CN210559591U - Microbial electrochemical system with integral sludge collection device - Google Patents

Abstract

The utility model discloses a microorganism electrochemistry system with whole sludge collection device, including anode chamber and cathode chamber, the bottom of anode chamber and cathode chamber is provided with sludge collection device, anode chamber, cathode chamber and sludge collection device communicate mutually, and sewage gets into the cathode chamber from the anode chamber baffling. By integrally collecting the excess sludge, a large number of collecting units aiming at the sludge of the cathode and anode arrays can be prevented from being arranged in a multi-module biological cathode microbial electrochemical system, and meanwhile, the centralized treatment of the subsequent sludge is facilitated.

Description

Microbial electrochemical system with integral sludge collection device

Technical Field

The utility model belongs to the technical field of sludge treatment, concretely relates to microorganism electrochemical system with whole sludge collection device.

Background

The microbial electrochemical system takes microbes as a carrier or a catalyst to promote the oxidation reaction of a battery anode or the reduction reaction of a battery cathode, and has unique characteristics in the aspects of energy and resource recycling, environmental pollution remediation and the like. The biological cathode type microbial electrochemical system is mainly based on autotrophic or heterotrophic microbes attached to the surface of a cathode, takes an electrode as an electron donor and an energy source, utilizes an inorganic carbon source and a nitrogen source to reduce oxygen or other substances with strong oxidizability through self metabolism, and simultaneously utilizes protons transferred from an anode to supply self growth. The typical biological cathode microbial electrochemical system is a double-chamber structure, and a separation material is inserted between a cathode chamber and an anode chamber, so that a certain COD (chemical oxygen demand) gradient and DO (dissolved oxygen) gradient are formed between the two chambers. A typical biocathode microbial electrochemical system is shown in figure 1.

Ion or proton exchange membranes are mostly adopted as traditional separation materials, but the ion/proton exchange membranes are expensive and are not suitable for application. The porous material with large aperture is used as a substrate, a microorganism layer forms a microorganism diaphragm in water treatment equipment, the diaphragm has the characteristic of blocking oxygen and COD from directly diffusing between polar chambers, and allows anions and cations to directly permeate, so that the function same as that of an ion exchange membrane can be achieved. In a biocathode microbial electrochemical system with a microbial membrane (fig. 2), wastewater enters an anaerobic anode chamber, the anode degrades most of the COD, the anode effluent permeates laterally across the microbial membrane into the cathode chamber, which generally maintains an aerobic environment by means of aeration and further reduces a small amount of COD in the anode chamber effluent. The system solves the problems of mass transfer and diffusion between the cathode chamber and the anode chamber, reduces the cost of the system, has advantages for practical application, and still has some defects.

The biomembrane in the microbial diaphragm is in the dynamic balance of falling and regeneration, the fallen biomembrane can enter the cathode and anode chambers to form sludge, especially in an aerobic biological cathode system, although cathode microorganisms only degrade a small amount of COD from the anode chamber, under the condition of sufficient dissolved oxygen, the aerobic microorganisms can generate more biomass due to vigorous metabolism, and finally form a large amount of residual sludge, and the generated sludge can influence the water quality of effluent water and even cause the blockage of the inside of the system or a system pipeline, so in the practical application, the discharge of the residual sludge in the system cannot be ignored.

However, in the current biocathode microbial electrochemical system, there is a device for collecting and discharging system sludge, and the way of removing the excess biofilm (excess sludge) in the electrode or electrode chamber is mostly to take out the electrode to remove the biofilm, or to retain the sludge in the respective relatively isolated electrode chamber. The manual intervention is used for flushing or scraping the reactor and the electrodes, and the mode is destructive to the system, is not beneficial to the continuous and stable operation of the system, and is inconvenient to operate for a large-scale system. Leaving the sludge in separate electrode chambers presents challenges to further collection and disposal of the sludge. Sludge collection pipes are required to be arranged in each narrow electrode chamber for collecting sludge, and the sludge collection pipes are complex in structure and easy to block and lose effectiveness.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the not enough of prior art, separate the negative and positive pole mud that leads to completely to present biological negative pole microbial electrochemical system two polar chambers and collect inconvenient problem, through the mobile mode that changes sewage in the system to and add holistic sludge collection device in negative and positive pole chamber bottom, realize collecting simultaneously the mud that produces on negative, anode chamber and the microorganism separate the material. The utility model provides a microbial electrochemical system with whole sludge collection device. In the system, the sludge collecting device spanning the cathode and anode chambers is directly arranged at the bottom of the cathode and anode chambers, so that the redundant sludge collecting system is avoided, the structure is simple, and the practical application is convenient. Because of the added sludge collecting device, the system forms a baffling sewage flow mode, and the head loss of the system is reduced. At the same time, good collection of sludge can also prevent sludge from accumulating in the system resulting in internal clogging.

The technical scheme of the utility model is that: a microbial electrochemical system with an integral sludge collection device comprises an anode chamber and a cathode chamber, wherein the bottom parts of the anode chamber and the cathode chamber are provided with the sludge collection device, and the anode chamber, the cathode chamber and the sludge collection device are communicated with each other.

Preferably, the wastewater is baffled from the anode chamber into the cathode chamber.

Preferably, the shape of the sludge collection device is matched with the bottom shapes of the anode chamber and the cathode chamber.

Preferably, the shape of the sludge collection device is any one of a cube, a cuboid, a cone or a pyramid.

Preferably, the sludge collecting device is provided with a plurality of sludge collecting hoppers in parallel.

Preferably, the mud collecting hopper is provided with a mud discharging port.

Preferably, the side wall of the sludge collection device is inclined.

Preferably, the depth of the sludge collection device is at least 5 cm.

Preferably, a water distribution weir is arranged at the water inlet of the anode chamber.

Preferably, the anode chamber and the cathode chamber comprise a flat plate type cathode/anode chamber or a tubular type cathode/anode chamber.

Has the advantages that: the utility model has the advantages over the prior art that,

1. the microorganism electrochemical coupling water treatment system, the mud collection device is add to the bottom, mixes the surplus mud of collecting in the cathode and anode chamber:

①, the sludge of the system is integrally collected, so that a sludge collecting hopper is not arranged in each polar chamber, and the subsequent sludge treatment is facilitated;

the large-aperture porous material and the self-generated microbial diaphragm layer formed in the operation process of the large-aperture porous material replace an ion/proton exchange membrane to be used as a separation material of a biological cathode microbial electrochemical system, so that the high cost of the ion/proton exchange membrane is avoided, and the service life of the separation material is prolonged;

the system is communicated with the water flow, sewage is directly baffled to the cathode from the anode, the structure is simple, the system is suitable for continuous operation of a large-scale system, redundant structures such as pipelines are reduced, and the internal blockage of the system is avoided.

2. The utility model discloses directly add mud collection device in two room microbial electrochemical system negative, anode chamber bottom, mix and collect the mud in negative, the anode chamber, this makes anode chamber, cathode chamber and mud collection device rivers intercommunication, the anaerobism environment that the microorganism that produces electricity in maintenance microbial electrochemical system positive pole that can be good needs and the good oxygen and the low COD environment that the cathode microorganism needs, consequently, this system is mixing the whole mud of collection system, the production electric energy that can be stable.

3. The utility model discloses an adopt concentrated bottom mud to collect the structure, realize collecting when negative pole chamber excess sludge among the biological negative pole type microorganism electrochemical system. The sewage of the cathode and the anode is communicated at the bottom through the sludge collecting hopper additionally arranged at the bottom, and the sewage enters the cathode chamber through the anode chamber in a baffling manner, so that the head loss of the system is reduced. The anolyte can be directly baffled to enter a cathode, meanwhile, a large-aperture porous material is adopted as a cathode and anode separation medium, microorganisms spontaneously generated in the sewage immersion and permeation processes and a retentate layer are utilized to form a microbial film separation medium, the high COD anolyte in the anode chamber is retained, oxygen in the cathode chamber is retained, and ion conduction between the cathode chamber and the anode chamber can be maintained. The system can collect the sludge of the system without increasing the complexity of the structure, and is suitable for constructing an application type biological cathode microbial electrochemical treatment process.

Drawings

FIG. 1 is a typical microbial electrochemical system of a biological cathode.

Fig. 2 is a biocathode microbial electrochemical system with a microbial membrane.

Fig. 3 is a hydraulic flow direction schematic diagram of the system.

FIG. 4 is a structural diagram of a microbial electrochemical system with an integral sludge collection device:

a-system structure diagram;

b-structure diagram of mud collecting hopper;

c-water inlet water distribution weir and water outlet structure diagrams;

d-porous material and porous plate layer structure diagram.

Fig. 5 is a multi-module structure form related to the system:

a-single cathode chamber and single anode chamber configuration schematic diagram;

b-single cathode chamber and double anode chamber configuration schematic diagram;

c-a schematic configuration diagram of a single anode chamber with double cathode chambers;

d-a schematic diagram of a plurality of mud collecting hoppers in a stacking system in parallel connection;

e-top view of the tubular structure.

Fig. 6 is a plot of system polarization curve versus power density.

FIG. 7 is a graph showing the change of effluent COD with time.

Reference numerals: 1-water distribution weir, 2-anode chamber, 3-cathode chamber, 4-sludge collection hopper, 5-porous material, 6-porous plate, 7-water outlet, 8-sludge discharge port and 9-clamping groove.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

The utility model relates to a microorganism electrochemical system with whole sludge collection device mainly includes water distribution weir 1 that makes the even water distribution of system, anode chamber 2, cathode chamber 3, mud collecting bucket 4, porous material 5, perforated plate 6, delivery port 7, mud discharging port 8. The three regions of negative and positive chambers and sludge-collecting hopper are directly communicated, there is not unnecessary baffle or guide plate, the partition material between the negative and positive chambers, disect insertion two pole room meets border department, both sides are by 6 pressfittings of perforated plate, use the fixed perforated plate 6 positions of draw-in groove 9, the water distribution weir 1 that intakes through anode chamber upper portion evenly gets into anode chamber 2, the part gets into the negative pole through separating the material seepage flow, all the other parts get into the negative pole through separating the material bottom from the positive pole baffling, then flow out through negative pole upper portion delivery port 7, mud in the negative and positive chambers can directly subside and get into sludge-collecting hopper 4 and collect, finally through the 8 discharge system of mud discharge port.

The utility model discloses a structural style that system relates to: as shown in fig. 5a-e

(1) ④ flat plate type cathode/anode chamber has ④ advantages that ④ cathode and anode chambers are of a flat layer structure in ④ whole state, but have various sectional area forms, can be built into ④ shapes of a square, a rectangle, a trapezoid and ④ like to be matched with ④ structure of a sewage structure, ④ bottom sludge collecting device has various forms, and ④ top structure can be built into ④ shapes of a cube, a cuboid, a cone, a pyramid and ④ like, ④ sewage enters a cathode through a separation material from ④ anode chamber in continuous flow operation, or is downwards baffled to ④ cathode chamber without ④ separation material and is discharged out of ④ system after treatment, ④ cathode chamber and ④ anode chamber are arranged in parallel, ④ proportion of ④ corresponding cathode chamber can be 1:1, or one layer of cathode can be matched with multiple layers of anodes or opposite, one or more sludge collecting units can be arranged in an integral stacking system, and ④ sludge collecting units at least one pair of cathode and anode chambers are collected by ④ concentrated sludge collecting units, so ④ number of ④ sludge collecting units is smaller than ④ number of ④ cathode and anode chambers in ④ stacking system.

(2) ① cathode/anode chamber, ③ cathode/anode chamber is located at ③ inner and outer sides of ③ ① structure formed by porous material and separating medium, ③ sludge collecting device is located at ③ bottom of ③ cathode/anode chamber to collect ③ sludge of ③ whole system, ③ continuous flow operation is performed, ③ sewage flows or baffls from ③ anode to ③ cathode side, ③ electrode located at ③ inner side is cylindrical with ③ separating material as ③ boundary, ③ electrode chamber located at ③ outer side can not have obvious boundary, ③ ① structure formed by a plurality of separating medium can be installed in a water treatment structure, and ③ centralized sludge collecting unit at least collects ③ sludge generated by a pair of ① cathode/anode chambers.

(3) the three-dimensional porous electrode ③ comprises a carbon-based porous electrode, such as a carbon felt, a graphite felt, porous activated carbon, granular carbon filler, a graphite column and the like, and a corrosion-resistant metal-based electrode, such as foam copper, foam iron, foam nickel and the like.

(4) the sludge collection device is characterized by comprising a sludge collection unit, a sludge collection device, a sludge discharge port and a sludge discharge port, wherein the sludge collection unit is generally positioned at the bottom of the whole system, and sludge in a cathode chamber and an anode chamber can sink and enter the sludge collection device under the disturbance of gravity and water flow.

(5) ③ the arrangement of ③ the baffling points is shown in figure 3, wherein ③ the sludge collection unit is positioned at ③ the bottom of ③ the whole system, namely a sewage baffling and sludge gathering interval is formed from ③ the lowest part of ③ the separation medium to ③ the bottom of ③ the sludge collection unit, ③ the lowest part of ③ the separation medium is ③ the baffling point, ③ the baffling point is required to be away from ③ the lowest end of ③ the anode and ③ the aeration point of ③ the cathode by a certain height difference, so that oxygen at ③ the aeration point of ③ the cathode cannot influence ③ the anaerobic environment of ③ the anode backwards in a baffling direction, ③ the height difference range is not less than 5cm, ③ the baffling point is required to keep a certain height difference from sludge gathered in ③ the collection unit, ③ the sludge is prevented from being carried into ③ the cathode chamber by sewage flowing into ③ the anode, water suspended matters (SS) are increased and blocked, ③ the height difference range between ③ the baffling point and ③ the sludge collection surface at ③ the highest position is not less than 5cm, ③ the volume from ③ the highest sludge collection surface below ③ the baffling point to ③ the bottom of ③ the sludge collection unit is ③ the maximum sludge collection capacity, and ③ the sludge collection unit is required to carry out sludge collection capacity or exceed ③ the sludge collection capacity.

(6) ③ microbial diaphragm layer base material is characterized in that a ② large-aperture porous material base layer comprises a porous carbon-based material (graphite felt, activated carbon felt and ③ like), a foamed metal (such as nickel iron and ③ like), a porous ceramic, a natural wire/artificial wire/chemical fiber/metal wire textile (such as a stainless steel net, a bolting silk, an industrial filter cloth, an ester non-woven fabric, a polypropylene non-woven fabric, a polyester screen mesh, a polyamide screen mesh) and ③ like, ③ aperture range of ③ ② large-aperture porous material is larger and can be 0.1 mu m to 5mm, ③ thickness range can be adjusted according to ③ aperture size and ③ sectional area of a reaction system and can be 1 mu m to 10cm, ③ porous material layer can be a composite layer of one or more porous materials, and for example, a layer of carbon felt, a polyurethane sponge, a melamine sponge, a sponge rattan biochemical cotton and ③ like are sandwiched between two layers of industrial filter cloth precoated with manganese dioxide powder, ③ stainless steel net, ③.

(7) the use mode of the substrate layer is that (but not necessary) the porous material layer can be compressed to a certain extent so as to reduce the thickness and reduce the porosity, the reduction of the thickness can reduce the distance between the cathode and the anode and reduce the internal resistance, the reduction of the porosity in a certain range is favorable for maintaining the gradient of dissolved oxygen and organic matters, and the excessive reduction of the porosity reduces the overflowing flux (m) of the separating material³m^-2h^-1) the surface of the porous material layer can be coated with natural substances such as kaolin, clay, argil, diatomite and the like, and nanoparticles or powder particles of metal oxides such as zirconium oxide, manganese dioxide, iron oxide and the like, carbon-based nanoparticles or powder particles such as carbon fiber, activated carbon powder, carbon black, carbon nano tubes and the like, and the coating can enable the surface of the porous material layer to be easily attached with microorganisms and intercept particle pollutants to form a stable microorganism diaphragm filter layer, so that the water treatment function (water seepage, cathode and anode ion conduction and maintenance of dissolved oxygen and gradient of cathode and anode chambers) is realized.

(8) domestication of the microbial diaphragm layer ② the bacteria source of the microbial diaphragm layer is from sewage, or anaerobic or aerobic sludge forms a sludge layer on the surface of the substrate layer in advance to accelerate domestication and enrichment of the microbial diaphragm layer.

Example (b):

the quality of the treated wastewater in this example was as follows: the inlet water is artificial water distribution prepared by taking artificial lake accumulated water (COD is 35-60mg/L, and is derived from nearby rainwater catchments and a small amount of treated domestic sewage of nearby buildings) as a substrate, and sucrose, ammonium chloride, sodium dihydrogen phosphate and yeast extract are added to prepare artificial domestic sewage, wherein the COD value is about 350mg/L, the total nitrogen is 45-50mg/L, and the conductivity is 1300-1600 mu S/cm. The adopted system structure is as follows: the cathode and the anode respectively adopt two carbon fiber brushes which are arranged in parallel and have the diameter of 4cm and the effective length of 65cm as the cathode and the anode.

The large-aperture porous medium used as the cathode and anode chamber separation material is compounded with two materials, which are divided into three layers, namely industrial filter cloth-carbon felt-industrial filter cloth, the separation material is pressed in an organic glass plate frame with a hollow middle part, two sides of the separation material are clamped by porous organic glass plates, the organic glass plates are directly inserted into the middle part of the device, and the positions of the organic glass plates are fixed by clamping grooves on the side surface and the bottom. The internal sizes of the cathode chamber and the anode chamber of the device are 788cm in height, 10cm in length and 5cm in width, the total liquid volume of the system is about 10L, and the volume of the sludge collection device at the bottom of the cathode chamber and the anode chamber is about 2L. The sewage uniformly enters from the water distribution weir at the upper part of the anode, part of the sewage flows into the cathode chamber through the porous separation material layer, and the rest part of the sewage flows into the cathode chamber from the bottom of the anode chamber, namely the lower end of the separation material, and then flows out from a water outlet at the top of the cathode chamber. The sludge generated in the cathode chamber and the anode chamber enters the sludge collecting device through sedimentation, and is discharged through a sludge discharge port at the bottom of the sludge collecting hopper after a period of time.

The embodiment monitors the sludge collection amount of the system, the electricity generation performance of the system and the water treatment efficiency. Wherein, the sludge in the sludge collection device of the system is discharged through a sludge discharge pipe, and then is dried in an oven at 103 plus or minus 2 ℃ to constant weight, and the mass of the sludge is taken as the sludge yield of the system. The power generation performance of the system is measured by a mode of reducing the resistance in a gradient manner, the system is firstly opened for 2h to be stable, the open-circuit voltage is recorded, then a plurality of external resistance values are reduced in a gradient manner (the external resistances are 510 omega, 200 omega, 100 omega, 50 omega, 30 omega, 20 omega, 10 omega and 5 omega), the stable time is longer than 30min under each external resistance condition to obtain stable output voltage, and the corresponding current density or output power density is calculated based on the effective area of the separation material according to the corresponding current or output power. The water treatment efficiency of the system is characterized by the reduction of Chemical Oxygen Demand (COD), the COD is tested by a digestion colorimetric method, and a digestion reagent is a COD digestion reagent produced by American Hash company. During digestion, 2ml of sample is accurately measured in a digestion tube by using a pipette, a cover is tightly covered and the sample is gently shaken and mixed, the digestion is carried out in a digestion instrument (DRB200, USA) at 150 ℃, and the digestion is carried out, then the digestion is taken out and cooled to room temperature, and the room temperature is measured in a spectrophotometer (DR3900, USA).

Effect data:

1. sludge collection

The system sludge collecting device is used for integrally mixing and collecting sludge in the cathode chamber and the anode chamber, wherein the sludge is mainly from a biological film fallen off from an aerobic biological cathode. And (3) under an operation mode that the hydraulic retention time is 12h, emptying sludge in the sludge collection device at intervals, drying and weighing to obtain the following sludge yield:

TABLE 1 relationship between sludge collecting time and sludge yield

2. Electric energy production effect

Fig. 6 can illustrate that the sludge collecting device for mixed collection of cathode and anode sludge is additionally arranged at the bottom of the biocathode-type microbial electrochemical system, a porous material is used as a separation medium, and under the condition that a baffled sewage flow mode exists in the system, the COD gradient and dissolved oxygen gradient at two sides of an anode chamber and a cathode chamber of the biocathode-type microbial electrochemical system can be maintained, and ion conduction of the two electrode chambers is kept, so that stable current and voltage output between electrodes of the system is ensured.

3. Effect of water treatment

The influent water (COD value is about 350mg/L) prepared by taking lake water (COD is 35-60mg/L) as a substrate is basically stabilized at 50mg/L under the hydraulic retention time of 12h, and good sewage treatment efficiency is realized, as shown in figure 7.

It should be understood that the embodiments discussed herein are for illustrative purposes 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 (10)

1. A microbial electrochemical system with an integrated sludge collection device comprises an anode chamber (2) and a cathode chamber (3), and is characterized in that the bottom of the anode chamber (2) and the bottom of the cathode chamber (3) are provided with the sludge collection device, and the anode chamber (2), the cathode chamber (3) and the sludge collection device are communicated with each other.

2. The microbial electrochemical system with integral sludge collection device of claim 1 wherein the wastewater is baffled from the anode chamber into the cathode chamber.

3. The microbial electrochemical system with integral sludge collection means of claim 1 wherein the sludge collection means is shaped to fit the bottom shape of the anode chamber (2) and cathode chamber (3).

4. The microbial electrochemical system with integral sludge collection device of claim 3, wherein the sludge collection device is in the shape of any one of a cube, a cuboid, a cone or a pyramid.

5. The microbial electrochemical system with integrated sludge collection device according to claim 1, wherein the sludge collection device is provided with a plurality of sludge hoppers (4) in parallel.

6. The microbial electrochemical system with integrated sludge collection device according to claim 5, wherein the sludge hopper (4) is provided with a sludge discharge opening (8).

7. The microbial electrochemical system with an integral sludge collection device of claim 1 wherein the side walls of the sludge collection device are disposed at an incline.

8. The microbial electrochemical system of claim 1, wherein the depth of the sludge collection means is at least 5 cm.

9. The microbial electrochemical system with integral sludge collection device of claim 1 wherein the water inlet of the anode chamber (2) is provided with a water distribution weir (1).

10. The microbial electrochemical system with integrated sludge collection apparatus of claim 1, wherein the anode chamber (2) and cathode chamber (3) comprise a flat plate type cathode/anode chamber or a tubular type cathode/anode chamber.

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