CN103539256A - Nitrosation granular sludge recovery method - Google Patents

Abstract

The invention relates to a nitrosation granular sludge recovery method, and belongs to the fields of city domestic sewage treatment and resource utilization. According to the invention, under normal temperature, domestic sewage is adopted as basic water; and through controlling inlet water ammonia nitrogen concentration, dissolved oxygen, and aeration time, nitrosation granular sludge recovery is realized. Compared with existing nitrosation granular sludge starting methods, the method provided by the invention has the advantages of short recovery period and good recovery effect. The sludge can be recovered within two weeks, and nitrosation rate can be higher than 98%.

Description

A kind of restoration methods that is applicable to nitrosated granular sludge

Technical field

The invention belongs to city domestic sewage and process and resource utilization field, be specifically related to the restoration methods of nitrosated granular sludge.

Background technology

At present, take novel process that autotrophic denitrification is core provides new thinking as city domestic sewage biological denitrificaion.Wherein, Anammox is the simplest and the most direct wastewater biological denitrificaion approach of finding at present, with traditional nitrated-denitrification denitrogenation technique compares, have flow process simple and direct, process that load is high, oxygen-consumption is few, without additional organic and inorganic carbon source, sludge yield is low and the many merits such as non-secondary pollution, is the ideal chose of municipal effluent denitrogenation.At present, for the research of this technique, with split type in the majority, be about to this technique and be divided into nitrosification unit and Anammox unit.Nitrosification, as the preliminary processes of Anammox, for Anammox provides into water, is the prerequisite and basis of Anammox, and its treatment effect and efficiency directly affect follow-up anaerobic ammonia oxidation process.And nitrosated granular sludge has special AOB membrane structure because of it, thereby can reach efficient operation.

There is from outside to inside obvious substrate concn gradient and oxyty gradient in granule sludge, the ammonia oxidation bacteria (AOB) dissolved oxygen to higher affinity is easy in granule sludge surface growth, suppress to a certain extent the growth of weak NOB (NOB) of oxygen affinity, and the higher ammonia nitrogen concentration in surface can form higher free ammonia, also can suppress the growth of NOB, and then be beneficial to the stable nitrosification system of formation.Nitrosated granular sludge in forming enough processes along with the lifting of reactor nitrosification performance, AOB has obtained further enrichment in reactor, and the growth of NOB has been subject to inhibition, therefore, being attached to the outer field AOB of granule sludge increases gradually, and the quantity of NOB is to reducing.

But the steady running for nitrosated granular sludge not yet obtains effective means at present.After nitrosated granular sludge forms, along with the variation of sanitary sewage water quality, the nitrosification performance of granule sludge can not get long-term steady running, tends to cause deterioration, the even collapse of destruction of nitrosification performance.And nitrous rate after collapse declines, produce a large amount of nitre nitrogen.And due to the special construction of nitrosated granular dirt, make NOB only be present in the inside of particle, therefore for NOB superseded, have certain difficulty.Thereby can not provide stable water outlet for subsequent technique.

Summary of the invention

The object of the invention is to provide the restoration methods of nitrosated granular sludge.

The present invention is under normal temperature condition, take sanitary sewage as basic water, and ammonia nitrogen mass concentration, dissolved oxygen and the aeration time of intaking by control realized the recovery of nitrosated granular sludge.Said method comprising the steps of:

1) in sanitary sewage, add ammonia nitrogen and sodium bicarbonate, take sanitary sewage as water inlet, making into water FA is 6-8mg/L, and basicity is with CaCO ₃meter mass concentration is 8-10 times of ammonia nitrogen mass concentration, by controlling aeration time at 3.5-4h, makes the oxidation ratio of ammonia nitrogen remain on 58%-62%, and water outlet FA is controlled at 1-2mg/L, and is 0.4L/min by controlling aeration rate, makes dissolved oxygen at 2-3mg/L; Operation, makes nitrous rate maintain 90%-100% more than mono-week with this understanding; Afterwards by extending aeration time to 4-5h, make the oxidation ratio of ammonia nitrogen be controlled at 80%-85%, more than one week, be 2L/min by controlling aeration rate subsequently working time, make dissolved oxygen be controlled at 7-8mg/L and move more than one week, and nitrous rate during this maintains 95%-100% always; Be that nitrous rate is restored;

2) take sanitary sewage as water inlet, water inlet FA is 1-2mg/L, control aeration time is 1-1.25h, make the oxidation ratio of ammonia nitrogen remain on 80%-85%, water outlet FA is 0.5-1mg/L, and control aeration rate is 2L/min, make dissolved oxygen at 7-8mg/L, move more than one week, the nitrous rate that obtains granule sludge maintains 98%-100% all the time, and nitrosated granular sludge is successfully recovered.

Compare with existing startup nitrosated granular sludge method, the present invention has following beneficial effect:

1) time of recovering is short, and recovery effective in two weeks, just can recover, and nitrous rate can reach more than 98%;

2) method is simple, only need in sanitary sewage, add a certain amount of ammonia nitrogen, and the oxidation ratio of restriction aeration rate and ammonia nitrogen can complete nitrosifying recovery;

3) application is convenient, applicable to engineering.

Accompanying drawing explanation

Fig. 1 is nitrosification failure stage.

Fig. 2 is that nitrosification recovers the stage.

Fig. 3 is the nitrosification steady stage.

Embodiment

Embodiment 1:

Test adopts the column sequencing batch reactor at intermittence of virtual height 80cm, internal diameter 8cm, and aspect ratio is 10, and at ambient temperature, temperature is generally at 25 ± 1 ℃.The operation scheme in each cycle of reactor is water inlet, aeration, precipitation, draining.

0-17 days is the failure stage of nitrosated granular sludge, and the nitrosated granular sludge forming in SBR is through 17 days, the extended aeration in 34 cycles, and nitrous rate reduces gradually, and last lands vertically to, and to be close to be zero.Nitrosated granular sludge is destroyed, and the operating performance of nitrosification failure stage is referring to Fig. 1;

Within 18-38 days, be the recovery stage of nitrosated granular sludge, add ammonia nitrogen and sodium bicarbonate in sanitary sewage, making influent ammonium concentration is 150-200mg/L, and basicity is with CaCO ₃the 8-10 that meter concentration is ammonia nitrogen concentration doubly, controls ammonia nitrogen oxidation ratio in 60% left and right, and aeration rate is at 0.4L/min, and nitrous rate starts to recover.When reaction operation is after one week, nitrous rate reverts to 90% left and right.Increase subsequently ammonia oxidation rate, ammonia oxidation rate is maintained more than 80%, move after one week, nitrous rate still can maintain more than 90%, finally aeration rate is returned to original 2L/min, moves one week, nitrous rate does not almost change, and still can be stabilized in more than 90%.Nitrosification is thoroughly recovered, and nitrosification recovers the operating performance in stage referring to Fig. 2;

39-45 days is the steady stage of nitrosated granular sludge, take sanitary sewage as water inlet, water inlet NH ₄ ⁺-N is 51-58mg/L, and COD is 240-284mg/L, and basicity is with CaCO ₃count 385-415mg/L, control aeration rate is 2L/min, and ammonia oxidation rate is more than 80%, and steady running is after one week, and nitrous rate is substantially all more than 98%.Nitrosification is stablized, and the operating performance of nitrosification steady stage is referring to Fig. 3.

Claims (1)

1. a restoration methods that is applicable to nitrosated granular sludge, is characterized in that, said method comprising the steps of:

1) in sanitary sewage, add ammonia nitrogen and sodium bicarbonate, take sanitary sewage as water inlet, making into water FA is 6-8mg/L, and basicity is with CaCO ₃meter mass concentration is 8-10 times of ammonia nitrogen mass concentration, by controlling aeration time at 3.5-4h, makes the oxidation ratio of ammonia nitrogen remain on 58%-62%, and water outlet FA is controlled at 1-2mg/L, and is 0.4L/min by controlling aeration rate, makes dissolved oxygen at 2-3mg/L; Operation, makes nitrous rate maintain 90%-100% more than mono-week with this understanding; Afterwards by extending aeration time to 4-5h, make the oxidation ratio of ammonia nitrogen be controlled at 80%-85%, more than one week, be 2L/min by controlling aeration rate subsequently working time, make dissolved oxygen be controlled at 7-8mg/L and move more than one week, and nitrous rate during this maintains 95%-100% always; Be that nitrous rate is restored;

2) take sanitary sewage as water inlet, water inlet FA is 1-2mg/L, control aeration time is 1-1.25h, make the oxidation ratio of ammonia nitrogen remain on 80%-85%, water outlet FA is 0.5-1mg/L, and control aeration rate is 2L/min, make dissolved oxygen at 7-8mg/L, move more than one week, the nitrous rate that obtains granule sludge maintains 98%-100% all the time, and nitrosated granular sludge is successfully recovered.

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