CN107228822A - Water piping system corrosion electrochemical test system and method are regenerated under current system - Google Patents
Water piping system corrosion electrochemical test system and method are regenerated under current system Download PDFInfo
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- 230000007797 corrosion Effects 0.000 title claims abstract description 67
- 238000005260 corrosion Methods 0.000 title claims abstract description 67
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 37
- 238000000034 method Methods 0.000 title claims abstract description 27
- 238000000840 electrochemical analysis Methods 0.000 title abstract description 9
- 238000012360 testing method Methods 0.000 claims abstract description 47
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 26
- 229910001141 Ductile iron Inorganic materials 0.000 claims abstract description 23
- 230000008569 process Effects 0.000 claims abstract description 20
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 13
- 229910021607 Silver chloride Inorganic materials 0.000 claims abstract description 12
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 claims abstract description 12
- 229910052751 metal Inorganic materials 0.000 claims description 43
- 239000002184 metal Substances 0.000 claims description 43
- 239000004020 conductor Substances 0.000 claims description 25
- -1 polytetrafluoroethylene Polymers 0.000 claims description 24
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 24
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 24
- 239000003792 electrolyte Substances 0.000 claims description 15
- 239000000645 desinfectant Substances 0.000 claims description 14
- 230000010287 polarization Effects 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 9
- 238000001453 impedance spectrum Methods 0.000 claims description 7
- 229920006395 saturated elastomer Polymers 0.000 claims description 6
- 238000005259 measurement Methods 0.000 claims description 5
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 claims description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- 230000002572 peristaltic effect Effects 0.000 claims description 4
- 230000005611 electricity Effects 0.000 claims description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 2
- 230000014759 maintenance of location Effects 0.000 claims description 2
- 238000000691 measurement method Methods 0.000 claims description 2
- 239000007769 metal material Substances 0.000 claims description 2
- 230000008929 regeneration Effects 0.000 claims description 2
- 238000011069 regeneration method Methods 0.000 claims description 2
- 238000010998 test method Methods 0.000 claims description 2
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- 238000007796 conventional method Methods 0.000 abstract 1
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- 238000002474 experimental method Methods 0.000 description 11
- 244000005700 microbiome Species 0.000 description 7
- 238000012544 monitoring process Methods 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 5
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 4
- 229910052801 chlorine Inorganic materials 0.000 description 4
- 239000000460 chlorine Substances 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- OSVXSBDYLRYLIG-UHFFFAOYSA-N chlorine dioxide Inorganic materials O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 3
- 230000001808 coupling effect Effects 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 238000002848 electrochemical method Methods 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
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- 239000000523 sample Substances 0.000 description 2
- 239000010865 sewage Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- QBWCMBCROVPCKQ-UHFFFAOYSA-N chlorous acid Chemical compound OCl=O QBWCMBCROVPCKQ-UHFFFAOYSA-N 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000006056 electrooxidation reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000012165 high-throughput sequencing Methods 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 238000012625 in-situ measurement Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000000813 microbial effect Effects 0.000 description 1
- 230000000877 morphologic effect Effects 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 238000010606 normalization Methods 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 241000894007 species Species 0.000 description 1
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- G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
- G01N17/02—Electrochemical measuring systems for weathering, corrosion or corrosion-protection measurement
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Abstract
The present invention relates to the electrochemical testing device that water piping system corrosion is regenerated under a kind of current system, to overcome the defect that conventional method influences detailed process corrosion mechanism to determine；And can not preferably simulate the defect of actual pipeline flow regime in static electrochemical testing device, a kind of electrochemical testing device that can be real-time for a long time, lossless is provided, and then discontinuity sample test results are aided in, be conducive to the analysis of the corrosion mechanism to regenerating water piping system under current system.For this, the technical solution adopted by the present invention is, water piping system corrosion electrochemical test system is regenerated under current system, includes ring-reactor, the motor of 1 spheroidal graphite cast-iron working electrode, the platinized platinum auxiliary electrode of 1 Ag/AgCl reference electrode and 1 purity 99.99% and 1 supporting outer wall perforate.Present invention is mainly applied to regenerate the electro-chemical test of water piping system corrosion.
Description
Technical Field
The invention relates to an electrochemical testing device for corrosion of a regenerated water pipeline system under a flow system, which can be used for real-time and nondestructive monitoring of a pipeline corrosion mechanism under the flow system. In particular to a device for electrochemically testing corrosion of a regenerated water pipeline system under a flowing system.
Background
The electrochemical method is an important method for researching the metal corrosion process, and aims to disclose the corrosion mechanism and explore the corrosion rule by researching the electrochemical change process of a metal/electrolyte interface (double electric layers). Corrosion electrochemical measurement techniques offer many advantages over other physical or chemical research methods. Firstly, the method is an in-situ measurement technology, and cannot damage and destroy a working electrode; meanwhile, the test speed is high, and the test sensitivity is high; the instantaneous corrosion change condition of the corrosion metal electrode under the influence of external conditions can be measured; and the change of the corrosion condition of the metal surface can be continuously observed. Therefore, the research on the corrosion characteristics of the metal by using the electrochemical testing device is of great significance.
The annular reactor is an important device for researching pipeline corrosion, which is applied more at present, but is mostly used for measuring uniform corrosion rate, and monitoring SEM and XRD of corrosion products on the surface of a metal hanging piece in a discontinuous and non-time sampling manner cannot monitor the corrosion condition of a system in real time. Therefore, the research designs the electrochemical testing electrode which can be arranged on the outer wall of the annular reactor on the basis of the annular reactor, and can carry out real-time and nondestructive monitoring on the basis that the annular reactor is always in a flowing state, which has important significance for really understanding and explaining the corrosion mechanism.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to overcome the defects that the traditional annular reactor device can only sample and analyze irregularly and discontinuously to influence the corrosion mechanism determination of a specific process; and the static electrochemical testing device can not better simulate the flowing state of the actual pipeline, so that the electrochemical testing device which can realize long-term real-time and nondestructive testing is provided, the intermittent sampling test result is further assisted, and the analysis of the corrosion mechanism of the sewage system of the flowing system is facilitated. Therefore, the technical scheme adopted by the invention is that the electrochemical testing device for corrosion of the regenerated water pipeline system under the flowing system comprises 1 nodular cast iron working electrode, 1 Ag/AgCl reference electrode, 1 platinum sheet auxiliary electrode with the purity of 99.99 percent, 1 matched annular reactor with an outer wall provided with a hole and a motor; wherein,
the working electrode is a nodular cast iron cylindrical electrode, the outer surface of the working electrode is provided with a polytetrafluoroethylene material seal, one side of the working electrode is provided with a hard metal conductor joint which is conveniently connected with an external electrochemical testing device, and the middle of the working electrode is connected with the hard metal conductor joint and the nodular cast iron electrode on the other side by a metal lead and is encapsulated in the polytetrafluoroethylene material;
the reference electrode adopts a polytetrafluoroethylene cylindrical barrel-shaped shell, and an electrolyte chamber is arranged at the longitudinal middle position of the cylinder; a saturated Ag/AgCl electrolyte is arranged in the electrolyte chamber, and the electrode cavity is connected with the polytetrafluoroethylene shell through threads so as to prevent the loss of the electrolyte; the other side of the electrode is provided with a hard metal conductor joint which is convenient to be connected with an external electrochemical testing device; the middle part adopts a metal lead to connect the electrolyte chamber of the reference electrode and the hard metal conductor joint so as to conduct electricity;
the auxiliary electrode adopts a platinum sheet with the purity of 99.99 percent, and is also packaged by a polytetrafluoroethylene shell, the other side of the auxiliary electrode is provided with a hard metal conductor joint which is conveniently connected with an external electrochemical testing device, and the middle of the auxiliary electrode adopts a metal lead to connect the platinum sheet of the auxiliary electrode and the metal conductor joint and is packaged in a polytetrafluoroethylene material so as to be conductive; meanwhile, considering that the distance between the inner drum provided with the ductile cast iron hanging piece and the pipe wall is small, the auxiliary electrode is flattened and tightly attached to the inner pipe wall and is opposite to the reference electrode to form a complete electrochemical testing system;
wherein the working surfaces of the working electrode, the reference electrode and the auxiliary electrode are all tightly attached to the inner wall of the pipeline; and is connected with the outer wall of the annular reactor through the thread of the encapsulated polytetrafluoroethylene shell; the 3 electrodes and the annular reactor filled with the reclaimed water form a complete electrolytic cell, and only 3 hard metal conductor joints in the whole system are exposed to the outside and connected with an electrochemical testing device to test the current condition in the corrosion process; the three-electrode system contains two loops: a circuit consisting of a working electrode and a reference electrode, for testing the potential of the working electrode, since the potential of the reference electrode is known; the other loop consists of a working electrode and an auxiliary electrode, plays a role of transmitting electrons to form a loop, leads the current on the working electrode to be smooth and is used for testing the current;
the annular reactor is internally provided with a rotary drum, the rotary drum is internally provided with hanging pieces, and the rotary drum is externally connected with a motor.
The invention has the characteristics and beneficial effects that:
1. the invention relates to a device for electrochemically testing corrosion of a regenerated water pipeline system under a flowing system, which can carry out real-time and nondestructive electrochemical monitoring on the corrosion condition of a nodular cast iron electrode in an annular reactor so as to more accurately probe the corrosion process and mechanism of the regenerated water pipeline;
2. the working electrode can perform nondestructive monitoring on the continuously growing corrosion scale layer, so that the microscopic morphology of the corrosion scale layer on the metal hanging piece and the crystal scale can be taken out periodically to perform comprehensive analysis, and the analysis accuracy of the corrosion process is greatly improved;
3. the device can be used for measuring an electrochemical system under various working conditions, such as a control experiment without adding disinfectant, an experiment with adding disinfectant, an experiment under the coupling action of disinfectant and microorganism and the like, and can accurately obtain various electrochemical data, such as a polarization curve, alternating current impedance, linear volt-ampere analysis and the like so as to better analyze the corrosion mechanism of the nodular cast iron pipeline when various media coexist;
4. the working electrode manufacturing method is standard and feasible, the reaction area is convenient to calculate, the whole system is stable and easy to control, and the accuracy and the normalization of corrosion electrochemical measurement can be greatly improved;
5. the working electrode has small sectional area, thin thickness and smaller main body volume, avoids the operation that other working electrodes with larger sectional areas or larger thicknesses need to be cut, ensures that the subsequent experimental operation for detecting the microscopic appearance of the coating by using a large instrument is more convenient and quicker, is convenient for comprehensively applying various detection methods, and better analyzes the microscopic appearance characteristics and the local corrosion characteristics of the regenerated water pipeline.
Description of the drawings:
FIG. 1 is a physical diagram of a working electrode, a reference electrode and an auxiliary electrode of a regenerated water pipeline corrosion electrochemical testing device under a flowing system of the invention; wherein, a is a working electrode, b is a reference electrode, and c is an auxiliary electrode.
FIG. 2 is a schematic view of a loop reactor incorporating a three-electrode system according to the present invention.
FIG. 3 is a schematic view of a loop reactor equipped with a three-electrode system in connection with an external electrochemical test apparatus;
FIG. 4 is a polarization curve measured according to an embodiment of the present invention;
fig. 5 is an ac impedance spectrum measured in accordance with an embodiment of the present invention.
Detailed Description
The electrochemical corrosion tester for the regenerated water pipeline system in flowing system includes self-made reference electrode, working electrode, auxiliary electrode and matched annular reactor. The method is characterized in that:
1. the working electrode in the device is made of the same nodular cast iron material as the hanging pieces in the annular reactor drum and is cut and polished into 0.65cm2Size; with polytetrafluoroethylene casingThe polytetrafluoroethylene shell of the installed working electrode is also connected with the outer wall of the annular reactor through threads and forms a whole with the tube wall; the other side of the electrode is provided with a hard metal conductor joint, so that the electrochemical test is convenient to carry out; the middle part adopts a metal lead to connect the nodular cast iron electrode and the hard metal conductor joint and is encapsulated inside the polytetrafluoroethylene material so as to be conductive;
2. the reference electrode of the device adopts a saturated Ag/AgCl electrode, and is packaged in the inner cavity of a polytetrafluoroethylene cylindrical barrel-shaped shell in order to prevent the loss of an Ag/AgCl solution, and a part of inner core is left to be in contact with the electrolyte in the reactor; the Ag/AgCl electrode has very good electrode potential repeatability and stability, provides a stable electrode potential in the measuring process, basically has no current passing on the reference electrode, and is used for forming a loop with the working electrode to measure the electrode potential of the working electrode; the inner cavity filled with the saturated Ag/AgCl solution is connected with a polytetrafluoroethylene shell through threads (the height is about 8.0 cm); the other side of the electrode is provided with a hard metal conductor joint, so that the electrochemical test is convenient to carry out; the middle part adopts a metal lead to connect the electrolyte chamber of the reference electrode and the hard metal conductor joint so as to conduct electricity; the polytetrafluoroethylene outer shell provided with the reference electrode inner core is connected with the outer wall of the annular reactor through threads and is integrated with the tube wall, and the electrode with constant potential is used as a reference in the whole test system;
3. the auxiliary electrode is 1.0cm2The platinum sheet with the purity of 99.99 percent is also packaged by a polytetrafluoroethylene shell (the height is about 5.0cm), and the polytetrafluoroethylene shell of the auxiliary electrode is also connected with the outer wall of the annular reactor through threads to form a whole with the tube wall; the other side of the electrode is provided with a hard metal conductor joint, so that the electrochemical test is convenient to carry out; the middle of the metal lead is connected with a platinum sheet of the auxiliary electrode and a metal conductor joint and is encapsulated in the polytetrafluoroethylene material so as to be conductive; the auxiliary electrode has a larger surface area than the working electrode so that externally applied polarization acts mainly on the working electrode; the auxiliary electrode is used in the whole test systemA loop which can allow current to pass is formed, and stable current cannot pass through the loop outside only one electrode; in addition, considering that the width of the auxiliary electrode platinum sheet is larger, the auxiliary electrode platinum sheet is directly arranged in the annular reactor and is easy to prevent the growth of a thicker corrosion scale layer on the later nodular cast iron hanging sheet, so the auxiliary electrode platinum sheet is flattened and tightly attached to the wall of the inner pipe; the other side of the electrode is also provided with a hard metal conductor joint, so that the electrochemical test is convenient to carry out;
4. considering the narrow distance between the rotary drum and the outer wall in the reactor, the working surfaces of the working electrode, the reference electrode and the auxiliary electrode are all tightly attached to the inner wall of the pipeline; and is connected with the outer wall of the annular reactor through the thread of the encapsulated polytetrafluoroethylene shell; the 3 electrodes and the annular reactor filled with regenerated water form a complete electrolytic cell, and only 3 hard metal conductor joints connected with the 3 electrodes through leads are exposed outside and connected with an electrochemical testing device in the whole system
5. The three electrodes and the annular reactor filled with regenerated water as electrolyte form a complete primary battery system (current passes through during corrosion); the length of the hard metal conductor joint is 2cm, and the tail end of the hard metal conductor joint is exposed and connected with a lead of an external electrochemical measuring device; the device is used for measuring the current and resistance conditions generated in the corrosion process and indirectly reflecting the corrosion process through a polarization curve and alternating current impedance; the overall connection and the test device are shown in figure 3.
Taking the three-electrode system installed on the annular reactor as an example, the corrosion mechanism in the regenerated water pipeline system under the action of the disinfectant and the microbial system is simulated. A 1.5L annular reactor is adopted to simulate a reclaimed water pipeline system, and all components of the annular reactor are sterilized by an ultraviolet lamp for 30min on a super clean bench before use due to the consideration of the action of microorganisms; then all parts are assembled, and the reactor is firstly washed once by using absolute ethyl alcohol, and then regenerated water is fed; wherein, the nodular cast iron hanging pieces are hung on a rotary drum in the reactor and driven by a brushless direct current motor (BL 2203C manufactured by Beijing and Lithou Motor technology Co., Ltd.); reactor tubePeristaltic pump (b)Baoding Raffet speed regulation type peristaltic pump-BT 300S) Feeding water from the bottom, and controlling the rotating speed of a rotor of a peristaltic pump to be about 1r/min so as to maintain the hydraulic retention time of the reactor to be 8 h; the rotating speed of the brushless DC motor is 0.25N/m2The flow rate of the simulated pipeline is about 0.5 m/s;
the experiment researches the corrosion mechanism of a reclaimed water pipeline system under the coupling action of a disinfectant and microorganisms, and NaClO and ClO with three concentrations of 1mg/L, 2mg/L and 4mg/L are respectively adopted2Disinfectant experiments are carried out for 30 days respectively; in the test process, the characteristics (7.8 g/cm) of the ductile iron metal material are input into an electrochemical test device (electrochemical workstation: CS350, Wuhan Keste instruments, Ltd.)3) And experimental conditions (at 25 ℃); after the open-circuit potential is stable, selecting a measurement method as polarization curve measurement, selecting a reference electrode as a saturated Ag/AgCl reference electrode, and setting a potential interval: 0.5mV, initial potential vs. open circuit potential-0.1V, termination potential vs. open circuit potential 0.1V, scan rate 0.5mV/s, coordinate type: potential-lg current, the measurement result is shown in fig. 4; in addition, measurement of an alternating current impedance spectrum, a test method, steady state test, impedance and frequency scanning are carried out, parameter setting is carried out, and an alternating current amplitude value: 10mv, initial frequency: 100000Hz, stop frequency: 0.01Hz, 10 points and 10 frequency doubling, and the test result is shown in figure 5;
in the whole experiment process, the working electrode, namely the nodular cast iron electrode to be detected is in contact with the regenerated aqueous electrolyte in the annular reactor to generate corrosion reaction, so that the main component Fe of the nodular cast iron working electrode loses electrons (1-1) at the anode, the cathode obtains electrons (1-2), and the reaction of the cathode and the anode forms a primary battery to form a corrosion product (1-3) and current passes through; connecting a working electrode, a reference electrode and an auxiliary electrode with an electrochemical measuring device through a hard metal conductor joint exposed outside, wherein the working electrode and the reference electrode form a loop to monitor the corrosion condition of the working electrode, the auxiliary electrode forms a loop through current passing in the whole test system, and the electrochemical workstation can be used for testing the working electrode in a polarization curve, an alternating current impedance spectrum and the like so as to better analyze the corrosion process of the nodular cast iron;
adding NaClO and ClO2In the case of disinfectants, ClO produced by hydrolysis thereof-And ClO2The molecules directly participate in the cathode reaction process and lose electrons with the anode to obtain Fe2+Forming a layer of erosion scale (1-4; 1-5) by different reaction processes; the results show that the addition of NaClO and ClO is comparable to the control experiment without adding disinfectant2The cathode of corrosion is promoted in the case of the disinfectant, the corrosion rate becomes higher, but for a single disinfectant species, the corrosion process becomes slower as the corrosion time increases and the corrosion scale layer accumulates on the surface of the metal hanging piece, regardless of whether the anode process of the control experiment or the disinfectant adding experiment is gradually slowed down, which is consistent with the results of the literature.
Fe→Fe2++2e-(1-1)
6Fe2++3ClO-+3H2O→2Fe(OH)3+4Fe3++3Cl-(1-4)
ClO2+5Fe2++13H2O→5Fe(OH)3+HCl+10H+(1-5)
The invention solves the problem that the common annular reactor device in the existing regenerated water pipeline system can not carry out electrochemical monitoring in real time without damage, and also solves the monitoring problem of a common static electrochemical system, and the simulation flow state is closer to the actual regenerated water pipeline running condition; on the other hand, the manufacturing method of the electrode system in the device is standard and feasible, and the connection with the annular reactor is convenient to disassemble and assemble; meanwhile, the working electrode is small in sectional area, thin in thickness and small in main body size, the operation that other working electrodes with larger sectional areas or larger thicknesses need to be cut is avoided, the subsequent experiment operation for detecting the microscopic appearance of the coating by using a large instrument is more convenient and quicker, various detection methods are conveniently and comprehensively applied, the microscopic appearance characteristics and the local corrosion characteristics of the regenerated water pipeline are better analyzed, the corrosion condition of the regenerated water pipeline under a flowing system can be more accurately simulated, and the corrosion mechanism is more accurately explored.
The invention is used for installing a three-electrode system on the basis of an annular reactor, connecting a current signal in the corrosion process to an electrochemical workstation through a hard metal joint by using a lead, and analyzing a corrosion electrochemical mechanism in real time and without damage by measuring polarization curve and alternating-current impedance spectrum characteristics; and the experimental process can be carried out simultaneously with the sampling of the nodular cast iron hanging pieces on the rotary drum in the reactor, so as to better combine the morphological characteristics and the crystallization state of the corrosion scale layer to analyze the corrosion mechanism. Therefore, the device is simple and convenient, realizes real-time and nondestructive detection of the corrosion state of the pipeline in the flow system, and has certain application value.
The following is an example of the present invention.
Example 1
In the urban sewage recycling-urban miscellaneous water quality, the residual chlorine content after the water in a clean water tank of a pipe network contacts for 30min is determined to be more than or equal to 1.0mg/L, and the residual chlorine content at the tail end of the pipe network is required to be more than or equal to 0.2mg/L, and the chlorine consumption is larger due to the higher concentration of AOC and suspended matters in the recycled water, so that the requirement of the residual chlorine content at the tail end of the pipe network is difficult to ensure particularly in long-distance pipeline transportation, and a large amount of microorganisms are propagated. Therefore, the subject has conducted NaClO and ClO with three concentrations of 1mg/L, 2mg/L and 4mg/L in the inlet water2The disinfectant experiment is carried out for 30 days, the diversity of microorganisms in the corrosion scale layer is determined by adopting a microorganism high-throughput sequencing means, the corrosion mechanism of a regenerated water pipeline in a flowing system under the coupling action of the disinfectant and the microorganisms is researched, and the result is obtainedThe polarization curve and the alternating-current impedance spectrum are found to be capable of better analyzing the corrosion mechanism and the corrosion process in the polarization curve and the alternating-current impedance spectrum.
Claims (2)
1. A device for electrochemically testing corrosion of a regenerated water pipeline system under a flowing system is characterized by comprising 1 nodular cast iron working electrode, 1 Ag/AgCl reference electrode, 1 platinum sheet auxiliary electrode with the purity of 99.99 percent, 1 matched annular reactor with an outer wall provided with a hole and a motor; wherein,
the working electrode is a nodular cast iron cylindrical electrode, the outer surface of the working electrode is provided with a polytetrafluoroethylene material seal, one side of the working electrode is provided with a hard metal conductor joint which is convenient to be connected with an external electrochemical testing device, and the middle of the working electrode is connected with the hard metal conductor joint and the nodular cast iron electrode on the other side by a metal lead and is encapsulated in the polytetrafluoroethylene material;
the reference electrode adopts a polytetrafluoroethylene cylindrical barrel-shaped shell, and an electrolyte chamber is arranged at the longitudinal middle position of the cylinder; a saturated Ag/AgCl electrolyte is arranged in the electrolyte chamber, and the electrode cavity is connected with the polytetrafluoroethylene shell through threads so as to prevent the loss of the electrolyte; the other side of the electrode is provided with a hard metal conductor joint which is convenient to be connected with an external electrochemical testing device; the middle part adopts a metal lead to connect the electrolyte chamber of the reference electrode and the hard metal conductor joint so as to conduct electricity;
the auxiliary electrode adopts a platinum sheet with the purity of 99.99 percent, and is also packaged by a polytetrafluoroethylene shell, the other side of the auxiliary electrode is provided with a hard metal conductor joint which is convenient to be connected with an external electrochemical testing device, and the middle of the auxiliary electrode adopts a metal lead to connect the platinum sheet of the auxiliary electrode and the metal conductor joint and is packaged in a polytetrafluoroethylene material so as to be conductive; meanwhile, considering that the distance between the inner drum provided with the ductile cast iron hanging piece and the pipe wall is small, the auxiliary electrode is flattened and tightly attached to the inner pipe wall and is opposite to the reference electrode to form a complete electrochemical testing system;
wherein the working surfaces of the working electrode, the reference electrode and the auxiliary electrode are all tightly attached to the inner wall of the pipeline; and is connected with the outer wall of the annular reactor through the thread of the encapsulated polytetrafluoroethylene shell; the 3 electrodes and the annular reactor filled with the reclaimed water form a complete electrolytic cell, and only 3 hard metal conductor joints in the whole system are exposed to the outside and connected with an electrochemical testing device to test the current condition in the corrosion process; the three-electrode system contains two loops: a circuit consisting of a working electrode and a reference electrode, for testing the potential of the working electrode, since the potential of the reference electrode is known; the other loop consists of a working electrode and an auxiliary electrode, plays a role of transmitting electrons to form a loop, leads the current on the working electrode to be smooth and is used for testing the current;
the annular reactor is internally provided with a rotary drum, the rotary drum is internally provided with hanging pieces, and the rotary drum is externally connected with a motor.
2. The electrochemical testing method for the corrosion of the flow system sewer regeneration water pipeline system according to claim 1, which is realized by using 1 nodular cast iron working electrode, 1 Ag/AgCl reference electrode, 1 platinum sheet auxiliary electrode with the purity of 99.99 percent, 1 matched annular reactor with an opening on the outer wall and a motor, and comprises the following steps:
sterilizing the annular reactor and each electrode with ultraviolet lamp for 30min before use; then all parts are assembled, and the reactor is firstly washed once by using absolute ethyl alcohol, and then regenerated water is fed; the nodular cast iron hanging pieces are hung on a rotary drum in the annular reactor and driven by a brushless direct current motor above the rotary drum; the annular reactor is filled with water from the bottom through a peristaltic pump, and the rotating speed of a rotor of the peristaltic pump is controlled to be about 1r/min so as to maintain the hydraulic retention time of the reactor to be 8 h; the rotating speed of the brushless DC motor is 0.25N/m2The flow velocity of the simulated pipe is about 0.5 m/s;
NaClO and ClO are respectively adopted at three concentrations of 1mg/L, 2mg/L and 4mg/L2The disinfectant is input into the annular reactor for 30 days respectively; inputting the characteristics and temperature parameters of the nodular cast iron metal material into an electrochemical testing device in the testing process; after the open-circuit potential is stable, selecting a measurement method as polarization curve measurement, selecting a reference electrode as a saturated Ag/AgCl reference electrode, and setting a potential interval: 0.5mV, initial potential vs. open circuit potential-0.1V, termination potential vs. open circuit potential 0.1V, scan rate 0.5mV/s, coordinate type: potential-lg current; in addition, measurement of an alternating current impedance spectrum, a test method, steady state test, impedance and frequency scanning are carried out, parameter setting is carried out, and an alternating current amplitude value: 10mv, initial frequency: 100000Hz, stop frequency: 0.01Hz, 10 points and 10 times frequency.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710206854.9A CN107228822B (en) | 2017-03-31 | 2017-03-31 | Electrochemical testing device and method for corrosion of flow system sewer regeneration water pipeline system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201710206854.9A CN107228822B (en) | 2017-03-31 | 2017-03-31 | Electrochemical testing device and method for corrosion of flow system sewer regeneration water pipeline system |
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| CN107727564A (en) * | 2017-10-24 | 2018-02-23 | 天津大学 | The electrochemical testing device of metal microbiologic(al) corrosion under current system |
| CN108344784A (en) * | 2018-02-07 | 2018-07-31 | 东南大学 | A kind of vacuum condensing system with corrosion of piping on-Line Monitor Device |
| CN108760837A (en) * | 2018-07-20 | 2018-11-06 | 中国石油化工股份有限公司 | A kind of orifice-plate type oilfield sewage fouling on-line monitoring probe |
| CN109883939A (en) * | 2019-01-08 | 2019-06-14 | 清华大学 | A kind of Electrochemical Simulation test platform of research water process pipeline pipe scale development and rupture |
| CN110274940A (en) * | 2019-05-28 | 2019-09-24 | 清华大学 | It is a kind of to simulate the electrochemical appliance and test method that pipe scale is quickly formed |
| CN111470580A (en) * | 2020-04-07 | 2020-07-31 | 天津大学 | Electrochemical reaction system capable of exploring corrosion of tap water pipe wall and microbial growth |
| CN112920942A (en) * | 2021-01-27 | 2021-06-08 | 华东交通大学 | Water supply pipe network biofilm growth simulation device with multiple variable working conditions |
| CN113237827A (en) * | 2021-06-25 | 2021-08-10 | 清华大学 | Electrochemical test system for molten salt corrosion experiment |
| CN114112884A (en) * | 2021-12-07 | 2022-03-01 | 江苏容大材料腐蚀检验有限公司 | Detection method for steel corrosion performance under simulated seawater environment |
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| CN114739896A (en) * | 2022-05-16 | 2022-07-12 | 山东大学 | Simulated corrosion device and method meeting hanging piece experiment and three-electrode electrochemical experiment |
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| CN107727564A (en) * | 2017-10-24 | 2018-02-23 | 天津大学 | The electrochemical testing device of metal microbiologic(al) corrosion under current system |
| CN108344784A (en) * | 2018-02-07 | 2018-07-31 | 东南大学 | A kind of vacuum condensing system with corrosion of piping on-Line Monitor Device |
| CN108760837A (en) * | 2018-07-20 | 2018-11-06 | 中国石油化工股份有限公司 | A kind of orifice-plate type oilfield sewage fouling on-line monitoring probe |
| CN109883939A (en) * | 2019-01-08 | 2019-06-14 | 清华大学 | A kind of Electrochemical Simulation test platform of research water process pipeline pipe scale development and rupture |
| CN109883939B (en) * | 2019-01-08 | 2021-11-02 | 清华大学 | Electrochemical simulation test platform for development and breakage of scale of water treatment pipeline |
| CN110274940A (en) * | 2019-05-28 | 2019-09-24 | 清华大学 | It is a kind of to simulate the electrochemical appliance and test method that pipe scale is quickly formed |
| CN111470580A (en) * | 2020-04-07 | 2020-07-31 | 天津大学 | Electrochemical reaction system capable of exploring corrosion of tap water pipe wall and microbial growth |
| CN112920942A (en) * | 2021-01-27 | 2021-06-08 | 华东交通大学 | Water supply pipe network biofilm growth simulation device with multiple variable working conditions |
| CN113237827A (en) * | 2021-06-25 | 2021-08-10 | 清华大学 | Electrochemical test system for molten salt corrosion experiment |
| CN114199973A (en) * | 2021-11-18 | 2022-03-18 | 中国电建集团江西省电力设计院有限公司 | Flow accelerated corrosion experiment test analysis method and system thereof |
| CN114112884A (en) * | 2021-12-07 | 2022-03-01 | 江苏容大材料腐蚀检验有限公司 | Detection method for steel corrosion performance under simulated seawater environment |
| CN114739896A (en) * | 2022-05-16 | 2022-07-12 | 山东大学 | Simulated corrosion device and method meeting hanging piece experiment and three-electrode electrochemical experiment |
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