Arsenic-containing regenerated catalyst wastewater treatment system

Abstract

The utility model discloses an arsenic-containing regenerated catalyst wastewater treatment system, which relates to the technical field of wastewater treatment and comprises a filter, a reverse osmosis device, a reaction tank and a curing reactor. The waste liquid after regeneration of the denitration catalyst is subjected to solid-liquid separation through a filter, then high-salinity waste water generated by reverse osmosis concentration treatment is subjected to high-temperature oxidation reaction in a reaction tank, and curing treatment is carried out by utilizing the adsorption effect of scorodite on arsenic. According to the utility model, a large amount of highly toxic wastewater is converted into recyclable industrial water after being subjected to reverse osmosis treatment, and toxic substances are cured, so that the toxic substances are prevented from being discharged, and the operability is strong.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a system for treating wastewater containing arsenic-containing regenerated catalyst. Background Art

[0002] Denitration catalyst is the core of the selective catalytic reduction (SCR) technology. Since the denitration transformation in 2011, a large number of denitration catalysts have entered the deactivated state. After 2020, it will stabilize at 210,000-240,000m 3 / year, so the treatment of waste catalysts is an urgent problem to be solved. As early as 2010, the Ministry of Environmental Protection began to encourage the regeneration of failed denitration catalysts. During the regeneration of failed catalysts, a large amount of waste liquid containing toxic metals is inevitable. Among them, the more common denitration catalysts are poisoned by alkali metals and arsenic poisoning. The regenerated waste liquid will contain low concentrations of arsenic, which will cause great harm to the environment if not handled in time. Since the deactivated catalyst contains less arsenic, the current chemical method for arsenic removal is aimed at removing a large amount of arsenic, and the treatment facilities are complicated. Therefore, it is urgent to develop an economical and efficient method for treating low-concentration arsenic-containing waste liquid. Utility Model Content

[0003] In order to solve the problem of treating low-concentration arsenic-containing wastewater after regeneration of denitrification catalysts caused by alkali metal poisoning and arsenic poisoning, the utility model proposes a system for treating arsenic-containing regenerated catalyst wastewater. The above purpose can be achieved through the implementation of the following technical solutions:

[0004] A system for treating wastewater containing arsenic-containing regenerated catalyst, comprising:

[0005] A reverse osmosis treatment device is used to perform reverse osmosis treatment on arsenic-containing regenerated catalyst wastewater to obtain high-salt wastewater and low-salt water;

[0006] A reaction tank, the reaction tank is connected to the reverse osmosis treatment device, and the reaction tank is used to react the high-salt wastewater with ferric chloride and hydrochloric acid to obtain oxidized wastewater;

[0007] The solidification reactor is connected to the reaction tank and is provided with a heating device; the solidification reactor is used to precipitate the arsenic in the oxidized wastewater.

[0008] Optionally, the system further includes:

[0009] The filter is connected to the reverse osmosis treatment device and is used to filter the arsenic-containing regenerated catalyst wastewater. The filtered arsenic-containing regenerated catalyst wastewater is sent to the reverse osmosis treatment device.

[0010] Optionally, the low-salt water is returned to the catalyst regeneration process through a circulating water pipeline.

[0011] Optionally, the reaction pool is provided with a reaction pool heating device, which can heat the reaction pool and facilitate the oxidation reaction.

[0012] Optionally, a ferric chloride dosing pipeline is provided on the reaction tank.

[0013] Optionally, a pH regulating pipe is provided on the reaction tank, and the pH in the reaction tank can be regulated by adding hydrochloric acid through the pH regulating pipe.

[0014] Optionally, scorodite is placed inside the solidification reactor.

[0015] Optionally, the filter inlet is connected to the outlet of the regeneration waste liquid pipeline, and the filter outlet is connected to the inlet of the reverse osmosis treatment device through a filtered water pipeline; the high-salt wastewater outlet of the reverse osmosis treatment device is connected to a high-salt wastewater pipeline, and the low-salt water outlet of the reverse osmosis treatment device is connected to a circulating water pipeline; the outlet of the high-salt wastewater pipeline is connected to the reaction tank, and the outlet of the reaction tank is connected to the inlet of the solidification reactor through an oxidation wastewater pipeline.

[0016] Optionally, the regeneration waste liquid pipeline, filtered water pipeline, high-salt waste water pipeline, ferric chloride dosing pipeline, oxidation waste water pipeline, circulating water pipeline, and regulating pipeline are all made of polytetrafluoroethylene pipelines.

[0017] The technical solution of the utility model has the following advantages:

[0018] The utility model is suitable for a low-concentration arsenic-containing regeneration catalyst wastewater treatment system. Alkali metal poisoning and arsenic poisoning denitrification catalysts are usually regenerated by acid washing. The wastewater generated after regeneration is acidic, which can effectively save the amount of hydrochloric acid added, which is conducive to the occurrence of ferric chloride oxidation of trivalent arsenic reaction and reduce costs. In addition, the sodium and potassium ions in the waste liquid after regeneration do not need special treatment, and can be concentrated and solidified and precipitated. This system converts a large amount of highly toxic wastewater into industrial water that can be recycled after reverse osmosis treatment, and solidifies toxic substances to prevent the discharge of toxic substances, and has strong operability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a system schematic diagram of the utility model.

[0021] In the figure: filter 1, reverse osmosis 2, reaction tank 3, solidification reactor 4, regeneration waste liquid pipeline 5, filtered water pipeline 6, high-salt waste water pipeline 7, ferric chloride dosing pipeline 8, oxidation waste water pipeline 9, circulating water pipeline 10, pH adjustment pipeline 11. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and through examples. The following examples are provided to explain the present invention, but the present invention is not limited to the following examples.

[0023] Example 1

[0024] The system of this embodiment refers to Figure 1 , including a filter 1, a reverse osmosis treatment device 2, a reaction tank 3, a solidification reactor 4, a regeneration waste liquid pipeline 5, a filtered water pipeline 6, a high-salt waste water pipeline 7, a ferric chloride dosing pipeline 8, an oxidation waste water pipeline 9, a circulating water pipeline 10, and a pH adjustment pipeline 11.

[0025] The inlet of the filter 1 is connected to the outlet of the regeneration waste liquid pipeline 5, and the filtered waste water flows into the inlet of the reverse osmosis treatment device 2 through the filtered water pipeline. The reverse osmosis treatment device 2 is provided with two outlets respectively connected to the inlet of the circulating water pipeline 10 and the inlet of the high-salt waste water pipeline 7. The reaction tank 3 is provided with three inlets respectively connected to the outlet of the high-salt waste water pipeline 7, the outlet of the ferric chloride dosing pipeline 8, and the pH adjustment pipeline 11. The outlet of the reaction tank 3 is connected to the inlet of the oxidation waste water pipeline 9, and the outlet of the oxidation waste water pipeline 9 is connected to the inlet of the solidification reactor 4.

[0026] The filter 1 separates the solid waste contained in the waste liquid after the regeneration of the denitration catalyst, and the liquid enters the next stage of treatment;

[0027] The reverse osmosis treatment device 2 separates the solute and the solvent in the filtered water, and the separated high-salt wastewater enters the next stage of treatment through the high-salt wastewater pipeline 7, and the low-salt water can be used as pure water to return to the catalyst regeneration process through the circulating water pipeline 10 for recycling;

[0028] The reaction pool 3 is provided with a ferric chloride dosing pipeline 8 and a pH adjustment pipeline 11. A reaction pool heating device is provided inside the reaction pool 3 to oxidize all trivalent arsenic compounds contained in the high-salt wastewater into pentavalent arsenic compounds; the pH in the reaction pool can be adjusted by adding hydrochloric acid through the pH adjustment pipeline.

[0029] The solidification reactor 4 is provided with a heating device, and scorodite is placed inside the solidification reactor 4. The precipitate formed after the arsenic and iron ions are combined will be adsorbed and combined on the scorodite, which is conducive to the cleaning of the solidified precipitate;

[0030] Furthermore, since the wastewater after catalyst regeneration is often acidic, the regeneration waste liquid pipeline 5, the filtered water pipeline 6, the high-salt waste water pipeline 7, the ferric chloride dosing pipeline 8, the oxidation waste water pipeline 9, the circulating water pipeline 10, and the pH adjustment pipeline 11 should be made of polytetrafluoroethylene material to prevent corrosion;

[0031] The specific operation of the system is as follows: the waste liquid after the regeneration of the denitrification catalyst flows into the filter 1 through the regeneration wastewater pipeline 5, the solid-liquid separation is carried out in the regenerated wastewater, the waste liquid flows into the reverse osmosis 2 inlet through the filtered water pipeline, and the solute and solvent are separated. The high-salt wastewater flows into the reaction tank 3 through the high-salt wastewater pipeline 7 at the outlet of the reverse osmosis treatment device 2, and the low-salt water enters the circulating water pipeline and can be used as water for other processes. The ferric chloride dosing pipeline 8 adds ferric chloride to the reaction tank 3 to oxidize the trivalent arsenic in the high-salt wastewater, and hydrochloric acid is added through the pH adjustment pipeline. The oxidized high-salt wastewater flows into the solidification reactor 4 through the oxidation wastewater pipeline 9. The solidification reactor 4 is provided with a heating device, and scorodite is placed inside. The scorodite solidifies the arsenic precipitation adsorption, which is beneficial to the cleaning of the solidified precipitation.

[0032] Example 2

[0033] 1000 mg / L of arsenic-containing regenerated catalyst wastewater was fed into the system in Example 1. Ferric chloride was added to the reaction tank of the obtained high-salt arsenic-containing wastewater, and the amount of ferric chloride added was 3 g / L. Hydrochloric acid was added to adjust the pH between 1 and 4. The setting and temperature of the solidification reactor was 80-100°C, and the arsenic content in the wastewater after the reaction was less than 0.3 mg / L.

[0034] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention of the utility model.

Claims

1. A system for treating arsenic-containing regenerated catalyst wastewater, characterized in that: include A reverse osmosis treatment device is used to perform reverse osmosis treatment on arsenic-containing regenerated catalyst wastewater to obtain high-salt wastewater and low-salt water; A reaction tank, the reaction tank is connected to the reverse osmosis treatment device, and the reaction tank is used to react the high-salt wastewater with ferric chloride and hydrochloric acid to obtain oxidized wastewater; The solidification reactor is connected to the reaction tank and is provided with a heating device; the solidification reactor is used to precipitate the arsenic in the oxidized wastewater.

2. The arsenic-containing regenerated catalyst wastewater treatment system according to claim 1, characterized in that: The system further comprises: The filter is connected to the reverse osmosis treatment device and is used to filter the arsenic-containing regenerated catalyst wastewater. The filtered arsenic-containing regenerated catalyst wastewater is sent to the reverse osmosis treatment device.

3. The arsenic-containing regenerated catalyst wastewater treatment system according to claim 1, characterized in that: The low-salt water is returned to the catalyst regeneration process through a circulating water pipeline.

4. The arsenic-containing regenerated catalyst wastewater treatment system according to claim 1, characterized in that: The reaction pool is provided with a reaction pool heating device.

5. The arsenic-containing regenerated catalyst wastewater treatment system according to claim 1, characterized in that: The reaction tank is provided with a ferric chloride dosing pipeline.

6. The arsenic-containing regenerated catalyst wastewater treatment system according to claim 1, characterized in that: The reaction tank is provided with a pH regulating pipeline.

7. The arsenic-containing regenerated catalyst wastewater treatment system according to claim 1, characterized in that: Scorodite is placed inside the solidification reactor.

8. The arsenic-containing regenerated catalyst wastewater treatment system according to claim 2, characterized in that: The filter inlet is connected to the outlet of the regeneration waste liquid pipeline, and the filter outlet is connected to the inlet of the reverse osmosis treatment device through a filtered water pipeline; the high-salt wastewater outlet of the reverse osmosis treatment device is connected to a high-salt wastewater pipeline, and the low-salt water outlet of the reverse osmosis treatment device is connected to a circulating water pipeline; the outlet of the high-salt wastewater pipeline is connected to a reaction tank, and the outlet of the reaction tank is connected to the inlet of a solidification reactor through an oxidation wastewater pipeline.

9. The arsenic-containing regenerated catalyst wastewater treatment system according to claim 8, characterized in that: The regeneration waste liquid pipeline, the filtered water pipeline, the high-salt waste water pipeline, the ferric chloride dosing pipeline, the oxidation waste water pipeline, the circulating water pipeline, and the pH adjustment pipeline are all made of polytetrafluoroethylene pipelines.

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