CN102249397A

CN102249397A - Bio-electrochemical enhanced waste water treatment device

Info

Publication number: CN102249397A
Application number: CN201110124707XA
Authority: CN
Inventors: 金松; 保罗·付格林; 崔康平
Original assignee: Hefei University of Technology
Current assignee: Hefei University of Technology
Priority date: 2011-05-16
Filing date: 2011-05-16
Publication date: 2011-11-23

Abstract

The invention discloses a bio-electrochemical enhanced waste water treatment device, which is characterized in that: anodes which are soaked in water and are uniformly distributed are fixedly arranged in an aeration basin; the anodes are connected with cathodes which float on the surface of a water body through leads; and a resistor is connected in series to the leads. In the treatment device, electrochemical and biochemical treatment technologies are integrated, molecular oxygen in the air can be directly utilized, and aeration in the biological treatment process of waste water is eliminated or reduced, so that the treatment device has the advantages of good waste water treatment effect, low energy consumption, long electrode service life and small investment.

Description

Bioelectrochemistry is strengthened wastewater treatment equipment

Technical field

The present invention relates to wastewater treatment equipment, a kind of bioelectrochemistry of more specifically saying so is strengthened wastewater treatment equipment.

Background technology

Aeration tank and oxidation ditch are current application biological wastewater treatment technologies the most widely, continue at aerator under the condition of oxygen supply, aerobic and double oxygen animalcule is degraded to simple compounds with complex organic compound, and its final product is a carbonic acid gas, thereby cuts down the COD and the BOD concentration of waste water.Dissolved oxygen in the electron reduction water that produces in the biodegradation process generates water.Dissolved oxygen in the waste water derives from the air in the aerator introducing water, needs to consume a large amount of energy consumptions in aeration process.According to statistics, according to waste water quality, the energy consumption of aerating apparatus consumption accounts for 30%～70% of municipal sewage plant's total energy consumption.The decades in past, though the technical feature of gas blower and aerating apparatus is greatly improved,, improved oxygen transfer efficiency significantly as adopting the micro-pore aeration technology, reduced aeration energy consumption, because the influence of biofouling etc., actual consumption is still very high.

Bioelectrochemistry technology (be called for short BEC) be a kind of economy with eco-friendly reinforcement waste water in the method for wastewater treatment of organic pollutant degradation.Comprise the circuit that anode, negative electrode and a lead are connected, various types of BEC designs and research report have shown that it can improve biological degradation efficient (the Jeffree Mo Lisi etc. of hydrocarbon polymer, phenol and other organic pollutants, microbiological fuel cell is strengthened the anaerobic degradation of diesel oil. chemical engineering, 2009,146:161-167.; Luo Haiping etc., the microbiological fuel cell degradation of phenol. chemical engineering, 2009,147:259-264.; Zhang Cuiping etc., microbiological fuel cell degraded pyrimidine. toxicology impurity, 2009,172:465-471.).The bioelectrochemistry technology also is applied to organic removal in underground water and the surface water, and the while electrogenesis (Scotts etc. are the fuel battery cathode material research of raw material electrogenesis with the seawater settling. biological chemistry science and technology, 2008,83:1244-1254.; Peace etc., the multidimension electrode microbiological fuel cell of synchronous electrogenesis from water and sediment-filled phase symbiosis organism. environmental science and technology, 2010,44:7145-7150.).In the above-mentioned research, in anolyte compartment's anaerobic zone, microbiological deterioration organic contamination deposits yields and metastatic electron are to anode, by lead these electric transmission are arrived negative electrode, combine and consume with the electron acceptor(EA) of cathode zone, in most cases, the terminal electronic acceptor is a dissolved oxygen.Cathodic area, positive column are separated by proton exchange membrane or salt bridge in the BEC system of these types, and it allows proton to shift between anode and negative electrode, reduces oxygen simultaneously as far as possible and contacts with anodic.But owing to use proton exchange membrane or salt bridge, not only increased the structure difficulty and the cost of BEC system, and limited the structure scale of BEC system, be difficult to be applied to engineering practice.

Summary of the invention

The objective of the invention is to overcome the weak point of existing bioelectrochemistry technology, provide a kind of processing efficiency height, energy consumption is low, electrode life is long, material is cheap bioelectrochemistry to strengthen wastewater treatment equipment.

Technical solution problem of the present invention adopts following technical scheme:

The constructional feature that bioelectrochemistry of the present invention is strengthened wastewater treatment equipment is to be provided with to be immersed under water and equally distributed anode in the aeration tank, described anode is connected with the negative electrode that floats on water surface by lead, and series connection is provided with a resistor on described lead.

The constructional feature that bioelectrochemistry of the present invention is strengthened wastewater treatment equipment also is:

The described negative electrode that floats on water surface is to remain on the interface of water body and air with auxiliary member, and negative electrode remains moistening surface with it and is exposed in the ambient air.

Described resistor is an adjustable resistor.

Described negative electrode is that porous material is made.

The facade of described negative electrode is a multilayered structure.

The transfer transport mechanism of BEC can improve organic degradation rate in the waste water by two kinds of approach.At first, the existence of high conductive electrode and negative electrode ambient air can be kept a transfer transport fast, accelerate the electron extraction that the organic matter degradation process produces in the waste water, the direct necessity that contacts elimination or weakened the wastewater treatment process aeration of negative electrode and air.Secondly, the electronics that the organic matter degradation process produces has only small part to be utilized by microorganism self, all the other major parts can produce electric energy by the electrode transmission, therefore, in the process of microbiological deterioration organic pollutant, increase a competitive electronic receiver, will further stimulate microorganism, realize higher organic matter biodegradation speed, therefore, the BEC technology can significantly improve the degradation rate of organic pollutant, thereby improves waste water treatment efficiency.Compared with the prior art, beneficial effect of the present invention is embodied in:

1, current collection chemistry of the present invention and biologic treating technique are in one, and treatment effect is good, energy consumption is low, electrode life is long, reduced investment;

2, the present invention adopts unsteady negative electrode, has overcome the influence of aeration tank operational process change of level, and can directly and make full use of airborne oxygen be electron acceptor(EA), saves or reduces aeration, effectively reduces the water treatment energy consumption;

3, the present invention adopts porous material to make negative electrode, or the facade that negative electrode is set is multilayered structure, can enlarge markedly electrode specific surface area, improves current efficiency, cuts down the consumption of energy and cost for wastewater treatment;

4, the present invention adopts the anode that immersion is evenly distributed, make anode and waste water full contact, can in time collect and transmit the electronics that the organic matter degradation process produces fast, and provide the habitat for microorganism, improve the aeration tank microorganism concn, increase the volumetric loading rate, improve wastewater treatment speed and efficient;

5, anode of the present invention and negative electrode are in same water body environment, have saved proton exchange membrane, have not only saved construction cost greatly, and have been completely free of the restriction of the scale that makes up, and have solved the difficult problem that the bioelectrochemistry wastewater processing technology is difficult to the mass-producing practical application.

Description of drawings

Fig. 1 is the application example floor map of the present invention in the sewage disposal plant aeration tank.

Fig. 2 is the application example elevational schematic view of the present invention in the sewage disposal plant aeration tank.

Fig. 3 handles the comparison diagram of high concentrated organic wastewater COD removal effect for the present invention and traditional aeration tank, anaerobic pond.

Number in the figure: 1 aeration tank; 2 negative electrodes; 3 anodes; 4 leads; 5 resistors; 6 anchor ingots; 7 water surface; 8 welds; 9 auxiliary members.

Embodiment

Referring to Fig. 1 and Fig. 2, present embodiment is to be provided with to be immersed under water and equally distributed anode 3 in aeration tank 1, anode 3 is fixedly installed by anchor ingot 6, and anode 3 is connected with the negative electrode 2 that floats on water surface by lead 4, and series connection is provided with a resistor 5 on lead 4.

Anode 3 is to adopt electro-conductive materials such as carbon cloth, Stainless Steel Fibre, Stainless Steel Cloth or packed graphite granule to be processed into such as porous, three-dimensional shape such as multilayer, formation is than bigger serface, be installed in the aeration tank 1, fixed by anchor ingot 6, prevent that anode from drifting about in aeration tank 1 or hinder the aerator that is positioned at aeration tank bottom normally to move, anchor ingot 6 is coated with the metalwork of insulating material for plastic component or appearance;

As shown in Figure 2, the negative electrode 2 that floats on water surface is to remain on the interface of water body and air with auxiliary member 9, and negative electrode 2 is exposed in the ambient air with its moistening surface; Negative electrode 2 adopts electro-conductive materials such as carbon cloth, stainless (steel) wire, stainless steel plate, three-dimensional Rotating Stainless Steel Cage to make, and is processed into such as porous, and three-dimensional shape such as multilayer form than bigger serface; Negative electrode 2 is the water surface that floated on aeration tank 1 by the support of the buoyancy of auxiliary member 9, and auxiliary member 9 adopts the buoyancy material of suctions such as foamed glue, cork, sponge to make; Make negative electrode 2 can keep surface wettability, the surface can fully be contacted with ambient air;

Resistor 5 is set to adjustable resistor, resistor 5 is placed on the water surface of aeration tank 1, or being arranged on bank beyond the aeration tank, the resistance of resistor 5 can be regulated at 10～10000 ohm, to adapt to the demand of resistance to external world of different operating periods of BEC system;

Electrical conductor in the lead 4 adopts electro-conductive materials such as stainless steel, titanium, copper, and the two ends of lead 4 are welded to connect with anode 3 and negative electrode 2 respectively, and place, weld 8 positions adopts Resins, epoxy or silica gel to seal;

Organism in the waste water is the Degradation by microorganism in aeration tank 1, produce electronics, proton, electronics is passed to anode 3 by microorganism, transfer to the surface of negative electrode 2 through lead 4 and resistor 5, proton arrives negative electrode 2 surfaces by diffusion, on the surface of negative electrode 2, electronics, proton and airborne molecular oxidation symphysis Cheng Shui.

The magnitude of voltage at the two ends of resistor 5 is generally at 0.01mV-300mV, starting stage after the BEC system puts into operation, general voltage is very low, show the electrogenesis microbe population account in the aeration tank the microorganism ratio seldom, or microorganism under-activity, along with the magnitude of voltage at resistor 5 two ends raises gradually, show that the electrogenesis microbial numbers increases gradually, activity strengthens gradually.Therefore, the magnitude of voltage at resistor 5 two ends can show active degree and the quantity of microorganism among the BEC indirectly.

Usually, at the BEC system installation and operation initial stage, regulator resistor flows to allow the electric current in the circuit fast to the low value scope, excites the electrogenesis microbic activity, improves the increment speed of electrogenesis microorganism.When the voltage at resistor two ends increases to 20mV when above, 5 to bigger resistance values of regulator resistor help to form microbial film on anode 3, and the resistance value of resistor 5 can increase or reduce according to the concrete needs of wastewater treatment.

In addition, in concrete the enforcement, the chemical oxygen demand of waste water COD concentration that can need handle according to reality, calculate the useful volume of required aeration tank 1 and the quantity of anode 3 by the COD volumetric loading, and, determine the quantity of negative electrode 2 and whether need auxiliary aeration and aeration rate according to the surface-area of the required negative electrode 2 of removal total of COD.

The BEC system has carried out test on a small scale in the laboratory.In 2000 milliliters wide-mouth vial, 3 kinds of processing are arranged: anaerobism (not aeration, the square icon among Fig. 3), normal aeration (the rhombus icon among Fig. 3), and the BEC device (triangle icon among Fig. 3.Experiment has been carried out 11 days, has comprised the starting period of beginning.The result as shown in Figure 3.Under the anaerobic condition, chemical oxygen demand (COD) (COD) 11 days drops to 4000 milligrams per liters from about 6000 milligrams per liters.This condition simulation does not have COD degradation rate (33%) under the situation of aeration.Under normal aeration condition, dropped to about 2000 milligrams per liters from about 6500 milligrams per liters in COD11 days.COD degradation rate (69%) under the normal aeration situation of the general sewage work of this condition simulation.Start at the BCE device, do not have under the aeration condition, dropped to about 500 milligrams per liters from about 6500 milligrams per liters in COD11 days.BEC is installing but the COD degradation rate (92%) under the aeration situation not in this condition simulation sewage work.The BEC system is not no energy consumption during COD in degraded under the aeration condition.In scale is used, estimate that BEC can substitute or reduce the part aeration, realize the wastewater treatment rate of energy-saving benefit and increase.

Claims

1. A bioelectrochemical enhanced wastewater treatment device is characterized in that an anode (3) submerged in water and evenly distributed is set in the aeration tank (1), and the anode (3) is connected with the wire (4) by the anode (3). The cathodes (2) floating on the surface of the water body are connected, and a resistor (5) is arranged in series on the wire (4).

2. The bioelectrochemical enhanced wastewater treatment device according to claim 1, characterized in that: the cathode (2) floating on the surface of the water body is maintained on the interface between the water body and the air with an auxiliary part (9), and the cathode ( 2) Exposure to ambient air with its surface kept wet.

3. The bioelectrochemically enhanced wastewater treatment device according to claim 1, characterized in that the resistor (5) is an adjustable resistor.

4. The bioelectrochemically enhanced wastewater treatment device according to claim 1, characterized in that the cathode (2) is made of a porous material.

5. The bioelectrochemically enhanced wastewater treatment device according to claim 1, characterized in that the facade of the cathode (2) is a multi-layer structure.