CN115367843A - Sulfuric acid/perchloric acid co-doped polypyrrole modified anode and application thereof in electric flocculation treatment of electroplating wastewater - Google Patents

Sulfuric acid/perchloric acid co-doped polypyrrole modified anode and application thereof in electric flocculation treatment of electroplating wastewater Download PDF

Info

Publication number
CN115367843A
CN115367843A CN202211166389.8A CN202211166389A CN115367843A CN 115367843 A CN115367843 A CN 115367843A CN 202211166389 A CN202211166389 A CN 202211166389A CN 115367843 A CN115367843 A CN 115367843A
Authority
CN
China
Prior art keywords
sulfuric acid
perchloric acid
anode plate
ppy
electrolyte
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202211166389.8A
Other languages
Chinese (zh)
Inventor
张松
范明霞
袁道伟
范加胜
于杰
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Wuxi Xilian Water Conservancy Technology Co ltd
Original Assignee
Wuxi Xilian Water Conservancy Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Wuxi Xilian Water Conservancy Technology Co ltd filed Critical Wuxi Xilian Water Conservancy Technology Co ltd
Priority to CN202211166389.8A priority Critical patent/CN115367843A/en
Publication of CN115367843A publication Critical patent/CN115367843A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C02F1/46104—Devices therefor; Their operating or servicing
    • C02F1/46109—Electrodes
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C02F1/463—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrocoagulation
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C02F1/46104—Devices therefor; Their operating or servicing
    • C02F1/46109—Electrodes
    • C02F2001/46133—Electrodes characterised by the material
    • C02F2001/46138—Electrodes comprising a substrate and a coating
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/20—Heavy metals or heavy metal compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/16—Nature of the water, waste water, sewage or sludge to be treated from metallurgical processes, i.e. from the production, refining or treatment of metals, e.g. galvanic wastes
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2201/00—Apparatus for treatment of water, waste water or sewage
    • C02F2201/46—Apparatus for electrochemical processes
    • C02F2201/461—Electrolysis apparatus
    • C02F2201/46105—Details relating to the electrolytic devices
    • C02F2201/4612—Controlling or monitoring
    • C02F2201/46125—Electrical variables
    • C02F2201/46135—Voltage
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2201/00—Apparatus for treatment of water, waste water or sewage
    • C02F2201/46—Apparatus for electrochemical processes
    • C02F2201/461—Electrolysis apparatus
    • C02F2201/46105—Details relating to the electrolytic devices
    • C02F2201/4612—Controlling or monitoring
    • C02F2201/46125—Electrical variables
    • C02F2201/4614—Current
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2201/00—Apparatus for treatment of water, waste water or sewage
    • C02F2201/46—Apparatus for electrochemical processes
    • C02F2201/461—Electrolysis apparatus
    • C02F2201/46105—Details relating to the electrolytic devices
    • C02F2201/4616—Power supply
    • C02F2201/4617—DC only
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2303/00—Specific treatment goals
    • C02F2303/08—Corrosion inhibition
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2303/00—Specific treatment goals
    • C02F2303/14—Maintenance of water treatment installations

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Organic Chemistry (AREA)
  • Water Treatment By Electricity Or Magnetism (AREA)

Abstract

The invention discloses a sulfuric acid/perchloric acid codoped polypyrrole modified anode and application thereof in electrolytic flocculation treatment of electroplating wastewater, and belongs to the field of wastewater treatment. The method for preparing the sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate comprises the following steps: (1) Dispersing pyrrole, sulfuric acid and perchloric acid in water, and uniformly mixing to form electrolyte; (2) Placing the anode plate in electrolyte, and carrying out electropolymerization at an oxidation potential of 0.9-1V; and after the completion of the washing, drying to obtain the sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate. The sulfuric acid/perchloric acid co-doped polyaniline modified anode plate has high removal rate of nickel and copper in electroplating wastewater, and the removal rate of nickel reaches over 66 percent and can reach 82.24 percent; the copper removal rate reaches more than 97 percent, can reach 99.99 percent, and the corrosion inhibition efficiency is about 35 percent.

Description

Sulfuric acid/perchloric acid co-doped polypyrrole modified anode and application thereof in electric flocculation treatment of electroplating wastewater
Technical Field
The invention relates to a sulfuric acid/perchloric acid codoped polypyrrole modified anode and application thereof in electrolytic flocculation treatment of electroplating wastewater, belonging to the field of wastewater treatment.
Background
Due to the high toxicity, teratogenicity and biological accumulation of heavy metals, the efficient removal of heavy metals from various industrial waste waters of metal electroplating and smelting processes and the like is of great interest. Particularly, copper, nickel, etc. existing in the nickel-copper alloy electroplating wastewater in an ionic or chelated form may be accumulated and concentrated, resulting in serious deterioration of water resources and public health, and proper treatment is not performed.
To date, there have been many reports of physical and chemical methods for removing heavy metals from electroplating wastewater, such as: chemical precipitation, electroflocculation, adsorption, membrane filtration, and biological methods. However, the chemical precipitation method cannot be used for removing a large amount of metals in a complicated state, further treatment is required, and the treatment process is complicated; the adsorbent used in the biological and adsorption method occupies a large space and is difficult to regenerate. Compared with the traditional treatment method, the electric flocculation can provide a practical alternative method for the treatment of the electroplating wastewater. In the electroflocculation process, the anode metal plate loses electrons and is oxidized into metal cations, then hydrolysis reaction occurs, and the hydrolyzed ions finally undergo a series of complex reactions to generate various hydroxyl complexes, such as Fe (OH) 2 、Fe(OH) 3 These hydrolyzed hydroxides can remove metal contaminants which are difficult to treat from wastewater by adsorption-bridge formation, precipitation-net capture, and the like.
At present, the removal rate of heavy metals such as nickel, copper and the like by adopting electric flocculation can stably reach more than 80%, but the problems of low metal utilization rate and high cost caused by corrosion of an electrode plate are to be solved. In the electric flocculation treatment, an iron plate or an aluminum plate is usually adopted as a sacrificial anode, but the iron plate or the aluminum plate has poor corrosion resistance, and can be corroded in a short time after the electric flocculation reaction is started, so that a thick passivation layer is generated on the surface of the anode, and the release speed of metal ions and the electric flocculation reaction efficiency are reduced. Therefore, the modification of the electrocoagulation anode plate is realized, the corrosion resistance is improved to reduce unnecessary loss, the utilization efficiency of anode metal is improved, the stable metal removal rate is obtained, and the cost is reduced, so that the method becomes a direction worthy of research.
Disclosure of Invention
[ problem ] to
The anode plate in the electrocoagulation treatment process is seriously corroded, the metal utilization rate is low, and the cost is high.
[ solution ]
In order to solve the problems, the method firstly prepares the sulfuric acid/perchloric acid codoped polypyrrole modified anode plate, and then is used for treating nickel-copper alloy electroplating wastewater in the electric flocculation, so that irreversible corrosion in the electric flocculation operation process is inhibited, the anode replacement frequency is reduced, and the cost is reduced.
In addition, the conductive polypyrrole, the sulfuric acid and the perchloric acid are polymerized on the surface of the anode plate in a co-doping manner in an electrochemical deposition manner, so that a certain corrosion inhibition effect is exerted on the anode plate under the condition that the conductivity of the plate is not influenced and the stable heavy metal treatment efficiency is obtained, and no relevant electrocoagulation research reports that the sulfuric acid/perchloric acid co-doped polypyrrole coating is used on the anode to inhibit the electrode corrosion.
The first purpose of the invention is to provide a method for preparing a sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate, which comprises the following steps:
(1) Preparing an electrolyte:
dispersing pyrrole, sulfuric acid and perchloric acid in water, and uniformly mixing to form electrolyte;
(2) Electropolymerization:
placing the anode plate in electrolyte, and carrying out electropolymerization at an oxidation potential of 0.9-1V; and after the completion of the washing, drying to obtain the sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate.
In one embodiment of the present invention, the electrolyte in step (1) has a pyrrole concentration of 0.05 to 0.15M, a sulfuric acid concentration of 0.5 to 1.5M, and a perchloric acid concentration of 0.5 to 1.5M; more preferably: the pyrrole concentration was 0.1M, the sulfuric acid concentration was 1M, and the perchloric acid concentration was 1M.
In one embodiment of the present invention, the purity of the sulfuric acid in step (1) is 96-98%; the purity of perchloric acid is 70-72%; the purity of pyrrole is 96-98%; sulfuric acid, perchloric acid, and pyrrole are all commercially available.
In one embodiment of the present invention, the electrolyte in step (2) is purged with nitrogen for 10 to 30 minutes before electropolymerization.
In one embodiment of the present invention, the electropolymerization in step (2) is carried out at an oxidation potential of 0.95V.
In one embodiment of the present invention, the electropolymerization time in step (2) is related to the area of the anode plate, such as: electropolymerizing 1 × 1 × 0.1cm anode plate for 1000 s.
In one embodiment of the present invention, the temperature of the electropolymerization in step (2) is 20 to 30 ℃ (room temperature).
In one embodiment of the present invention, in the electropolymerization in step (2), the anode plate is used as a working electrode, the platinum sheet electrode is used as a counter electrode, and the saturated silver/silver chloride electrode is used as a reference electrode, and the constant potential polymerization is performed in an electrolyte.
In one embodiment of the present invention, the anode plate in step (2) comprises a stainless steel plate.
In one embodiment of the invention, the anode plate in the step (2) needs to be pretreated before electropolymerization, and the pretreatment is to soak the anode plate in 1mol/L hydrochloric acid solution for 20min after being polished by 500-mesh sand paper to remove oxides on the surface of the electrode; soaking in standard ethanol solution for degreasing; finally, washing the mixture with water and then putting the mixture into an oven for drying.
The second purpose of the invention is to obtain the sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate prepared by the method.
The third purpose of the invention is to apply the sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate in the electric flocculation treatment of electroplating wastewater.
In one embodiment of the invention, the application is that the sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate is used as an anode, and an aluminum plate is used as a cathode to perform an electrocoagulation reaction; wherein the conditions of the electric flocculation reaction are as follows: initial pH of 6-8, treatment time of 80-120min, and current density of 20-40mA cm -2 。
In one embodiment of the invention, the distance between the anode and the cathode in said application is 1-3cm, more preferably 2cm.
In one embodiment of the invention, the anode is connected with a direct current power supply in a constant current mode in the application, and the voltage and the current of 0-15V and 0-5A are provided.
In one embodiment of the invention, the cathode is connected with a DC power supply in a constant current mode in the application, and the voltage and the current of 0-15V and 0-5A are provided.
In one embodiment of the invention, the electroplating wastewater in the application is nickel-copper alloy electroplating wastewater, and the specific parameters are that nickel is 6.35mg/L, copper is 8.14mg/L, pH is 7.28, conductivity is 5.14mS/cm, and chemical oxygen demand is 414.54mg/L; wherein, both nickel and copper exist in a complex state.
The fourth purpose of the invention is to provide a method for treating nickel and copper in electroplating wastewater by electroflocculation, which comprises the following steps:
taking the sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate as an anode and an aluminum plate as a cathode to perform an electrocoagulation reaction; wherein the conditions of the electric flocculation reaction are as follows: initial pH of 6-8, treatment time of 80-120min, and current density of 20-40mA cm -2 。
In one embodiment of the present invention, the conditions of the electrocoagulation reaction are: initial pH of 7, treatment time of 100min, and current density of 30 mA-cm -2 。
[ advantageous effects ]
(1) The sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate provided by the invention has the advantages that the anode plate is integrated under the conditions that the conductivity of the plate is not influenced and the stable heavy metal treatment efficiency is obtainedDefinite corrosion inhibition effect. The open-circuit potential of the sulfuric acid/perchloric acid co-doped polypyrrole-modified anode plate reaches-249mV pore Value 17.47 (Ω cm) 2 )，R ct Reach 1496.80 omega cm 2 The corrosion current is only 18.70 muA cm -2 The corrosion potential reaches-252 mV, and the protection efficiency reaches 96.67%.
(2) The sulfuric acid/perchloric acid co-doped polyaniline modified anode plate has high removal rate of nickel and copper in electroplating wastewater, and the removal rate of nickel reaches over 66 percent and can reach 82.24 percent; the copper removal rate reaches more than 97 percent, can reach 99.99 percent, and the corrosion inhibition efficiency is about 35 percent.
Drawings
FIG. 1 shows the open circuit potential trends of SS, SP-PPy, S-PPy and P-PPy in 0.1M hydrochloric acid solution.
FIG. 2 shows the results of testing the AC impedance of SP-PPy, S-PPy and P-PPy; where the inset shows the results of testing the ac impedance of the uncoated SS.
FIG. 3 shows the results of Tafel tests for SS, SP-PPy, S-PPy and P-PPy.
FIG. 4 is a schematic diagram of the corrosion prevention of the electric flocculation process of the present invention.
FIG. 5 shows the results of the test of 10 lots in example 6.
Detailed Description
The following description is of preferred embodiments of the invention, and it is to be understood that the embodiments are for the purpose of illustrating the invention better and are not to be taken in a limiting sense.
The test method comprises the following steps:
1. and (3) testing open circuit potential:
A1M hydrochloric acid solution is used as a test electrolyte, the test time is 3000s, and a three-electrode system of an electrochemical workstation is used for testing (the working electrode is an anode plate (1 multiplied by 0.1 cm), and a platinum wire electrode (Pt 005 phi 0.5mm L37 mm) and a saturated silver/silver chloride electrode are respectively used as a counter electrode and a reference electrode).
2. EIS test:
the frequency range of the EIS measurements was 10mHz to 100kHz with 10mV amplitude using 1M hydrochloric acid solution as the test electrolyte, and the EIS data were fitted using ZSimp Win 3.20d fitting software (princeton application study).
3. Tafel test:
the initial potential and the terminal potential of the Tafel test are-1000 mV and 100mV respectively, and the scanning speed is 10mV s -1 The electrolyte is 1M hydrochloric acid solution.
The parameters of the electroplating wastewater used in the examples are shown in Table 1:
TABLE 1 parameters of electroplating wastewater (nickel and copper exist in a complex state)
Index of water quality Copper (Cu) Nickel (II) pH Electrical conductivity of Chemical Oxygen Demand (COD)
Parameter(s) 8.14mg/L 6.35mg/L 7.28 5.14mS/cm 414.54mg/L
The raw material sources and specifications used in the examples were:
sulfuric acid: the purity is 96-98%, and the product is purchased from chemical reagents of national drug group;
perchloric acid: purity of 70-72%, purchased from chemical reagents of national drug group, ltd;
pyrrole: the purity is 96-98%, and the product is purchased from chemical reagents of national drug group;
hydrochloric acid: the purity is 96-98%, and the product is purchased from chemical reagents of national drug group, inc.;
the method comprises the following steps that pretreatment is needed before electropolymerization of a 430 stainless steel polar plate SS, wherein the pretreatment is to use 500-mesh sand paper for polishing and then soak the stainless steel polar plate SS in 1mol/L hydrochloric acid solution for 20min to remove oxides on the surface of an electrode; soaking in standard ethanol solution for degreasing; finally, washing the mixture with water and then putting the mixture into an oven for drying.
Example 1SP-PPy
A method for preparing a sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate comprises the following steps:
(1) Preparing an electrolyte:
dispersing pyrrole, sulfuric acid and perchloric acid in water, and uniformly mixing to form electrolyte; wherein the concentration of pyrrole in the electrolyte is 0.1M, the concentration of sulfuric acid is 1M, and the concentration of perchloric acid is 1M;
(2) Electropolymerization:
taking a 430 stainless steel polar plate SS (8 multiplied by 5 multiplied by 0.2 cm) as a working electrode, a platinum sheet electrode (1 multiplied by 0.1 cm) as a counter electrode and a saturated silver/silver chloride electrode as a reference electrode, and carrying out constant potential electropolymerization for 1000s in the electrolyte of the step (1) at an oxidation potential of 0.95V; and after the reaction is finished, washing with water and drying at 50 ℃ to obtain the sulfuric acid/perchloric acid co-doped polypyrrole (SP-PPy) modified anode plate.
Comparative example 1S-PPy
A method for preparing a sulfuric acid-doped polypyrrole modified anode plate comprises the following steps:
(1) Preparing an electrolyte:
dispersing pyrrole and sulfuric acid in water, and uniformly mixing to form electrolyte; wherein, the concentration of pyrrole in the electrolyte is 0.1M, and the concentration of sulfuric acid is 1M;
(2) Electropolymerization:
taking a 430 stainless steel polar plate SS (8 multiplied by 5 multiplied by 0.2 cm) as a working electrode, a platinum sheet electrode (1 multiplied by 0.1 cm) as a counter electrode and a saturated silver/silver chloride electrode as a reference electrode, and carrying out constant potential electropolymerization for 1000s in the electrolyte of the step (1) at an oxidation potential of 0.95V; and after the reaction is finished, washing with water, and drying at 50 ℃ to obtain the sulfuric acid doped polypyrrole (S-PPy) modified anode plate.
Comparative example 2P-PPy
A method for preparing a perchloric acid doped polypyrrole modified anode plate comprises the following steps:
(1) Preparing an electrolyte:
dispersing pyrrole and perchloric acid in water, and uniformly mixing to form electrolyte; wherein the concentration of pyrrole in the electrolyte is 0.1M, and the concentration of perchloric acid is 1M;
(2) Electropolymerization:
taking a 430 stainless steel polar plate SS (8 multiplied by 5 multiplied by 0.2 cm) as a working electrode, a platinum sheet electrode (1 multiplied by 0.1 cm) as a counter electrode and a saturated silver/silver chloride electrode as a reference electrode, and carrying out constant potential electropolymerization for 1000s in the electrolyte of the step (1) at an oxidation potential of 0.95V; and after the reaction is finished, washing with water, and drying at 50 ℃ to obtain the perchloric acid doped polypyrrole (P-PPy) modified anode plate.
The anode plates obtained in example 1 and comparative examples 1 and 2 were subjected to an open circuit potential test, an EIS test, and a tafel test; the test results were as follows:
FIG. 1 shows the open circuit potential trends of SS, SP-PPy, S-PPy and P-PPy in 0.1M hydrochloric acid solution. As can be seen from fig. 1: for bare steel SS, an initial potential of-572 mV was observed, which then dropped to a steady state of-652 mV after a short soak time. In contrast, the initial potentials of all PPy coatings were-406 mV (S-PPy), -353mV (P-PPy), and-249 mV (SP-PPy), respectively, significantly greater than bare steel SS. And the final potential of the PPy coating is far higher than that of a bare steel group (-652 mV), which is-543 mV (S-PPy), -488mV (P-PPy) and-365 mV (SP-PPy) respectively. For the electrochemical open circuit potential test, a higher potential indicates better corrosion protection, so the initial potential and the final potential of SP-PPy are always the highest of the three coatings, representing the best corrosion protection of the coating.
FIG. 2 and Table 2 show the results of testing the AC impedance of SS, SP-PPy, S-PPy and P-PPy. As can be seen from fig. 2 and table 2: the polypyrrole coated electrode has a resistance value (Rct) significantly greater than the bare steel electrode SS. The impedance values of S-PPy, P-PPy and SP-PPy reach 534.00, 552.70 and 1496.80 omega cm respectively 2 While the resistance of the SS group of the bare steel only reaches 49.04 omega cm 2 . In addition, the SP-PPy group impedance reaches a maximum, indicating that it is best resistant to corrosion. At the same time, R pore To the extent that the ability of the coating to resist corrosive agents can be reflected, SP-PPy exhibits the greatest R pore A value of 17.47 (Ω. Cm) 2 ) The protective properties proved to be optimal.
TABLE 2 results of testing AC impedance of S-PPy, P-PPy and SP-PPy
Figure BDA0003861567260000061
FIG. 3 and Table 3 show the results of Tafel tests for SS, SP-PPy, S-PPy and P-PPy. As can be seen from fig. 3 and table 3: the corrosion potential of the SP-PPy coating was the largest and the corrosion current was the smallest.
TABLE 3 Tafel test results for SS, S-PPy, P-PPy and SP-PPy
Index (I) SS S-PPy P-PPy SP-PPy
Corrosion current I corr (μA·cm -2 ) 562.40 162.34 141.47 18.70
Corrosion potential E corr (mV) -596 -450 -409 -252
Protective efficiency eta (%) -- 71.13 74.85 96.67
Table 4 shows the atomic force microscope coating surface roughness data for S-PPy, P-PPy and SP-PPy, as can be seen from Table 4: the roughness of SP-PPy is the highest, which shows that the surface of the coating has the largest electroactive surface area and the best electrochemical performance, and is consistent with the electrochemical test result.
TABLE 4 atomic force microscope coating surface roughness data for S-PPy, P-PPy and SP-PPy
Coating layer S-PPy P-PPy SP-PPy
Coating surface roughness (nm) 61 79 92
Comparative example 3PPy
A method for preparing a polypyrrole modified anode plate comprises the following steps:
(1) Preparing an electrolyte:
dispersing pyrrole in water and uniformly mixing to form electrolyte; wherein the concentration of pyrrole in the electrolyte is 0.1M;
(2) Electropolymerization:
taking a 430 stainless steel polar plate SS (8 multiplied by 5 multiplied by 0.2 cm) as a working electrode, a platinum sheet electrode (1 multiplied by 0.1 cm) as a counter electrode and a saturated silver/silver chloride electrode as a reference electrode, and carrying out constant potential electropolymerization for 1000s in the electrolyte of the step (1) at an oxidation potential of 0.95V; and after the reaction is finished, washing with water, and drying at 50 ℃ to obtain the polypyrrole modified anode plate.
Comparative example 4HClP-PPy
The sulfuric acid in the example 1 is adjusted to be hydrochloric acid, and the rest is consistent with the example 1, so that a hydrochloric acid/perchloric acid (HClP-PPy) co-doped modified anode plate is obtained.
EIS test, tafel test and atomic force microscope test are carried out on the anode plates obtained in the example 1 and the comparative examples 3 and 4; the test results were as follows:
table 5 shows EIS, tafel and atomic force microscopy test data for PPy, HClP-PPy and SP-PPy, as seen in Table 5: the SP-PPy has the highest impedance, the smallest corrosion current and the largest corrosion potential, and the corrosion resistance is proved to be obviously superior to that of a blank polypyrrole coating and a hydrochloric acid perchloric acid co-doped polypyrrole coating; the roughness of SP-PPy is the highest, which shows that the sulfuric acid/perchloric acid co-doped polypyrrole coating has larger electroactive surface area and better electrochemical performance than the hydrochloric acid/perchloric acid co-doped polypyrrole coating.
TABLE 5 EIS, tafel and atomic force microscopy test data for PPy, HClP-PPy and SP-PPy
Coating layer PPy HClP-PPy SP-PPy
R ct (Ωcm 2 ) 460.64 1052.46 1496.80
Corrosion current I corr (μA·cm -2 ) 186.24 85.40 18.70
Corrosion potential E corr (mV) -502 -376 -252
Coating surface roughness (nm) 49 75 92
Example 2
The application of the sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate in the electric flocculation treatment of electroplating wastewater comprises the following steps:
the sulfuric acid/perchloric acid codoped polypyrrole modified anode plate obtained in example 1 is used as an anode, an aluminum plate is used as a cathode, the distance between the anode and the cathode is 2cm, and the anode is connected with a direct current power supply in a constant current mode and provides voltage and current of 0-15V and 0-5A; the cathode is connected with a DC power supply in constant current mode, and provides voltage and current of 0-15V and 0-5A at initial pH of 7, treatment time of 100min, and current density of 30mA cm -2 Carrying out an electrocoagulation reaction under the condition of (1); removing copper and nickel in the electroplating wastewater.
Example 3
As shown in Table 6, the pH in example 2 was adjusted so that the reaction time was 100min and the current density was 30mA cm -2 Otherwise, the electrocoagulation treatment was carried out in accordance with example 2.
Meanwhile, a 430 stainless steel polar plate SS which is not subjected to coating treatment is adopted as a comparison, namely: bare steel anodes.
The results of the treatments are shown in tables 6 and 7:
as can be seen from tables 6 and 7: the copper removal rate reached the highest when the initial pH was 7, and the copper and nickel removal rates were 99.99% and 82.24%, while at low pH (1 and 2) the floc accumulation was insufficient and the metal removal efficiency was low. Under the neutral condition, the coating can effectively inhibit the corrosion of the plate, ensure the controllable iron ion dissolution amount and simultaneously obtain the more stable heavy metal removal rate. The corrosion inhibition efficiency is continuously reduced along with the increase of the pH value, and the coating can obtain higher corrosion inhibition efficiency because the metal is more easily corroded under the strong acid condition.
Table 6 results of copper and nickel removal rate test in example 3
Figure BDA0003861567260000081
Table 7 test results of corrosion inhibition efficiency in example 3
Figure BDA0003861567260000082
Example 4
As shown in Table 8, the initial pH was 7, and the current density was 30mA cm -2 Otherwise, the electrocoagulation treatment was carried out in accordance with example 2.
Meanwhile, 430 stainless steel plates SS which are not subjected to coating treatment are adopted as comparison, namely: bare steel anodes.
The results of the treatments are shown in tables 8 and 9:
as can be seen from tables 8 and 9: the removal of both copper and nickel increases with increasing reaction time because as the reaction proceeds, the anode produces more metal hydroxide that is converted to floe, thereby increasing the metal removal efficiency. The test result of the removal rate of the coated anode after 100min is similar to that of the 430 stainless steel anode without the coating, and the test result also proves that the coated anode can achieve good anticorrosion effect while ensuring a certain heavy metal removal rate. In view of running cost, a reaction time of 100min is preferable.
Table 8 results of copper and nickel removal rate test in example 4
Figure BDA0003861567260000091
Table 9 test results of corrosion inhibition efficiency in example 4
Figure BDA0003861567260000092
Example 5
Current density in example 2 was adjusted as shown in Table 10, the initial pH was 7, the reaction time was 100min, and the electrocoagulation treatment was carried out in conformity with example 2.
Meanwhile, 430 stainless steel plates SS which are not subjected to coating treatment are adopted as comparison, namely: bare steel anodes.
The treatment results are shown in tables 10 and 11;
as can be seen from tables 10 and 11: the removal efficiency of heavy metal ions is increased along with the increase of current density, and when the current density is low, metal cations released by the anode participate in corrosion more, so that the corrosion inhibition efficiency of the coating anode is higher. Under the condition of lower current density, the coating anode has better corrosion resistance. There is a difference in the removal efficiency of nickel and copper because more agglomerates are required for nickel removal than for copper removal. In consideration of cost, a current density of 30mA cm is selected -2 。
Table 10 results of copper and chromium removal test in example 5
Figure BDA0003861567260000093
TABLE 11 test results for corrosion inhibition efficiency in example 5
Figure BDA0003861567260000094
Example 6
Example 2 was run in multiple batches (10) using 430 stainless steel plates SS without coating treatment for comparison, i.e.: bare steel anodes.
The test results are shown in fig. 5: as can be seen from fig. 5: for bare steel anodes, the removal rate of copper ions and nickel ions in each batch is basically stabilized at about 99.99 percent and 84 percent, and the removal rate of the copper ions and the removal rate of the nickel ions after electrode modification respectively reach 99.99 percent and 82.24 percent. Meanwhile, after 10 batches of electrocoagulation treatment, the corrosion inhibition effect is relatively stable by about 35 percent.
Comparative example 5
A method for preparing a polyaniline/montmorillonite modified anode plate comprises the following steps:
(1) Preparing an electrolyte:
dispersing polyaniline and montmorillonite in water, and uniformly mixing to form electrolyte; wherein the concentration of polyaniline in the electrolyte is 0.1M, and the concentration of montmorillonite is 5g/250mL;
(2) Electropolymerization:
taking a 430 stainless steel polar plate SS (8 multiplied by 5 multiplied by 0.2 cm) as a working electrode, a platinum sheet electrode (1 multiplied by 0.1 cm) as a counter electrode and a saturated silver/silver chloride electrode as a reference electrode, and carrying out constant potential electropolymerization for 1000s in the electrolyte of the step (1) at an oxidation potential of 0.7V; and after the reaction is finished, washing with water, and drying at 60 ℃ to obtain the polyaniline-modified anode plate.
The electrodes obtained in comparative examples 1 to 5 were subjected to an electroflocculation test in the manner of example 2, and the test results were as follows:
TABLE 12 test results of example 2 and comparative examples 1 to 5
Example (b) Copper removal (%) Nickel removal Rate (%) Corrosion inhibition efficiency (%)
Example 2 99.99 82.24 35.24
Comparative example 1 95.30 75.26 30.45
Comparative example 2 95.12 76.61 31.72
Comparative example 3 95.48 77.50 29.75
Comparative example 4 95.90 74.67 28.80
Comparative example 5 94.26 76.58 30.82
Table 13 shows the results of molecular dynamics simulation of the interaction of polypyrrole PPy coatings with the stainless steel surface for the plates of example 1 and comparative examples 1 to 3, as shown in table 13: the adsorption energy of PPy and each coating on the surface of Fe is negative, which shows that the surfaces of the pole plates have certain protection effect, wherein the adsorption energy of SP-PPy has the largest negative value, which shows that the binding capacity is strongest and the protection performance is best, which is consistent with the results of previous experiments.
Table 13 test results of the electrode plates of example 1 and comparative examples 1 to 3
Coating layer PPy S-PPy P-PPy SP-PPy
Adsorption energy (kJ/mol) -75.26 -105.59 -113.90 -169.42
Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (10)

1. The method for preparing the sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate is characterized by comprising the following steps of:
(1) Preparing an electrolyte:
dispersing pyrrole, sulfuric acid and perchloric acid in water, and uniformly mixing to form electrolyte;
(2) Electropolymerization:
placing the anode plate in electrolyte, and carrying out electropolymerization at an oxidation potential of 0.9-1V; and after the completion of the washing, drying to obtain the sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate.
2. The method according to claim 1, wherein the electrolyte of step (1) has a pyrrole concentration of 0.05 to 0.15M, a sulfuric acid concentration of 0.5 to 1.5M, and a perchloric acid concentration of 0.5 to 1.5M.
3. The process of claim 1, wherein said electropolymerization of step (2) is carried out at an oxidation potential of 0.95V; in the electropolymerization, an anode plate is used as a working electrode, a platinum sheet electrode is used as a counter electrode, a saturated silver/silver chloride electrode is used as a reference electrode, and constant potential polymerization is carried out in electrolyte.
4. The sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate prepared by the method of any one of claims 1 to 3.
5. The use of the sulfuric acid/perchloric acid co-doped polypyrrole-modified anode plate described in claim 4 in the treatment of electroplating wastewater by electroflocculation.
6. The application of claim 5, wherein the sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate of claim 4 is used as an anode, and an aluminum plate is used as a cathode to perform an electroflocculation reaction; wherein the conditions of the electric flocculation reaction are as follows: initial pH of 6-8, treatment time of 80-120min, and current density of 20-40mA cm -2 。
7. Use according to claim 6, wherein the distance between the anode and the cathode is 1-3cm.
8. The application of claim 6, wherein the electroplating wastewater in the application is nickel-copper alloy electroplating wastewater, and the specific parameters are 6.35mg/L of nickel, 8.14mg/L, pH of copper, 5.14mS/cm of conductivity, 414.54mg/L of chemical oxygen demand; wherein both nickel and copper exist in a complex state.
9. The method for treating nickel and copper in electroplating wastewater by using electroflocculation is characterized by comprising the following steps of:
the sulfuric acid/perchloric acid co-doped polypyrrole modified anode plate of claim 4 is used as an anode, an aluminum plate is used as a cathode, and an electrocoagulation reaction is carried out; wherein the conditions of the electric flocculation reaction are as follows: initial pH of 6-8, treatment time of 80-120min, and current density of 20-40mA cm -2 。
10. The method according to claim 9, wherein the conditions of the electroflocculation reaction are: initial pH of 7, treatment time of 100min, and current density of 30mA cm -2 。
CN202211166389.8A 2022-09-23 2022-09-23 Sulfuric acid/perchloric acid co-doped polypyrrole modified anode and application thereof in electric flocculation treatment of electroplating wastewater Pending CN115367843A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211166389.8A CN115367843A (en) 2022-09-23 2022-09-23 Sulfuric acid/perchloric acid co-doped polypyrrole modified anode and application thereof in electric flocculation treatment of electroplating wastewater

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211166389.8A CN115367843A (en) 2022-09-23 2022-09-23 Sulfuric acid/perchloric acid co-doped polypyrrole modified anode and application thereof in electric flocculation treatment of electroplating wastewater

Publications (1)

Publication Number Publication Date
CN115367843A true CN115367843A (en) 2022-11-22

Family

ID=84072348

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211166389.8A Pending CN115367843A (en) 2022-09-23 2022-09-23 Sulfuric acid/perchloric acid co-doped polypyrrole modified anode and application thereof in electric flocculation treatment of electroplating wastewater

Country Status (1)

Country Link
CN (1) CN115367843A (en)

Similar Documents

Publication Publication Date Title
Sun et al. Electrochemical Ni-EDTA degradation and Ni removal from electroless plating wastewaters using an innovative Ni-doped PbO2 anode: Optimization and mechanism
CN100587126C (en) Method for erosion of supervoltage high specific volume anode foil
CN106745557B (en) Titanium-based tin iridium oxide electrode and preparation method thereof
CN111634982B (en) Preparation method of anode material for efficient phenol wastewater degradation
JP3961434B2 (en) Manufacturing method of fuel cell separator
CN107256975B (en) Method for modifying aluminum alloy bipolar plate for proton exchange membrane fuel cell by using boron nitride nanosheets
Liu et al. Elongation the duration of steel anode with polypyrrole modification during the electrocoagulation treatment process of electroplating wastewater
Yu et al. Insight into the corrosion inhibition of the iron anode with electro-deposited polyaniline during the electrocoagulation treatment process of electroplating wastewater
JP2010097840A (en) Fuel cell separator and method for manufacturing thereof
KR102012834B1 (en) method for manufacturing graphene complex electrolysis electrodes for wastewater processing and sterilization
CN115367843A (en) Sulfuric acid/perchloric acid co-doped polypyrrole modified anode and application thereof in electric flocculation treatment of electroplating wastewater
CN108060451B (en) Preparation method of hydrophobic natural fiber composite lead dioxide anode
CN112777693B (en) Modified anode and application thereof in electric flocculation treatment of electroplating wastewater
CN114540824B (en) Method for regenerating titanium anode plate by using waste acid solution
JP2009249705A (en) Electrode for electrolysis and use thereof
CN108264134B (en) High-salt high-COD wastewater electrolytic electrode and electrolytic oxidation treatment method
CN110342618B (en) Device and method for cooperatively treating pickling waste liquid and electroplating sludge by utilizing electrodialysis technology
GB2385333A (en) A Treatment for Stainless Steel Plates Used in Electrochemical Cell Assemblies
KR100523591B1 (en) Electrode and its manufacturing method using rare earth element
JP2004265695A (en) Separator for fuel cell
CN114525537B (en) Rapid micro-nano reconstruction processing method for copper metal and application thereof
CN111762850B (en) Titanium alloy composite material
CN110642339B (en) Porous Ti/IrO2-Nb2O5-Bi2O3Preparation method and application of electrode
KR102005521B1 (en) Multi-track system for electolytic phosphate coating treatment and how to use
KR20010028158A (en) Elextrolysis electrode for treating wastewater and method of making the same

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination