CN103102008A - SBR nitrosation starting method suitable for municipal household sewage - Google Patents

Abstract

An SBR nitrosation starting method suitable for municipal household sewage belongs to the field of treatment and resource of municipal sewage. Complete nitrification sludge is inoculated under normal temperature conditions, and municipal household sewage is the research object. In an initial sludge acclimatization, first the concentration of DO is controlled at 0.8-1.0 mg / L for running of 10d (20 cycles), so that AOB and NOB can be rapidly proliferated; from the 11th day, oxygen is limited, and concentration of DO is controlled to 0.3-0.5mg / L, and ammonia oxidation rate is controlled at around 50%. After 44 days, nitrosation rate reaches higher than 90%, and COD removal rate reaches higher than 80%, so as to successfully realize SBR nitrification start-up of household sewage at normal temperature.

Description

A kind of city domestic sewage SBR nitrosification starting method that is applicable to

Technical field

The invention belongs to municipal sewage treatment and resource utilization field.Be specifically related to be exclusively used in the method that under normal temperature condition, city domestic sewage SBR nitrosification starts.

Background technology

In waste water, the removal of nitrogen mainly comprises Physical, chemical method and biological denitrificaion method, compare with the physical chemistry denitride technology, bio-denitrification technology have technique simple, with low cost, more easily promote, and be difficult for causing the advantage such as secondary pollution, therefore, more and more be subject to people's favor.Traditional biological denitrification process is by ammonification, the organonitrogen in water to be converted into ammonia nitrogen, is then nitric nitrogen by nitration reaction with mineralized nitrogen, then is that nitrogen is overflowed from water by denitrification with nitrate-nitrogen reduction.Yet, traditional nitrated/denitrification biological denitrogenation technique exist long flow path, oxygen-supplying amount high, need the problems such as additional carbon, sludge yield height, above problem will increase initial cost and working cost greatly.Therefore, with short distance nitration (NH ₄ ⁺-NO ₂ ^-) become the study hotspot of current nitrogenous effluent treatment, such as short-cut nitrification and denitrification technology, short distance nitration-anaerobic ammoxidation technology etc. for the short-cut denitrification technology of core.The short distance nitration technology is at NO the nitration reaction process control ₂ ^-Generation phase stops NO ₂ ^-Be further oxided and be NO ₃ ^-Its autotrophic denitrification technique that forms with the Anammox technical combinations has reduced 25% oxygen requirement, 100% carbon source and 50% sludge yield than traditional complete nitrification technology.Therefore short distance nitration with its many advantage, is subject to paying close attention to more and more widely in field of waste water treatment.And the realization of short distance nitration and steady running are the key issues of vast scholar's research.

In recent years, short distance nitration was applied to the processing of the high-concentration ammonia-nitrogen waste water such as the nitrated supernatant liquor of mud, coking chemical waste water, percolated liquid in city refuse landfill, high ammonia nitrogen gourmet powder waste water, and had obtained good treatment effect.Aspect the sanitary sewage of processing low ammonia nitrogen, some successful stories are arranged also.But these research major parts are all under the condition of high-concentration ammonia-nitrogen, utilize the favourable condition of high free ammonia to realize the startup of short distance nitration.When processing the sanitary sewage of low ammonia nitrogen concentration, this Starting mode not only needs artificial interpolation to contain in a large number ammonia reagent, also the situation of fluctuation of service may occur when transferring the low ammonia-nitrogen sewage of processing to.And the Starting mode under low ammonia nitrogen concentration condition has not only been saved added regent, can also guarantee the stable of subsequent disposal effect.

Summary of the invention

The object of the present invention is to provide a kind ofly for city domestic sewage, namely under normal temperature, low ammonia nitrogen condition, start nitrosifying method by common nitrifying sludge.

The invention provides city domestic sewage SBR nitrosification starting method under a kind of normal temperature condition, it is characterized in that:

A kind of normal temperature city domestic sewage SBR nitrosification starting method that is applicable to is characterized in that:

the inoculation nitrifying sludge, be placed in the sbr reactor device, pass into city domestic sewage, operation is 10-15 days under the DO=0.80-1.00mg/L condition, and then reduce dissolved oxygen to 0.30-0.50mg/L, move 20-30 days, and the ammonia oxidation rate that keeps this stage, the ratio that is Inlet and outlet water ammonia nitrogen difference and influent ammonia nitrogen is 40%-70%, continue with this understanding acclimation sludge, calculate the nitrous rate, nitrite and the nitrite of accumulation and the ratio of nitrate sum of i.e. reaction accumulation, and COD clearance, be the ratio of Inlet and outlet water COD concentration difference and inlet COD concentration, the nitrous rate reaches more than 90% and the COD clearance reaches more than 80%, can successfully start nitrosification.

The method that nitrosification provided by the present invention starts, under normal temperature, low ammonia nitrogen condition, take actual cities sewage as basic water, by DO=0.80-1.00mg/L(10-15 days)-DO=0.30-0.50mg/L(20-30 days) the aeration control strategy and the control strategy of ammonia oxidation rate (40%-70%), realize the nitrosification of municipal effluent in sequence bioreactor (SBR) mode.Concrete steps are as follows:

Step 1: reactor is built

Reactor adopts the sbr reactor device, and reactor is equipped with aerating apparatus, can control dissolved oxygen concentration in reactor waste water by regulating aeration rate.Reactor arranges simple automatic control device, automatically realizes water inlet, reaction, precipitation, drainage flow path.

Step 2: seed sludge

Inoculate common nitrifying sludge, be placed in the sbr reactor device, pass into city domestic sewage, the beginning aeration, and the control dissolved oxygen is 2.0-3.0mg/L.This step is intended to allow seed sludge shake down, and carries out 2 cycles every day, carries out 2 days totally 4 cycles.

Step 3: start nitrosification

Controlling DO concentration is 0.80-1.00mg/L, makes AOB and NOB all can obtain fast breeding, moves 10-15 days (20-30 cycle), makes the water outlet ammonia nitrogen that residue be arranged.Rear control DO concentration is 0.3-0.5mg/L, ammonia oxidation rate is 40%-70%, move 20-30 days (40-60 cycle), with enrichment AOB, suppress NOB, NOB eliminates out system the most at last, continues in 7 days to start successful sign greater than 80% as sanitary sewage SBR nitrosification greater than 90%, COD clearance with the nitrous rate.

Compare with traditional method, advantage of the present invention is:

The first, under the low ammonia nitrogen condition of normal temperature, namely under actual cities sanitary sewage condition of water quality, namely realized nitrosifying startup by controlling dissolved oxygen and ammonia oxidation rate.Need not add ammonia nitrogen and rising temperature, save working cost.

The second, utilize the specific growth rate of AOB, two kinds of bacteriums of NOB different, by hyperoxia, limit oxygen and control the mode of ammonia oxidation rate, realized startup nitrosification purpose, this strategy especially is fit to AOB content in initial mud and is difficult for less the mud that starts.

The 3rd, can synchronously realize the device nitrosification of sanitary sewage sbr reactor and remove the purpose of COD.

The invention will be further described below in conjunction with embodiment, but protection scope of the present invention is not limited to this.

Description of drawings

Fig. 1 is reactor nitrogen transformation design sketch in the present invention, and wherein the △ nitrite nitrogen is Inlet and outlet water nitrite nitrogen concentration difference; The △ nitrate nitrogen is Inlet and outlet water nitrate nitrogen concentration difference.

Embodiment

Test is take certain community life sewage as basic water, and concrete water quality is as follows: COD=300-400mg/L, BOD ₅=120-150mg/L, SS=76-114mg/L, TP=5.75-6.30mg/L, NH ₄ ⁺-N=75-90mg/L, NO ₂ ^--N≤0.25mg/L, NO ₃ ^--N≤1.5mg/L, TP≤1mg/L, pH=7.0-7.8, basicity is that 550.59-610.78mg/L(is with CaCO ₃Meter).

Concrete processing is as follows:

In sludge acclimatization in the early stage, at first controlling DO concentration is 0.8-1.0mg/L 10d(20 cycle of operation), make AOB, NOB all can obtain fast breeding, limit oxygen since 11d, control DO concentration to 0.3-0.5mg/L, and control ammonia oxidation rate in 50% left and right, utilize the dual control of low DO and ammonia oxidation rate with enrichment AOB, superseded NOB.The changing trend diagram of three nitrogen concentrations, ammonia oxidation rate and nitrous rate unloading phase that Fig. 1 being.

As shown in Figure 1, the accumulation of nitrite nitrogen does not appear in service at front 10d in water outlet, ammonia nitrogen all is converted into nitrate nitrogen, and the accumulation of nitrite nitrogen has appearred in rear reduction DO and ammonia oxidation rate during to 29d, the nitrous rate is 43%, and during to 40d, the nitrous rate reaches 92.67%.So 41d begins, ammonia oxidation rate is controlled at more than 80%, the adaptation of ensuing 3d (the nitrous rate slightly has decline) after date, nitrous rate continuous 7d always is stabilized in more than 90%, indicates that sanitary sewage SBR nitrosification has realized successfully starting.

Start-up course mid-early stage DO is under the condition of 0.8-1.0mg/L, although AOB, NOB all obtain fast breeding, but can produce the AOB of 0.146g and the NOB of 0.020g owing to transforming the 1g ammonia nitrogen, the productive rate of AOB is 7.3 times of NOB productive rate, therefore the rate of propagation of AOB will far above NOB, also can be eliminated out system with the NOB that is adapted to hypoxemia.Rear reduction dissolved oxygen is during to 0.30-0.50mg/L, because AOB is 0.2-0.4mg/L to the avidity (DO semi-saturation constant is 1.2-1.4mg/L) of dissolved oxygen greater than NOB(DO semi-saturation constant), therefore a large amount of AOB that DO had stronger avidity preferentially obtain dissolved oxygen, NOB weakens nitrification owing to lacking dissolved oxygen, thereby limited the generation of nitrate, be conducive to accumulation of nitrite; In addition, complete because nitrifying process was divided into for two steps, at first AOB is with NH ₄ ⁺-N is converted into NO ₂ ^--N, then NOB is with NO ₂ ^--N is converted into NO ₃ ^--N.Therefore ammonia oxidation rate is controlled at 50% left and right (average is 58.4%), water outlet is kept account for into half ammonia nitrogen of water, so the inferior nitrogen of the required matrix of NOB growth also is conducive to enrichment AOB, suppresses NOB always lower than the required matrix ammonia nitrogen of AOB growth.

In start-up course, the COD clearance is always higher, and greater than 80%, water outlet COD all below 50mg/L, meets municipal sewage plant one-level A standard.

Therefore, by controlling DO=0.80-1.00mg/L(10-15 days)-DO=0.30-0.50mg/L(20-30 days) the aeration control strategy and the control strategy of ammonia oxidation rate (40%-70%) realized the nitrosifying startup of normal temperature city domestic sewage SBR, and have good COD removal effect.

Claims (1)

1. one kind is applicable to city domestic sewage SBR nitrosification starting method, it is characterized in that:

the inoculation nitrifying sludge, be placed in the sbr reactor device, pass into city domestic sewage, operation is 10-15 days under the DO=0.80-1.00mg/L condition, and then reduce dissolved oxygen to 0.30-0.50mg/L, move 20-30 days, and the ammonia oxidation rate that keeps this stage, the ratio that is Inlet and outlet water ammonia nitrogen difference and influent ammonia nitrogen is 40%-70%, continue with this understanding acclimation sludge, calculate the nitrous rate, nitrite and the nitrite of accumulation and the ratio of nitrate sum of i.e. reaction accumulation, and COD clearance, be the ratio of Inlet and outlet water COD concentration difference and inlet COD concentration, the nitrous rate reaches more than 90% and the COD clearance reaches more than 80%, can successfully start nitrosification.

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