CN1146432A

CN1146432A - Continuous type air aeration sewage treatment method

Info

Publication number: CN1146432A
Application number: CN96117664A
Authority: CN
Inventors: 李开春
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-08-19
Filing date: 1996-08-19
Publication date: 1997-04-02
Anticipated expiration: 2016-08-19
Also published as: CN1061323C

Abstract

After the sewage flowed in the closed aeration system composed of at least two closed reactors with top inlet and bottom outlet and connected with pipe successively, at the inlet side of each reactor, the pressurized air of 0.1-0.6 MPa is led in the system separately with the dose of air/liquid=0.2-0.6 (v/v) and mixed with the sewage. After the mixed sewage has been treated in the closed system for 1-3 hours, the dregs and water are separated in open state and water liquid and floating dregs are drained separately.

Description

Continuous type air aeration sewage treatment method

What the present invention relates to is a kind of aeration type sewage water treatment method.

The aeration type sewage water treatment method is a kind of tradition and a method commonly used of handling multiple industry and sanitary sewage at present.Its mechanism is to utilize airborne oxygen to carrying out biochemical reaction with organism in the sewage sewage to be purified by aerobic microbiological.It is to carry out in open aeration tank that traditional aeration is handled.Owing to be under condition of normal pressure, to utilize airborne oxygen to carry out the aeration biochemical reaction, its oxygen partial pressure is not high, so dissolution rate is slow, transport velocity is slow, therefore sometimes even will reach tens of hours efficient is low, and floor space is big the residence time of sewage in the aeration tank, investment is high, and the limitation that the expansion treatment scale is subjected to is big.For solving these problem, the deep well aeration method of introducing in " water supply and drainage " 1996 (3) is a kind of improved method, sewage pumped into pump gos deep in the subterranean aeration deep-well pipe, and entrained air, with the duration of contact of prolongation air and sewage, and save floor space.But because airborne oxygen partial pressure do not become, and along with the continuity of gas-liquid contact time, the oxygen partial pressure in the gas is more and more lower because of consumption, and biological degradation efficient also constantly reduces thereupon.For improving oxygen partial pressure, accelerate the oxygen transport velocity, the pure oxygen aeration of introducing in " the chemical industry plumbing design " 1990 (3) is at present a kind of typical improved procedure.Replace normal air with pure oxygen, can make oxygen partial pressure improve nearly 4 times, oxygen in water transport velocity and the saturation value of oxygen in water greatly improve, mass transfer velocity is accelerated, biochemical reaction speed also speeds naturally.But the residence time that the full scale plant of actual use report is disposed of sewage still needs 4～5 hours.Simultaneously, be subjected to conditionality, unless have outside unnecessary ready-made pure oxygen can utilize on the spot, it is big to aim at this energy consumption that oxygenerator is set, the cost height.If when hydrocarbonaceous material such as oils is arranged in the sewage, might produce mixed gas in the treating processes, therefore the detection alarm and the treatment system of pair inflammable gas must be arranged with explosion hazard.

At the problems referred to above, it is little that the purpose of invention provides a kind of floor space, and system is simple, it is convenient to handle, and can make the oxygen concentration of ordinary dissolution height in the sewage, rate of mass transfer height, thereby the sewage disposal time shortens dramatically the air aeration sewage treatment method that processing efficiency obviously improves.

The present invention is a kind of air aeration sewage treatment method of continous way.Closed reaction vessel that discharge port is arranged above the opening for feed is arranged below at least by two in pipeline order successively connects the sealing aerating system that become, after sewage enters this system, at the charging oral-lateral of each reaction vessel, be that the amount system that feeds of 0.2～0.6 (V/V) is mixed with sewage with the forced air of 0.1～0.6MPa (gauge pressure) with gas/liquid respectively.This sewage that is mixed with forced air is handled 1～3 hour in the sealing aerating system after, make pulp water and separate under open state, water liquid and scum silica frost discharge respectively.The aeration treating processes is to carry out continuously in the system that each reaction vessel became of being connected by pipeline, and from a certain angle, also being can be considered by placed in-line each closed reaction vessel is some sections of expanding in the conveying pipe.Because air is pressurized to feeding system behind 0.1～0.6MPa, oxygen partial pressure in the unit volume gas can be 1～6 times of oxygen partial pressure in the atmospheric air, and along with air pressure increases, when not changing volume, oxygen partial pressure also improves synchronously, even can be higher than the oxygen partial pressure of pure oxygen, thereby transport velocity and the saturation value in liquid of oxygen in sewage liquid can improve greatly, even the effect can surpass pure oxygen aeration the time.On the other hand, because the charging oral-lateral at each aerated reaction container all has the forced air of the same pressure system that feeds to mix with sewage, constantly replenish the fresh forced air of the same pressure that enters, make with sewage blended gas in remaining very high oxygen partial pressure, solved along with the aeration process biochemical reaction carries out the density loss of dissolved oxygen in the liquid and make the slack-off problem of reaction effectively.These conditions are all keeping having in the aeration process very high rate of mass transfer and chemical-biological activities effectively.Through observing, gas in the gas-liquid mixture in aerating system substantially all is the equally distributed milkiness state of superfine microbubble, improved greatly that aerobic microbiological adheres to, the ability of absorption, decomposing organic matter, improved treatment effect and processing speed, the aeration treatment time of sewage in system can shorten to only uses 1～3 hour.Handle the back in the pulp water sepn process, that utilizes under the open state residual gas in the gas-liquid mixture escapes the come-up motion, and solid-state slag particle is easy to realize that with bubble floating pulp water separates, and can finish in general 5～20 minutes.Water liquid after pulp water separates is comparatively clear and bright usually, and item indexs such as its COD, BOD, SS and pH all can reach direct emission standards.Can send to after scum silica frost separates and make processed, and can be as the operation of conventional aeration, with the part scum silica frost, the scum silica frost as 2～10% returns and mixes with treatment sewage and circulate.

Through test, aforesaid method of the present invention can be widely used in the sewage disposal in multiple fields such as city domestic sewage, oilfield sewage, petrochemical effluent, and generally handle in room temperature condition, all can obtain satisfied effect.Because what adopt is forced air, required equipment is simple, investment, energy consumption and cost are all lower, operate also simple, and the potentially dangerous that does not have flammable explosiveness, and the aeration treatment time can shorten dramatically, floor space is little, enlarge treatment scale and do not have restraining factors, thereby aspect sewage disposal, have obvious significance and value.

By the working process of aforesaid method of the present invention and principle be appreciated that the high keto sectional pressure air that improves and remain valid and make it with the sewage uniform mixing be core and key.Therefore, according to the pollution level of different sources sewage and/or the oxidized complexity difference of pollutent, take to adjust intake pressure, the air input of forced air, the measures such as number of aerated reaction container, by changing oxygen partial pressure height, reaction times length, even can also adjust conditions such as temperature of reaction, make the aeration effect adjust to satisfaction the most.

Below method of the present invention is further described in detail with some embodiment and Comparative Examples.But should therefore not be interpreted as that the scope of the above-mentioned theme of the present invention only is confined to following example.

Fig. 1 sewage water treatment method schematic flow sheet of the present invention.

As shown in the figure, the sealing aerating system that has the opening for feed top to have the closed reaction vessel 5 of discharge port to be become by four belows in this sewage continuous aeration system through pipeline order connection successively, its place ahead connects with sewage storage tank 3 through pipeline and sewage fresh feed pump 4; Its rear connects with the pulp water separation vessel of opening 6 through pipeline.The dreg removing system that the outlet of pulp water separation vessel 6 is respectively the water exhaust system that connects through wet-pit 7 and connects through scum silica frost storage tank 8 and transferpump 9.Be provided with the forced air inlet pipe 10 that links through air cushioning groove 2 and air compressor 1 at the feed pipe place of each reaction vessel 5 opening for feed front end.Sewage feed rate and forced air air pressure, flow etc. can be kept away row control and adjustment by computer.

Example 1

With above-mentioned system handles city domestic sewage, handle by 2 cubic metres scale per hour.The forced air gauge pressure that feeds is 0.2～0.4MPa, air flow is gas/liquid=0.2～0.4,15～25 ℃ of feeding temperatures, gas-liquid mixed sewage is after the residence time is 1～2 hour in the sealing aerating system, enter the pulp water separation vessel, stop after 5～15 minutes, the clear water after the processing is discharged by the bottom, and scum silica frost is spilled over to the scum silica frost storage tank by the top.Be back to first or second reaction vessel recycle except that 2～10% in the scum silica frost, all the other send to drying through dreg removing system.Related detection index before and after the sewage disposal sees Table 1.

Example 2

Adopt the conventional same city domestic sewage of Wastewater Treated by Activated Sludge Process to compare test, treatment scale is with example 1.Sewage aeration residence time during processing is 12 hours, and temperature is 15～20 ℃, carries out aeration with high pressure blower.Related detection index before and after the sewage disposal is with seeing Table 1.

Example 3

Handle petrochemical wastewater with above-mentioned system shown, treatment scale and example 1 are together.Waste water is kept away 20～30 ℃ of material temperature, continuously feeding.Forced air gauge pressure 0.4～0.5MPa, air input is gas/liquid=0.3～0.5.Gas-liquid mixture stops in aerating system after 2～3 hours and enters the pulp water separation vessel.With aftertreatment with example 1.Related detection index before and after handling the results are shown in Table 2.

Example 4

Adopt the conventional activated sludge method to handle same petrochemical wastewater, as the controlled trial of example 3.Treatment scale and operational condition are with example 2.Related detection index result before and after handling is with seeing Table 2.

The contrast of table 1 city domestic sewage result

	Example 1		Example 2
	Example 1		Example 2		Before the processing	After the processing	Before the processing	After the processing
	COD _Cr(mg/l)	????340	??87.5	??340	Before the processing	After the processing	Before the processing	After the processing	???132.0
?BOD5(mg/l)	COD _Cr(mg/l)	????340	??87.5	??340	????170	??20.6	??168	????35.6	???132.0
?BOD5(mg/l)	?SS?(mg/l)	????250	??11.7	??200	????170	??20.6	??168	????35.6	????45.3
????pH	?SS?(mg/l)	????250	??11.7	??200	????7～8	?6.5～7	??7～8	?6.5～7.2	????45.3

The contrast of table 2 petrochemical wastewater result

	Example 1		Example 2
	Example 1		Example 2		Before the processing	After the processing	Before the processing	After the processing
	CODcr(mg/l)	???584	??61.3	??545	Before the processing	After the processing	Before the processing	After the processing	??253.0
?BOD5(mg/l)	CODcr(mg/l)	???584	??61.3	??545	???218	??25.5	??226	???69.6	??253.0
?BOD5(mg/l)	?SS??(mg/l)	???250	??12.5	??220	???218	??25.5	??226	???69.6	???89.5
??pH	?SS??(mg/l)	???250	??12.5	??220	??6～8	??6～7	??6～8	??6～6.5	???89.5

Claims

1, a kind of continuous type air aeration sewage treatment method, it is characterized in that having below at least by two closed reaction vessel that discharge port is arranged above the opening for feed in pipeline order successively connects the sealing aerating system that become, after sewage enters this system, charging oral-lateral at each reaction vessel, be that the amount system that feeds of 0.2～0.6 (V/V) is mixed with sewage with the forced air of 0.1-0.6MPa (gauge pressure) with gas/liquid respectively, this mixed state sewage is handled 1～3 hour in the sealing aerating system after, make pulp water and separate under open state, water liquid and scum silica frost discharge respectively.

2, sewage water treatment method as claimed in claim 1 is characterized in that said forced air all enters and mixes with sewage liquid in the input duct of each reaction vessel opening for feed front end.

3, sewage water treatment method as claimed in claim 1 is characterized in that said sewage enters the sealing aerating system and mixes with forced air under room temperature.

4, sewage water treatment method as claimed in claim 1, it is characterized in that said pulp water is separated in the opening container carries out.

5, sewage water treatment method as claimed in claim 1 is characterized in that said pulp water disengaging time is 5～20 minutes.

6, sewage water treatment method as claimed in claim 1,2～10% in the moisture scum silica frost after it is characterized in that said pulp water separated are back to and mix with treatment sewage liquid and circulate.