CN107459127B

CN107459127B - In-situ regulation and control municipal sewage pipeline sulfur conversion system and operation method thereof

Info

Publication number: CN107459127B
Application number: CN201710570436.8A
Authority: CN
Inventors: 远野; 卞爱琴; 丁成; 王爱杰; 陈天明; 李朝霞
Original assignee: Yancheng Institute of Technology
Current assignee: Yancheng Institute of Technology
Priority date: 2017-07-13
Filing date: 2017-07-13
Publication date: 2020-12-08
Anticipated expiration: 2037-07-13
Also published as: CN107459127A

Abstract

An in-situ regulation and control municipal sewage pipeline sulfur conversion system and an operation method thereof. The system comprises a municipal sewage pipeline sewage well cover, a microbial electrochemical system and a lifting frame system, wherein the upper end of the lifting frame system is fixed on the sewage well cover, the lower end of the lifting frame system is connected with the microbial electrochemical system, the lifting frame system comprises an upper support, a telescopic module, a lower support and a fixture, the telescopic module is fixed on the sewage well cover through the fixture, the upper support and the lower support form an X shape, the upper support and the upper end of the lower support are respectively fixed on two sides of the telescopic module, the lower end of the upper support is fixed on the lower support, the lower end of the lower support is connected with the microbial electrochemical system, the electrochemical system comprises a cathode group, an anode group, a lead and a telescopic sleeve, the cathode group and the anode group are connected through the lead sleeved with the telescopic sleeve, the telescopic sleeve is connected with the lower end of the lower support. The system has simple structure, good sulfur conversion effect and no pollution to the environment.

Description

In-situ regulation and control municipal sewage pipeline sulfur conversion system and operation method thereof

Technical Field

The invention belongs to the technical field of sewage treatment, and particularly relates to an in-situ regulation and control municipal sewage pipeline sulfur conversion system and an operation method thereof.

Background

Municipal sewer corrosion represents up to billions of dollars in worldwide economic losses per year, with hydrogen sulfide (H)₂S) corrosion by release has become one of the leading causes of sewer "shortlife". At the same time, the sewer line H₂Poisoning events caused by S release are frequent, and great threat is brought to the life health of municipal drainage facility maintenance workers. With the accelerated urbanization process of China, the total length of municipal drainage networks (rainwater and sewage pipelines) reaches 51 kilometers in the 'twelve five' period, and meanwhile, the municipal drainage networks are about to be gradually brought into an underground comprehensive pipe gallery in the 'thirteen five' period, so that the research on the municipal sewage pipelines H₂And the S control meets the national major engineering technical requirements.

Sulfate (SO) in municipal sewage₄ ^2-) The concentration is usually 20-200 mg/L, and the node discharge of the production wastewater of some enterprises into a pipe network can obviously increase SO₄ ^2-And (4) concentration. In anaerobic zones at the bottom of municipal sewage pipes, SO₄ ^2-Firstly, the sludge is converted into sulfide (S) under the action of bottom sludge Sulfate Reducing Bacteria (SRB)^2-），S^2-Then with hydrogen ions (H) in water⁺) Binding to produce H₂And S escapes. Municipal sewage pipeline is difficult to set up H₂S concentrates the collection processing means, hence, from H₂The source of S production, i.e. S in the wastewater^2-Generation and transformation of H₂The S release problem has strong practical significance. The traditional method is to add bactericide (such as sodium hypochlorite, molybdate and the like), strong base, metal ions and the like into a pipeline, inactivate through SRB, increase pH, and precipitate S^2-By suppressing or eliminating S in equal manner^2-Has the advantages of quick effect, high cost and adverse factors for the subsequent biochemical treatment of sewage plants. Biological conversion of S^2-The technology is relatively clean, mainly utilizes nitrate Nitrogen (NO)₃ ^-) Oxygen (O)₂) Isoelectron acceptor of S^2-Conversion to other form of compound sulfur (S)⁰，SO₄ ^2-，S₂O₃ ^2-Etc.) and the biological method is at S^2-The controllability of the converted target product is superior, and the cost is relatively low, so that the method becomes a hotspot and a key point of research and technical application.

In some key discharge points or sewage storage places in the sewage pipeline, such as discharge ports of residential dense areas, water outlets of chemical plants, key pump stations and other pipeline joints, S generated at the bottom of the pipeline is generally^2-Higher concentration of H₂The S release is stronger. NO₃ ^-The electronic receptors flow together with sewage in the pipeline, and the advantage is that the sewage pipeline with a certain length can be provided with the S of non-point source^2-And (5) controlling. At present, for generating S^2-The sewage pipeline nodes with higher concentration lack the point source sulfur conversion technology with strong applicability.

The microbial electrochemical technology/System (Bio-electrochemical System, Bes) is a redox reaction performed by at least one side of an anode and a cathode of a traditional electrochemical System under the catalysis of microorganisms, combines the advantages of the microorganisms and electrochemistry, can be used as a 'fixed' electron acceptor of the microorganisms, and has the advantages of no need of additionally providing the electron acceptor, strong reaction continuity, no secondary pollution and the like. The method is rapidly developed in the research fields of wastewater treatment, groundwater, bottom mud, soil remediation, energy recovery and the like, and aims to solve the problem of point source nature S of a sewage pipeline^2-The control provides a breach.

Disclosure of Invention

Aiming at the problem that the existing adding flowing electron acceptor is difficult to generate S for municipal sewage pipe network^2-The invention relates to a sewage well point position with higher concentration for strengthening control, and aims to provide a municipal sewage pipeline sulfur conversion system with in-situ regulation and control and an operation method thereof.

An in-situ regulation and control municipal sewage pipeline sulfur conversion system comprises a municipal sewage pipeline sewage well cover, a microbial electrochemical system and a lifting frame system, wherein the upper end of the lifting frame system is fixed on the sewage well cover, the lower end of the lifting frame system is connected with the microbial electrochemical system, the lifting frame system comprises an upper support, a telescopic module, a lower support and a fixture, the telescopic module is fixed on the sewage well cover through the fixture, the upper support and the lower support form an X shape, the upper ends of the upper support and the lower support are respectively fixed on two sides of the telescopic module, the lower end of the upper support is fixed on the lower support, the lower end of the lower support is connected with the microbial electrochemical system, the electrochemical system comprises a cathode group, an anode group, a lead and a telescopic sleeve, the cathode group and the anode group are connected through leads, the telescopic sleeve is sleeved outside the lead, and the telescopic sleeve is, the cathode set is located at the junction of the sewage surface and the air, and the anode set is located at the bottom of the sewage pipeline.

The improved sewage well cover structure is characterized in that the telescopic module consists of a spring and thick wires, the upper ends of the upper support and the lower support are respectively fixed on two sides of the spring, two ends of the spring are connected through the thick wires, one end of each thick wire is fixed on a screw, and the screw is fixed on a sewage well cover.

The improvement is that the cathode group is horizontally arranged at the junction of the sewage surface and the air, and the anode group is arranged at an angle of 0-90 degrees with the pipeline.

The improvement is that the lead is positioned outside the telescopic sleeve and is wrapped by a PE pipe, the anode group is formed by connecting three pairs of anode electrodes in parallel, each pair of anode electrodes is longitudinally symmetrical, and the cathode group is formed by connecting three cathode electrodes in parallel.

The improvement is that each anode electrode is a cylinder surrounded by four carbon fiber conductive brushes, and the diameter of each carbon fiber conductive brush is 50-100 mm and the length of each carbon fiber conductive brush is 150-500 mm.

As a modification, each cathode electrode is a cylinder composed of four oval spirals made of carbon paper.

The improvement is that the anode electrodes in the anode group are subjected to film forming treatment before installation, and are connected to the lead in parallel.

As an improvement, the lifting frame system also comprises a bearing platform, wherein the bearing platform is fixed on the sewage well cover and is connected and fixed with the telescopic module through a fixture.

The operation method of the in-situ regulation and control municipal sewage pipeline sulfur conversion system comprises the following steps: installing sewage well cover, lifting frame system and microbial electrochemical system, and municipal sewage pipeline containing SO₄ ^2-The sewage is reduced into S by sulfate reducing bacteria in the sludge at the bottom of the municipal sewage pipeline^2-Then oxidized into S by an anode electrode in an anode group of an anaerobic zone at the bottom of the municipal sewage pipeline⁰Simultaneously generated S⁰Rapidly separating the anode electrode from the cathode electrode by the action of hydraulic scouring; and a cathode electrode in the cathode group arranged at the junction of the sewage surface and the air receives electrons transmitted by the anode group to reduce oxygen into water, and the positions of the anode group and the cathode group are respectively adjusted by the crane system and the telescopic sleeve in the operation process to finish the conversion of sulfur in the sewage.

Has the advantages that:

the cathode group of the invention adopts a floating electrode which is automatically adjusted along with the change of water level and is formed by making four carbon papers with lighter weight into an elliptical spiral shape, when water flows pass through, the water flow can be used for pushing the cathode to rotate so as to bring oxygen in the air into the water surface, the concentration of dissolved oxygen near the cathode is improved, and the reaction rate of the oxygen receiving electrons at the cathode to be reduced into water is accelerated;

the anode electrode material of the anode group is the carbon fiber brush with good biocompatibility, the cost is low, the specific surface area is large, the attachment growth of microorganisms is facilitated, the film forming effect is good, the transfer of electrons can be promoted, the current density is increased, when water flows, the water flow scours the electrode, elemental sulfur is rapidly separated from the electrode, meanwhile, the rotation of the anode is also promoted, the reaction contact area is increased, and the conversion from sulfide to elemental sulfur is accelerated;

because a single electrode is influenced by factors such as water power, water quality, flow velocity, microbial metabolism speed, extracellular electron transfer rate and the like, the electron flow of the single electrode is greatly limited, the cathode group and the anode group of the invention all adopt a parallel connection mode, the cathodes are arranged at the junction of the sewage surface and the air side by side, the anodes are arranged at the bottom of the sewage pipeline side by side, the arrangement angle of the cathode group is parallel to the water flow direction, and thus, the reduction reaction rate of the cathodes is greatly improved; the crane system in the invention provides great convenience for the maintenance and overhaul of the microbial electrochemical system.

Drawings

FIG. 1 is a schematic structural view of a system according to example 1 of the present invention, wherein 1-a manhole cover, 2-an upper rack, 3-sulfate reducing bacteria, 4-a lower rack, 5-a fixture, 7-a cathode set, 8-an anode set, 9-a telescopic tube, 10-a spring, 11-a thick line, 12-a carrier, and 13-a screw;

FIG. 2 is a top view of an anode stack in the system of the present invention;

FIG. 3 is a top view of a cathode assembly in the system of the present invention;

FIG. 4 is a view of the internal structure of the sleeve at the junction of the anode and cathode sets in the system of the present invention, with 6-wires;

FIG. 5 shows the sun in the system of the present inventionWhen the pole group and the pipeline form different angles, sewage SO₄ ^2-Sulfur conversion product (SO) in the wastewater under the condition of concentration of 150 +/-5 mg/L₄ ^2-、S^2-、S⁰、H₂S、S₂O₃ ^2-) The concentration ratio of (a);

FIG. 6 shows the system of the present invention in different concentrations of SO₄ ^2-Sulfur conversion product (SO) in wastewater₄ ^2-、S^2-、S⁰、H₂S、S₂O₃ ^2-) The concentration ratio of (a);

FIG. 7 shows different SO concentrations₄ ^2-Sulfur conversion products (SO) in sewer lines₄ ^2-、S^2-、S⁰、H₂S、S₂O₃ ^2-) The concentration ratio of (a).

Detailed Description

The technical scheme of the invention is explained in detail by combining the attached drawings and the embodiment.

Example 1

The utility model provides an in situ control municipal administration sewage pipe sulphur conversion system, includes municipal administration sewage pipe sewer well lid, microbial electrochemical system and crane system, crane system upper end is fixed on sewer well lid 1, and the microbial electrochemical system is connected to the lower extreme, crane system includes upper bracket 2, flexible module, lower carriage 4, fixture 5, flexible module passes through fixture 5 to be fixed on sewer well lid 1, upper bracket 2 forms the X type with lower carriage 4, and upper bracket 2 and the upper end of lower carriage 4 are fixed respectively in flexible module both sides, and flexible module shrink changes the size of X type angle, accomplishes flexible purpose, realizes the change of microbial electrochemical system's position. The lower end of the upper support 2 is fixed on the lower support 4, the lower end of the lower support 4 is connected with a microbial electrochemical system, the electrochemical system comprises a cathode group 7, an anode group 8, a lead 6 and a telescopic sleeve 9, the cathode group 7 and the anode group 8 are connected through the lead 6, the telescopic sleeve 9 is sleeved outside the lead 6, the telescopic sleeve 9 is connected with the lower end of the lower support 4, the cathode group 7 is located at the junction of a sewage surface and air, and the anode group 8 is located at the bottom of a sewage pipeline.

In order to prevent short circuit, the part of the lead 6 outside the telescopic sleeve 9 is wrapped by a PE tube, and then the lead and an external resistor are connected by adopting conductive paste and a plastic clamp to form a closed loop. In addition, when the cathode group 7 changes along with the water level, the PE tube of the cathode group 7 connected with the upper part of the telescopic sleeve 9 moves up and down along with the water level, the PE tube of the anode group 8 connected with the lower part of the telescopic sleeve 9 is fixed on the lifting frame, and the lead 6 in the telescopic sleeve 9 can be prolonged or shortened along with the change of the position of the cathode group 7.

The telescopic module is composed of a spring 10 and a thick line 11, the upper ends of the upper support 2 and the lower support 4 are respectively fixed on two sides of the spring 10, two ends of the spring 10 are connected through the thick line 11, one end of the thick line 11 is fixed on a screw 13, and the screw 13 is fixed on the sewage well cover 1. In the operation process, the thick line 11 is drawn by rotating the screw 13 to drive the spring 10 to deform, so that the degree of the X-shaped included angle between the upper bracket 2 and the lower bracket 4 is changed, the upper bracket 2 and the lower bracket 4 are close to or far away from the sewage well cover 1, and the position change of the microbial electrochemical system is completed; when all supports are close to the sewage well cover 1, the lifting frame system and the microbial electrochemical system can be taken out together by moving the sewage well cover 1, so that the maintenance and overhaul of the microbial electrochemical system are facilitated.

In a further improvement, the lifting frame system further comprises a bearing table 12, wherein the bearing table 12 is fixed on the sewage well cover 1 and is fixedly connected with the telescopic module through a fixing object 5. The distance change at the two ends of the spring can be realized by rotating the screw 13, the contraction process is completed, and the bearing table 12 can reduce the abrasion of the screw 13 to the sewage well cover.

Each anode electrode of the anode group 8 is a cylinder surrounded by four carbon fiber conductive brushes, the diameter of the carbon fiber conductive brush is 50-100 mm, and the length is 150-500 mm, the carbon fiber conductive brush is selected because the carbon fiber has good biocompatibility and large specific surface area, which is beneficial to the attachment growth of microorganisms, and the film hanging effect is good, thereby promoting the transmission of electrons and increasing the electrode density, when water flows through, the electrode is washed, so that elemental sulfur is rapidly separated from the electrode, meanwhile, the rotation of the anode is also promoted, the reaction contact area is increased, and the conversion of sulfide to elemental sulfur is accelerated.

As an improvement, the anode electrode of the anode group 8 can acclimate the anode sulfur oxidation biological membrane with catalytic activity by an electroactive microorganism enrichment potential before installation, namely, the membrane hanging treatment comprises the following specific steps: adopting a three-electrode system and Ag/AgCl as a reference electrode, and mixing the crushed anaerobic granular sludge and the simulated sulfide-containing sewage according to the proportion of 1: adding the sludge into a working electrode chamber of an electrochemical reactor which is sterilized by high pressure in a ratio of 1, taking the sludge from a device which is subjected to denitrification desulfurization acclimation before, and then aerating mixed gas of 70% nitrogen and 30% carbon dioxide for 20 min to remove dissolved oxygen in a culture solution and air at the top of the reactor. The 8 high-efficiency sulfur-oxidizing strains screened earlier were shake-cultured overnight (at 180 rpm at 30 ℃) in LB medium. Taking 2 mL of 8 high-efficiency sulfur oxidation strains cultured overnight, inoculating the 8 high-efficiency sulfur oxidation strains in an electrochemical reaction working electrode chamber, controlling the pH value in the electrochemical reaction working chamber to be 8.0-8.5, and controlling the potential of the working electrode through an electrochemical workstation to keep the potential at-0.27V. The anaerobic sludge and the simulated sulfide-containing sewage are replaced every day in the first 5 days, and then the pure simulated sulfide-containing sewage is used for culturing, in the process, the working electrode chamber is continuously aerated, and the temperature is kept at 30 ℃.

Each cathode electrode in the cathode group 7 is a cylinder consisting of four oval helices made of carbon paper, and the cathode group 7 is positioned at the junction of the sewage surface and the air and is parallel to the water flow direction during installation, so that the reduction reaction rate of the cathode is greatly improved.

Example 2

The operation method for in-situ regulation and control of the municipal sewage pipeline sulfur conversion system comprises the following steps: installing sewage well cover, lifting frame system and microbial electrochemical system, and municipal sewage pipeline containing SO₄ ^2-The sewage is reduced into S by sulfate reducing bacteria 3 in the sludge at the bottom of the pipeline^2-Then oxidized into S by the anode in the anode group 8 of the anaerobic zone at the bottom of the pipeline⁰Simultaneously generated S⁰Rapidly separating the anode by the action of hydraulic scouring; cathode set arranged at junction of sewage surface and airThe cathode in 7 receives the electrons from the anode to reduce oxygen into water. And in the operation process, the microbial electrochemical system is maintained and overhauled by the crane system. The invention samples the sewage in the system to monitor the concentration change of the sulfur conversion product and samples the gas above the sewage well cover 1 to determine H₂The concentration of S.

Example 3

SO in general sewage₄ ^2-The concentration fluctuation range is 20-200 mg/L, and in order to investigate the value of the angle between the anode group and the pipeline, the invention has the best effect on the sulfur conversion of the sewage pipeline₄ ^2-A set of control cases (i.e., the anode group and the tube are at 0 degree, 30 degree, 45 degree, 60 degree and 90 degree) was made at a concentration of 150 + -5 mg/L, and the procedure and the contents were the same as above except that the angles of the anode group and the tube were different.

From FIG. 5, it can be seen that in SO₄ ^2-When the concentration is 150 +/-5 mg/L and the anode group and the pipeline form an angle of 0 degree, 30 degrees, 45 degrees, 60 degrees and 90 degrees, S in the sulfur conversion product⁰The percentage of S in the sulfur form is 67%, 70%, 83%, 68%, 60%, respectively^2-The proportion is 19%, 8%, 4%, 9% and 14%, therefore, the arrangement of 45 degrees between the anode group and the pipeline is more beneficial to the sulfur conversion of the sewage pipeline relative to other angles, the conversion from sulfide to elemental sulfur is accelerated, the mass transfer rate of the electrode and the liquid phase and the separation rate of elemental sulfur, toxic substances and the electrode by water flow scouring are improved.

Example 4

On the basis of example 3, under the condition that the included angle between the anode group and the pipeline is 45 degrees, different sewage SO are used₄ ^2-The concentration (50 + -1.6 mg/L, 100 + -3.4 mg/L, 150 + -5 mg/L, 200 + -4.5 mg/L) is used for inspecting the SO content in the sewage₄ ^2-The operation stability and the operation effect of the system under the concentration fluctuation. At the same time, a control group contrast S is set^2-、H₂S a reduction effect.

As can be seen from FIG. 6, the system of the present invention produces sulfur conversion products (SO) at different wastewater concentrations₄ ^2-、S^2-、S⁰、H₂S、S₂O₃ ^2-) Ratio of (A) to (B), S^2-The removal rate is up to more than 90 percent, S⁰Conversion greater than 85%, H₂The S yield is lower than 4%;

as can be seen in figure 7, S is produced in the sewer without implanted electrodes^2-No significant change in concentration, H₂The S yield is higher than 20%, so that the effect of in-situ regulation and control of the municipal sewage pipeline sulfur conversion system is obvious, and the sulfur conversion effect is stable under different sewage concentration fluctuations.

In addition, the present invention is not limited to the above embodiments, and may be implemented in various ways without departing from the scope of the invention.

Claims

1. An in-situ regulation and control municipal sewage pipeline sulfur conversion system is characterized by comprising a municipal sewage pipeline sewage well cover, a microbial electrochemical system and a lifting frame system, wherein the upper end of the lifting frame system is fixed on the sewage well cover, the lower end of the lifting frame system is connected with the microbial electrochemical system, the lifting frame system comprises an upper support, a telescopic module, a lower support and a fixture, the telescopic module is fixed on the sewage well cover through the fixture, the upper support and the lower support form an X shape, the upper ends of the upper support and the lower support are respectively fixed on two sides of the telescopic module, the lower end of the upper support is fixed on the lower support, the lower end of the lower support is connected with the microbial electrochemical system, the electrochemical system comprises a cathode group, an anode group, a lead and a telescopic sleeve, the cathode group and the anode group are connected by leads, the telescopic sleeve is sleeved outside the leads, and the telescopic sleeve is connected, the cathode group is positioned at the junction of the sewage surface and the air, and the anode group is positioned at the bottom of the sewage pipeline; the telescopic module consists of a spring and thick wires, the upper ends of the upper bracket and the lower bracket are respectively fixed on two sides of the spring, two ends of the spring are connected by the thick wires, one end of each thick wire is fixed on a screw, and the screw is fixed on a sewage well cover; the cathode group is horizontally arranged at the junction of a sewage surface and air, and the anode group and the pipeline form an angle of 45 degrees; the lead is positioned outside the telescopic sleeve and is wrapped by a PE pipe, the anode group is formed by connecting three pairs of anode electrodes in parallel, each pair of anode electrodes are longitudinally symmetrical, and the cathode group is formed by connecting three cathode electrodes in parallel; each anode electrode is a cylinder surrounded by four carbon fiber conductive brushes, the diameter of each carbon fiber conductive brush is 50-100 mm, and the length of each carbon fiber conductive brush is 150-500 mm; each cathode electrode is a cylinder consisting of four oval helices made of carbon paper; the anode electrodes in the anode group are subjected to film forming treatment before being installed, and are connected in parallel and then connected to the lead; the lifting frame system also comprises a bearing table, wherein the bearing table is fixed on the sewage well cover and is connected and fixed with the telescopic module through a fixture; the film forming method comprises the following specific steps: adopting a three-electrode system and Ag/AgCl as a reference electrode, and mixing the crushed anaerobic granular sludge and the simulated sulfide-containing sewage according to the proportion of 1: adding the sludge into a working electrode chamber of an electrochemical reactor which is sterilized by high pressure in a proportion of 1, taking the sludge from a device which is subjected to denitrification, desulfurization and acclimation before, and then aerating mixed gas of 70% nitrogen and 30% carbon dioxide for 20 min to remove dissolved oxygen in a culture solution and air at the top of the reactor; carrying out shake culture on 8 high-efficiency sulfur-oxidizing strains screened at the early stage in LB culture solution overnight; taking 2 mL of 8 high-efficiency sulfur oxidation strains cultured overnight, inoculating the 8 high-efficiency sulfur oxidation strains in an electrochemical reaction working electrode chamber, controlling the pH value in the electrochemical reaction working chamber to be 8.0-8.5, and controlling the potential of a working electrode through an electrochemical workstation to keep the potential of the working electrode at-0.27V; the anaerobic sludge and the simulated sulfide-containing sewage are replaced every day in the first 5 days, and then the pure simulated sulfide-containing sewage is used for culturing, in the process, the working electrode chamber is continuously aerated, and the temperature is kept at 30 ℃.

2. The method of claim 1 for in-situ regulation of operation of a municipal sewage pipeline sulfur conversion system, comprising the steps of: installing a sewage well cover, a lifting frame system and a microbial electrochemical system, wherein SO4 is contained in a municipal sewage pipeline^2-The sewage is reduced into S by sulfate reducing bacteria in the sludge at the bottom of the municipal sewage pipeline^2-Then oxidized into S by an anode electrode in an anode group of an anaerobic zone at the bottom of the municipal sewage pipeline⁰Simultaneously generated S⁰Through the action of hydraulic scouring and the anode electrodeSeparating rapidly; and a cathode electrode in the cathode group arranged at the junction of the sewage surface and the air receives electrons transmitted by the anode group to reduce oxygen into water, and the positions of the anode group and the cathode group are respectively adjusted by the crane system and the telescopic sleeve in the operation process to finish the conversion of sulfur in the sewage.