, chromium-containing wastewater, alkali liquor and a flocculating agent can be introduced into the flocculation impurity removal mechanism, so that impurity metal ions in the chromium-containing wastewater are precipitated; supernate of the flocculation impurity removal mechanism can be introduced into the first filter pressing part for filter pressing; acid liquor can be introduced into the acidification mechanism so as to adjust the pH of supernate of the flocculation impurity removal mechanism and the pH of supernate of the first filter pressing part; the ion exchange mechanism can adsorb hexavalent chromium ions in the supernate, and the alkali desorption solution desorbs and regenerates the adsorbed hexavalent chromium ions into a chromium concentrated solution; chromic acid can be introduced into the crystallization mechanism to acidify the chromium concentrated solution, and the acidified chromium concentrated solution can be concentrated and dried to obtain dichromate. According to the hexavalent chromium-containing wastewater treatment and chromium resource recovery system provided by the utility model, the chromium-containing wastewater is treated, and the chromium recovery amount is increased.

Description

TECHNICAL FIELD

[0001] The utility model relates to sewage treatment technical field especially is involved in a kind of hexavalent chromium-containing wastewater treatment and chromium resource recovery system. BACKGROUND

[0002] Chromium metal has good corrosion resistance, can keep its luster for a long time, wear resistance, heat resistance, high hardness and other performances, therefore, chromium metal has wide application in electroplating (such as electroplated hard chromium, electroplated decorative chromium, zinc-chromium plating passivation, etc.); In the electroplating process, due to the rinsing of plated parts, the scrapping of bath solution, the replacement and cleaning of filter cloth filter core of plating solution filter machine, etc., a certain amount of chromium-containing wastewater will be generated, and the main pollution factors in chromium-containing wastewater include Cr2O7 2- , Cr 3+ , Zn 2+ , Cu 2+ , Fe 3+ , Ni 2+ , etc.; The conventional chromium water treatment method is reduction-neutralization flocculation method, Cr2O7 2- is reduced to Cr 3+ by adding a reducing agent under acidic conditions, and then the pH value of wastewater is adjusted by adding alkali, so that metal ions are all converted into corresponding hydroxides to be precipitated and removed; The chromium mud obtained by the method has complex composition, low chromium content, and is not easy to be reused. CONTENT OF UTILITY MODEL

[0003] The utility model aims at providing a kind of hexavalent chromium-containing wastewater treatment and chromium resource recovery system to solve the problems existing in the above-mentioned prior art, to treat chromium-containing wastewater and improve chromium recovery amount.

[0004] To achieve the above-mentioned purpose, the utility model provides the following scheme:

[0005] The utility model provides a kind of hexavalent chromium-containing wastewater treatment and chromium resource recovery system, including flocculation and impurity removal mechanism, first filter pressing part, acidification mechanism, ion exchange mechanism and crystallization mechanism;Flocculation and impurity removal mechanism can be passed into chromium-containing wastewater, lye and flocculating agent, chromium-containing wastewater, lye and flocculating agent are mixed in the flocculation and impurity removal mechanism, to make the impurity metal ion in chromium-containing wastewater precipitate;First filter pressing part is communicated with the flocculation and impurity removal mechanism, and the supernatant of the flocculation and impurity removal mechanism can be passed into the first filter pressing part and carries out filter pressing;Acidification mechanism is communicated with the flocculation and impurity removal mechanism and the first filter pressing part, and the supernatant of the flocculation and impurity removal mechanism and the supernatant of the first filter pressing part can be passed into the acidification mechanism, and the acidification mechanism can be passed into acid liquor to adjust the pH of supernatant;Ion exchange mechanism is communicated with the acidification mechanism, and the supernatant after acidification can be passed into the ion exchange mechanism, and the ion exchange mechanism can adsorb hexavalent chromium ion in supernatant, and base elution liquid can also be passed into the ion exchange mechanism to regenerate chromium concentrate liquid from the adsorbed hexavalent chromium ion;Crystallization mechanism is communicated with the ion exchange mechanism, and chromium concentrate liquid can be passed into the crystallization mechanism, and the crystallization mechanism can pass into chromic acid to acidify chromium concentrate liquid, and can concentrate and dry acidified chromium concentrate liquid solution to obtain dichromate.

[0006] Preferably, the flocculation and impurity removal mechanism includes impurity removal pool and first flocculation settling tank communicated in sequence, the impurity removal pool is used for passing in chromium-containing wastewater and lye, the mixed solution in the impurity removal pool is passed into the first flocculation settling tank, flocculating agent is passed into the first flocculation settling tank, the first flocculation settling tank is communicated with the first filter pressing part and the acidification mechanism, and the supernatant in the first flocculation settling tank can be passed into the acidification mechanism and the first filter pressing part respectively.

[0007] Preferably, the acidification mechanism includes supernatant adjusting pool, the supernatant adjusting pool is communicated with flocculation and impurity removal mechanism and the first filter pressing part and is used for passing in supernatant, and acid liquor is passed into the supernatant adjusting pool;And the supernatant adjusting pool is also communicated with the ion exchange mechanism.

[0008] Preferably, the ion exchange mechanism includes ion exchange column, the ion exchange column is communicated with the acidification mechanism and is used for passing in supernatant after acidification, the ion exchange column is used for adsorbing hexavalent chromium ion in supernatant, and base elution liquid can be passed into the ion exchange column to regenerate chromium concentrate liquid from the adsorbed hexavalent chromium ion;The ion exchange column is also communicated with the crystallization mechanism.

[0009] Preferably, the crystallization mechanism comprises a neutralization tank, a concentration device and a drying device connected in sequence, the neutralization tank is communicated with the ion exchange mechanism and used for feeding the chromium concentrated solution, and the neutralization tank is further used for feeding chromic acid to acidify the chromium concentrated solution, the concentration device is used for concentrating the acidified chromium concentrated solution and feeding the concentrated solution into the drying device to obtain bichromate.

[0010] Preferably, the post-exchange liquid adjusting mechanism is further communicated with the ion exchange mechanism, the post-exchange liquid of the ion exchange mechanism is used for feeding into the post-exchange liquid adjusting mechanism, and the post-exchange liquid adjusting mechanism is used for reducing the hexavalent chromium in the post-exchange liquid and capable of flocculating and settling the reduced post-exchange liquid.

[0011] Preferably, the post-exchange liquid adjusting mechanism comprises a post-exchange liquid adjusting tank and a second flocculation and sedimentation tank communicated, the post-exchange liquid adjusting tank is communicated with the ion exchange mechanism and used for feeding the post-exchange liquid and a reducing agent, and the reduced post-exchange liquid in the post-exchange liquid adjusting tank can be fed into the second flocculation and sedimentation tank, and a flocculating agent can be fed into the post-exchange liquid in the second flocculation and sedimentation tank to perform flocculation and sedimentation.

[0012] Preferably, the second pressure filtration part is further communicated with the second flocculation and sedimentation tank, and the supernatant of the second flocculation and sedimentation tank can be fed into the second pressure filtration part to perform pressure filtration.

[0013] Preferably, the supernatant of the second flocculation and sedimentation tank and the supernatant in the second pressure filtration part can be communicated with an external treatment system.

[0014] Preferably, a defluorination tank is further communicated between the post-exchange liquid adjusting tank and the second flocculation and sedimentation tank, and a defluorination agent can be fed into the post-exchange liquid in the defluorination tank.

[0015] The utility model discloses relative to prior art has obtained following technical effect:

[0016] The utility model discloses provided containing hexavalent chromium wastewater treatment and chromium resource recovery system, first with the chromium containing wastewater is fed into flocculation and removes sundry mechanism to carry out wastewater treatment, through the alkali liquor and flocculating agent are added to the chromium containing wastewater is carried out and is deposited and is pretreated, and the impurity metal ions such as Cr 3+ , Zn 2+ , Cu 2+ , Fe 3+ , Ni 2+ Form flocculation and deposit in wastewater, and the supernatant obtained can enter acidification mechanism and mix with acid liquor and adjust into acidity, in addition, the part of the supernatant close to flocculation and deposit in supernatant can enter first pressure filtration part and carry out pressure filtration treatment to remove impurities, and the clear liquid after pressure filtration is fed into acidification mechanism and mixes with acid liquor and adjusts into acidity, and the supernatant after acidification enters ion exchange mechanism, and the Cr 6+and the adsorbed Cr is eluted by alkaline solution 6+ The elution regeneration is a chromium concentrate liquid, the chromium concentrate liquid is introduced into a crystallization mechanism, the crystallization mechanism introduces a chromic acid to neutralize and acidify the chromium concentrate liquid, and then concentrates, dries and obtains relatively pure dichromate; in this way, the impurity metal ions are removed by precipitation in advance, and the Cr 6+ is adsorbed and eluted, so as to improve the recovery content of hexavalent chromium. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0018] Figure 1 The flowchart of the hexavalent chromium-containing wastewater treatment and chromium resource recovery system provided in Embodiment One is shown.

[0019] In the figure: 1-flocculation and impurity removal mechanism; 11-impurity removal tank; 12-first flocculation and sedimentation tank; 2-first pressure filtration part; 3-acidification mechanism; 31-supernatant adjustment tank; 4-ion exchange mechanism; 41-ion exchange column; 5-crystallization mechanism; 51-neutralization tank; 52-concentration device; 53-drying device; 6-post-exchange liquid adjustment mechanism; 61-post-exchange liquid adjustment tank; 62-second flocculation and sedimentation tank; 63-defluorination tank; 7-second pressure filtration part. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0021] The purpose of the present application is to provide a hexavalent chromium-containing wastewater treatment and chromium resource recovery system to solve the problems in the prior art and to treat chromium-containing wastewater and improve the chromium recovery amount.

[0022] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in combination with the drawings and specific embodiments.

[0023] Embodiment One

[0024] Embodiment One provides a hexavalent chromium-containing wastewater treatment and chromium resource recovery system, please refer toFigure 1 The system includes a flocculation and impurity removal mechanism 1, a first filter press 2, an acidification mechanism 3, an ion exchange mechanism 4, and a crystallization mechanism 5. The flocculation and impurity removal mechanism 1 can be used to introduce chromium-containing wastewater, alkaline solution, and flocculant. These components are mixed within the flocculation and impurity removal mechanism 1 to precipitate impurity metal ions from the chromium-containing wastewater. The first filter press 2 is connected to the flocculation and impurity removal mechanism 1, and the supernatant from the flocculation and impurity removal mechanism 1 can be fed into the first filter press 2 for filtration. The acidification mechanism 3 is connected to both the flocculation and impurity removal mechanism 1 and the first filter press 2, and the supernatant from both the flocculation and impurity removal mechanism 1 and the first filter press 2 can be fed into the acidification mechanism 3. The acidification unit 3 can introduce acid to adjust the pH of the supernatant; the ion exchange unit 4 is connected to the acidification unit 3, and the acidified supernatant can enter the ion exchange unit 4. The ion exchange unit 4 can adsorb hexavalent chromium ions in the supernatant. The ion exchange unit 4 can also introduce alkaline desorption solution to desorb and regenerate the adsorbed hexavalent chromium ions into a chromium concentrate; the crystallization unit 5 is connected to the ion exchange unit 4, and the chromium concentrate can enter the crystallization unit 5. The crystallization unit 5 can introduce chromic acid to acidify the chromium concentrate, and can concentrate and dry the acidified chromium concentrate solution to obtain dichromate.

[0025] First, the chromium-containing wastewater is passed into the flocculation and impurity removal unit 1 for wastewater treatment. Alkali solution and flocculant are added to pre-treat the chromium-containing wastewater through precipitation, removing impurities such as Cr metal cations from the wastewater. 3+ Zn 2+ Cu 2+ Fe 3+ Ni 2+ After flocculation and precipitation, the chromate anions remain in the supernatant. This supernatant then enters the acidification unit 3 and is mixed with acid to adjust the pH. Additionally, the portion of the supernatant near the flocculated precipitate may be turbid; this portion can be filtered in the first pressure filter unit 2 to remove impurities. The filtered supernatant is then passed into the acidification unit 3 and mixed with acid to adjust the pH. The acidified supernatant then enters the ion exchange unit 4 to adsorb Cr from the supernatant. 6+ And the adsorbed Cr is removed by alkaline elution solution 6+ The regenerated solution is a chromium concentrate, which is then passed into crystallization unit 5. Chromic acid is introduced into crystallization unit 5 to neutralize and acidify the chromium concentrate. After concentration and drying, a relatively pure dichromate is obtained. This process removes impurity metal cations through pre-precipitation and improves the chromium content. 6+ Adsorption and desorption are performed to improve the recovery rate of hexavalent chromium.

[0026] In the optional solution of the embodiment, preferably, the flocculation and impurity removal mechanism 1 comprises an impurity removal tank 11 and a first flocculation and sedimentation tank 12 connected in sequence, the impurity removal tank 11 is used for feeding the chromium-containing wastewater and lye, the mixed solution in the impurity removal tank 11 is fed into the first flocculation and sedimentation tank 12, the first flocculation and sedimentation tank 12 is fed with a flocculating agent, the first flocculation and sedimentation tank 12 is connected with the first pressure filtration part 2 and the acidification mechanism 3, and the supernatant in the first flocculation and sedimentation tank 12 can be fed into the acidification mechanism 3 and the first pressure filtration part 2, respectively; the first pressure filtration part 2 can perform pressure filtration treatment on the turbid supernatant to reduce the influence of impurities on the subsequent process; specifically, the impurity removal tank 11 is provided with a pH meter, the added lye is 30% liquid lye, the pH is controlled to be 8.5-10.5, and the flocculating agent is 1wt% non-ionic polyacrylamide solution coagulant.

[0027] In the optional solution of the embodiment, preferably, the acidification mechanism 3 comprises a supernatant adjusting tank 31, the supernatant adjusting tank 31 is connected with the flocculation and impurity removal mechanism 1 and the first pressure filtration part 2 and is used for feeding the supernatant, and the supernatant adjusting tank 31 is fed with acid liquid; and the supernatant adjusting tank 31 is also connected with the ion exchange mechanism 4; specifically, the pH control range is 3-3.5, and the added acid liquid is 10% sulfuric acid.

[0028] In the optional solution of the embodiment, preferably, the ion exchange mechanism 4 comprises an ion exchange column 41, the ion exchange column 41 is connected with the acidification mechanism 3 and is used for feeding the acidified supernatant, the ion exchange column 41 is used for adsorbing the hexavalent chromium ions in the supernatant, and the ion exchange column 41 can be fed with an alkali elution liquid to elute and regenerate the adsorbed hexavalent chromium ions into chromium concentrate liquid; the ion exchange column 41 is also connected with the crystallization mechanism 5; wherein the ion exchange column 41 adopts an anion adsorption and exchange column, and forms a matched anion exchange resin system with an elution liquid preparation tank; the acidified supernatant is connected to the inlet of the ion exchange column 41, the post-exchange liquid outlet of the ion exchange column 41 is connected to the post-exchange liquid adjusting mechanism 6; after the resin in the ion exchange column 41 is saturated, the elution liquid is used for elution and regeneration, the elution liquid with a suitable concentration is pumped into the ion exchange column 41 for adsorption, and the elution liquid flowing out of the outlet is fed into the crystallization mechanism 5; wherein the elution liquid is obtained by using 10% potassium hydroxide to elute the saturated resin tank, and the chromium concentrate liquid is obtained.

[0029] In an optional solution of the embodiment, preferably, the crystallization mechanism 5 comprises a neutralization tank 51, a concentration device 52 and a drying device 53 connected in sequence, the neutralization tank 51 is connected with the ion exchange mechanism 4 and used for passing the chromium concentrated solution, and the chromium concentrated solution is also passed into the neutralization tank 51 to be acidified by chromic acid, the concentration device 52 is used for concentrating the acidified chromium concentrated solution and passing into the drying device 53 to be dried to obtain potassium dichromate; wherein the neutralization tank 51 is acidified by chromic acid, and the pH is controlled at 2-4, the concentration device 52 is an evaporation concentration device, the chromium concentrated solution is concentrated in the evaporation concentration device to precipitate a large amount of crystalline salt, the condensate generated by evaporation concentration can be returned to the ion exchange 4, and the crystalline salt is sent to the drying device 53 to be dried, such as drum drying or spray drying, to obtain potassium dichromate; K2Cr2O7 (potassium dichromate) as a chemical raw material has a very important position in the field of chromium salt chemical industry; K2Cr2O7 is orange red powder at room temperature, showing good light resistance and chemical stability, and has different technical requirements in different application fields.

[0030] In an optional solution of the embodiment, preferably, the chromium-containing wastewater treatment and chromium resource recovery system provided by the embodiment further comprises a post-ion exchange liquid adjusting mechanism 6 connected with the ion exchange mechanism 4, the post-ion exchange liquid of the ion exchange mechanism 4 is used to pass into the post-ion exchange liquid adjusting mechanism 6, the post-ion exchange liquid adjusting mechanism 6 is used to reduce the hexavalent chromium in the post-ion exchange liquid, and can flocculate and settle the reduced post-ion exchange liquid; the chromium is completely reduced, and the reduced chromium is recovered by flocculation and sedimentation.

[0031] In an optional solution of the embodiment, preferably, the post-ion exchange liquid adjusting mechanism 6 comprises a post-ion exchange liquid adjusting tank 61 and a second flocculation and sedimentation tank 62 connected in sequence, the post-ion exchange liquid adjusting tank 61 is connected with the ion exchange mechanism 4 and used for passing the post-ion exchange liquid and a reducing agent, the reduced post-ion exchange liquid in the post-ion exchange liquid adjusting tank 61 can pass into the second flocculation and sedimentation tank 62, and a flocculating agent can be passed into the post-ion exchange liquid in the second flocculation and sedimentation tank 62 to perform flocculation and sedimentation; the reducing agent is 10% sodium pyrosulfite, and the ORP value is controlled at 230-270mv to ensure that the chromium is completely reduced; the flocculating agent is 1wt% non-ionic polyacrylamide solution coagulant.

[0032] Further preferably, 10% sulfuric acid is also passed into the post-ion exchange liquid adjusting tank 61, and the pH is controlled at 2-3, preferably 2-2.5, the acid is adjusted to ensure that the residual hexavalent chromium in the post-ion exchange liquid is more easily removed by deep reduction.

[0033] In an optional solution of the embodiment, preferably, the hexavalent chromium-containing wastewater treatment and chromium resource recovery system provided by the embodiment further comprises a second filter pressing part 7, which is in communication with the second flocculation sedimentation tank 62, and the supernatant of the second flocculation sedimentation tank 62 can be introduced into the second filter pressing part 7 for filter pressing; the residual chromium-containing impurities in the supernatant of the second flocculation sedimentation tank 62 are filter pressed for recovery; and the first filter pressing part 2 and the second filter pressing part 7 can both be plate-and-frame filter presses.

[0034] In an optional solution of the embodiment, preferably, the supernatant of the second flocculation sedimentation tank 62 and the supernatant in the second filter pressing part 7 can both be communicated with an external treatment system such as an SCR recovery system, so as to recover the supernatant.

[0035] In an optional solution of the embodiment, preferably, a defluorination tank 63 is further communicated between the post-interaction liquid adjusting tank 61 and the second flocculation sedimentation tank 62, and a defluorination agent can be introduced into the post-interaction liquid in the defluorination tank 63 to perform defluorination by the defluorination agent, so as to reduce the corrosion of fluorine on the SCR system.

[0036] In the hexavalent chromium-containing wastewater treatment and chromium resource recovery system of the embodiment, pumps can be used to drive the fluid flow between the reaction tanks, and agitators can be arranged in the reaction tanks as needed to improve the reaction efficiency.

[0037] The principles and implementation modes of the present application are described by using specific examples in the present application, and the above description of the embodiments is only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation modes and application ranges will be changed. In conclusion, the content of the present application should not be understood as a limitation of the present application.

Claims

1. A system for treating wastewater containing hexavalent chromium and recovering chromium resources, characterized in that: The application relates to a chromium-containing wastewater treatment device, which comprises the following parts: a flocculation and impurity removal mechanism (1) capable of introducing chromium-containing wastewater, lye and flocculants, wherein the chromium-containing wastewater, lye and flocculants are mixed in the flocculation and impurity removal mechanism (1) to precipitate impurity metal ions in the chromium-containing wastewater; a first pressure filtration part (2) in communication with the flocculation and impurity removal mechanism (1), wherein supernatant of the flocculation and impurity removal mechanism (1) can be introduced into the first pressure filtration part (2) to be subjected to pressure filtration; an acidification mechanism (3) in communication with the flocculation and impurity removal mechanism (1) and the first pressure filtration part (2), wherein the supernatant of the flocculation and impurity removal mechanism (1) and the supernatant of the first pressure filtration part (2) can be introduced into the acidification mechanism (3), and the acidification mechanism (3) can be introduced with acid to adjust the pH of the supernatant; an ion exchange mechanism (4) in communication with the acidification mechanism (3), wherein the acidified supernatant can be introduced into the ion exchange mechanism (4), the ion exchange mechanism (4) can adsorb hexavalent chromium ions in the supernatant, and the ion exchange mechanism (4) can be introduced with alkali to elute the adsorbed hexavalent chromium ions to regenerate chromium concentrate; and a crystallization mechanism (5) in communication with the ion exchange mechanism (4), wherein the chromium concentrate can be introduced into the crystallization mechanism (5), the crystallization mechanism (5) can be introduced with chromic acid to acidify the chromium concentrate, and the acidified chromium concentrate solution can be concentrated and dried to obtain bichromate.

2. The system for treating wastewater containing hexavalent chromium and recovering chromium resources according to claim 1, characterized in that: The flocculation and impurity removal mechanism (1) comprises an impurity removal tank (11) and a first flocculation and sedimentation tank (12) in sequence, the impurity removal tank (11) is used for introducing chromium-containing wastewater and lye, the mixed solution in the impurity removal tank (11) is introduced into the first flocculation and sedimentation tank (12), the first flocculation and sedimentation tank (12) is introduced with flocculants, the first flocculation and sedimentation tank (12) is in communication with the first pressure filtration part (2) and the acidification mechanism (3), and the supernatant in the first flocculation and sedimentation tank (12) can be introduced into the acidification mechanism (3) and the first pressure filtration part (2) respectively.

3. The system for treating wastewater containing hexavalent chromium and recovering chromium resources according to claim 1, characterized in that: The acidification mechanism (3) comprises a supernatant adjusting tank (31) in communication with the flocculation and impurity removal mechanism (1) and the first pressure filtration part (2) and used for introducing supernatant, and the supernatant adjusting tank (31) is introduced with acid; and the supernatant adjusting tank (31) is also in communication with the ion exchange mechanism (4).

4. The system for treating wastewater containing hexavalent chromium and recovering chromium resources according to claim 1, characterized in that: The ion exchange mechanism (4) comprises an ion exchange column (41) in communication with the acidification mechanism (3) and used for introducing acidified supernatant, the ion exchange column (41) is used for adsorbing hexavalent chromium ions in the supernatant, and the ion exchange column (41) can be introduced with alkali to elute the adsorbed hexavalent chromium ions to regenerate chromium concentrate; and the ion exchange column (41) is also in communication with the crystallization mechanism (5).

5. The system for treating wastewater containing hexavalent chromium and recovering chromium resources according to claim 1, characterized in that: The crystallization mechanism (5) comprises a neutralization tank (51), a concentration device (52) and a drying device (53) connected in sequence, the neutralization tank (51) is communicated with the ion exchange mechanism (4) and used for passing the chromium concentration liquid, and the chromium acid is also passed into the neutralization tank (51) to acidify the chromium concentration liquid, the concentration device (52) is used for concentrating the acidified chromium concentration liquid and passing into the drying device (53) to obtain the dichromate by drying.

6. The system for treating wastewater containing hexavalent chromium and recovering chromium resources according to claim 1, characterized in that: The post-exchange liquid adjusting mechanism (6) is also included and communicated with the ion exchange mechanism (4), the post-exchange liquid of the ion exchange mechanism (4) is used for passing into the post-exchange liquid adjusting mechanism (6), the post-exchange liquid adjusting mechanism (6) is used for reducing the hexavalent chromium in the post-exchange liquid, and the post-exchange liquid after reduction can be flocculated and settled.

7. The system for treating wastewater containing hexavalent chromium and recovering chromium resources according to claim 6, characterized in that: The post-exchange liquid adjusting mechanism (6) comprises a post-exchange liquid adjusting tank (61) and a second flocculation and sedimentation tank (62) communicated, the post-exchange liquid adjusting tank (61) is communicated with the ion exchange mechanism (4) and used for passing the post-exchange liquid and the reducing agent, the post-exchange liquid after reduction in the post-exchange liquid adjusting tank (61) can pass into the second flocculation and sedimentation tank (62), and the flocculating agent can be passed into the post-exchange liquid in the second flocculation and sedimentation tank (62) to be flocculated and settled.

8. The system for treating wastewater containing hexavalent chromium and recovering chromium resources according to claim 7, characterized in that: The second pressure filtration part (7) is also included and communicated with the second flocculation and sedimentation tank (62), and the supernatant of the second flocculation and sedimentation tank (62) can pass into the second pressure filtration part (7) to be pressure filtered.

9. The system for treating wastewater containing hexavalent chromium and recovering chromium resources according to claim 8, characterized in that: The supernatant of the second flocculation and sedimentation tank (62) and the supernatant in the second pressure filtration part (7) can be communicated with an external treatment system.

10. The system for treating wastewater containing hexavalent chromium and recovering chromium resources according to claim 7, characterized in that: The defluorination tank (63) is also communicated between the post-exchange liquid adjusting tank (61) and the second flocculation and sedimentation tank (62), and the defluorination agent can be passed into the post-exchange liquid in the defluorination tank (63).

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