Chromium removal device for cold rolling wastewater

Abstract

The utility model provides a chromium removal device for cold rolling wastewater, which comprises at least two ion exchange tanks filled with acidic cation exchange resin, the at least two ion exchange tanks are connected in series, and / or the at least two ion exchange tanks are connected in parallel; one end of the liquid inlet assembly is used for being communicated with a raw water pool, and the other end of the liquid inlet assembly is used for being communicated with an ion exchange tank; and the ion concentration measuring instrument is arranged on the liquid inlet assembly. According to the utility model, the ion exchange tanks can be selected to be connected in series or in parallel according to the chromium ion concentration, so that the cold rolling wastewater is effectively and efficiently treated, the amount of treatable wastewater is large, resin in the ion exchange tanks can be regenerated only by using acid, the maintenance cost is low, the process steps are simple, and the regenerated waste acid can be recycled.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment technology, in particular to a chromium removal device for cold rolling wastewater. Background Art

[0002] With the rapid development of global industrialization, heavy metal water pollution poses a serious threat to human health and the environment. Chromium-containing wastewater is widely present in the fields of electroplating and metallurgical production, which not only causes resource loss, but also causes serious environmental pollution. Chromium-containing industrial wastewater discharged into the environment will cause serious harm to organisms in the water body and even cause them to become extinct. It will also spread through the food chain and cause human diseases. Therefore, the discharge of chromium-containing wastewater must be strictly controlled.

[0003] Currently, there are two main methods for treating chromium-containing wastewater, one is chemical precipitation and the other is ion exchange.

[0004] The chemical precipitation method is to add reagents to the wastewater to convert the dissolved trivalent chromium into water-insoluble compound precipitation, such as chromium hydroxide precipitation, and then separate it from the water to achieve the purpose of removing heavy metals. However, the chemical precipitation method has the disadvantages of complex operation, long reaction time, and difficulty in wastewater treatment.

[0005] The ion exchange method uses ion exchangers to exchange and separate harmful substances in wastewater. Commonly used ion exchangers include humic acid substances, zeolites, ion exchange resins, ion exchange fibers, etc. The ion exchange method is widely used in the field of water treatment. Ion exchange can completely remove inorganic salts in water. The operation of ion exchange includes four steps: exchange, backwashing, regeneration, and cleaning. The ion exchange method has good treatment effect and simple operation. It does not require complex equipment and technology. Ion exchangers such as ion exchange resins can be used repeatedly. After exchanging a certain amount of chromium ions, ion exchange resins will gradually lose the adsorption and exchange capacity of chromium ions. Only the resin needs to be regenerated, and the ion exchange resin can continue to be used. However, the maintenance cost of ion exchangers is high. Sometimes the regeneration of ion exchange resins requires both acid and alkali, and the consumption of regeneration agents is large. Utility Model Content

[0006] The utility model aims to provide a chromium removal device for cold rolling wastewater, which can select the series or parallel connection of ion exchange tanks according to the chromium ion concentration, so as to effectively and efficiently treat the cold rolling wastewater, and can treat a large amount of wastewater. Only acid is needed to regenerate the resin in the ion exchange tank, and the maintenance cost is low and the process steps are simple.

[0007] In order to achieve the above object, the utility model provides a chromium removal device for cold rolling wastewater, which comprises:

[0008] At least two ion exchange tanks, each of which is filled with an acidic cation exchange resin, wherein at least two of the ion exchange tanks are connected in series, and / or at least two of the ion exchange tanks are connected in parallel;

[0009] A liquid inlet assembly, one end of which is used to communicate with the raw water tank, and the other end of which is used to communicate with the ion exchange tank;

[0010] An ion concentration measuring instrument is arranged on the liquid inlet component.

[0011] Optionally, the chromium removal device includes an acid supply component, which includes an acid storage tank and an acid supply pipe, one end of the acid supply pipe is connected to the acid storage tank, and the other end of the acid supply pipe is used to connect to the ion exchange tank.

[0012] Optionally, the acid supply component includes an acid discharge pipe, and the ion exchange tank is connected to the acid discharge pipe.

[0013] Optionally, the liquid inlet component includes a raw water pump and a raw water pipeline, the raw water pump is arranged on the raw water pipeline, one end of the raw water pipeline is used to connect to the raw water pool, and the other end of the raw water pipeline is used to connect to the ion exchange tank.

[0014] Optionally, the raw water pipeline includes a water supply main pipe and multiple water supply branches corresponding to the ion exchange tanks one by one, one end of the water supply main pipe is used to connect to the raw water pool, and the other end of the water supply main pipe is connected to multiple water supply branches, and the water supply branches are connected to the corresponding ion exchange tanks. Each of the water supply branches is provided with a water inlet valve, and the raw water pump is arranged on the water supply main pipe.

[0015] Optionally, a flow meter is provided on the liquid inlet assembly, and when a reading of the flow meter is greater than a threshold value, at least two of the ion exchange tanks are connected in parallel.

[0016] Optionally, the ion concentration measuring instrument is used to measure the chromium ion concentration of the raw water pool. When the chromium ion concentration is greater than a first preset value, at least two of the ion exchange tanks are connected in series; when the chromium ion concentration is less than or equal to a second preset value, at least two of the ion exchange tanks are connected in parallel.

[0017] Optionally, a series water outlet pipe is connected between at least two ion exchange tanks, and a series water outlet valve is provided on the series water outlet pipe.

[0018] Optionally, the chromium removal device includes a water outlet component, and the water outlet component is connected to the bottom of the ion exchange tank.

[0019] Optionally, the chromium removal device includes a filtering component, which is used to filter the wastewater and discharge it into the raw water pool.

[0020] As configured above, the utility model sets at least two of the ion exchange tanks in series, and / or at least two of the ion exchange tanks in parallel, and sets an ion concentration measuring instrument. The series or parallel connection of the ion exchange tanks can be selected according to the chromium ion concentration measured by the ion concentration measuring instrument. When the chromium ion concentration is high, at least two of the ion exchange tanks can be selected in series, and when the chromium ion concentration is low, at least two of the ion exchange tanks can be selected in parallel. It can be understood that when the chromium ion concentration is high, after the wastewater is treated by an ion exchange tank, there may be a lot of chromium ions in the wastewater that have not been removed. Therefore, the wastewater flows into another ion exchange tank for treatment again, so as to remove the remaining chromium ions in the wastewater as much as possible. This is at least two ion exchange tanks in series; when the chromium ion concentration is low, the chromium ion content in the wastewater after being treated by an ion exchange tank is already small enough and meets the emission standards. At this time, at least two ion exchange tanks can be selected in parallel, that is, at least two ion exchange tanks are simultaneously treated with wastewater, or, a part of the ion exchange tanks in the parallel ion exchange tanks are treated with wastewater, and another part of the ion exchange tanks are regenerated with resin. Moreover, the ion exchange tank of the utility model is filled with acidic cation exchange resin, which can be regenerated by using only acid, reducing the amount of regeneration agent, simplifying the process steps, and reducing maintenance costs. The waste acid after regeneration can be recycled, further reducing the cost of wastewater treatment.

[0021] In summary, the utility model can select the series or parallel connection of ion exchange tanks according to the chromium ion concentration, so as to effectively and efficiently treat cold rolling wastewater, and can treat a large amount of wastewater. Only acid is needed to regenerate the resin in the ion exchange tank, with low maintenance cost and simple process steps. The regenerated waste acid can be recycled, further reducing the cost of wastewater treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Those skilled in the art should understand that the drawings provided are for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0023] Figure 1 This is a schematic diagram of a chromium removal device for cold rolling wastewater according to an embodiment of the utility model;

[0024] Figure 2 This is a working flow chart of a chromium removal device for cold rolling wastewater according to an embodiment of the utility model.

[0025] The reference numerals are as follows:

[0026] 1- ion exchange tank; 21- raw water pump; 22- raw water pipeline; 221- main water supply pipe; 222- branch water supply pipe; 223- water inlet valve; 23- flow meter; 24- ion concentration measuring instrument; 3- raw water tank; 41- acid storage tank; 42- acid supply pipe; 43- acid discharge pipe; 5- series outlet pipe; 51- series outlet valve; 61- main drainage pipe; 62- branch drainage pipe; 63- drainage valve. DETAILED DESCRIPTION

[0027] In this document, unless otherwise specified, the terms "upper", "lower", "left", "right", "inside", "outside", "front", "back", "top", "bottom", etc. are used to indicate directions or positional relationships based on the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction and operation. Therefore, they cannot be understood as limiting the present invention.

[0028] The following will describe the specific implementation of the utility model in more detail with reference to the schematic diagram. The advantages and features of the utility model will become clearer according to the following description. It should be noted that the drawings are all in a very simplified form and are not in exact proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model.

[0029] The preferred embodiments of the present utility model are given below in conjunction with the accompanying drawings and described in detail.

[0030] Figure 1 This is a schematic diagram of a chromium removal device for cold rolling wastewater according to an embodiment of the utility model. Figure 2 This is a working flow diagram of a chromium removal device for cold rolling wastewater according to an embodiment of the utility model. Figure 1 and Figure 2 If there are two ion exchange tanks, please refer to Figure 1 and Figure 2 The embodiment of the utility model provides a chromium removal device for cold rolling wastewater, which includes at least two ion exchange tanks 1, a liquid inlet component and an ion concentration measuring instrument 24.

[0031] The ion exchange tank 1 is filled with an acidic cation exchange resin. As an example, the acidic cation exchange resin used in the present embodiment is a sulfonic acid functional group gel-type ion exchange resin, which is also a high-grade strong acid type nuclear-grade ion exchange resin, and has excellent oxidation resistance and efficient operating performance, and can make the effluent water quality meet the discharge standard. The resin is in a wet spherical shape, contains a nuclear-grade sulfonic acid functional group, and has excellent physical and chemical properties, is particularly suitable for water treatment, and is suitable for working under a wide range of pH ranges and high temperature conditions. Due to the use of this sulfonic acid functional group gel-type ion exchange resin, it is only necessary to use acid to regenerate this sulfonic acid functional group gel-type ion exchange resin, such as using hydrochloric acid, which simplifies the process steps and has low maintenance costs.

[0032] At least two ion exchange tanks 1 are connected in series, and / or at least two ion exchange tanks 1 are connected in parallel. It can be understood that the series connection can remove the chromium ions in the wastewater more cleanly, and the parallel connection can improve the efficiency of wastewater treatment.

[0033] One end of the liquid inlet assembly is used to connect to the raw water pool 3, and the other end of the liquid inlet assembly is used to connect to the ion exchange tank 1, so as to transport the wastewater in the raw water pool 3 to the ion exchange tank 1. The present embodiment does not limit the structure of the liquid inlet assembly. As an example, the liquid inlet assembly includes a raw water pump 21 and a raw water pipeline 22. The raw water pump 21 is arranged on the raw water pipeline 22. One end of the raw water pipeline 22 is used to connect to the raw water pool 3, and the other end of the raw water pipeline 22 is used to connect to the ion exchange tank 1. Further, the raw water pipeline 22 includes a water supply main pipe 221 and a plurality of water supply branch pipes 222 corresponding to the ion exchange tank 1. One end of the water supply main pipe 221 is used to connect to the raw water pool 3, and the other end of the water supply main pipe 221 is connected to a plurality of water supply branch pipes 222. The water supply branch pipes are connected to the corresponding ion exchange tank 1. Each water supply branch pipe 222 is provided with a water inlet valve 223. The raw water pump 21 is arranged on the water supply main pipe 221.

[0034] The ion concentration measuring instrument 24 is arranged on the liquid inlet component, for example, the ion concentration measuring instrument 24 can be arranged on the water supply main pipe 221. It can be understood that the chromium ion concentration in the water supply main pipe 221 is the same as the chromium ion concentration in the raw water pool 3, so the ion concentration measuring instrument 24 also measures the chromium ion concentration of the raw water pool 3. When the chromium ion concentration is greater than the first preset value, at least two ion exchange tanks 1 are connected in series, and when the chromium ion concentration is less than or equal to the second preset value, at least two ion exchange tanks 1 are connected in parallel. In other embodiments, a flow meter 23 is provided on the water supply main pipe 221, and when the reading of the flow meter 23 is greater than a threshold value, at least two ion exchange tanks 1 are connected in parallel. It can be understood that when the number of ion exchange tanks 1 is at least three, the utility model can have both ion exchange tanks 1 connected in series and ion exchange tanks 1 connected in parallel, and the specific connection relationship between the ion exchange tanks 1 can be determined according to actual conditions. When the chromium ion concentration is between the first preset value and the second preset value, the series and parallel connection of the ion exchange tanks 1 depends on the actual situation, and the reading of the flow meter 23 can also be combined to comprehensively determine how many ion exchange tanks 1 are connected in series and how many ion exchange tanks 1 are connected in parallel.

[0035] Furthermore, a series water outlet pipe 5 is connected between at least two ion exchange tanks 1, and a series water outlet valve 51 is provided on the series water outlet pipe 5 to realize the series connection of the corresponding two ion exchange tanks 1. If the corresponding two ion exchange tanks 1 need to be connected in series, the series water outlet valve 51 is opened after the ion exchange tank 1 at the upstream end has finished treating the wastewater, so that the wastewater can flow from the ion exchange tank 1 at the upstream end into the ion exchange tank 1 at the downstream end for further treatment.

[0036] It can be understood that by controlling the opening and closing of the above-mentioned water inlet valves 223 and the series water outlet valves 51, the series or parallel connection between the ion exchange tanks 1 can be switched freely. It can be manually controlled or automatically controlled by PLC program control. The use of PLC program can improve the degree of automation of the equipment and make the operation easier.

[0037] The chromium removal device includes a water outlet assembly, which is connected to the bottom of the ion exchange tank 1. The water outlet assembly includes a drainage main pipe 61 and a drainage branch pipe 62 corresponding to the ion exchange tank 1. The drainage branch pipe 62 is connected to the bottom of the corresponding ion exchange tank 1. Each drainage branch pipe 62 is provided with a drainage valve 63. It can be understood that the wastewater needs to stay in the ion exchange tank 1 for a period of time so that the functional groups on the ion exchange resin can react with the chromium ions in the wastewater. After a certain period of treatment, the functional groups on the ion exchange resin will adsorb the chromium ions and remove the chromium ions in the wastewater. Therefore, the corresponding drainage valve 63 needs to be closed for a period of time. The water outlet assembly also includes a metering pump, which is used to add alkali (such as sodium hydroxide) to the wastewater output from the ion exchange tank to adjust the pH value. After the pH value is adjusted to neutral, the wastewater can be discharged.

[0038] Generally speaking, the chromium removal device also includes a filtering component, which is used to filter the wastewater and discharge it into the raw water pool 3.

[0039] As is well known, after exchanging a certain amount of chromium ions, the ion exchange resin will gradually lose the adsorption and exchange capacity of chromium ions. At this time, the resin needs to be regenerated so that the ion exchange resin can continue to be used. Therefore, the chromium removal device also includes an acid supply component, which includes an acid storage tank 41 and an acid supply pipe 42. One end of the acid supply pipe is connected to the acid storage tank 41, and the other end of the acid supply pipe 42 is used to connect to the ion exchange tank 1. Specifically, the acid storage tank 41 is filled with acid liquid such as hydrochloric acid, and the acid supply pipe 42 is used to pass the hydrochloric acid in the acid storage tank 41 into the ion exchange tank 1 to regenerate the ion exchange resin. The acid supply component also includes an acid discharge pipe 43, and each ion exchange tank 1 is connected to an acid discharge pipe 43. It can be understood that after the ion exchange resin in the ion exchange tank 1 is regenerated, the waste acid is discharged from the ion exchange tank 1 through the acid discharge pipe 43. Furthermore, the waste acid can be recycled. For example, after the waste acid is discharged from the ion exchange tank 1, the waste acid can be added to the wastewater pretreatment process (the pretreatment process before the device of the utility model) to help reduce the hexavalent chromium in the wastewater in the pretreatment process to trivalent chromium, and then some chromium ions are precipitated. The wastewater after the pretreatment process still contains chromium ions, and the chromium ion content does not meet the emission standards, and the wastewater needs to continue to be treated.

[0040] As configured above, the utility model sets at least two ion exchange tanks 1 in series, and / or at least two ion exchange tanks 1 in parallel, and sets an ion concentration measuring instrument 24. The series or parallel connection of the ion exchange tanks 1 can be selected according to the chromium ion concentration measured by the ion concentration measuring instrument 24. When the chromium ion concentration is high, at least two ion exchange tanks 1 can be selected in series, and when the chromium ion concentration is low, at least two ion exchange tanks 1 can be selected in parallel. It can be understood that when the chromium ion concentration is high, after the wastewater is treated by an ion exchange tank 1, there may be a lot of chromium ions in the wastewater that have not been removed. Therefore, the wastewater flows into another ion exchange tank 1 again for treatment, so as to remove the remaining chromium ions in the wastewater as much as possible. This is at least two ion exchange tanks 1 in series; when the chromium ion concentration is low, the chromium ion content in the wastewater after being treated by an ion exchange tank 1 is already small enough and meets the emission standards. At this time, at least two ion exchange tanks 1 can be selected in parallel, that is, at least two ion exchange tanks 1 are simultaneously treated with wastewater, or, a part of the ion exchange tanks 1 in the parallel ion exchange tanks 1 are treated with wastewater, and another part of the ion exchange tanks 1 are regenerated with resin. Moreover, the ion exchange tank 1 of the utility model is filled with acidic cation exchange resin, which can be regenerated by using only acid, thereby reducing the amount of regeneration agent, simplifying the process steps, and reducing maintenance costs.

[0041] For example, two groups of wastewater samples were taken. The trivalent chromium ion concentration of the first group of wastewater samples was reduced from 0.622 mg / L to 0.032 mg / L after being treated by the device of the utility model. The trivalent chromium ion concentration of the second group of wastewater samples was reduced from 0.516 mg / L to 0.030 mg / L after being treated by the device of the utility model, both of which met the requirements of the "Water Pollutant Emission Standard for Iron and Steel Industry".

[0042] In summary, the utility model can select the series or parallel connection of the ion exchange tank 1 according to the chromium ion concentration, so as to effectively and efficiently treat the cold rolling wastewater, the amount of wastewater that can be treated is large, and only acid is needed to regenerate the resin in the ion exchange tank, the maintenance cost is low, the process steps are simple, and the regenerated waste acid can be recycled, which further reduces the cost of wastewater treatment. The resin exchange capacity of the utility model is large, the regeneration cycle is long, and it is generally regenerated once every 1 to 2 weeks. The utility model effectively solves the problem of chromium ion pollution in cold rolling wastewater with low-cost green water treatment technology, has significant advantages in treating chromium-containing wastewater, can effectively reduce the emission of chromium pollutants, and can also treat wastewater into a reusable water source, thereby realizing resource conservation and environmental protection. Therefore, the utility model has both economic and environmental protection effects, and has good social and environmental benefits. The utility model fully reflects the effect of energy saving and emission reduction, and is an environmentally friendly green production process.

[0043] It should be noted that references to "one embodiment", "an embodiment", "a specific embodiment", "some embodiments", etc. in the specification only indicate that the described embodiment may include a particular feature, structure or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure or characteristic is described in conjunction with an embodiment, whether or not explicitly described, it is within the knowledge of a person skilled in the relevant art to implement such feature, structure or characteristic in conjunction with other embodiments.

[0044] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0045] It should also be noted that, although the present invention has been disclosed as a preferred embodiment, the above embodiment is not intended to limit the present invention. For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the above disclosed technical content can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

[0046] It should also be understood that, unless otherwise specified or indicated, the terms "first", "second", "third", etc. in the specification are merely used to distinguish between the various components, elements, steps, etc. in the specification, and are not used to indicate the logical relationship or sequential relationship between the various components, elements, steps, etc.

[0047] It should also be recognized that the terms described herein are only used to describe specific embodiments and are not used to limit the scope of the utility model. It must be noted that the singular forms "one" and "a kind" used herein and in the appended claims include plural references unless the context clearly indicates the opposite meaning. For example, a reference to "a step" or "a device" means a reference to one or more steps or devices, and may include secondary steps and secondary devices. All conjunctions used should be understood in the broadest sense. And, the word "or" should be understood to have a logical "or" definition, rather than a logical "exclusive or" definition, unless the context clearly indicates the opposite meaning. In addition, the implementation of the method and / or device in the embodiment of the utility model may include performing the selected task manually, automatically, or in combination.

Claims

1. A chromium removal device for cold rolling wastewater, characterized in that: include: At least two ion exchange tanks, each of which is filled with an acidic cation exchange resin, wherein at least two of the ion exchange tanks are connected in series, and / or at least two of the ion exchange tanks are connected in parallel; A liquid inlet assembly, one end of which is used to communicate with the raw water tank, and the other end of which is used to communicate with the ion exchange tank; An ion concentration measuring instrument is arranged on the liquid inlet component.

2. The chromium removal device for cold rolling wastewater according to claim 1, characterized in that: The chromium removal device comprises an acid supply component, which comprises an acid storage tank and an acid supply pipe, one end of the acid supply pipe is connected to the acid storage tank, and the other end of the acid supply pipe is used to connect to the ion exchange tank.

3. The chromium removal device for cold rolling wastewater according to claim 2, characterized in that: The acid supply component comprises an acid discharge pipe, and the ion exchange tank is connected to the acid discharge pipe.

4. The chromium removal device for cold rolling wastewater according to claim 1, characterized in that: The liquid inlet assembly comprises a raw water pump and a raw water pipeline. The raw water pump is arranged on the raw water pipeline. One end of the raw water pipeline is used to connect to the raw water pool, and the other end of the raw water pipeline is used to connect to the ion exchange tank.

5. The chromium removal device for cold rolling wastewater according to claim 4, characterized in that: The raw water pipeline includes a water supply main pipe and multiple water supply branches corresponding to the ion exchange tanks one by one. One end of the water supply main pipe is used to connect to the raw water pool, and the other end of the water supply main pipe is connected to multiple water supply branches. The water supply branches are connected to the corresponding ion exchange tanks. Each of the water supply branches is provided with a water inlet valve, and the raw water pump is arranged on the water supply main pipe.

6. The chromium removal device for cold rolling wastewater according to claim 1, characterized in that: A flow meter is provided on the liquid inlet assembly. When the reading of the flow meter is greater than a threshold value, at least two ion exchange tanks are connected in parallel.

7. The chromium removal device for cold rolling wastewater according to claim 1, characterized in that: The ion concentration measuring instrument is used to measure the chromium ion concentration of the raw water pool. When the chromium ion concentration is greater than a first preset value, at least two of the ion exchange tanks are connected in series. When the chromium ion concentration is less than or equal to a second preset value, at least two of the ion exchange tanks are connected in parallel.

8. The chromium removal device for cold rolling wastewater according to claim 1, characterized in that: A series water outlet pipe is connected between at least two ion exchange tanks, and a series water outlet valve is arranged on the series water outlet pipe.

9. The chromium removal device for cold rolling wastewater according to claim 1, characterized in that: The chromium removal device comprises a water outlet component, and the water outlet component is communicated with the bottom of the ion exchange tank.

10. The chromium removal device for cold rolling wastewater according to claim 1, characterized in that: The chromium removal device comprises a filtering component, and the filtering component is used for filtering the wastewater and discharging the wastewater into the raw water pool.

Images