Background technology
1, the generation of consumer waste infiltration liquid:
The processing method of domestic waste mainly contains and burns and landfill at present, no matter the sort of method disposal of refuse, all will produce percolate, consumer waste infiltration liquid is compared with industrial wastewater with city domestic sewage, percolate has more tangible characteristics, be the composition complexity, water quality and quantity changes greatly and is aperiodicity, and stable treated is brought big difficulty to it being carried out effectively undoubtedly.
2, percolate characteristic:
Percolate belongs to high concentrated organic wastewater.Cod codcr concentration range 20000~70000mg/L in the ordinary circumstance percolate, BOD BOD5 concentration range 10000~40000mg/L, ss suspended solid is about 6000mg/L, pH4~6, ammonia-nitrogen content is at 1000-2000mg/L, salt content is at 20000-60000mg/L, also contain multiple organic matter and inorganic matter (containing poisonous harmful components) simultaneously, thereby its water quality is quite complicated, pollutant kind is many, and there is the complexity of short-term fluctuation and change in long term in concentration.
3. treatment technology:
Along with the raising of various countries to the standard of environmental protection requirement, existing conventional garbage filter liquid processing method can not be satisfied the demand, and shown in Fig. 1 is the garbage filter liquid processing method of existing a kind of routine.
This technology said method comprising the steps of:
(1) sewage carries out pre-treatment step after regulating reservoir is fully regulated, and this pre-treatment step is included in flocculation basin 1, the flocculation basin 2 and adds flocculant, enters the preliminary sedimentation tank precipitation then;
(2) after the sewage that is come out by preliminary sedimentation tank enters PH adjustment pond adjusting PH, carry out biological respinse in anaerobic pond, anoxic and Aerobic Pond (contact-oxidation pool), the mud that comes out from Aerobic Pond is back to anaerobic pond, sewage enters into coagulation reaction tank;
(3) sewage that comes out of coagulation reaction tank enters the mud-water separation pond again and carries out mud-water separation by sedimentation basin, and the mud that comes out in the mud-water separation pond enters sludge concentration tank and concentrates, and the mud after concentrating enters the sludge dewatering system dehydration, the mud outward transport after the dehydration; The sewage that comes out in the mud-water separation pond enters MBR film reaction pond;
(4) carrying out the MBR film in MBR membrane biological reaction pond handles;
(5) handle effluent adopting RO system (counter-infiltration system) technology for MBR (membrane bioreactor) film and carry out advanced treating, dense water returns regulating reservoir and handles again; Clean water enters the discharging pond and carries out qualified discharge.
This processing method, the organic matter and the inorganic matter that contain in the percolate are to a certain degree being handled, but still contain the organic matter that exceeds standard in the dense water that RO produces, handle again if directly do not get back to regulating reservoir through processing, can be to the microorganisms damaging effect.
And, exist following obviously not enough further:
(1) sewage carries out pre-treatment step after regulating reservoir is fully regulated, and this pre-treatment step does not fully take into account the heavy metal composition that municipal refuse contains, and does not consider to remove the medicament reaction of heavy metal composition;
(2) before advancing biochemical treatment, do not consider the very high harmfulness of ammonia nitrogen concentration of this water quality to microorganism, the measure of removing ammonia nitrogen of not adopting;
(3) because this water quality SS is dense, between employing anaerobism, anoxic and aerobic the processing, do not consider the consumption of mud to dissolved oxygen, make the effective rate of utilization of Aerobic Pond oxygen reduce greatly.
Summary of the invention technical problem to be solved by this invention provides a kind of can further the processing the organic matter that exceeds standard that contains in the dense water after the advanced treating, thereby can reduce the organic content in the dense water, make that water after the processing can qualified discharge rubbish leachate treatment method.
Method of the present invention may further comprise the steps:
(1) percolate carries out pre-treatment step after regulating reservoir is fully regulated, and this pre-treatment step comprises percolate is added the flocculant preformed precipitate of flocculating;
(2) sewage after the pre-treatment step carries out Anaerobic Treatment;
(3) sewage after the Anaerobic Treatment is carried out Aerobic Process for Treatment (denitrification+nitrated);
(4) enter in the MBR membrane biological reaction pond through the sewage after the Aerobic Process for Treatment;
(5) in MBR membrane biological reaction pond sewage being carried out the MBR film handles;
(6) handle water outlet for the MBR film and carry out advanced treating: clean water enters the discharging pond and carries out qualified discharge; The dense water of nanofiltration enters ozone contact tank (ultrafiltration+nanofiltration);
(7) the dense water of nanofiltration carries out ozone oxidation reaction at ozone contact tank;
(8) water after ozone oxidation reaction is begged for speaks into the discharging pond and says capable qualified discharge.
Be under alkali condition, to add flocculant in the pre-treatment step described in the step (1).Can remove the part metals ion in the percolate like this.
Described method also comprises steps A after step (1): carry out the part denitrogenation through circulation blow-removing pond and stripping tower, the sewage after the denitrogenation enters step (2) and carries out Anaerobic Treatment.Can be more suitable for anaerobe nutrition ratio so that enter the water quality ammonia nitrogen concentration of anaerobic reaction like this.
Anaerobic Treatment is carried out in the UASB anaerobic reactor in the described step (2).This anaerobic reactor treatment effeciency moves more stable than general anaerobic pond treatment effeciency height.
In the described step (2), percolate flows into before the UASB anaerobic reactor, is introduced into the middle pond of anaerobism, and stop is no less than 3 days in the middle pond of anaerobism.Can guarantee that like this mud fully precipitates.
After the described step (2), also comprise step B: after the sewage after the Anaerobic Treatment enters the anaerobic sludge separate tank anaerobic sludge is concentrated, be back to pond in the middle of the anaerobism.Can guarantee that like this returned sludge guarantees not add medicament, the backflow effect is better.
After the described step (2), also comprise step C: the sewage after the Anaerobic Treatment is carried out digestion process, and the sewage after the digestion process enters the mud-water separation pond, and the mud that separate in the mud-water separation pond concentrates, the outward transport of dehydration back; The sewage that separate in the mud-water separation pond enters step (3) and carries out Aerobic Process for Treatment.Carry out mud-water separation after the reaction,, make the available oxygen utilization rate that enters Aerobic Pond improve greatly, just improved the treatment effect of Aerobic Pond because most of biological sludge separates in the mud-water separation pond.
Advanced treating described in the described step (6) is to adopt ultrafiltration+nanofiltration technique to carry out advanced treating.This processing method is than the more anti-obstruction of RO.
After the described step (7), also comprise step D: the water of ozone Oxidation Treatment is sent into chemical reaction pond again, and the chemical reaction pond treated water enters the discharging pond.Can remove other harmful substances that contain in the ozone Oxidation Treatment treated water by further chemical reaction like this.
In the described steps A: described stripping tower inside is equipped with multipole eddy flow plate, the water counter current contacting that air stream sprays through multipole eddy flow plate and top from bottom to top.The air stream that can allow of this multipole eddy flow plate is done repeatedly eddy flow from bottom to top, fully contacts with the water with the top spray.
The present invention is owing to pass through ozone oxidation reaction again to the dense water after the advanced treating, and through the virus killing of ozone, oxidation such as fade, organic matter has been removed in degraded, can make the water qualified discharge after the processing.
The specific embodiment
The invention will be further described below in conjunction with accompanying drawing and preferred embodiment.
The specific embodiment is the percolate sewage disposal process of a garbage incinerating power plant, and this power plant day disposal of refuse amount is 1200 tons.The percolate that dumping produces is 300 tons/day, and this percolate is a kind of organic sewage of high concentration, contains the pollutants such as ammonia nitrogen, organic matter of high concentration.In this embodiment, percolate is when entering system, CODGr (COD) peak value reaches 70000mg/L, BOD5 (five-day BOD) peak value reaches 30000mg/L, SS (suspension) is up to 6000mg/L, mean value is about 3000mg/L, and the ammonia nitrogen peak value reaches 2000mg/L.
As Fig. 2, percolate is at first collected by collecting-tank, and the pump hole is established in the collecting-tank bottom, regularly takes the mud that is trapped in the collecting-tank bottom away.
The sewage that collecting-tank flows out enters regulating reservoir, regulates the sewage water yield, even water quality, and percolate is through 3-5 days stop in regulating reservoir simultaneously, and the clearance of COD is about 10-15%.
The sewage that is flowed out by regulating reservoir enters the two poles of the earth flocculation basin again, and add the flocculation of lime/NaOH therein, PH is controlled between 9-11, lime/NaOH dosing pump adopts Frequency Converter Control, the control of flocculation basin pH value adopts analog quantity output signals to give frequency converter by setting the control bound of PH instrument, and frequency converter is according to analog output signal, what of adding lime/amount of sodium hydroxide are the operating frequency of adjusting the lime dosing pump determine, thus the pH value of control flocculation basin.Sewage and then enter preliminary sedimentation tank, sedimentation time 3h.Preliminary sedimentation tank adopts vertical sedimentation basin.After the preliminary sedimentation tank processing, the COD place to go rate of percolate is 20%-30%, and the clearance of SS (suspension) is about 65%.
Through after the above-mentioned pre-treatment step, again sewage is imported the circulation blow-removing pond.The percolate ammonia-nitrogen content reaches more than the 2000mg/L, then be difficult to realize biological denitrificaion if allow it directly enter biochemical treatment apparatus, therefore utilize the alkalization stripping tower to carry out the part denitrogenation earlier, promptly at first adding alkali makes percolate be alkalescence (ph〉9), ammonium ion wherein is converted into free ammonia, sends into stripping tower then and removes free ammonia with spray and air blast stripping mode.But the ammonia that stripping comes out is qualified discharge after handle on the ammonia absorption tower.After sewage flows into the circulation blow-removing pond, pump to the stripping tower top with pump and to spray water distribution.Establish multipole eddy flow plate in the stripping tower, force flow through from bottom to top multipole eddy flow plate and fully mix with the water adverse current of air stream is contacted, reach the purpose of stripping by two air blasts installing at the stripping tower rear portion.Sewage is 4 hours in the time of staying of this step, from the circulation blow-removing pond with pump draw water to the recycle ratio of stripping tower be 20: 1.Described recycle ratio is meant the cycle-index of water between stripping tower and circulation blow-removing pond of unit volume, is example with 20:1, refers to 1m
3Former water between stripping tower and circulation blow-removing pond, circulate 20 times.The gas-water ratio of air blast blow air is 200: 1.In order to improve ammonia stripping rate, the bottom in circulation blow-removing pond further is provided with aerator ammonia is carried out preliminary stripping, can further guarantee the high clearance of ammonia.In this step, to ammonia-N removal rate 50%-70%.With traditional comparing with the filler stripping tower, adopt above-mentioned blow-removing system that following advantage is arranged: big (2) simple structure (3) running resistance little (4) energy consumption lower (5) of (1) gas flux need not to clean.
Enter PH through the sewage behind the circulation blow-removing and adjust in the pond, hydraulic detention time is 0.5h herein, and pH value is controlled at about 7-8, enters next unit afterwards and continues to handle.
Next step flows into the sewage that comes out in PH adjustment pond in the middle pond of pulling flow type anaerobism, and stops about 10 days.In this step, utilize the time of staying of overlength, make through pretreated percolate sewage and carry out abundant hydrolysis acidification.This handles the primary stage processing as the UASB anaerobic reactor.After the normal operation of UASB anaerobic reactor, can use the mud more than needed of its output that pond in the middle of the anaerobism is inoculated, further improve the treatment effect in the middle pond of anaerobism.The advantage of setting up the middle pond of this anaerobism is as follows: (1) realizes the regulating reservoir function, regulates and handles the water yield; (2) influent load of buffering UASB anaerobic reactor; (3) further reduce SS (suspension), guarantee that reactor water inlet safety (4) improves UASB anaerobic reactor water inlet biochemical.Through the COD clearance after this cell processing about 30%, SS (suspension)≤100mg/L.
Behind pond in the middle of the anaerobism, percolate enters the UASB anaerobic reactor, and sewage carries out anaerobic reaction at this, and larger molecular organics is decomposed into less molecule organic matter, improves the biodegradability of percolate.Sewage is 5 days in effective time of staying of UASB reactor.In running, the afterheat steam that utilizes refuse-burning plant makes it reaction temperature and is stabilized in about 35-38 ℃ for the heating of UASB reactor.Water inlet adopts equally distributed perforated pipe water-locator to make sewage be incorporated into the bottom of UASB reactor equably, and sewage is upwards by comprising the Sludge Bed of granule sludge or floc sludge.Anaerobic reaction occurs in the contact process of sewage and mud granule, and the biogas that reaction produces has caused inner circulation.Adhere to or and rise to reactor head, hit three phase separator gas expelling plate, cause the mud flco degassing of adhering to bubble attached to the biogas on the mud.Bubble discharges the surface that the back mud granule will be deposited to Sludge Bed, and gas is collected into the collection chamber of the three phase separator of reactor head.Some mud granules can enter the settling zone through the separator slit.
UASB anaerobic reactor in the present embodiment is of a size of 11x11x12 rice, 12 meters of pond body head rooms, and available depth is 10.5 meters, 5 days time of staying.
The startup of UASB anaerobic reactor:
Start and be divided into three phases: (1) sludge acclimatization culture period (2) load (3) oepration at full load phase raising phase.
Phase I sludge acclimatization culture period: select for use through the mud of taming and inoculate, anaerobic sludge divides 5 days access 1300m
3, the sludge concentration of reaction of inoculation device is 34mg/L, inserts 260m in every day
3Behind the anaerobic sludge, add the middle pond water outlet of the anaerobism of COD after the dilution about 3000mg/L, dosage is 260m
3, after 5 days vaccinizations and adding dilute sewage, be full of whole UASB anaerobic reactor.Because the temperature of seed sludge does not reach the design and operation temperature about 26 °, therefore, need to improve temperature of reactor.Adopt the little water yield intermittent water inflow every day, advanced 4 hours, stopped two hours, the water yield is controlled at 10m
3/ h, COD are about 3000mg/L, and volumetric loading is controlled at 0.4kgCOD/ (m
3.d), temperature raise 1 ° in per two days.When temperature was brought up to 36 °, amount of inlet water remained unchanged, and the pond water outlet directly enters without dilution in the middle of the anaerobism, and COD is between 16800mg/L-20000mg/L in water inlet, moves for 2 weeks continuously, and the clearance of later stage COD progressively improves, and clearance reaches about 80%.About 45 days consuming time of this stage.
Second stage is the load raising phase: anaerobic reactor is through after the operation of phase I, and beginning progressively improves the operating load of reactor, improves load by increasing amount of inlet water.Water inlet is continuously adopted in water inlet, and 1-15 days, the processing water yield was 6m
3/ h, COD is between 16800mg/L-20000mg/L in water inlet, and reactor load improves by 4kgCOD/ (m
3.d) bring up to 6kgCOD/ (m
3.d), the clearance of COD was stabilized in 75% water outlet SS (suspension)≤47mg/L in several days in the back.During 16-35 days, handle the water yield and rise to 13m
3/ h, intaking is pond water outlet in the middle of the anaerobism, reactor load is increased to 7kgCOD/ (m
3.d), in ensuing 2 months, amount of inlet water is brought up to design water yield 40m gradually
3/ h, reactor load is increased to 9kgCOD/ (m
3.d) clearance of later stage water outlet COD is stabilized in more than 75%, water outlet SS (suspension)≤40mg/L.
Phase III is the oepration at full load phase: reach 40m in water inlet
3Behind/the h, reactor water outlet 100%-200% refluxes, and organic loading reaches 9-12kgCOD/ (m
3.d), gas production also improves gradually, factor of created gase 7-9m
3/ (m
3.d).Microscopy reactor organisms kind branch is reasonable, and generating has granule sludge.Through after the processing of anaerobic reactor, the clearance of COD is more than 80%, SS (suspension)≤30mg/L.
Between the starting period of UASB anaerobic reactor, a PH instrument is installed on the reactor water inlet pipe, according to coming the regimen condition, an alkali measuring pump is set, controlled by the PH instrument, the reactor pH value is stabilized in about 7.5, avoid because the water inlet acidifying makes reactor unbalance.
After the processing of UASB anaerobic reactor, organic pollution in the percolate such as aliphatic acid, hydro carbons, phenols, heterocyclic arene class, multiring aromatic hydrocarbon etc. are all effectively removed, or be decomposed into the little molecule of easier degraded, obviously reduced the toxicity of percolate, heavy metals etc. have also obtained effective removal through behind a series of flocculation sediments.
UASB is on average intake COD about 30000mg/L, and reactor is after taming through inoculation, and disposal ability improves gradually, and the clearance of COD is stabilized between 75-80%, and reactor water outlet COD<6000mg/L, organic loading are 10kgCOD/m
3.d.The mud-water separation pond is set behind the UASB reaction tank, catch the anaerobic sludge that water outlet is together taken out of though pounce on, vertical sedimentation basin is adopted in the mud-water separation pond, 3 hours time of staying, in establish mud backflow water pump, with anaerobic sludge and part anaerobism effluent recycling pond front end to the anaerobism, 100%-200% capacity of returns.
The water outlet of UASB anaerobic reactor according to oozing the high characteristics of drop liquid sewage ammonia nitrogen content, aims at its design nitrification and denitrification biological denitrificaion unit through flowing into nitrated/anti-nitration reaction unit after the mud-water separation, and nitrification refers to NH
3Be oxidized to NO
- 3Process, nitrification is participated in by two bacterioids, nitrococcus is with NH
3Be oxidized to NO
- 2Bacterium nitrobacter is with NO
- 2Be oxidized to NO
- 3The energy that they all utilize oxidizing process to discharge makes CO
2Synthesize the organic substance of cell, because of it is a class chemosynthetic bacteria, when operational management, should create the environment that is fit to from the nitrobacteria growth and breeding of nourishing one's nature, nitrifying process is the key of biological denitrificaion.
NH
4 ++20
2→NO
- 3+2H
++H
2O+(307.1-438.9)×10
3J
The nitrification process will exhaust a large amount of oxygen, makes a part NH
4 +-N is completely oxidized to NO
- 3Need exhaust the oxygen of 2 molecules, i.e. 4.57mgO
2/ mgNH
4 +-N.Nitrifying process makes the acid enhancing of environment.
In nitration reaction,, prolong sludge retention time and guarantee carrying out smoothly of nitrification by the lower load of control.
Denitrification is the process that nitrate and nitrite is reduced into gaseous nitrogen and nitrous oxide by denitrifying bacterium.Denitrifying bacterium mostly is the facultative anaerobic bacteria of heterotrophism, and it utilizes various organic matters as the electron donor in the denitrification process (carbon source), in denitrification process, and organic being oxidized to:
5C (organic C)+H
2O+4NO
- 3→ 2N
2+ 4OH
-+ 5CO
2
The oxygen that exhausts in the nitrification process can be repeated to use in the denitrification process, makes organic oxidation.
The denitrification pond time of staying is 16 hours, and DO (dissolved oxygen) controls less than 0.3mg/L, and the nitration reaction pond time of staying is 48 hours, and DO (dissolved oxygen) is controlled between 2.0-3.0mg/L.And the mud-water separation pond is set behind the nitration reaction pond, and the time of staying is 3 hours, and form is a vertical sedimentation basin, in establish mud cocurrent flow pump, separated sludge is back to carries out denitrification in the anti-nitration reaction pond, remove ammonia nitrogen.About 75%, ammonia nitrogen removal frank is about 75% to the clearance of COD in the percolate for this element, and the BOD clearance is about 80%.
Flow into one-level contact oxidation pond through the mud-water separation pond water outlet behind the nitration reaction pond and carry out aerobic reaction.This segment process main feature is in same structures, by structures being divided into different zones, be equipped with different aeration rates, being under anoxic, the aerobic situation of sewage purified the organic matter in the sewage, ammonia nitrogen and phosphorus degraded by the different microorganisms flora, enter follow-up MBR membrane biological reaction pond at last, carry out mud-water separation, excess sludge enters the mud collecting pit, by mud backflow water pump it is being distributed.
The contact oxidation treatment system time of staying that this unit adopted is 24 hours.Be divided into first order catalytic oxidation district, anoxic zone, second level catalytic oxidation district according to different functions.The first catalytic oxidation district hydraulic detention time is 8 hours, is received the activated sludge mixed processing of water outlet of mud-water separation pond and partial reflux, and dissolved oxygen DO is controlled at 2.0-3.0mg/L; Adopting the fiber soft-filler is the biomembrane contact medium, and characteristics are that specific area is big, voidage is high, hydraulic resistance is little, steady chemical structure, low, the in light weight (2-3kg/m of cost
3) etc., gas-water ratio is at 10-15:1; The anoxic zone hydraulic detention time is 4 hours, in this stage, water is not carried out aeration, allows double oxygen bacterium in the water remaining oxygen in the consume water in metabolic process, carries out denitrification denitrogenation; Catalytic oxidation district, second level hydraulic detention time is 12 hours, and adopting the fiber soft-filler is the biomembrane contact medium, and this stage dissolved oxygen DO value is controlled at 2.0-2.5mg/L.COD clearance through contact oxidation pond processing unit is stabilized in about 85%, and unit water outlet COD<600mg/L, organic loading are 2.5kgCOD/m
3.d.
Next step enters sewage in the MBR reaction tank, and carries out the MBR film and handle.For guaranteeing that discharging water quality reaches primary standard, design immersion MBR membrane treatment appts in the MBR reaction tank.Sewage carries out the nitrification and denitrification reaction in the MBR reaction tank, can further remove pollutants such as COD, BOD, ammonia nitrogen.Membrane bioreactor (MBR) technology is the novel sewage disposal technology that membrane separation technique and biotechnology organically combine, and it utilizes membrane separation plant that activated sludge in the biochemical reaction tank and larger molecular organics are held back, and saves second pond.Film-bioreactor technology has been strengthened the function of bioreactor greatly by the isolation technics of film, through two-stage aerobic biochemical treatment before, biodegradability in the water is reduced to about 0.23 (BOD/COD), biochemical reduces, in conventional treatment process, the water in this stage is intractable, but in membrane bioreactor, by holding back to activated sludge, bacterium, make the bacterium of some hardly degraded organic substances of degraded be kept propagation, cultivation, domestication through 2 months activated sludge improve activated sludge concentration greatly, and bacterial species significantly increases.Membrane bioreactor can be controlled its hydraulic detention time (HRT) and sludge retention time (SRT) respectively simultaneously.
MBR reaction tank available depth is 5.5 meters.Reaction tank is divided into backwater mixed zone and film treatment region two parts.Membrane module adopts hollow fiber ultrafiltration membrane, and membrane material is Kynoar (PVDF), and membrane aperture is 0.1-0.2 μ m, monolithic membrane area 20m
2. aquifer yield is 3.6m
3/ sheet .d.The film treatment region time of staying is 16 hours, and sludge concentration is 8500mg/L, water outlet COD about 300mg/L, SS≤3, SDI value≤3, turbidity≤0.46NTU meets nanofiltration water inlet requirement.
System is behind the process aerobic biochemical, COD biodegradability in the sewage also progressively reduces, adopt conventional aeration method can not effectively reduce COD in the water, and the employing membrane bioreactor, it can be in water outlet, do not take away activated sludge, the microorganism of having handled difficult degradation COD for slower some of propagation since like this provides a good growing environment, and this is not accomplish in conventional aerobic activated sludge process.
The water outlet of process MBR membrane bioreactor is owing to contain a certain amount of difficult biochemical substances (humus, lignin etc.), can not in the limited time, be removed largely by bacterium, therefore can further pass through ultrafiltration (MOF)+nanofiltration (NF) and handle the back discharging in the MBR water outlet.The aperture of nanofiltration mostly is nanoscale, and the boundary is between ultrafiltration and reverse osmosis filter.Nanofiltration promotes by external pressure, and the TDS in the water is held back.Because reverse osmosis membrane all has very high rejection to all ions in the water, and the NF membrane selectivity higher to holding back of water intermediate ion, NF membrane is that the organic matter of 200-1000 has very high rejection to divalent ion and molecular weight only.Therefore, select the technology of nanofiltration for use, and do not select reverse osmosis process for use, promptly can guarantee has higher removal to COD in the water, has avoided the dirty stifled problem in the long-time back of reverse osmosis membrane again, has prolonged the service life of system, simultaneously, the driving pressure in nanofiltration system when operation is compared little many of counter-infiltration, has reduced energy consumption, has reduced the operating cost of system.
Can adopt the ozone that further produces in ozone contact tank, to carry out oxidation processes for the dense water of nanofiltration with the oxygen rich source ozone generator, oxidization time is not less than 40 minutes, further remove other harmful substances that contain in the water through entering chemical reactor again, make sewage up to standard, with ultrafiltration water outlet qualified discharge.
In the present embodiment, nanofiltration adopts 2+1 to arrange, and uses the antipollution NF membrane of 24 U.S. TFC series, aquifer yield 〉=15m
3/ h adopts constant pressure frequency conversion control, and pressure is controlled at 0.35-0.7Mpa, produce water COD≤50mg/L, electricity is led≤3000 μ s.cm, and system's water outlet is better than " integrated wastewater discharge standard " (GB8978-1996) first discharge standard, and many index reaches the reclaimed water standard.
Concrete water quality index such as following table:
Preface |
Project |
Unit |
Numerical value |
1 |
CODCr |
mg/L |
≤100mg/L |
2 |
BOD5 |
mg/L |
≤20mg/L |
3 |
Ammonia nitrogen (in N) |
mg/L |
≤15mg/L |
4 |
SS |
mg/L |
≤70mg/L |
5 |
Total phosphorus (in P) |
mg/L |
≤0.5mg/L |
6 |
pH |
|
6~9 |