CN112047560A

CN112047560A - High-concentration pharmaceutical wastewater treatment method

Info

Publication number: CN112047560A
Application number: CN202011046619.8A
Authority: CN
Inventors: 闫娟
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2020-12-08

Abstract

The invention discloses a method for treating high-concentration pharmaceutical wastewater, which comprises the following steps: step one, grid filtering; step two, acid precipitation and flocculation; step three, iron-carbon micro-electrolysis-electro-Fenton combined treatment; step four, enrichment and photocatalytic degradation; and step five, nanofiltration and electro-adsorption desalting. According to the invention, firstly, impurities and large suspended matters are removed through a grid, then sulfuric acid acidification is adopted to achieve a good effect on removal of COD, then iron-carbon micro-electrolysis-electro-Fenton combined treatment is adopted to achieve the effects of nitrogen and phosphorus removal and reduction of chroma and COD of wastewater, the enrichment and photocatalytic degradation sections can synchronously achieve enrichment and photocatalytic degradation of pollutants in a water body, then trace organic pollutants and part of inorganic salts remained in water are removed through filtration of a nanofiltration membrane filter, the water quality is improved, the treatment efficiency is greatly improved, and finally, an electro-adsorption system is adopted to desalt water, so that the effluent quality meets the pharmaceutical industry water pollutant discharge standard.

Description

High-concentration pharmaceutical wastewater treatment method

Technical Field

The invention relates to the technical field of environmental protection, in particular to a pharmaceutical wastewater treatment method.

Background

The pharmaceutical wastewater has complex components, various organic matters, large water quality fluctuation, COD and BOD₅Low ratio, deep chromaticity, high toxicity and high concentration of suspended solid, and the traditional physical and chemical and biochemical treatment method is difficult to reach the current discharge standard. Therefore, the method for treating the pharmaceutical wastewater, which is efficient, free of secondary pollution and flexible in process, is very important to find.

Disclosure of Invention

Aiming at the defects of the existing high-concentration pharmaceutical wastewater treatment method, the invention provides the high-concentration pharmaceutical wastewater treatment method which is simple in process, high in pollutant removal rate and free of secondary pollution.

The purpose of the invention is realized by the following technical scheme:

a method for treating high-concentration pharmaceutical wastewater comprises the following steps:

step one, grid filtration: the pharmaceutical wastewater is respectively treated by a coarse grid cleaner and a fine grid cleaner to remove larger impurities and suspended matters;

step two, acid precipitation-flocculation: introducing the pharmaceutical wastewater treated by the grating into an adjusting tank, adding sulfuric acid to adjust the pH to 2.5, stirring to uniformly mix, adding a flocculating agent into an emulsion when the emulsion appears in the solution, stirring, standing and separating; the flocculating agent is ferric chloride, and the adding amount is 2-4 kg/t;

step three, iron-carbon micro-electrolysis-electro-Fenton combined treatment: introducing the supernatant obtained in the step two into an iron-carbon micro-electrolysis reactor, reacting for 0.5-1 h, and then introducing the iron-carbon micro-electrolysis effluent into an electro-Fenton reaction tank for treating for 0.5-1 h; the iron-carbon micro-electrolysis reactor comprises an electrolysis reaction tank, an air compressor, an aeration head and a carbon fiber filler strip, wherein the carbon fiber filler strip is fixed through a fixed clamping groove on the wall of the reaction tank, and a plurality of carbon fiber filler strips are distributed in the reaction tank in a staggered manner; the electro-Fenton reaction tank is a two-electrode single-chamber reaction system, and the electrolyte solution is 0.05M of Na₂SO₄The method comprises the following steps of (1) preparing a solution, wherein a cathode material is a modified graphite felt, an anode material is a platinum sheet, and a direct-current power supply provides output in a constant-current mode;

step four, enrichment and photocatalytic degradation: the method comprises the following steps that effluent of an electro-Fenton reactor enters an adjusting tank, then enters a photocatalytic reactor from the adjusting tank, composite hydrogel microspheres are added, a mechanical stirring device is started, the composite hydrogel microspheres move in the reactor and adsorb pollutants, after complete adsorption, mechanical stirring is stopped, a dielectrophoresis device is started, electric fields are regulated and controlled by a waveform controller to enable the composite hydrogel microspheres to move directionally until the composite hydrogel microspheres are orderly arranged at the sunken parts of array electrodes on the wall of the right side of the photocatalytic reactor, then a light source is started, the pollutants adsorbed by the composite hydrogel microspheres are subjected to photocatalytic degradation, after the degradation is completed, the dielectrophoresis device is closed, mechanical stirring is started, the composite hydrogel microspheres are released into a water body, and the process can be repeated for multiple times according to the concentration of the pollutants; the photocatalytic reactor comprises a reactor main body, a mechanical stirring device, a dielectrophoresis device and visible light sources, wherein the visible light sources are distributed around the array electrodes; the dielectrophoresis device comprises an array electrode positioned on the right wall of the reactor, a counter electrode positioned on the left wall of the reactor and a waveform controller connected with the array electrode; the composite hydrogel microsphere consists of a porous structure matrix material capable of adsorbing pollutants and a visible light catalyst loaded on the surface of the matrix material;

step five, nanofiltration and electro-adsorption desalination: the outlet water of the photocatalytic reactor is directly used as the inlet water of a nanofiltration filter, the water quality is further improved, and finally, the electric adsorption system is used for desalting to detect the quality of the outlet water; the nanofiltration filter adopts doped SiO₂The PDA/PEI co-deposition nanofiltration membrane.

Furthermore, in the third step, the carbon fiber filler strip is prepared by bonding the end parts of two layers of long-strip-shaped carbon fiber non-woven fabrics, a cavity formed between the layers is divided into a plurality of small cavities, and iron-carbon alloy filler is filled in each small cavity.

Further, the preparation method of the modified graphite felt in the third step comprises the following steps: (1) cleaning the graphite felt, removing stains and grease on the graphite felt, and drying for later use; (2) adding ultrapure water and isopropanol into carbon nano tubes and polytetrafluoroethylene, performing ultrasonic treatment to uniformly disperse the mixture to obtain a mixed solution, immersing a graphite felt into the mixed solution, performing ultrasonic treatment, and coating the rest mixed solution on two sides of the graphite felt; (3) and (3) putting the graphite felt coated with the mixed solution into a muffle furnace, calcining for 1-2 h at 350-380 ℃, and cooling to obtain the modified graphite felt.

Further, the mass ratio of the carbon nano tubes to the polytetrafluoroethylene in the mixed solution is 1: 7.

Further, the porous structure matrix material of the composite hydrogel microspheres in the fourth step is one or more of sodium alginate, calcium alginate, graphene oxide, polyacrylamide, chitosan and sodium carboxymethylcellulose; the visible light catalyst loaded on the surface of the material is AgO, polypyrrole-TiO₂、Ag-TiO₂Monoclinic BiVO₄、AgPO/BiVO、ZnIn₂S₄One or more of (a).

Further, the doped SiO in step five₂The preparation method of the PDA/PEI codeposition nanofiltration membrane comprises the following steps: (1) mixing SiO₂Adding the nano particles into the prepared dopamine solution, fully stirring to enable dopamine to be oxidized, self-polymerized and modified to SiO₂The surface of the nanoparticle; (2) adding the prepared Polyethyleneimine (PEI) solution into the solution obtained in the step (1) to obtain a codeposition solution; (3) rapidly immersing the hydrolyzed polyacrylonitrile ultrafiltration membrane support base membrane into the codeposition solution prepared in the step (2) to obtain a composite membrane modified by the codeposition layer, and crosslinking by using a glutaraldehyde solution; (4) and (3) immersing the crosslinked composite membrane into a PEI solution again, so that the aldehyde group, catechol and other active groups on the surface of the composite membrane and PEI generate covalent reaction, and grafting the PEI onto the surface of the composite membrane to improve the electropositivity of the surface of the composite membrane.

The invention firstly removes impurities and large suspended matters in high-concentration pharmaceutical wastewater through a coarse grid and a fine grid, and then adopts sulfuric acid for acid precipitation to achieve good effect on removing COD, probably because the solubility of macromolecular organic matters in the wastewater is reduced under an acidic condition, after the ferric chloride flocculating agent is added, the precipitated macromolecular organic matters can be quickly adsorbed and settled because the ferric chloride also has good flocculation effect in an acidic environment, and sulfate radicals in sulfuric acid and certain metal ions in the pharmaceutical wastewater such as Ba can be mixed with the sulfuric acid radicals²⁺、Zn²⁺And solid precipitates are formed, so that floc substances can form larger flocs by taking the particles as centers more easily, the flocculation sedimentation rate is accelerated, and the separation time is shortened. In addition, the acidification can also reduce the viscosity of the wastewater, reduce the stirring resistance and improve the separation efficiency.

According to the iron-carbon micro-electrolysis reactor, the number and the distribution of the carbon fiber filler strips can be adjusted according to the concentration of pollutants in wastewater, the amount of iron-carbon alloy fillers in the carbon fiber filler strips can be adjusted, and a series of experiments show that the micro-electrolysis treatment effect of filling the iron-carbon alloy fillers in the carbon fiber filler strips is better than the effect of directly stacking the iron-carbon alloy fillers together. The reason for the presumption may be two: first, this packing pattern provides a very large specific surface area and uniform water and gas flow channels, providing greater current density and better catalytic reaction for wastewater treatment; secondly, after the iron-carbon alloy filler is filled into the carbon fiber cavity, the part of the alloy in direct contact with the carbon fiber forms a macro battery, which is equivalent to further strengthen the micro-electrolysis effect on the basis that iron in the iron-carbon alloy filler is corroded by a micro battery, so that the treatment effect is improved.

The invention combines the iron-carbon micro-electrolysis and the electro-Fenton, and can utilize Fe generated by the iron-carbon micro-electrolysis²⁺As a catalyst of an electro-Fenton system, Fe does not need to be added additionally²⁺The electrolyte solution and the cathode generate hydrogen peroxide in situ, the limitation of the Fenton technology is well overcome, and the generated hydrogen peroxide and Fe in the solution²⁺The catalyst reacts to generate strong oxidant hydroxyl free radical [ OH ]]And is of Fe²⁺Limited reduction at the cathode, hence Fe²⁺The catalyst function is assumed in the reaction.

The invention can obviously increase the yield of hydrogen peroxide by modifying the cathode material graphite felt, because the carbon nano tube loaded on the graphite felt has great influence on the cathode electro-catalytic activity, the capability of generating hydrogen peroxide in situ is greatly improved. The polytetrafluoroethylene is applied to modification of the graphite felt, acts as a binder in the modification process, is beneficial to the attachment of the carbon nano tubes on the surface of the graphite felt when the using amount of the polytetrafluoroethylene is increased, but increases the resistance of an electrode when the using amount of the polytetrafluoroethylene is excessive, and causes the current response to be reduced.

The photocatalytic reactor comprises a stirring device and a dielectrophoresis device, the composite hydrogel microspheres are dispersed by the stirring device, the aggregation and ordered arrangement of the composite hydrogel microspheres are realized by the dielectrophoresis device, firstly, the stirring is started, the composite hydrogel microspheres move and disperse in the reactor to adsorb pollutants in a water body, then, the stirring is closed, the dielectrophoresis is started, the composite hydrogel microspheres move directionally under the action of the dielectrophoresis and are finally and orderly arranged on the surface of an array electrode on the right side of the wall of the reactor, the enrichment of the pollutants in the water body is indirectly realized by the enrichment of the composite hydrogel microspheres, a visible light source surrounding the array electrode is started, as the surface of the composite hydrogel microspheres is loaded with a high-activity visible light catalyst, the adsorbed organic pollutants can be mineralized completely in a moment, compared with the existing mode of separately processing adsorption and photocatalysis, high treating efficiency and no secondary pollution.

The working process of the electric adsorption system comprises the following steps: after raw water enters the system, anions and cations move directionally under the drive of electric field force; meanwhile, the anion and cation exchange membrane sieves the ions and finally adsorbs the ions on the surface of the material to achieve the purpose of removing salt ions, namely the electro-adsorption process; and then, the discharge is realized by changing an external power supply, salt ions are separated from the adsorption material and are converged into the solution, and the generated concentrated water is discharged to a concentrated water tank for centralized treatment, namely, the desorption regeneration process. Compared with the problems of membrane pollution and periodic backwashing faced by reverse osmosis, the electric adsorption system is simple to operate and convenient to post-treat.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention firstly carries out coarse and fine grid treatment on the wastewater to remove impurities and large suspended matters, then adopts acid precipitation-flocculation to promote the precipitation of macromolecular organic matters through acid precipitation, sedimentation and water separation are carried out under the flocculation action of the flocculating agent, so that COD is obviously reduced, and meanwhile, the effluent is acidic, which provides convenience for the subsequent iron-carbon micro-electrolysis reaction, then adopting iron-carbon micro-electrolysis-electro-Fenton combined treatment, integrating the functions of oxidation, reduction, electrodeposition, flocculation, adsorption, bridging, coprecipitation and the like into a whole through micro-electrolysis reaction, having low treatment cost, being capable of greatly removing organic pollutants and heavy metals, playing the roles of removing nitrogen and phosphorus and reducing the chromaticity and COD of the wastewater, and combining with electro-Fenton, by modifying the graphite felt electrode material, the efficiency of hydrogen peroxide generated in situ by the cathode is greatly improved, and the hydrogen peroxide and Fe in the solution are greatly improved.²⁺The catalyst reacts to generate strong oxidant hydroxyl free radical [ OH ]]The method has the advantages that the refractory organic pollutants in the pharmaceutical wastewater are efficiently removed under the actions of anodic oxidation, electro-adsorption and the like, so that compared with the common Fenton treatment, the method saves the medicament cost and achieves higher treatment efficiency;

(2) the enrichment and photocatalytic degradation section of the invention adopts a photocatalytic reactor comprising a stirring device and a dielectrophoresis device, can synchronously realize the enrichment and photocatalytic degradation of pollutants in water, the process can be repeated for a plurality of times by the dispersion and ordered arrangement of composite hydrogel microspheres, the process has high process flexibility, is suitable for treating wastewater with different concentrations, a light source is started after enrichment, the photocatalyst loaded on the surface of the composite hydrogel microspheres has high visible light catalysis efficiency, the degradation of the pollutants adsorbed in the nearby water and the composite hydrogel can be instantly completed by directly utilizing visible light, then the process of repeating the composite hydrogel is released, after the final degradation is completed, the composite hydrogel microspheres are ordered and arranged at the sunken parts of the array electrodes, therefore, the composite hydrogel microspheres do not need to be separated from the water, the reactor can directly discharge water, the operation is simple, the photocatalytic degradation is combined with the interception effect of the nanofiltration filter in the next step to ensure the thorough removal of organic pollutants, greatly reduce the energy consumption and shorten the wastewater treatment time;

(3) the invention removes impurities, suspended matters, organic pollutants, heavy metals and colloid by pretreatment, reduces the load of the subsequent working section, and the Fe generated in the iron-carbon micro-electrolysis treatment process by the iron-carbon micro-electrolysis-electro-Fenton combined treatment²⁺Directly used as an electro-Fenton catalyst, reduces the treatment cost, shortens the treatment time, can thoroughly remove organic pollutants, thoroughly mineralizes refractory organic matters in the wastewater through photocatalytic treatment, and then dopes SiO₂The PDA/PEI codeposition nanofiltration membrane filter removes residual trace organic pollutants and partial inorganic salts in water by filtration, improves the water quality, greatly improves the treatment efficiency, and finally adopts an electric adsorption system for desalination; the invention has compact process, high flexibility and high operation efficiency, and the effluent quality meets the discharge standard of pharmaceutical industry water pollutants.

Drawings

FIG. 1 is a schematic diagram of an iron-carbon micro-electrolysis reactor, wherein 1 is an air compressor, 2 is a water inlet pipe, 3 is a water pump, 4 is a valve, 5 is a flow meter, 6 is an electrolysis reaction tank, 7 is a carbon fiber packing belt, 8 is a water outlet pipe, 9 is an aeration head, and 10 is a sewage discharge pipe.

Fig. 2 is a schematic view of a structural band of carbon fiber packing.

FIG. 3 is a schematic diagram of a photocatalytic reactor, in which 11-a wave shaper, 12-array electrodes, 13-a visible light source, 14-a water outlet, 15-a water inlet, 16-a counter electrode, and 17-a stirring device.

Detailed Description

To further illustrate the technical means and effects of the present invention, the following detailed description is given with reference to the accompanying drawings and specific embodiments.

The following examples and comparative examples all treated high concentration pharmaceutical wastewater collected from pharmaceutical factories, and the wastewater quality inspection method was performed according to the CJ/T51-2004, national standard industry code. The process inflow water quality detection result is as follows: pH 3.2, COD42340mg/L, BOD₅14720mg/L, SS 566mg/L, color 62 times, NH₄ ⁺-N745 mg/L, TOC 15463mg/L, salt content 6580 mg/L.

Example 1

step one, grid filtration: respectively treating the high-concentration pharmaceutical wastewater by a coarse grid dirt removing machine and a fine grid dirt removing machine to remove larger impurities and suspended matters;

step two, acid precipitation-flocculation: introducing the pharmaceutical wastewater treated by the grating into an adjusting tank, adding sulfuric acid to adjust the pH to 2.5, stirring to uniformly mix, adding a flocculating agent into an emulsion when the emulsion appears in the solution, stirring, standing and separating; the flocculating agent is ferric chloride, and the adding amount is 3 kg/t;

step three, iron-carbon micro-electrolysis-electro-Fenton combined treatment: introducing the supernatant obtained in the step two into an iron-carbon micro-electrolysis reactor (shown in figure 1) for reaction for 0.8h, and then introducing the iron-carbon micro-electrolysis effluent into an electro-Fenton reaction tank for treatment for 0.5 h; the iron-carbon micro-electrolysis reactor comprises an electrolysis reaction tank (6 in figure 1), an air compressor (1 in figure 1), an aeration head (9 in figure 1) and a carbon fiber filler strip (7 in figure 1), wherein the carbon fiber filler strip is fixed through a fixed clamping groove on the wall of the reaction tank, and the 9 carbon fiber filler strips are distributed in the reaction tank in a staggered manner, as shown in figure 1; the carbon fiber filler strip is prepared by bonding the end parts of two layers of long-strip-shaped carbon fiber non-woven fabrics, a cavity formed between the layers is divided into 4 small cavities, and iron-carbon alloy filler (Longantai, model LAT-TLC03) is filled in each small cavity, as shown in figure 2; the electric heaterThe Duton reaction tank is a two-electrode single-chamber reaction system, and the electrolyte solution is 0.05M of Na₂SO₄The method comprises the following steps of (1) preparing a solution, wherein a cathode material is a modified graphite felt, an anode material is a platinum sheet, and a direct-current power supply provides output in a constant-current mode;

step four, enrichment and photocatalytic degradation: the effluent of the electro-Fenton reactor firstly enters an adjusting tank, then enters a photocatalytic reactor (shown in figure 3) from the adjusting tank, and graphene oxide/Ag-TiO is added according to 0.5g/L₂Starting a mechanical stirring device (17 in figure 3), enabling the composite hydrogel microspheres to move in a reactor and adsorb pollutants, completely adsorbing for 3min, closing the mechanical stirring device and starting a dielectrophoresis device, regulating and controlling an electric field by a wave form controller (11 in figure 3) to enable the composite hydrogel microspheres to directionally move until the composite hydrogel microspheres are orderly arranged at the concave positions of array electrodes (12 in figure 3) on the wall of the right side of a photocatalytic reactor, then starting a visible light source (13 in figure 3), and enabling the pollutants adsorbed by the composite hydrogel microspheres to be Ag-TiO loaded on the surfaces of the pollutants₂Degrading under the action of a photocatalyst, completely mineralizing, turning off a dielectrophoresis device after 1min of degradation is finished, simultaneously turning on mechanical stirring, releasing composite hydrogel microspheres into a water body, completely adsorbing for 3min, turning off a stirring device, turning on the dielectrophoresis device, re-enriching the composite hydrogel microspheres on the surface of an array electrode, turning on a light source, and waiting for 1min of degradation finished, wherein the composite hydrogel is orderly arranged at the sunken parts of the array electrode, and the dielectrophoresis direction is kept unchanged at the moment, so that the composite hydrogel can be seen not to be influenced by the flow of the water body, and the composite hydrogel can be discharged without a water body separation reactor; the photocatalytic reactor comprises a reactor main body, a mechanical stirring device, a dielectrophoresis device and visible light sources, wherein the visible light sources are distributed around the array electrodes; the dielectrophoresis device comprises an array electrode positioned on the right wall of the reactor, a counter electrode positioned on the left wall of the reactor and a waveform controller connected with the array electrode;

Example 1 COD treatment effect at different stages is shown in Table 1 below:

TABLE 1 COD treatment effect (unit: mg/L) of example 1 at different stages

Example 1 the final effluent test results are shown in table 2:

table 2 example 1 water inlet and outlet test results and removal rate

Test item	Inflow water	Discharging water	Removal rate
				pH	3.2	6.8	--
COD(mg/L)	42340	19	99.9％
				BOD₅(mg/L)	14720	10	99.9％
SS(mg/L)	566	11	98.1％
				Color intensity	62	0	100％
NH₄ ⁺-N(mg/L)	745	14	98.1％
				TOC(mg/L)	15463	22	99.9％
Salinity (%)	6580	204	96.9％

Comparative example 1

The procedure is as in example 1 except that the iron-carbon alloy filler in the iron-carbon micro-electrolysis reactor in the second step is directly deposited.

Comparative example 2

Except that the cavity formed between the carbon fiber filler material belt layers in the iron-carbon micro-electrolysis reactor in the second step is not divided, namely, the iron-carbon alloy filler is directly filled into the whole cavity formed by the two layers of carbon fibers, the rest is the same as the embodiment 1.

Comparative example 3

The procedure is as in example 1 except that the photocatalytic reactor in step four does not include a dielectrophoresis device, the walls of the reactor are all provided with visible light sources, the treatment is carried out for the same time (8min), and the composite hydrogel microspheres are removed by a filtration method.

Comparative example 4

The same procedure as in example 1 was repeated, except that the photocatalytic reactor in step four did not contain a stirring device, and that the composite hydrogel microspheres were dispersed by reverse dielectrophoresis for the same treatment time (8 min).

The COD treatment effects of the different sections of comparative examples 1-4 are shown in the following Table 3:

TABLE 3 COD treatment effect (unit: mg/L) of comparative examples 1 to 4 at different stages

Comparative example 5

The same procedure as in example 1 was repeated, except that the nanofiltration filter was not included in the fifth step.

Comparative example 6

The procedure of example 1 was followed except that the reverse osmosis system was used for desalting in the fifth step.

The final effluent quality detection results of the comparative examples 1 to 6 are shown in the following table 4:

TABLE 4 detection results of final effluent quality in comparative examples 1-6

As can be seen from table 4, the final effluent quality indexes of comparative example 1 and comparative example 2 are not as good as those of example 1, and the COD treatment effects at different working sections in table 3 are presumed to be that under the condition that the iron-carbon microelectrolysis treatment time is the same, the direct accumulation treatment effect of the iron-carbon filler is poorer than that of the carbon fiber filler belt, so that the load of the subsequent process is greatly increased, and the overall treatment effect is poorer than that of example 1, in comparative example 2, although the iron-carbon filler is filled into the carbon fiber filler belt, the water-air flow channel is not smooth enough due to no segmentation, so that the treatment effect is poorer than that of example 1; the effluent result of the comparative example 3 shows that the COD removal effect is much worse than that of the example 1, and the combination of COD treatment effects of different sections in the table 3 shows that dielectrophoresis is very important in the aspects of pollutant enrichment and photocatalytic degradation efficiency improvement, and simultaneously shows that the enrichment and photocatalytic degradation processes play a key role in removing organic pollutants; the COD removal effect of the treatment result of the comparative example 4 is greatly different from that of the example 1, and the combination of the COD treatment effects of different sections in the table 3 shows that the mechanical stirring also plays an important role in the aspects of pollutant enrichment and photocatalytic degradation efficiency improvement; comparative example 5 does not contain the nanofiltration filter, and the indexes of the effluent quality are slightly reduced compared with those of example 1, which shows that the nanofiltration filter has the effect of comprehensively improving the water quality; comparative example 6 adopts a reverse osmosis desalination system, and the desalination effect and the heavy metal removal effect are slightly reduced compared with example 1.

The above description is only for the specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and other modifications or equivalent substitutions made by the technical solution of the present invention by the ordinary skilled in the art should be covered within the scope of the claims of the present invention without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. The method for treating the high-concentration pharmaceutical wastewater is characterized by comprising the following steps of:

2. The method for treating high-concentration pharmaceutical wastewater according to claim 1, wherein in step three, the carbon fiber filler strip is prepared by bonding the ends of two layers of long carbon fiber non-woven fabrics, the cavity formed between the layers is divided into a plurality of small cavities, and each small cavity is filled with iron-carbon alloy filler.

3. The method for treating high-concentration pharmaceutical wastewater according to claim 1, wherein the preparation method of the modified graphite felt in the third step comprises the following steps: (1) cleaning the graphite felt, removing stains and grease on the graphite felt, and drying for later use; (2) adding ultrapure water and isopropanol into carbon nano tubes and polytetrafluoroethylene, performing ultrasonic treatment to uniformly disperse the mixture to obtain a mixed solution, immersing a graphite felt into the mixed solution, performing ultrasonic treatment, and coating the rest mixed solution on two sides of the graphite felt; (3) and (3) putting the graphite felt coated with the mixed solution into a muffle furnace, calcining for 1-2 h at 350-380 ℃, and cooling to obtain the modified graphite felt.

4. The method for treating high-concentration pharmaceutical wastewater according to claim 3, wherein the mass ratio of the carbon nanotubes to the polytetrafluoroethylene in the mixed solution is 1: 7.

5. The method for treating high-concentration pharmaceutical wastewater according to claim 1, wherein the porous matrix material of the composite hydrogel microspheres in step four is one or more of sodium alginate, calcium alginate, graphene oxide, polyacrylamide, chitosan and sodium carboxymethylcellulose; the visible light catalyst loaded on the surface of the material is AgO, polypyrrole-TiO₂、Ag-TiO₂Monoclinic BiVO₄、AgPO/BiVO、ZnIn₂S₄One or more of them.

6. The method for treating high concentration pharmaceutical wastewater according to claim 1, wherein the doped SiO in step five₂The preparation method of the PDA/PEI codeposition nanofiltration membrane comprises the following steps: (1) mixing SiO₂Adding the nano particles into the prepared dopamine solution, fully stirring to enable dopamine to be oxidized, self-polymerized and modified to SiO₂The surface of the nanoparticle; (2) adding the prepared Polyethyleneimine (PEI) solution into the solution obtained in the step (1) to obtain a codeposition solution; (3) rapidly immersing the hydrolyzed polyacrylonitrile ultrafiltration membrane support base membrane into the codeposition solution prepared in the step (2) to obtain a composite membrane modified by the codeposition layer, and crosslinking by using a glutaraldehyde solution; (4) immersing the crosslinked composite membrane into a PEI solution again to ensure that aldehyde groups, catechol and other active groups on the surface of the composite membrane and PEI generate covalent reaction, and grafting the PEI onto the surface of the composite membrane to improve the positive electricity of the surface of the composite membraneAnd (4) sex.