CN103911421A - Method used for quantitative measurement of bacteria activity of full autotrophic nitrogen removal technology - Google Patents

Abstract

The invention relates to a method for quantitatively measuring the activity of bacterial flora in a full autotrophic denitrification process, which belongs to the field of low ammonia nitrogen wastewater treatment and regeneration. In the six-way reactor, with alkalinity as the main influencing factor, the changes of AOB and Anammox bacterial activity under different alkalinity/NH ₄ ⁺ -N conditions were studied, and the ammonia oxidation rate was used as the characterization of the bacterial community activity. When the initial alkalinity/NH ₄ ⁺ -N=4.1, the ammonia nitrogen can be completely consumed in a short period of time, and the ammonia oxidation rate is higher, that is, the activity of AOB and Anammox bacteria is higher; when the alkalinity/NH ₄ ⁺ -N<1.6, the ammonia nitrogen The oxidation rate increases with the increase of the ratio, that is, the activity of AOB and Anammox bacteria increases with the increase of the ratio; when alkalinity/NH ₄ ⁺ -N>7.5, the ammonia oxidation rate decreases with the increase of the ratio, which shows that the optimum alkalinity is exceeded The range will inhibit the reaction, and the inhibitory effect will be more obvious with the increase of the alkalinity, that is, the activity of AOB and Anammox bacteria will decrease with the increase of the ratio. It provides a certain technical reference for the deeper research of CANON technology.

Description

A Quantitative Method for Determining the Bacteria Activity in the Whole Autotrophic Nitrogen Removal Process

technical field

The invention belongs to the field of treatment and regeneration of low ammonia nitrogen sewage and waste water. Specifically, it involves solving the problem of changing the activity of bacteria in the whole autotrophic denitrification process under the condition of low ammonia nitrogen and different alkalinity. the

Background technique

The problem of water resources is an important factor restricting social development. my country is rich in total water resources, but the per capita fresh water resources are only 28% of the world average. Due to the increasing unreasonable discharge of industrial and agricultural sewage, the quality of limited water resources has deteriorated. At the same time, the phenomenon of waste of water resources has become increasingly serious, making the insufficient fresh water resources more and more precious. In sewage, nitrogen pollution is one of the important factors of water pollution. Nitrogen pollution problems exist in urban domestic sewage, industrial wastewater, aquaculture wastewater, and landfill leachate. the

Nitrogen sources in water bodies come from multiple sources, mainly from urban domestic sewage, industrial wastewater, and agricultural wastewater. Urban domestic sewage nitrogen has the characteristics of low concentration, while industrial wastewater has a large concentration of high ammonia nitrogen wastewater, and agricultural wastewater generally has a high content of organic nitrogen. The main hazards of nitrogen pollution are: (1) threat to drinking water safety; (2) harm to fish and other water animals; (3) eutrophication of water body and vicious cycle of water ecosystem; (4) increasing difficulty and cost of water treatment . According to the 2012 Bulletin on the State of the Environment in China issued by the Ministry of Environmental Protection, in 2012, the discharge of ammonia nitrogen in the wastewater discharged nationwide was 2.536 million tons. The "Twelfth Five-Year Plan" also clearly regards ammonia nitrogen and nitrogen oxides as the main pollutants to be controlled. Therefore, the research on nitrogen advanced treatment process of sewage is of great significance. the

Among many ammonia nitrogen wastewater treatment processes, CANON (completely autotrophic nitrogen removal over nitrite) process has become a research hotspot due to its unique denitrification method. In 1999, Third et al. first proposed the CANON process, which is a single-stage whole-process biofilm autotrophic ammonia oxidation process. In this new denitrification process, ammonia oxidizing bacteria AOB and Anammox bacteria coexist in the same reactor, and the two act synergistically. AOB located in the outer layer of filler or sludge floc uses oxygen as an electron acceptor to convert NH ₄ ⁺ -N is oxidized to NO ₂ ^- -N; through mass transfer, Anammox bacteria located in the inner layer of filler or sludge flocs use NO ₂ ^- -N produced by nitrous bacteria as electron acceptor, and the remaining NH ₄ ⁺ -N is co-converted into N ₂ and released, and a small amount of NO ₃ ^- -N is produced. It can be seen that the efficiency of CANON process can be reflected by the activity of AOB and Anammox bacteria.

Alkalinity is the inorganic carbon source of AOB and Anammox bacteria, and also plays a buffer role. It is an important factor affecting the CANON process. Therefore, quantitative research on the effect of alkalinity content on the activity of the bacterial community is of great significance to the deeper research of the CANON process. the

Contents of the invention

The purpose of the present invention is to provide a method for quantitatively measuring the activity of bacterial flora in the whole autotrophic denitrification process. For reaching above-mentioned technical effect, technical scheme of the present invention is realized like this:

The present invention adopts six-connected reactors, provides rising flow rate and hydraulic shearing force by aeration, and makes the reactors mix uniformly. The specific operation is as follows:

A method for quantitatively measuring the activity of bacterial flora in a full-process autotrophic denitrification process, which is operated by a six-reactor reactor, is characterized in that it includes the following steps:

1) Reactor construction: The test uses a six-connected reactor, and a microporous aeration device is built into the six-connected beaker;

2) Inoculation seed sludge: The seed sludge in the reactor comes from the backwash sludge of the full autotrophic denitrification CANON biological filter column cultivated under high temperature and high ammonia nitrogen conditions, and the sludge concentration is 5-7g·L ^-1 ;

3) The operation method of the reactor is as follows: each cycle includes five stages of water intake, reaction, precipitation, drainage and idleness. Stage I: Influent water, using artificial simulated water distribution, control the mass concentration of ammonia nitrogen in the influent water to 50-80mg·L ^-1 , the mass concentration of phosphate to 1-3mg·L ^-1 , the difference in the influent water lies in the alkalinity mass concentration of the six beakers Different, that is, the mass concentration ratio of alkalinity alkalinity and NH ₄ ⁺ -N is different, alkalinity/NH ₄ ⁺ -N are 1 ^# 0.7-0.9, 2 ^# 1.4-1.8, 3 ^# 3.8-4.5, 4 ^# 7.2-7.8 , 5 ^# 11-12, 6 ^# 16-17; Phase II: reaction, at room temperature, the initial pH of the influent water is 7.9-8.1, and the concentration of dissolved oxygen is 0.2-0.3mg·L ^-1 , so that each beaker Ammonia nitrogen is completely removed; stage III: precipitation, the precipitation time is 10-20min; stage IV: drainage, water change ratio is 50%, and tap water is repeatedly added to wash the mud 3-5 times to ensure the accuracy of the next water intake; stage V : Idle, the idle time is 5-10h, and then cycle to the next cycle after idle. In order to ensure the authenticity and reliability of the data, three sets of effective parallel experiments were carried out for each experiment.

4) Bacteria activity expression method: only aerobic ammonium oxidizing bacteria AOB and anaerobic ammonium oxidizing bacteria Anammox exist in the reactor, and the aerobic ammonium oxidation rate is used to quantitatively characterize the activity of AOB. The aerobic ammonium oxidation rate refers to the mixed solution per unit time and unit volume The quality of ammonia nitrogen consumed by mesoaerobic ammonium oxidizing bacteria, that is, the quality of nitrite nitrogen generated by AOB using ammonia nitrogen in a unit volume of mixed solution per unit time; the activity of Anammox bacteria is quantitatively characterized by the rate of anammox, and the rate of anammox refers to The mass of nitrite nitrogen consumed by anammox bacteria in unit volume of mixed solution per unit time. the

The present invention has the following beneficial effects:

1) The present invention provides a feasible method for quantitatively measuring the activity of bacterial flora in the whole process of autotrophic denitrification process;

2) Established a more detailed alkalinity control model and found a more suitable alkalinity control range under the test conditions;

3) A new method to characterize the activity of AOB and Anammox bacteria by ammonia oxidation rate was proposed. the

Description of drawings:

Fig. 1 is a schematic diagram of a six-unit device used in the present invention. the

Fig. 2 is the change of ammonia oxidation rate under different alkalinity/NH ₄ ⁺ -N conditions in the reactor adopting the method of the present invention.

Fig. 3 is the change of total nitrogen under different alkalinity/NH ₄ ⁺ -N conditions in the reactor adopting the method of the present invention.

Fig. 4 is the variation of total nitrogen removal rate within a cycle under different alkalilinity/NH ₄ ⁺ -N conditions of the reactor adopting the method of the present invention.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto. the

The inoculation sludge of the reactor of the present invention is from the backwash sludge of the full autotrophic denitrification CANON biological filter column cultivated under high temperature and high ammonia nitrogen conditions, which provides guarantee for the test. the

The activity of AOB is quantitatively characterized by the rate of aerobic ammonia oxidation. The rate of aerobic ammonia oxidation refers to the mass of ammonia nitrogen consumed by the aerobic ammonia oxidizing bacteria in the mixed solution per unit volume per unit time, that is, AOB uses the ammonia nitrogen in the mixed solution per unit volume to generate nitrous acid per unit time. The quality of salt nitrogen; the activity of Anammox bacteria is quantitatively characterized by the rate of anammox oxidation, and the rate of anammox refers to the quality of nitrite nitrogen consumed by anammox bacteria in the mixed solution per unit time and unit volume. Calculated as follows:

$\begin{array}{c}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; AOB</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1.32</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; influential\; TN</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; effluentTN</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 1.02</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; effluent\; N</span>}{\mathrm{<span\; class="notranslate">\; o</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; influentialN</span>}{\mathrm{<span\; class="notranslate">\; o</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}\\ <span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; effluent\; N</span>}{\mathrm{<span\; class="notranslate">\; o</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}^{<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; 0.26</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; imfluentTN</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; effluentTN</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 1.02</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; influentialN</span>}{\mathrm{<span\; class="notranslate">\; o</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}^{<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}\end{array}$

Among them: influentialTN: influent total nitrogen (mg·L ^-1 ), efffluentTN: effluent total nitrogen (mg·L ^-1 ), influentialNO ₂ ^- -N: influent nitrite nitrogen (mg·L ^-1 ), effluentNO ₂ ^- -N: effluent nitrite nitrogen (mg·L ^-1 ), influentialNO ₃ ^- -N: influent nitrate nitrogen (mg·L ^-1 ), efffluentNO ₃ ^- -N: effluent nitrate nitrogen (mg· L ^-1 ), t: reaction time (h).

Specific embodiment one:

The method for quantitative determination of bacterial flora activity in the whole autotrophic denitrification process, reactor form: the reactor is a six-connected mixer of model ZR4-6, including six beaker reactors, each with an effective volume of 1.0L. The bottom is equipped with a microporous aeration device, and the amount of aeration is controlled by a gas rotameter. the

The seed sludge in the reactor comes from the backwash sludge of the fully autotrophic denitrification CANON biological filter column cultivated under high temperature and high ammonia nitrogen conditions, and the sludge concentration is 6g·L ^-1 ;

The operation mode includes five stages of water intake, reaction, sedimentation, drainage and idleness. Stage I: water inflow, water inflow is instantaneous water inflow, which is prepared by adding a certain amount of (NH ₄ ) ₂ SO ₄ , NaHCO ₃ and KH ₂ PO ₄ and appropriate amount of trace elements to tap water. The specific water quality is as follows: The mass concentration of ammonia nitrogen is 60mg·L ^-1 , and the mass concentration of phosphate is 2mg·L ^-1 . The difference in influent water lies in the difference in the mass concentration of alkalinity in the six beakers, that is, the ratio of the mass concentration of alkalinity to NH ₄ ⁺ -N is different, and the alkalinity /NH ₄ ⁺ -N are respectively 1 ^# 0.8, 2 ^# 1.6, 3 ^# 4.1, 4 ^# 7.5, 5 ^# 11.7, 6 ^# 16.7; The dosage of trace element mixed solution is 1mg·L ^-1 , including (mg·L ^-1 ): nutrient solution I: EDTA5.00FeSO ₄ .7H2O5.00 nutrient solution II: EDTA15.00H ₃ BO ₄ 0.014MnCl ₂ . _{4H2O0.099CuSO4.5H2O0.25ZnSO4.7H2O0.43NiCl2.6H2O0.19Na2SeO4.10H2O0.21Na2MoO4.2H2O0.22NaWO4.2H2O ; _ _ _ _ _ _ _ _ _ _ _ _ _} Stage II: Reaction, in the reaction stage, the water temperature is controlled at room temperature, the dissolved oxygen is 0.25mg·L ^-1 , the initial pH is 8.0, and the reaction time is 1 ^# 6.5h, 2 ^# 6.5h, 3 ^# 3.5h, 4 ^# 4.5h, 5 ^# 5h, 6 ^# 6.25h; Phase III: sedimentation, settling time 15min; Phase IV: drainage, drainage time 1min, water change ratio 50%, repeatedly adding tap water to wash mud 3-5 times, to ensure the next water intake Accurate; Phase V: idle, idle for 6h to the next cycle.

When the initial alkalinity/NH ₄ ⁺ -N is 0.8, the total nitrogen removal rate reaches 80.97%, the average aerobic ammonium oxidation rate of the three tests is 5.58mg·L ^-1 ·h ^-1 , and the average anaerobic ammonia oxidation rate is 5.77mg· L ^-1 ·h ^-1 ; when the initial alkalinity/NH ₄ ⁺ -N is 1.6, the total nitrogen removal rate reaches 81.15%, the average aerobic ammonia oxidation rate of three tests is 5.92mg·L ^-1 ·h ^-1 , the average anaerobic The oxygen ammonium oxidation rate is 6.13mg·L ^-1 ·h ^-1 ; when the initial alkalinity/NH ₄ ⁺ -N is 4.1, the total nitrogen removal rate reaches 83.56%, and the average aerobic ammonium oxidation rate of three tests is 10.07mg·L ^{- 1} ·h ^-1 , the average anammox rate was 10.43mg·L ^-1 ·h ^-1 ; when the initial alkalinity/NH ₄ ⁺ -N was 7.5, the total nitrogen removal rate reached 83.41%, and the average aerobic ammonium The oxidation rate is 9.59mg·L ^-1 ·h ^-1 , and the average anammox rate is 9.96mg·L ^-1 ·h ^-1 ; when the initial alkalinity/NH ₄ ⁺ -N is 11.7, the total nitrogen removal rate reaches 82.37 %, the average aerobic ammonium oxidation rate of the three tests was 7.51mg·L ^-1 ·h ^-1 , the average anaerobic ammonia oxidation rate was 7.79mg·L ^-1 ·h ^-1 ; the initial alkalinity/NH ₄ ⁺ -N was 16.7 , the total nitrogen removal rate reached 88.13%, the average aerobic ammonium oxidation rate of three tests was 6.67mg·L ^-1 ·h ^-1 , and the average anaerobic ammonium oxidation rate was 6.99mg·L ^-1 ·h ^-1 .

When the initial alkalinity/NH ₄ ⁺ -N=4.1, the ammonia nitrogen can be completely consumed in a short period of time, and the ammonia oxidation rate is higher, that is, the activity of AOB and Anammox bacteria is higher; when the alkalinity/NH ₄ ⁺ -N<1.6, the ammonia nitrogen The oxidation rate increases with the increase of the ratio, that is, the activity of AOB and Anammox bacteria increases with the increase of the ratio; when alkalinity/NH ₄ ⁺ -N>7.5, the ammonia oxidation rate decreases with the increase of the ratio, which shows that the optimum alkalinity is exceeded The range will inhibit the reaction, and the inhibitory effect will be more obvious with the increase of the alkalinity, that is, the activity of AOB and Anammox bacteria will decrease with the increase of the ratio.

Claims (1)

1. a method for quantitative assay Full Autotrophic Ammonium Removal Process bacterial activity, adopts six reactor operations, it is characterized in that: comprise the steps:

1) reactor is built: test adopt six reactors, six beakers built-in enter microporous aeration device;

2) inoculation kind of mud: the kind mud in reactor is from the backwashing sludge of the whole process autotrophic denitrification CANON biologic filter of cultivating under high temperature, high ammonia nitrogen condition, and sludge concentration is 5-7gL ^-1;

3) reactor operation method is: each cycle comprises into water, reaction, precipitation, draining, idle double teacher; The I stage: water inlet, adopt manual simulation's water distribution, control influent ammonia nitrogen mass concentration 50-80mgL ^-1, phosphoric acid salt mass concentration is 1-3mgL ^-1, water inlet difference is six beaker basicity mass concentration differences, i.e. basicity alkalinity and NH ₄ ⁺the mass concentration ratio difference of-N, alkalinity/NH ₄ ⁺-N is respectively 1 ^#0.7-0.9,2 ^#1.4-1.8,3 ^#3.8-4.5,4 ^#7.2-7.8,5 ^#11-12,6 ^#16-17; The II stage: reaction, under room temperature condition, the pH of initially intaking is 7.9-8.1, dissolved oxygen concentration is 0.2-0.3mgL ^-1, ammonia nitrogen in each beaker is removed completely; The III stage: precipitation, sedimentation time is 10-20min; The IV stage: draining, change water than 50%, repeatedly add from the beginning mud washing 3-5 time, guarantee water inlet next time accurately; The V stage: idle, idle mixing time, 5-10h, looped next cycle after leaving unused;

4) bacterial activity method for expressing: only have aerobic ammonia-oxidizing bacteria AOB and anaerobic ammonia oxidizing bacteria Anammox in reactor, with aerobic ammonia oxidation speed quantitatively characterizing AOB activity, aerobic ammonia oxidation speed refers to the ammonia nitrogen quality that aerobic ammonia-oxidizing bacteria in unit time unit volume mixed solution consumes, and AOB utilizes ammonia nitrogen in unit volume mixed solution to generate the quality of nitrite nitrogen in the unit time; With Anammox speed quantitatively characterizing Anammox bacterium activity, Anammox speed refers to the nitrite nitrogen quality that in unit time unit volume mixed solution, anaerobic ammonia oxidizing bacteria consumes.