A kind of method and apparatus of processing pharmaceutical wastewater by pulse electrocoagulation-MBR
Technical field
The invention belongs to the water treating equipment technical field, relate to a kind of method and apparatus of processing pharmaceutical wastewater by pulse electrocoagulation-MBR.
Background technology
The pharmacy waste water pollutent has that content height, concentration of suspension are big, strong toxicity, hard-degraded substance is many, the water quality and quantity luffing big and characteristics such as processing complexity, all is the emphasis and the difficult point of Industrial Wastewater Treatment all the time.Pharmacy waste water is handled physical chemistry methods such as generally adopting interior electrolysis, coagulation and biological process etc. at present, but physico-chemical process energy consumption height, investment are greatly, the biological process technical process is comparatively complicated, has long processing period simultaneously, is subjected to many characteristics such as the big and result instability of seasonal effect.The complicacy of pharmacy waste water and the high cost with low efficiency of conventional treatment process are to cause current a large amount of pharmacy waste water to be difficult to handle and be difficult for the immediate cause of qualified discharge.
Thereby the electricity flocculation is to make substrate generation redox reaction reach the method for degraded by the transmission of electric current.It adopts soluble anode (Al or Fe), generates A1 on anode
3+, Fe
2+, Fe
3+Deng positively charged ion, on anode, separate out O simultaneously
2Microbubble produces H on negative electrode
2Microbubble.The mechanism of action of electricity flocculation comprises electrolysis-coagulation, electrofloatation and electrolytic oxidation reduction.Electrolysis-coagulation is meant the hydrolysis of positively charged ion process, the polymerization that soluble anode produces, can produce a series of multinuclear hydroxyl complexing ions and oxyhydroxide, these materials can carry out the complexing throwing out to organic polymer material, pollution suspended substance and colloid in the water as flocculation agent, and it is removed from water.Electrofloatation is meant that water produces a spot of O when electrolysis
2And H
2Microbubble, the particle diameter and the density of these bubbles are all very little, have certain adsorptive power and floating loading capability, and the pollutent flocculation group that produces in the energy planar water also floats to the water surface, thereby reaches the effect of solid-liquid separation.The electrolytic oxidation reduction comprises two portions, the one, pollutent is directly in male or female generation redox reaction, the 2nd, oxidisability such as the OH free radical that produces in the electrolytic process are extremely strong, there is not the organic pollutant reaction in the direct and waste water of selecting, be degraded to carbonic acid gas, water and simple organic, and the Fe that anode produces
2+Stronger reductibility is arranged, some the oxidisability component in the reducible degrading waste water.The reaction formula of electricity flocculation process (Fe electrode) is as follows:
Anode: Fe-2e → Fe
2+, 2H
2O-4e → O
2+ 4H
+
Negative electrode: 2H
2O+2e → H
2+ 2OH
-
In the solution: Fe
2++ O
2+ H
+→ Fe
3++ HO
2, Fe
2++ HO
2+ H
+→ Fe
3++ H
2O
2,
Fe
2++H
2O
2→Fe
3++HO·+OH
-,Fe
2++HO·→Fe
3++OH
-
Fe
2++2OH
-→Fe(OH)
2,Fe
3++3OH
-→Fe(OH)
3;
What use comparative maturity at present is the direct current flocculence, but its shortcoming is energy consumption height and the easy passivation of electrode.The alternating pulse flow-thru electrode is adopted in the alternating pulse flocculation, constantly repeats the electrolytic process of " power supply-outage-power supply ", and this power supply mode is greatly improved electrolytic efficiency, and energy consumption reduces significantly.Owing to apply pulse signal, the reaction on the electrode helps diffusion off and on, reduces concentration polarization.Because the two poles of the earth polarity often changes, prevent that electrode from because of producing the oxide compound passivation, improving electrolytic efficient, help the dissolving of solubility electrode and stablizing of effluent quality.
Membrane bioreactor (MBR) be a kind of be to combine extensively in order to handle the device of sanitary sewage or trade effluent by biochemical reactor and membrane module, this reactor combines the advantage of membrane separation technique efficiently and traditional activated sludge process.The membrane filtration of the sewage that active sludge treatment is crossed in reactor held back materials such as suspended substance in the water and colloid, crosses directly qualified discharge or enter in the advanced treatment workshop section of next section of cleaner liquid, makes it to reach the standard of reuse water.The efficient crown_interception of film is trapped in the reactor microorganism fully simultaneously, helps long, propagation microbial growth and enrichments more slowly generation time such as nitrobacteria, has solved the sludge loss problem fully.
Summary of the invention
The object of the present invention is to provide a kind of method and apparatus of processing pharmaceutical wastewater by pulse electrocoagulation-MBR.This invention combines pulse electro-flocculation and is applied to the pharmacy waste water processing with membrane bioreactor, adopt pulse electro-flocculation-chemical oxidation-MBR main process; The alternating pulse flocculation has overcome the passivation and the polarization phenomena of electrode, has the advantages that energy consumption is low, processing efficiency is high, plays flocculation, air supporting and the effect of electrolytic oxidation reductive simultaneously, can remove the most of pollutent in the waste water; Chemical oxidization method utilizes strong oxidizer that the hardly degraded organic substance in the waste water is converted into biodegradable organism, strengthens oxidation effectiveness; Anoxic pond and membrane bioreactor are formed A/O technology, built-in efflux aerator efficiency of oxygen supply height in the membrane bioreactor, improved active sludge greatly to organic degradation rate, effective pollutents such as organism in the degrading waste water and ammonia nitrogen, waste water after the processing can reach industry one-level A standard through the membrane filtration water outlet.
The present invention is achieved through the following technical solutions:
This process unit comprises equalizing tank 1, electric flocculation reactor 2, chemical oxidation pond 3, anoxic pond 4 and membrane bioreactor 5 successively; Described electric flocculation reactor 2 comprises battery lead plate 6 and component pulse-changing power 7, and this battery lead plate 6 links to each other with component pulse-changing power 7; Described membrane bioreactor 5 comprises built-in membrane module 8 and efflux aerator 9; It is characterized in that, at least one group of battery lead plate 6 is arranged in parallel in the described electric flocculation reactor 2, the anode of this battery lead plate 6 and negative electrode are solubility electrodes such as aluminium sheet or iron plate, and described chemical oxidation pond adds hydrogen peroxide (or clorox, dioxide peroxide, ozone etc.) strong oxidizer.
The invention provides a kind of method that adopts the processing pharmaceutical wastewater by pulse electrocoagulation-MBR of said apparatus, it is characterized in that, this processing method comprises the steps:
(1) after waste water mixes in equalizing tank, enter electric flocculation reactor and carry out electrolytic reaction, apply the alternating impulse electric current on battery lead plate, strength of current is 1~15A, and the alternating impulse cycle is 1~20s; In this process, the alternating impulse electric current can overcome the passivation and the polarization problem of battery lead plate, prolongs battery lead plate work-ing life, cuts down the consumption of energy, and improves treatment effect;
(2) in electric flocculation reactor, the metal ion that soluble anode produces produces flocculation agents such as a series of multinuclear hydroxyl complexing ions and oxyhydroxide through hydrolysis, polymerization, separates out O simultaneously on anode
2Microbubble produces H on negative electrode
2Microbubble; Polymer organic pollutant, suspended substance and toxic substances etc. in this flocculation agent and the waste water carry out throwing out and form pollutent flocculation group, this O
2And H
2The pollutent flocculation group that produces in the microbubble planar water also floats to the water surface, produces the air supporting effect, reaches solid-liquid separation effect; Simultaneously, OH and the O that produces in the wastewater electrolytic process
2Larger molecular organics can be oxidized to small organic molecule in oxygenant, improve the biodegradability of waste water.In this process, most of organism is removed in the waste water;
(3) waste water enters chemical oxidation pond after electric flocculation reactor is handled, in chemical oxidation pond, add hydrogen peroxide (or clorox, dioxide peroxide, ozone etc.) strong oxidizer, hard-degraded substance in the waste water is converted into biodegradable small organic molecule, play the effect of strengthening oxygenolysis, waste water enters A/O technology afterwards;
(4) A/O technology is made up of anoxic pond and membrane bioreactor, and the built-in efflux aerator of membrane bioreactor improves the oxygen level of mixed solution in the reactor greatly, has strengthened organic degradation effect; After FEOL was handled, the biodegradability of waste water was greatly enhanced, thereby the organic pollutant in the waste water can effectively be removed in this technology, and this technology also can be removed pollution substances such as ammonia nitrogen in the waste water and phosphorus simultaneously;
(5) waste water after the A/O art breading is through the membrane filtration water outlet, and this membrane filtration water outlet can reach industry one-level A standard.
The processing method of above-described a kind of processing pharmaceutical wastewater by pulse electrocoagulation-MBR is characterized in that, alternating impulse strength of current is 1~10A in the electric flocculation reactor, and the alternating impulse cycle is 1~15s, and dutycycle r is 0.5~1.0;
The present invention compared with prior art, have the following advantages and the high-lighting effect: technical process is simple, maintenance management is convenient, less investment, energy consumption is low, anti impulsion load, treatment effect is good, stable effluent quality can reach industry one-level A standard, is a kind of pharmaceutical wastewater treatment process equipment that is worth wide popularization and application on market.
Description of drawings
Fig. 1 is the method process flow diagram of processing pharmaceutical wastewater by pulse electrocoagulation-MBR provided by the invention.
Among the figure: the 1-equalizing tank; 2-electricity flocculation reactor; The 3-chemical oxidation pond; The 4-anoxic pond; The 5-membrane bioreactor; The 6-battery lead plate; The 7-component pulse-changing power; The 8-membrane module; The 9-efflux aerator.
Embodiment
Describe embodiments of the present invention in detail below in conjunction with technical scheme and accompanying drawing.
By the method process flow diagram of processing pharmaceutical wastewater by pulse electrocoagulation-MBR as can be seen, this process unit comprises equalizing tank 1, electric flocculation reactor 2, chemical oxidation pond 3, anoxic pond 4 and membrane bioreactor 5 successively; Described electric flocculation reactor 2 comprises battery lead plate 6 and component pulse-changing power 7, and this battery lead plate 6 links to each other with component pulse-changing power 7; Described membrane bioreactor 5 comprises built-in membrane module 8 and efflux aerator 9; It is characterized in that, at least one group of battery lead plate 6 is arranged in parallel in the described electric flocculation reactor 2, the anode of this battery lead plate 6 and negative electrode are solubility electrodes such as aluminium sheet or iron plate, and described chemical oxidation pond adds hydrogen peroxide (or clorox, dioxide peroxide, ozone etc.) strong oxidizer.
The invention provides a kind of method that adopts the processing pharmaceutical wastewater by pulse electrocoagulation-MBR of said apparatus, it is characterized in that, this processing method comprises the steps:
(1) after waste water mixes in equalizing tank, enter electric flocculation reactor and carry out electrolytic reaction, apply the alternating impulse electric current on battery lead plate, strength of current is 1~15A, and the alternating impulse cycle is 1~20s; In this process, the alternating impulse electric current can overcome the passivation and the polarization problem of battery lead plate, prolongs battery lead plate work-ing life, cuts down the consumption of energy, and improves treatment effect;
(2) in electric flocculation reactor, the metal ion that soluble anode produces produces flocculation agents such as a series of multinuclear hydroxyl complexing ions and oxyhydroxide through hydrolysis, polymerization, separates out O simultaneously on anode
2Microbubble produces H on negative electrode
2Microbubble; Polymer organic pollutant, suspended substance and toxic substances etc. in this flocculation agent and the waste water carry out throwing out and form pollutent flocculation group, this O
2And H
2The pollutent flocculation group that produces in the microbubble planar water also floats to the water surface, produces the air supporting effect, reaches solid-liquid separation effect; Simultaneously, OH and the O that produces in the wastewater electrolytic process
2Larger molecular organics can be oxidized to small organic molecule in oxygenant, improve the biodegradability of waste water.In this process, most of organism is removed in the waste water;
(3) waste water enters chemical oxidation pond after electric flocculation reactor is handled, in chemical oxidation pond, add hydrogen peroxide (or clorox, dioxide peroxide, ozone etc.) strong oxidizer, hard-degraded substance in the waste water is converted into biodegradable small organic molecule, play the effect of strengthening oxygenolysis, waste water enters A/O technology afterwards;
(4) A/O technology is made up of anoxic pond and membrane bioreactor, and the built-in efflux aerator of membrane bioreactor improves the oxygen level of mixed solution in the reactor greatly, has strengthened organic degradation effect; After FEOL was handled, the biodegradability of waste water was greatly enhanced, thereby the organic pollutant in the waste water can effectively be removed in this technology, and this technology also can be removed pollution substances such as ammonia nitrogen in the waste water and phosphorus simultaneously;
(5) waste water after the A/O art breading is through the membrane filtration water outlet, and this membrane filtration water outlet can reach industry one-level A standard.
In the technology of the present invention, alternating impulse strength of current is 1~10A, and the alternating impulse cycle is 1~15s, and dutycycle r is 0.5~1.0.
Below enumerate several examples effect of the present invention is described, but claim scope of the present invention is not limited only to this.
Example 1: sewage source is certain pharmaceutical factory's waste water, and condition of water quality is: CODCr content 17000~20000mgL-1, BOD content 7000~9000mgL
-1, SS is 700mgL
-1, ammonia nitrogen is 700mgL
-1It is 8A that alternating impulse strength of current is set, and alternating impulse cycle 6s, dutycycle r are 0.7.After pulse electro-flocculation-MBR art breading, final outflow water COD
CrLess than 50mgL
-1, total nitrogen concentration is less than 10mgL
-1, turbidity is less than 0.5mgL
-1, reach industry discharging one-level A standard;
Example 2: sewage source is certain pharmaceutical factory's waste water, and condition of water quality is: COD
CrContent 5000~8000mgL
-1, BOD content 2500~10000mgL
-1, SS is 500mgL
-1, it is 8A that alternating impulse strength of current is set, alternating impulse cycle 6s, dutycycle r are 0.7.After pulse electro-flocculation-MBR art breading, final outflow water COD
CrLess than 50mgL
-1, turbidity is less than 0.5mgL
-1, reach industry discharging one-level A standard.