CN1188080A - Method for municipal sewage treatment by using biological adsorption and biological membrane filtering - Google Patents

Abstract

The method for treating municipal sewage by using biological adsorption biomembrane filtration includes two portions of A-grade and BF-grade, in which the said A-grade is identical to A-B method, and the discharge water after precipitation is fed into BF-grade from top (fed into biomembrane aeration filter tank). It is characterized by that the said BF-grade uses 1.6-1.8 m aeration filtering layer to make biological degradation of organic contaminant, then downward to 0.2-0.4m filtering layer to make mechanical filtration to further trap the suspended material in the water, then collects water in the bottom of filter tank and discharges water in the mode of high-level discharge. The time of the sewage water stayed in filter tank is 1 to 0.5h, filtering speed is 2-4 m/h and the aeration capacity is controlled according to the ratio of water: air= 1 : 6 about.

Description

A kind of novel method of utilizing biological adsorption and biological membrane filtration treatment municipal effluent

The present invention relates to urban construction plumbing, urban sewage treatment technology, specifically be meant a kind of novel method of utilizing biological adsorption and biological membrane filtration treatment municipal effluent, i.e. the A-BF method.

Comparatively advanced in the every biologic process for treating sewage technology that widely adopts at present with the A-B method.Its technological process as shown in Figure 1.In the A-B method, owing to adopted the A level of high loading to cancel settling tank again, make total hydraulic detention time shorten to 7h, thereby saved initial cost, reduced working cost, reduced building site.Compare with traditional active sludge biological facture, truly have very much progress.But the B level in its technological process still needs with underrun, and its hydraulic detention time still needs to have limited the further performance of its advantage more than 5 hours.

In order further to improve processing efficiency, reduce initial cost, save working cost, save energy consumption, dwindle the floor space of handling the station, must transform B level technology practical and effective.

For this reason, purpose of the present invention promptly is according to after the relevant sewage disposal achievement in research in past is carried out analysis-by-synthesis, a kind of novel method of utilizing biological adsorption and biological membrane filtration treatment municipal effluent is provided, promptly replaces B level in the A-B method, at the same time with biofilm aeration filter tank (BF level), cancelled settling tank, to reach the raising volumetric loading, reduce initial cost, save and take up an area of, cut down the consumption of energy, save the purpose of working cost.By feasibility study, determined the process structure and the filtrate in microbial film filter tank, confirm that by interim test this Technology is successful.

The novel method of biological adsorption and biological membrane filtration treatment municipal effluent of utilizing provided by the present invention comprises A level and BF level two portions; The processing condition of the A level in wherein said A level and the former A-B method are the same, be that municipal effluent is after grid is held back the coarse grain foreign material, sewage need directly not enter A level aeration tank through primary clarifier, the mixed solution sludge concentration maintains about 2g/L in the pond, regulating aeration rate is 0.5-1.0mg/l with dissolved oxygen concentration in the control pond, sewage enters A level settling tank (intermediate sedimentation pond) after A level aeration tank stops 0.5h, through the 1.7h post precipitation, part mud returns stays down into the A aeration tank, to keep the sludge concentration of A level aeration tank, part mud is discharged as excess sludge; And enter BF level (biofilm aeration filtering basin) from the top through the water outlet of post precipitation, aeration filtering layer biodegrade organic pollutant by 1.6-1.8m, in the further trap water of filtering layer mechanical filter of 0.2-0.4m of passing through down behind the suspended substance, catchment in the bottom, filter tank, mode with high-order water outlet is discharged, the time 1 that sewage stops in the pond is to 0.5h, filtering velocity is 2-4m/h, aeration rate is pressed water: gas=control about 1: 6, the selection of filtering velocity can be determined according to the requirement to water outlet, require height then to select low filtering velocity as the water outlet pledge, if then can select high filtering velocity for use to effluent quality is less demanding.

Because the biofilm aeration filter tank (BF level) among the present invention has been adopted bigger particle diameter filtrate and interlayer aeration mode, both overcome the obstruction in traditional wastewater filter tank, prolong the recoil cycle, again because the bottom, filter tank also remains with the static filtering layer of 0.2-0.4m, thereby the effective suspended substance in the trap water, it is one lower (on＜10ml/L) the level to make out water suspension remain on.Owing to loaded coke in the pond or haydite is made filtrate, have bigger specific surface area, filter material surface can form microbial film by the big coenosis of set, adds buoyant active sludge between filtrate, relative raising the sludge concentration in the pond, though BOD ₅The COD volumetric loading is very high, and BOD ₅The COD sludge loading then still maintains on the lower level, thus high processing efficiency, and guarantee that water outlet has stability preferably.By the scale 24-48m that disposes of sewage nearly 2 years day ³The obtained data of the test in place of/d proves, when raw waste water CODer is 315-716mg/l, BOD ₅81.5-183mg/l, SS is 50-1060mg/l, A level aeration tank hydraulic detention time 0.5h, A level settling tank hydraulic detention time 1.7h, BF level filtering velocity 2m/h (quite stopping 1 hour) and when following handles water outlet afterwards and is better than common secondary biochemical treatment technology and A-B method technology, under above-mentioned total residence time is 3.2 hours situations, the CODcr clearance is more than 90%, BOD ₅Clearance is more than 95%, and the SS clearance can obtain water outlet CODcr＜35mg/L, BOD more than 98% ₅＜7mg/L, the effect of SS＜10mg/L makes leading indicator reach the requirement of middle water water quality standard.

Biofilm aeration filter tank involved in the present invention (BF level) structure can be seen by Fig. 3, the filling particle diameter is that coke or the haydite of 2-6mm made filtrate in the pond, the filtering layer total thickness is 1800-2200mm, on the horizontal plane of distance filtering layer bottom 200-400mm, aeration tube is set, air is entered in the pond by the aeration tube qi-emitting hole, by being overflowed by top behind the filtering layer of 1600-1800mm.

In sum as can be known, the special construction pattern in biofilm aeration filter tank (BF level) and operation scheme are the keys that A-BF method biological treatment is succeedd, the BF level is compared with the B level in the A-B method, and its hydraulic detention time only is the 1/6-1/4 of B level, and construction costs is expected to save 40%; Floor space reduces 60%, and working cost can save 50%.It is strong that the A-BF treatment process has the anti impulsion load ability, stable, and energy consumption is low, the volumetric loading height, and the residence time is short, and organic pollutant removal is effective, saves advantages such as occupation of land and construction investment.Especially take up an area of to save, reduce construction investment and have more practical significance, China's present stage town sewage is handled played favourable promoter action.

The A-BF treatment process is develop on A-B method basis a kind of more efficient, the advanced novel combination process of municipal sewage treatment, it successfully combines technology of biological membrane with filtering technique, with the B level in the BF level replacement A-B method technology, be series at biological absorption (A level) efficiently afterwards, formed a kind of sewage treatment process more efficiently, has the processing efficiency height, the outstanding feature that effluent quality is good also has the volumetric loading height simultaneously, the residence time is short, construction investment is economized, energy consumption is low, take up an area of few, stable, adapt to change of water quality, ability is strong, advantages such as operational management is simple.Wherein, having more practical significance save to take up an area of, to reduce construction investment especially, is a kind of suitable China's national situation, sewage treatment technique with popularizations, practical value, from bigger economic benefit and real meeting benefit.The A-BF method can be used for the design of the production wastewater treatment of the close with it industrial and mining enterprises of large, medium and small type municipal sewage treatment design or water quality, is applicable to the reconstruction and the extension project of sewage work in the time of also.In the still unsound area of municipal Infrastructure, newly-built development area, tourist attractions etc., the pollution that can adopt the small-sized complete waste disposal plant according to the A-BF technological design to control environment.Compare with conventional activated sludge process, construction investment is saved 15-25%, and working cost is saved 15-25%, and floor space is saved 20-30%.

In every technology of sewage disposal, biological treatment compares with chemical method and physico-chemical processes, has the processing efficiency height, treatment effect is good, running expense is lower, design and running experience is than advantages such as horn of plenties, in engineering practice, widely use; But also there are deficiencies such as initial cost and energy consumption are higher, floor space is bigger, limited further processing efficiency height, and capital cost is lower, and the new bio treatment technology that floor space is less, energy consumption is economized has become the key that biologic treating technique develops.

For this reason, the inventor has carried out biological absorption one oxidation style (A-B method) Treating Municipal Sewage research from 1988 to 1992, obtained comparatively ideal effect, and used in engineering.This achievement obtains Ministry of Construction's scientific-technical progress third prize.

The key of A-B method high-efficiency low energy consumption is the A level, and according to the parameter that A-B method institute is recommended, the hydraulic detention time (HRT) of A level aeration tank only is 0.5-0.75h, and sludge loading is 2-5kgBOD ₅/ kgMLSS.d, and the hydraulic detention time of B level aeration tank is 2-4h, sludge loading≤0.3kgBOD ₅/ khMLSS.d promptly still need be by underload activated sludge process design, operation, but also the settling tank that need be aided with residence time 2-4h is to satisfy solid-liquid separation and activity sludge reflux needs.Can develop a kind of more efficient novel process on A-B method basis, its key be the B level is effectively transformed.

Biomembrance process is a kind of comparatively sophisticated biologic process for treating sewage, the inventor also once did cross comparatively deep research, and be applied to engineering practice.But, be subjected to certain limitation in therefore promoting because the organic pollutant degree of depth is lower in the water inlet of this processing requirement.We are connected on A level back with biomembrane process at imagination, the B level that replaces underload, raw waste water is after the A level is handled, the organic contamination substrate concentration significantly reduces, can satisfy the lower requirement of organic contamination substrate concentration in the only suitable water inlet of biomembrane process, give full play to biomembrane process volumetric loading height, the residence time is short, treatment effect is good, the better simply advantage of operational management, and use for reference " adopt biological carbon method and activated sludge process to carry out low-temperature biological and handle comparison test " data that French OTV S.A. introduced on " TSM " (90 years N07/8) publication, in biomembrane process, be aided with filtering technique, save B level secondary sedimentation basins.So not only shorten processing technological flow, can reduce construction investment, reduced construction land, and can high solid-liquid separation effect, effluent quality improved.

For this reason, in the past the test with the pertinent data analysis foundation on, the present invention proposes biological absorption-biofilm filtration method (being called for short the A-BF method) technology, listed " experimental study of biological absorption-biofilm filtration method Treating Municipal Sewage " invention in the institute scientific effort in 1992, and carried out small-scale test at the Yao Jiajing sewage pumping station, confirmed the feasibility of this Process for Treating Municipal, and the investigation by STRENGTH ON COKE, haydite (heaving shales), three kinds of different filtrate treatment effects of gac, carried out the selection of filtrate.On the small-scale test basis, carried out the interim test of " biological absorption-biofilm filtration method (A-BF method) Treating Municipal Sewage experimental study " in 1992.Owing to prepare to move south in Yao family well pump station, raw waste water concentration reduces, and lacks representativeness, through and the negotiation of Gaobeidian City sewage work, this test Gaobeidian City sewage work of moving into is carried out, from 1994 to nineteen ninety-five, cooperate with this factory, finished interim test.

The A-BF method is on A-B method and biomembrance process basis, and is aided with in the BF section and filters a kind of novel process hold art, and this technology is retrieved, and descriptor is not for establishing preliminary sedimentation tank, biological absorption connecting, be aided with filtration, Treating Municipal Sewage technology with biomembrance process.Result for retrieval was not for meeting this technology.

For this reason, the present invention at first intends exploring effect and the feasibility of A-BF technology to Treating Municipal Sewage, in conjunction with China's practical situation, after carrying out the selection test of BF level filtrate, focus on the BF level, by investigating the influence to treatment effect such as different hydraulic loads (filtering velocity meter in the name of), volumetric loading, gas-water ratio, comparatively systematically explore the characteristics of A-BF technology, determine to be fit to processing condition, design and the operating parameter of China's municipal effluent water quality condition.Last carry out the stability test of treatment effect, investigate to the reliability of this technology, stability and to the adaptability of municipal effluent change of water quality again according to the processing condition of recommending.

Study by the present invention, draw a kind of novel process combination of Treating Municipal Sewage, both kept, brought into play the load height that the A level is had in the A-B method, anti impulsion load, save energy consumption, reduce and take up an area of, save advantages such as construction investment, again owing to replace the B level with the BF level, make the subsequent disposal operation still have the load height, treatment effect is stable, save construction investment, reduce advantages such as occupation of land, compare with the A-B method, its state of the art before goes a step further again and is more economical, especially the effluent quality after handling can further improve, the principal pollutant index reaches or near middle water water quality standard, this is that traditional second-stage treatment technology is beyond one's reach.

Water environment pollution is on the rise, and has become the problem that presses for solution in China's process of economic development.Because A-BF technology has the processing efficiency height, energy consumption is low, advantages such as occupation of land is few, and construction investment is economized, and treat effluent water quality is better: the exploitation of this technology and application, for promoting the sewage treatment project construction, alleviate the pollution to water surrounding, the exploitation sewage resource is alleviated short situation, unit doubts can play positive promoter action, has remarkable social benefit, economic benefit and environmental benefit.

Experimental scale of the present invention and main economic and technical indices result are:

1, experimental scale:

Bench scale is: 0.305m ³/ d (12.7L/h);

Pilot scale is: 6.0m ³/ d (250L/h):

2, technico-economical comparison

By experimental study of the present invention, to release a kind of novel sewage biochemical processing process flow process, under the organic pollutant degradation effect prerequisite suitable with conventional activated sludge process, its key technical indexes (sewage is in intrasystem total residence time), major economic indicators (construction cost, running cost, floor space) reach domestic and international top standard.

Be that the total clearance of CODcr reaches below 80% BOD under the condition of 3.2h (wherein A level 2.2h, BF level 1.0h) promptly in the sewage total residence time ₅Total clearance reaches more than 90%.Handle that back effluent quality leading indicator reaches or (GJ251-89) or Beijing " middle water water quality standard " near nation-building portion " reclaimed water matter standard ".

Compare with conventional activated sludge process, the construction cost of handling structures is expected to save 20-30%; Running cost is saved 15-25%; And can reduce occupation of land 15-25%.

Wherein experimental study content comprises:

1, in view of in the experimental study of A-B method, to the A level and holding property and every processing parameter all carried out comparatively deep research, therefore research emphasis of the present invention is placed on the BF level, the A level is only moved, is that A level aeration tank hydraulic detention time (HRT) is 0.5h according to the processing parameter that A-B method institute is recommended, the mixed solution sludge concentration is 2-3g/L, the mixed solution settling ratio is 5-10%, and dissolved oxygen is controlled at 0.1-0.7mg/L in the pond; A level settling tank hydraulic detention time (HRT) is 1.7h.

2, tentatively investigate the treatment effect of BF level under 2m/h filtering velocity condition, confirm the feasibility of this Process for Treating Municipal.

3, carry out the selection test of BF level filtrate, determine the filtrate kind.

4, investigate BF treatment effect and the work period of level under different filtering velocitys, different gas-water ratio operating mode, optimize the operating parameter of stability test.

5, carry out stability test according to the operating parameter of recommending, investigate the stability of BF level and A-BF art breading effect, and the adaptive faculty that raw water quality is changed.

6, determine BF level back flushing condition, the relation of relation that investigation organic matter degradation and mud increase and organic matter degradation and oxygen-consumption, current consumption.

Five, experiment process, major equipment and test method

1, experiment process

The last process flow of small-scale test and interim test is seen accompanying drawing 1 and accompanying drawing 2

2, main testing installation

A level aeration tank: Φ 400 * 4500 (mm), available depth 4m, useful volume 0.5m ³

A level settling tank: Φ 1200 * 3500 (mm), available depth 1.5m, settling region useful volume 1.7m ³

Lab scale BF post, Φ 90 * 3000 (mm) synthetic glass post, packed height 2m, inside is loaded coke, haydite and carbon leaching material respectively, and the particle diameter of coke, haydite is 2-6mm, and gac is the cylindric 8# of Xinhua charcoal.

Pilot scale BF pond (microbial film filter tank): Φ 400 * 3500 (mm), packed height 2m, aeration tube 0.3m at the bottom of the post, the coke of filtrate 2-6mm.

3, test method

Test form is outdoor test in place

The small-scale test place is Yao family's well sewage pumping station, and former water is the municipal effluent of pumping plant wet well.

The interim test place is Gaobeidian City sewage work, and former water is this factory's aerated grit chamber water outlet.

Small-scale test is season early winter, and temperature is lower, and medium-sized test is annual Various Seasonal day-night observation.

The water yield, tolerance are measured with spinner-type flowmeter, and dissolved oxygen measures with digital DO instrument, regularly demarcate probe with chemical method.

The water sample of the raw waste water of being gathered, BF water inlet, BF water outlet is 12 hours compound samples.

The routine monitoring project is water temperature, temperature, pH value, CODcr, BOD ₅, SS, DO, SVI etc.

Regularly test item is MLSS, NH ₃-N, NO ₂-N, NO ₃-N, TN, TP and active sludge and biomembranous microorganism microscopy, wherein, water quality analysis is by " water and effluent monitoring analytical procedure ".

Achievement in research and application prospect are: interim test commencement of commercial operation 1 year, obtain 34200 of testing datas altogether, and wherein processing condition data (as DO, air input, sludge settling ratio, temperature etc.) are 26640; The water quality analysis data are (as CODcr, BOD ₅.SS, NH ₃-N etc.) 7560.Test-results shows:

1, the processing parameter operation of recommending by former A-B method institute when the A level, has promptly adopted with hybrid A level aeration tank, and hydraulic detention time is 0.5h, and gas-water ratio is 1.6-2.0: 1; A level settling tank hydraulic detention time is to move under the operating mode of 1.7h, and the treatment effect of A-BF technology depends on the filtering velocity of BF level, and along with the raising of BF level filtering velocity, treatment effect is on a declining curve.When BF level filtering velocity is 2m/h (corresponding HRT=1h) and when following, handling afterwards, effluent quality obviously is better than common secondary biochemical treatment technology and A-B method technology, CODcr＜35mg/L, BOD ₅＜7mg/L, main indication has reached the requirement of middle water water quality standard.

2, the microbial film filter tank (being the BF level) that technology of biological membrane is combined with filtering technique form, be series at biological efficiently adsorption tank (A level) afterwards, replace the B level in the A-B method, formed new process combination is not only feasible, and processing efficiency height, treatment effect and effluent quality all are better than the A-B method.When the sewage total residence time was 3.2h, the CODcr clearance of A-BF technology was more than 90%; BOD ₅Clearance is more than 95%; The SS clearance is more than 98%.

3, A-BF technology and BF level all change influent quality and the organism load variations of batching has excellent adaptability, latch up phenomenon do not occur, and the test-results of surely writing of pilot scale shows: when raw waste water CODcr is 315-776mg/L1, BOD ₅Be 81.5-182.9mg/L1, SS changes in the 50-1060mg/L scope, still has higher removal, and guarantees to have good effluent quality.

When the CODcr of BF level volumetric loading by 3.4kgCODcr/m ^aThe d height is to 8.9kgCOD _Cr/ m ³D; BOD ₅Volumetric loading is by 0.8kgBOD ₅/ m ³D is increased to 2.3kgBOD ₅/ m ³D, its CODcr and BOD ₅Clearance the maintenance good level is all arranged.

4, determined the design and the run parameter in BF level microbial film filter tank:

(1) filtering velocity is 2m/h (being HRT=1h);

(2) gas/water=6/1;

(3) more than the work period 60h, the back flushing water consumption rate is 4.84%;

(4) the every removal of BF level 1kgBOD ₅Sludge output be 0.72kg;

(5) the every removal of BF level 1kgBOD ₅Consumption and current consumption be respectively 3.39kg, 0.86kwh.

5, only compare with the B level in the A-B method with the BF level, its hydraulic detention time only is B level 1/6-1/4; Volumetric loading is 2.8 times of B level; Construction costs can save 40.0%; Floor space reduces 66.7%; Running cost can save 50.4%.

In sum, A-BF technology is used for Treating Municipal Sewage, have processing efficiency height, treatment effect main water-quality guideline good, that handle the back water outlet reached in the water water quality standard, and can reduce construction costs, save and take up an area of, save running cost, it is strong that raw water quality is changed adaptability, advantages such as technology is stable, management is simpler, its achievement can be used for the city sewage treatment works design of different scales, the trade effluent engineering design that water quality is similar also is applicable to tapping the potential and upgrade technologically of existing sewage work, to improve processing power, to improve effluent quality.

Because the process characteristic of A-BF, treatment plant can take A level, BF level to build by stages, so that alleviate the contradiction of should economization polluting, improving quality of water environment and lack of capital, builds the A level earlier, goes up the BF level when waiting to have ready conditions again, promotes sewage treatment project and accelerates construction.This achievement has good prospect in application.

Fig. 1 is an A-B method process flow diagram;

Fig. 2 is an A-BF method process flow diagram of the present invention;

Fig. 3 is a biological aerated filter process structure sketch.

Claims (2)

1, a kind of novel method of utilizing biological adsorption and biological membrane filtration treatment municipal effluent, comprising A level and BF level two portions: wherein said A level for municipal effluent after grid is held back the coarse grain foreign material, sewage need directly not enter A level aeration tank through primary clarifier, the mixed solution sludge concentration maintains about 2g/L in the pond, regulating aeration rate is 0.5-1.0mg/l with dissolved oxygen concentration in the control pond, sewage enters A level settling tank (intermediate sedimentation pond) after A level aeration tank stops 0.5h, through the 1.7h post precipitation, part mud returns stays down into the A aeration tank, to keep the sludge concentration of A level aeration tank, part mud is discharged as excess sludge; And enter BF level (biofilm aeration filtering basin) from the top through the water outlet of post precipitation, it is characterized in that: described BF level is by the aeration filtering layer biodegrade organic pollutant of 1.6-1.8m, in the further trap water of filtering layer mechanical filter of 0.2-0.4m of passing through down behind the suspended substance, catchment, discharge in the bottom, filter tank in the mode of high-order water outlet, the time 1 that sewage stops in the pond is to 0.5h, filtering velocity is 2-4m/h, and aeration rate is pressed water: gas=control about 1: 6.

2, the described a kind of novel method of utilizing biological adsorption and biological membrane filtration treatment municipal effluent of claim 1, it is characterized in that: the structure of described biofilm aeration filter tank (BF level) is that the filling particle diameter is that coke or the haydite of 2-6mm made filtrate in the pond, the filtering layer total thickness is 1800-2200mm, on the horizontal plane of distance filtering layer bottom 200-400mm aeration tube is set.

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