CN210021726U

CN210021726U - Device for biologically and ectopically degrading organic matters

Info

Publication number: CN210021726U
Application number: CN201821833070.5U
Authority: CN
Inventors: 李楠; 赵倩; 安敬昆; 王舒
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2018-11-08
Filing date: 2018-11-08
Publication date: 2020-02-07
Anticipated expiration: 2028-11-08

Abstract

The utility model discloses a device for biological ex-situ degradation of organic matter, which adopts microbial electrochemistry/advanced oxidation coupling to degrade organic matter system, and the system is composed of synthetic H₂O₂And UV/H₂O₂An advanced oxidation system; the synthesis of H₂O₂The microbial electrochemical system of (a) is constructed as follows: the carbon brush and the graphite-carbon black mixed roll-in air cathode are respectively used as an anode and a cathode; the UV/H₂O₂Construction of an advanced oxidation system: the system mainly comprises a reactor and magnetic stirringThe stirrer, the support frame and the low-pressure mercury lamp suspended above the reactor; the synthesis of H₂O₂The cathode chamber of the microbial electrochemical system is pumped with water to remove H₂O₂Transport to UV/H₂O₂In the reactor of the system. The utility model discloses avoid H₂O₂Transportation and storage.

Description

Device for biologically and ectopically degrading organic matters

Technical Field

The utility model relates to an organic pollutant degradation field, in particular to biological heterotopic degradation organic matter's device.

Background

Along with the improvement of living standard of people, the level of people to interior decoration is gradually improved, and the indoor air pollution degree is also correspondingly increased. According to statistics, the pollution degree of indoor air is generally 2-5 times that of outdoor air, and even exceeds 100 times in individual occasions. Formaldehyde (CH)₂O), as an important industrial raw material, is widely used in the industries of construction, wood processing, furniture, textiles, chemical engineering and the like, and formaldehyde is also one of the main indoor air pollutants, and is classified as a human carcinogen which may cause nasopharyngeal carcinoma and leukemia, and chronic poisoning, allergy, asthma, lung damage, cancer and even death can be caused after long-term exposure or exposure in a high-dose formaldehyde environment, so that a serious threat is brought to human health. Formaldehyde, a colorless liquid, is volatile, has an pungent odor, and is readily soluble in water, alcohols, and ethers. At present, various methods such as plant purification technology, gas stripping method, porous medium adsorption technology, biodegradation method, photocatalytic oxidation method, advanced oxidation technology and the like are available for removing formaldehyde.

Biological processes are considered to be an economical, green, environmentally friendly method of degrading organic pollutants. The biological method is to utilize microorganisms to degrade and metabolize organic matters into inorganic matters, and simultaneously, the organic matters provide energy and nutrients for the microorganisms. However, formaldehyde has antiseptic and bactericidal properties, and 35% -40% formaldehyde aqueous solution, namely formalin is commonly used for dipping biological specimens and disinfecting seeds, so that the biological toxicity of formaldehyde can cause the reduction of biological activity, thereby greatly inhibiting the application of formaldehyde in-situ degradation by a biological method.

Advanced Oxidation Processes (AOPs) are a promising approach to organic wastewater treatment. The advanced oxidation technology is to oxidize refractory organic matter into low-toxic or non-toxic organic matter by utilizing the free radicals with strong oxidizing property generated under the reaction conditions of high temperature, high pressure, electricity, sound, light radiation, catalyst, etcThe small molecule substance of (1). The advanced oxidation technology has the characteristics of strong oxidation capacity, small selectivity and high reaction speed, so the advanced oxidation technology is often used for removing environmental pollutants, and simultaneously has the problems of higher cost of chemical reagents, stricter requirements on reaction conditions (pH, temperature and the like), difficult catalyst recovery and the like. The advanced oxidation technique generally selects H₂O₂，H₂O₂The reagent is prepared by anthraquinone method. But anthraquinone oxidation process for H production₂O₂The steps are complicated, objective unsafe factors exist in the production process, the involved combustible and explosive substances have many varieties and large quantity, and H is₂O₂Is a strong oxidant, has active property and has strict requirements on external conditions and container materials in the processes of storage, packaging and transportation, so that an in-situ self-synthesized H is searched₂O₂The technique of (2) is particularly important.

Bioelectrochemical systems (BESs), also known as microbial electrochemical Systems (MXCs), are an emerging technology capable of effectively recovering energy (electricity, hydrogen, methane, etc.) and resources, have received widespread worldwide attention, and exhibit great and broad development potential. In recent years, studies have demonstrated the production of hydrogen peroxide (H) from renewable energy sources in wastewater₂O₂) The possibility of (a). BES mainly comprises an anode, a cathode and an ion exchange membrane, and the main principle is that Electrochemical Active Bacteria (EAB) on the anode directly oxidize soluble organic waste, and generated electrons are transferred to the cathode through an external circuit and are used for oxygen to generate water through a four-electron reduction way or generate hydrogen peroxide through a two-electron way. Synthesis of H in BES₂O₂In the synthesis of (a), carbon materials are often used as raw materials for BES cathodes due to their advantages of high conductivity, high catalytic activity, good stability, low cost, etc.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art and provide a device for the heterotopic degradation of organic matters in biology. Based on UV/H₂O₂The principle of advanced oxidation, combined with the microbial biosynthesis of BES for H₂O₂By BES and UV/H₂O₂The coupling of (a) to (b) to develop a microbial-based synthesis of H₂O₂UV/H of₂O₂The method for ectopically degrading the organic matters including formaldehyde in the system is green, efficient and rapid.

The utility model discloses a solve the technical problem who proposes in the background art, the technical scheme of adoption is: a device for ectopically degrading organic matters in organisms adopts a microbial electrochemistry/advanced oxidation coupling degradation organic matter system which synthesizes H₂O₂And UV/H₂O₂An advanced oxidation system;

the synthesis of H₂O₂The microbial electrochemical system of (a) is constructed as follows: the carbon brush and the graphite-carbon black mixed roll-in air cathode are respectively used as an anode and a cathode;

the power supply is respectively connected with the anode and the cathode through leads and is used for applying bias voltage to the microbial electrochemical system;

the UV/H₂O₂Construction of an advanced oxidation system: the system mainly comprises a reactor, a magnetic stirrer, a height-adjustable support frame and a low-pressure mercury lamp which is suspended above the reactor;

the synthesis of H₂O₂The cathode chamber of the microbial electrochemical system is pumped with water to remove H₂O₂Transport to UV/H₂O₂In the reactor of the system.

The graphite-carbon black mixed rolled air cathode consists of a catalytic layer, a diffusion layer and a stainless steel net.

The catalytic layer is prepared from the following components in percentage by mass of 5: 1, dissolving graphite and carbon black in absolute ethyl alcohol, ultrasonically stirring, dropwise adding a polytetrafluoroethylene suspension, ultrasonically stirring, evaporating redundant absolute ethyl alcohol in a water bath to form a dough, and rolling layer by a rolling machine to obtain the graphite and carbon black; the diffusion layer is made of carbon black through the steps, after calcination, the diffusion layer and the catalyst layer are respectively rolled on two surfaces of a steel mesh, and finally the graphite-carbon black mixed rolled air cathode is manufactured.

When the anode microorganisms are domesticated, the cathode is an activated carbon air cathode and consists of an activated carbon catalyst layer, a carbon black diffusion layer and a stainless steel net.

The distance between the low-pressure mercury lamp and the interface of the reaction liquid in the reactor is set to be 2-5 cm.

The bottom of the reactor is provided with a magnetic stirrer.

Advantageous effects

1. The microorganism does not need to be in direct contact with the formaldehyde pollutant to be treated, thereby avoiding the problem that the biological activity is inhibited due to the toxicity of formaldehyde in the formaldehyde which is degraded in situ by organisms.

2.UV/H₂O₂H in advanced oxidation systems₂O₂Derived from a microbial electrochemical system, is synthesized by microbes in an ectopic way, only needs to control the connection of a circuit and give a very low bias voltage without adding, saves the cost, and avoids H₂O₂Transportation and storage.

3. The system has low cost, and organic glass, a graphite-carbon black mixed air cathode, a water pump and a low-pressure mercury lamp are all cheap and easy to obtain.

4. The system can control the formaldehyde treatment speed and intensity by controlling the bias voltage and H₂O₂The time is accumulated, and the operation is simple and convenient.

5. The maximum degradation rate of the biological in-situ degradation formaldehyde can reach 40.3 percent, the time is 24 hours, but the same microorganism source is adopted, the microorganism consumes soluble organic matters by using a microorganism electrochemical system, and the generated electrons reach a cathode through an external circuit for H₂O₂Synthesis of (2), H produced₂O₂For UV/H₂O₂Degrading formaldehyde under the system, thereby realizing the ectopic degradation of the formaldehyde by microorganisms, the highest degradation rate of the formaldehyde under the same initial concentration of the formaldehyde can reach 100 percent, the degradation rate is improved by 1.48 times after 45min, the time is saved by 97 percent, and the method is used for synthesizing H₂O₂The BES system has low energy consumption.

6. The device is not only suitable for removing formaldehyde, but also suitable for BES/AOPs system for volatile organic compounds and refractory materialsRemoving decomposed organic matter by adjusting bias voltage H₂O₂And (4) optimizing treatment effects of experimental parameters such as accumulation time, pH and the like.

Drawings

FIG. 1 is a schematic structural diagram of an apparatus for heterotopic degradation of organic matters by a BES/AOPs coupling system.

Reference numerals: 1-carbon brush, 2-anode chamber, 3-cation exchange membrane, 4-cathode chamber, 5-graphite-carbon black mixed rolling air cathode, 6-microbial electrochemical system, 7-water pump, 8-power supply, 9-rubber tube, 10-low-pressure mercury lamp, 11-reactor, 12-magnetic stirrer, 13-support frame, 14-water outlet and 15-wire.

Detailed Description

The invention is further described with reference to the following figures and specific embodiments.

A device for ectopically degrading organic matters in organisms adopts a microbial electrochemistry/advanced oxidation coupling degradation organic matter system which synthesizes H₂O₂Microbial electrochemical System (BES)6 and UV/H₂O₂An advanced oxidation system; the synthesis of H₂O₂The cathode chamber 4 of the microbial electrochemical system (BES)6 is connected with H through a rubber tube 9 and a water pump 7₂O₂Transport to UV/H₂O₂Within the reactor 11 of the system; the synthesis of H₂O₂The microbial electrochemical system (BES)6 of (4) was constructed as follows: consists of an anode chamber 2 with the size of 4cm multiplied by 7cm and a cathode chamber 4 with the size of 2cm multiplied by 7cm, which are separated by a cation exchange membrane 3, and a carbon brush 1 and a graphite-carbon black mixed roller air cathode 5 which are respectively used as an anode and a cathode; the graphite-carbon black mixed rolled air cathode 5 consists of a catalyst layer, a diffusion layer and a stainless steel mesh: the catalytic layer is prepared from the following components in percentage by mass of 5: 1, dissolving graphite and carbon black in absolute ethyl alcohol, ultrasonically stirring, dropwise adding a polytetrafluoroethylene suspension, ultrasonically stirring, evaporating redundant absolute ethyl alcohol in a water bath to form a dough, and rolling layer by a rolling machine to obtain the graphite and carbon black; the diffusion layer is made of carbon black through the steps, after calcination, the diffusion layer and the catalyst layer are respectively rolled on two surfaces of a steel mesh, and finally the graphite-carbon black mixed rolled air cathode is manufactured. TameWhen the anode microorganisms are dissolved, the cathode is an activated carbon air cathode and consists of an activated carbon catalyst layer, a carbon black diffusion layer and a stainless steel net. After acclimatization, the graphite-carbon black air cathode is changed into a double chamber to produce hydrogen peroxide.

The UV/H₂O₂Construction of an advanced oxidation system: the system mainly comprises a reactor 11, a magnetic stirrer 12, a height-adjustable support frame 13 and a low-pressure mercury lamp 10 (power 4W, wavelength 254nm) (UV 254) which is suspended above the reactor 11; the distance between the low-pressure mercury lamp 10 and the interface of the reaction solution is set to be 2-5cm, and the pH value of the solution is adjusted to be 3 +/-0.5. The magnetic stirrer 12 is arranged at the bottom of the reactor 11.

The power supply 8 is connected to the anode carbon brush 1 and the graphite-carbon black mixed roll air cathode 5 through wires 15, respectively, for applying a bias voltage to the microbial electrochemical system (BES) 6.

The utility model discloses a working process: 3 carbon brushes 1 are used as carriers of anode microorganisms and are uniformly fixed at one end of an anode of a microbial electrochemical system (BES)6, a cathode is composed of a graphite-carbon black mixed rolled air cathode 5, and the middle of the cathode is separated by a cation exchange membrane 3 to form an anode chamber 2 and a cathode chamber 4 respectively. Wherein, the lower end of the cathode chamber 4 is provided with a water outlet 14. The microorganisms on the carbon brush of the anode chamber 4 consume acetate, electrons generated by metabolism reach the cathode through an external circuit, protons reach the cathode through the cation exchange membrane 3, and the graphite-carbon black mixed roll air cathode 5 catalyzes and synthesizes hydrogen peroxide. The hydrogen peroxide generated in the cathode chamber 4 is connected to a water pump 7 through a rubber pipe 9 from a water outlet, and one end of an outlet of the water pump 7 flows into a reactor 11 of the UV/H2O2 system through the rubber pipe 9. The low-pressure mercury lamp 10 and the magnetic stirrer 12 are turned on, the inflowing hydrogen peroxide and the pollutants in the reactor 11 react under the irradiation of UV, and finally the degradation of the pollutants is realized.

The utility model discloses an effect that the device biological dystopy degrades organic matter is explained in detail to following embodiment, adopts the better formaldehyde of representativeness to expand the explanation:

example 1

The in-situ biodegradation of formaldehyde is carried out by two methods, one is a microorganism suspension growth system, and the other is a biological membrane system, and the method comprises the following steps:

1) the suspended growth system is prepared by taking sewage from sewage treatment plant as the source of microorganism, and adding nutrient components [ sodium acetate 1.0 g.L ] required by microorganism^-1Phosphate buffer (50mM PBS, NH)₄Cl 0.31g·L^-1,KCl 0.13g·L^-1,NaH₂PO₄·2H₂O2.772g·L^-1,Na₂HPO₄4.576g·L^-1) 12.5 mL. L of metal solution^-1And vitamin solution 5 mL. L^-1]And (3) aerating oxygen to the solution for 10min, respectively adding high-concentration formaldehyde solutions to make the concentrations of the formaldehyde solutions be 6, 8, 10 and 20mg/L, respectively, sealing by using tinfoil paper and a preservative film, and treating for 24 h.

2) The biofilm system is that sewage from sewage treatment plant is used as the source of carbon cloth enriched microorganism, the nutrient components needed by microorganism are added, the microorganism is enriched on the carbon cloth after one week of culture, then the culture solution is replaced, oxygen is aerated for 10min, high-concentration formaldehyde solution is added respectively to make the concentration of the formaldehyde solution be 6mg/L, 8mg/L, 10mg/L and 20mg/L, and the solution is sealed by tinfoil paper and preservative film and treated for 24 h.

The experimental results show that: degrading formaldehyde in situ according to a microbial suspension growth system in the step 1) and degrading formaldehyde in situ according to microbes in a biofilm system in the step 2), wherein the degradation rates of formaldehyde with initial concentrations of 6mg/L, 8mg/L, 10mg/L and 20mg/L are 35.2%, 26.1%, 18%, 17.5% and 40.3%, 26%, 12% and 12% respectively.

Example 2

Adopt the utility model discloses, based on little biological electrochemical system synthesis H₂O₂And the method for biologically and ectopically degrading formaldehyde comprises the following steps:

1) placing graphite-carbon black mixed rolled air cathode into cathode chamber of microorganism electrochemical system with domesticated anode, separating the two chambers with cation exchange membrane to form dual-chamber BES, wherein the cathode chamber is 50mM Na₂SO₄Solution, and culturing for two periods to make the anode biological adapt to the environment.

2) Between cathode and anodeBias voltage of 0.6V for 1H, and water pump to accumulate H in cathode chamber₂O₂Transfer of the solution to UV/H₂O₂In the reaction vessel, high-concentration formalin solution was dropped so that the concentration was 6mg/L, 8mg/L, 10mg/L and 20mg/L, respectively, the pH of the solution was adjusted to 3, the light paths were set at 2cm and 5cm, and the stirrer and the low-pressure mercury lamp were turned on and irradiated for 30 min.

The experimental results show that: the degradation rates at optical path lengths of 2cm and 5cm for 6mg/L, 8mg/L, 10mg/L and 20mg/L initial concentrations of formaldehyde, according to step 1) by loading a graphite-carbon black hybrid roll-pressed air cathode into the BES and under the experimental parameters set in step 2) are given in Table 1 below:

TABLE 1

Example 3

2) Applying 0.6V bias voltage between the cathode and the anode for 0H, 0.5H, 1.0H and 1.5H, and transferring the hydrogen peroxide solution accumulated in the cathode chamber for 0H, 0.5H, 1.0H and 1.5H to UV/H with a water pump₂O₂In the reaction vessel, high concentration formalin solution was added dropwise to a concentration of 6mg/L, the pH of the solution was adjusted to 3, the optical path was set at 2cm, and the stirrer and the low-pressure mercury lamp were turned on to irradiate for 30 min.

The experimental results show that: loading graphite-carbon black mixed rolled air cathode into BES according to the step 1) and under the experimental parameters set in the step 2), under different H₂O₂The degradation rates at cumulative time (0h, 0.5h, 1.0h, 1.5h) for formaldehyde at an initial concentration of 6mg/L were 0.4%, 40.5%, 57.4% and 78.2%, respectively.

Example 4

2) Applying 0.6V bias voltage between the cathode and the anode for 1.5H, and pumping the hydrogen peroxide solution accumulated in the cathode chamber to UV/H₂O₂In the reaction vessel, high concentration formalin solution was dropped so that the concentration was 6mg/L, the pH of the solution was adjusted to 3, 7 and 10, respectively, the optical path was set at 2cm, and the stirrer and the low-pressure mercury lamp were turned on to irradiate for 30 min.

The experimental results show that: the degradation rates for 6mg/L of formaldehyde at the initial concentration of 6mg/L at different initial solution pH (3, 7, 10) were 78.2%, 59.6% and 50.5%, respectively, with the graphite-carbon black mixed rolled air cathode loaded into the BES according to step 1) and with the experimental parameters set in step 2).

Example 5

2) Applying 0.6V bias voltage between the cathode and the anode for 1.5H, and pumping the hydrogen peroxide solution accumulated in the cathode chamber to UV/H₂O₂Dropwise adding high-concentration formaldehyde solution into the reaction container to make the concentration of the formaldehyde solution be 6mg/L, 8mg/L, 10mg/L and 20mg/L, respectively adjusting the pH value of the solution to 3, setting the optical path to be 2cm, turning on a stirrer and a low-pressure mercury lamp, respectivelyIrradiating for 15, 30, 45, 60 min.

The experimental results show that: the degradation rates of formaldehyde at initial concentrations of 6mg/L, 8mg/L, 10mg/L and 20mg/L at different irradiation times (15, 30, 45, 60min) according to step 1) by loading a graphite-carbon black hybrid roll air cathode into BES and under the experimental parameters set in step 2) are given in table 2 below:

TABLE 2

It should be understood that the embodiments and examples discussed herein are illustrative only and that modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the purview of the appended claims.

Claims

1. The device for biologically and ectopically degrading organic matters is characterized in that a microbial electrochemistry/advanced oxidation coupling degradation organic matter system is adopted, and H is synthesized by the system₂O₂And UV/H₂O₂An advanced oxidation system;

the UV/H₂O₂Construction of an advanced oxidation system: the system mainly comprises a reactor, a magnetic stirrer, a support frame and a low-pressure mercury lamp suspended above the reactor;

2. An apparatus for ectopic biodegradation of organic matter according to claim 1 wherein said graphite-carbon black mixed rolled air cathode is comprised of a catalyst layer, a diffusion layer and stainless steel mesh.

3. The device for ectopic biodegradation of organic matters according to claim 1, wherein when the anode microorganisms are acclimated, the cathode is an activated carbon air cathode and is composed of an activated carbon catalyst layer, a carbon black diffusion layer and a stainless steel net.

4. An apparatus according to claim 1, wherein the low pressure mercury lamp is spaced from the reaction liquid interface in the reactor by a distance of 2-5 cm.

5. An apparatus for ectopic biodegradation of organic matter according to claim 1 wherein a magnetic stirrer is disposed at the bottom of said reactor.