CN-121974438-A - Resin regeneration treatment line and resin regeneration treatment method for chromium-containing wastewater

CN121974438ACN 121974438 ACN121974438 ACN 121974438ACN-121974438-A

Abstract

The resin regeneration treatment line comprises an ion exchange system, an alkaline washing system, a water washing system and an acid washing system, wherein the ion exchange system is provided with an ion exchange column, the ion exchange column is filled with ion exchange resin, a column bottom water distributor and a column bottom aerator are arranged below the ion exchange column, the column bottom water distributor is provided with a porous distribution plate, compressed gas is introduced into the column bottom aerator, an alkaline liquid storage tank is communicated with the column bottom water distributor through an alkaline washing pipe and is used for outputting alkaline liquid to the column bottom water distributor, the alkaline liquid is output into the ion exchange column through the porous distribution plate, an alkaline liquid output pump is arranged in the column bottom water distributor, the water washing system is communicated with the ion exchange column and is used for outputting cleaning water to the ion exchange column, and the acid washing system is communicated with the ion exchange column and is used for outputting acid liquid to the ion exchange column. The scheme solves the problems that the resin structure of the ion exchange column containing chromium wastewater is easy to be damaged after regeneration for a plurality of times, and the activity is reduced due to residues on the surface of the resin.

Inventors

FU WEIXIA
WANG FENG
GU XIANGHUA
LIU HUAHUA
LI LE

Assignees

广东广美环保科技有限公司

Dates

Publication Date: 20260505
Application Date: 20260227

Claims (10)

1. The resin regeneration treatment line for the chromium-containing wastewater is characterized by comprising an ion exchange system, an alkaline washing system, a water washing system and an acid washing system; The ion exchange system is provided with an ion exchange column, wherein ion exchange resin is filled in the ion exchange column, a column bottom water distributor and a column bottom aerator are arranged below the ion exchange column, the column bottom water distributor is provided with a porous distribution plate, and the column bottom aerator is provided with a micropore aerator pipe for introducing compressed gas; The alkaline washing system comprises an alkaline liquid storage tank, an alkaline washing pipe and an alkaline liquid output pump; The alkali liquor storage tank is communicated with the column bottom water distributor through the alkali washing pipe and is used for outputting alkali liquor to the column bottom water distributor, and the alkali liquor is output into the ion exchange column through the porous distribution plate; The washing system is communicated with the ion exchange column and used for outputting washing water to the ion exchange column, and the pickling system is communicated with the ion exchange column and used for outputting acid liquor to the ion exchange column.
2. The resin regeneration line for chromium-containing wastewater according to claim 1, wherein the ion exchange system further comprises a differential pressure sensor and a bubble control valve; The detection end of the pressure difference sensing device is positioned in the ion exchange column and is close to the ion exchange resin, the pressure difference sensing device is in communication connection with the bubble control valve, and the bubble control valve is arranged on the micropore aerator pipe.
3. The resin regeneration line for chromium-containing wastewater according to claim 1, wherein the ion exchange resin is a type D201 styrene-based basic anion exchange resin.
4. The resin regeneration treatment line for chromium-containing wastewater according to claim 2, wherein the porous distribution plate is provided with a plurality of diffusion holes distributed in an array.
5. The resin regeneration line for chromium-containing wastewater according to claim 1, wherein the ion exchange system comprises a series pipe, an internal valve and a plurality of the ion exchange columns; The ion exchange columns are connected in series, one output end of one ion exchange column is communicated with the input end of the other ion exchange column through the serial pipe, and the serial pipe is provided with the internal valve.
6. The resin regeneration line for chromium-containing wastewater according to claim 5, wherein the ion exchange system further comprises an external connecting pipe, an external valve, an adsorption monitoring device and a head column valve; the ion exchange column is provided with at least two input ends, one input end is used for connecting the serial pipes, the other input end is provided with a head column valve, the column bottom water distributor is communicated with the alkaline washing pipe through the outer connecting pipe, the outer valve is arranged on the outer connecting pipe, the ion exchange column is provided with the adsorption monitoring device, and the adsorption monitoring device is connected with the inner valve and the outer valve in a communication mode.
7. A resin regeneration line for chromium-containing wastewater according to any one of claims 1 to 6, wherein the pickling system comprises a concentrated sulfuric acid solution storage tank and a sulfuric acid dilution tank; The output end of the concentrated sulfuric acid liquid storage tank is communicated with the sulfuric acid dilution tank and is used for outputting concentrated sulfuric acid to the sulfuric acid dilution tank; one output end of the water washing system is communicated with the ion exchange column, the other output end of the water washing system is communicated with the sulfuric acid diluting tank and is used for outputting water to the sulfuric acid diluting tank so as to dilute concentrated sulfuric acid into dilute sulfuric acid; and water ports for communicating the water washing system are respectively arranged at the upper end and the lower end of the ion exchange column.
8. A resin regeneration treatment method of chromium-containing wastewater using the resin regeneration treatment line of chromium-containing wastewater according to any one of claims 1 to 7, characterized by comprising the steps of: S1, when the concentration of Cr ions in an ion exchange column rises to a preset threshold value, an alkaline washing system is connected to an ion exchange system; S2, turning on an alkali liquor output pump, outputting alkali liquor to the ion exchange column through an alkali washing pipe by an alkali liquor storage tank, outputting the alkali liquor below the ion exchange column through a column bottom water distributor, and passing through ion exchange resin from bottom to top; s3, opening an aerator at the bottom of the column, outputting compressed gas to the ion exchange column through a microporous aerator pipe, and forming bubbles in alkali liquor by the compressed gas through the microporous aerator pipe; S4, the washing system is connected to the ion exchange system, and the washing system outputs washing water to the ion exchange column to remove alkali liquor in the ion exchange column; S5, the acid washing system is connected to the exchange system, the acid washing system outputs acid liquor to the ion exchange column until the pH value of the liquid in the ion exchange column is stable and weak alkaline, and the acid washing system is disconnected.
9. The method for regenerating a resin for wastewater containing chromium according to claim 8, wherein in the step S1, a plurality of ion exchange columns are connected in series, an adsorption monitoring device is installed on the ion exchange columns, the adsorption monitoring device monitors the chromium concentration outputted from the ion exchange columns, when the detection value arranged on the first ion exchange column continuously exceeds 3mg/L, it is judged that the ion exchange column has reached an adsorption end point, the ion exchange column at the adsorption end point is isolated from an ion exchange system, and S2-S4 is executed, the next ion exchange column of the ion exchange column at the adsorption end point opens a head column valve, and the wastewater containing chromium is continuously introduced into the ion exchange column.
10. The method for regenerating a resin for treating chromium-containing wastewater according to claim 8, further comprising step S6; In the step S4, the cleaning water passes through the ion exchange resin from bottom to top, and after the pH of the ion exchange column is reduced to 7-9, the cleaning water passes through the ion exchange column from top to bottom, so that the pH of the ion exchange column is less than or equal to 8.5; In the step S5, the concentrated sulfuric acid is conveyed to a sulfuric acid dilution tank from a concentrated sulfuric acid liquid storage tank, the washing system outputs washing water to the sulfuric acid dilution tank, and dilute sulfuric acid solution is prepared in the sulfuric acid dilution tank; And S6, switching the water washing system into an ion exchange system, and sequentially carrying out slow washing and fast washing on the ion exchange column by using washing water.

Description

Resin regeneration treatment line and resin regeneration treatment method for chromium-containing wastewater Technical Field The invention relates to the field of chromium wastewater treatment, in particular to a resin regeneration treatment line and a resin regeneration treatment method for chromium-containing wastewater. Background The chromium-containing wastewater is used as typical high-toxicity and difficult-to-treat waste liquid in the industrial field and widely used in production links such as electroplating, tanning, pigment synthesis, stainless steel pickling, chemical catalysis and the like. In an electroplating workshop, chromic acid solution is largely used in the surface treatment process of metal parts, so that the concentration of hexavalent chromium (Cr (VI)) in the cleaning wastewater is often hundreds to thousands of mg/L, the pH value is generally lower than 3.0, and the solution is in a strong acid dark yellow liquid state and has strong oxidability and cell penetrating capacity. Cr (VI) can easily enter organisms through cell membranes in the form of chromic acid radical (CrO 4²-), and can generate active oxygen free radicals in the in-vivo reduction process to trigger DNA fragmentation and mutation, and is listed as a class I cancerogenic substance by the International agency for research on cancer (IARC), and the environmental hazard is far more than trivalent chromium (Cr (III)). Even if the low-concentration discharge is carried out, the water can be accumulated in water sediments for a long time, and ecological and human health are threatened after the water is enriched by a food chain. In the chromium wastewater treatment, structural damage and activity reduction of the ion exchange resin are easy to occur after repeated regeneration, and the core reasons are that hexavalent chromium (Cr (VI)) has strong oxidizing property and continuously erodes a resin high molecular framework and functional groups to cause irreversible chemical degradation, and meanwhile, high-valence metal ions such as trivalent chromium (Cr (III)) generated by reduction are firmly combined with the resin, are difficult to thoroughly elute and gradually accumulate during regeneration, so that precipitates such as chromium hydroxide are formed to block pore channels and cover active sites (namely resin poisoning). To remove residual chromium, the regeneration process often requires strengthening acid/base conditions, extending the duration of action, or increasing the frequency, further exacerbating oxidation, hydrolysis, and mechanical wear of the resin. The three components of oxidation damage, ion residue and regeneration stress are superposed, so that the embrittlement of the resin structure, the attenuation of the exchange capacity and the remarkable reduction of the treatment efficiency are finally caused, and the activity of the resin is reduced. Disclosure of Invention The invention aims at providing a resin regeneration treatment line of chromium-containing wastewater, wherein an alkali washing system outputs alkali liquor to an ion exchange column from bottom to top, and a column bottom aerator slowly releases fine bubbles synchronously, so that the bubbles can spirally rise between resin layers, thereby not only playing a role of macroscopic stirring, but also playing a role of stripping mechanical sediment on the surface of the resin. To achieve the purpose, the invention adopts the following technical scheme: a resin regeneration treatment line for chromium-containing wastewater comprises an ion exchange system, an alkaline washing system, a water washing system and an acid washing system; The ion exchange system is provided with an ion exchange column, wherein ion exchange resin is filled in the ion exchange column, a column bottom water distributor and a column bottom aerator are arranged below the ion exchange column, the column bottom water distributor is provided with a porous distribution plate, and the column bottom aerator is provided with a micropore aerator pipe for introducing compressed gas; The alkaline washing system comprises an alkaline liquid storage tank, an alkaline washing pipe and an alkaline liquid output pump; The alkali liquor storage tank is communicated with the column bottom water distributor through the alkali washing pipe and is used for outputting alkali liquor to the column bottom water distributor, and the alkali liquor is output into the ion exchange column through the porous distribution plate; The washing system is communicated with the ion exchange column and used for outputting washing water to the ion exchange column, and the pickling system is communicated with the ion exchange column and used for outputting acid liquor to the ion exchange column. Optimally, the ion exchange system further comprises a differential pressure sensing device and a bubble control valve; The detection end of the pressure difference sensing device is positioned in the ion exchange