Rapid start-up method of degradable carrier autotrophic denitrification biofilter process

Abstract

The present application belongs to the technical field of sewage treatment, and discloses a quick starting method of degradable carrier autotrophic denitrification biofilter process. Method: in the autotrophic denitrification biofilter filled with degradable carrier microbial membrane autotrophic denitrification filler, water is continuously fed, and accelerator A is added to the filter; when the first culture condition threshold is reached, accelerator B is added; when the second culture condition threshold is reached, accelerator C is added; when the third culture condition threshold is reached, the process is successfully started and enters the stable operation stage, and the addition of accelerator C is stopped. The present application reduces the starting time of the degradable carrier autotrophic denitrification biofilter, improves the filter starting rate, and achieves the purpose of quick starting.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sewage treatment, and more particularly relates to a rapid starting method of a degradable carrier autotrophic denitrification biofilter process. BACKGROUND

[0002] At present, most areas execute the first level A discharge standard in the Discharge Standard of Pollutants in Municipal Wastewater Treatment Plant (GB 18918-2002), in which the total nitrogen (TN) concentration is not more than 15 mg / L. Some areas execute local standards, and the total nitrogen concentration is required to be not more than 10 mg / L. In the sewage treatment process, the way of denitrification biological denitrification filter is usually used to remove nitrate nitrogen in water.

[0003] The principle of denitrification biological denitrification is that microorganisms use nitrate nitrogen or nitrite nitrogen in water as an electron acceptor, and use organic matter, hydrogen, sulfur or sulfur-containing compounds as an electron donor to reduce nitrate nitrogen or nitrite nitrogen to nitrogen gas under anoxic conditions through microbial metabolism. Denitrification biological denitrification can be divided into heterotrophic denitrification and autotrophic denitrification according to the growth characteristics of microorganisms, and the corresponding processes are heterotrophic denitrification biofilter and autotrophic denitrification biofilter.

[0004] The heterotrophic denitrification biofilter runs stably, and the reaction rate is relatively fast, but the organic carbon source needs to be continuously added during the operation, which will cause problems such as high sludge yield, high backwashing frequency, and fluctuation of effluent chemical oxygen demand (COD), increasing the water treatment cost;

[0005] In the autotrophic denitrification biofilter, specific inorganic chemoautotrophic Thiobacillus uses sulfite, elemental sulfur, sulfide, etc. as an electron donor, and uses nitrate nitrogen as an electron acceptor to reduce nitrate nitrogen to nitrogen gas under anoxic or anoxic conditions, and at the same time, oxidizes sulfur to sulfate, completing the autotrophic denitrification process. Compared with heterotrophic denitrification, autotrophic denitrification does not need external carbon source, has less sludge yield, low backwashing frequency, and lower operation cost, but the autotrophic denitrification microorganisms grow slowly, and it is difficult to quickly form a stable microbial membrane for rapid denitrification biological denitrification, which limits the use of autotrophic denitrification biological denitrification.

[0006] Therefore, it is urgent to propose a rapid starting method of a degradable carrier autotrophic denitrification biofilter process. SUMMARY

[0007] The purpose of the present application is to solve the problem of slow starting speed of the degradable carrier autotrophic denitrification biofilter, and to propose a rapid starting method of the degradable carrier autotrophic denitrification biofilter process. The present application reduces the starting time of the degradable carrier autotrophic denitrification biofilter, improves the starting rate of the filter, and achieves the purpose of rapid starting.

[0008] In order to achieve the above-mentioned purpose, the application provides a rapid starting method of a degradable carrier autotrophic denitrification biofilter process, which comprises the following steps:

[0009] S1: first culture stage

[0010] continuously feeding water into the autotrophic denitrification biofilter filled with the autotrophic denitrification microbial film degradable carrier; adding denitrifying sulfur bacteria growth promoter A into the autotrophic denitrification biofilter; monitoring the dissolved oxygen concentration and oxidation-reduction potential of the water in the autotrophic denitrification biofilter; when the dissolved oxygen concentration and oxidation-reduction potential of the water in the autotrophic denitrification biofilter reach the first culture condition threshold, entering the next culture stage;

[0011] S2: second culture stage

[0012] continuously feeding water into the autotrophic denitrification biofilter; adding denitrifying sulfur bacteria growth promoter B into the autotrophic denitrification biofilter; monitoring the dissolved oxygen concentration, oxidation-reduction potential and nitrate nitrogen removal rate of the effluent of the autotrophic denitrification biofilter; when the dissolved oxygen concentration, oxidation-reduction potential and nitrate nitrogen removal rate of the effluent of the autotrophic denitrification biofilter reach the second culture condition threshold, entering the next culture stage;

[0013] S3: third culture stage

[0014] continuously feeding water into the autotrophic denitrification biofilter; adding denitrifying sulfur bacteria growth promoter C into the autotrophic denitrification biofilter; monitoring the dissolved oxygen concentration, oxidation-reduction potential and nitrate nitrogen removal rate of the effluent of the autotrophic denitrification biofilter; when the dissolved oxygen concentration, oxidation-reduction potential and nitrate nitrogen removal rate of the effluent of the autotrophic denitrification biofilter reach the third culture condition threshold, marking that the process is successfully started and entering the stable operation stage, and stopping the addition of the denitrifying sulfur bacteria growth promoter C.

[0015] According to the application, preferably, the water temperature of the water fed into the autotrophic denitrification biofilter is 10-38℃.

[0016] According to the application, preferably, the water fed into the autotrophic denitrification biofilter comprises at least one of domestic sewage, industrial wastewater, secondary effluent of a sewage treatment plant, total effluent of a reclaimed water plant and landscape water body.

[0017] According to the application, preferably, the autotrophic denitrification biofilter is an upflow or downflow biofilter.

[0018] According to the application, preferably, the denitrifying sulfur bacteria growth promoter A comprises sodium thiosulfate, ammonium chloride, magnesium sulfate and ferrous sulfate.

[0019] According to the application, preferably, the denitrifying sulfur bacteria growth promoter B comprises ammonium chloride, magnesium sulfate, ferrous sulfate and sodium bicarbonate.

[0020] According to the present application, preferably, the Thiobacillus denitrificans growth promoter C comprises sodium bicarbonate and ammonium chloride.

[0021] According to the present application, preferably, the volume ratio of the addition amount of the Thiobacillus denitrificans growth promoter A to the water volume in the autotrophic denitrification biofilter is (0.8-1.2):1000.

[0022] According to the present application, preferably, the first culture condition threshold comprises: dissolved oxygen concentration is lower than 0.5mg / L, oxidation-reduction potential is lower than -150mv.

[0023] According to the present application, preferably, the first culture stage lasts for 10-18h.

[0024] According to the present application, preferably, in the second culture stage, the volume ratio of the addition amount of the Thiobacillus denitrificans growth promoter B to the water volume in the autotrophic denitrification biofilter is (0.5-1.0):10000.

[0025] According to the present application, preferably, the second culture condition threshold comprises: dissolved oxygen concentration is lower than 0.5mg / L, oxidation-reduction potential is lower than -150mv, and nitrate nitrogen removal rate is ≥90%.

[0026] According to the present application, preferably, the second culture stage lasts for 16-49h.

[0027] According to the present application, preferably, in the third culture stage, the volume ratio of the addition amount of the Thiobacillus denitrificans growth promoter C to the water volume in the autotrophic denitrification biofilter is (0.8-1.2):10000.

[0028] According to the present application, preferably, the third culture condition threshold comprises: dissolved oxygen concentration is lower than 0.5mg / L; oxidation-reduction potential is lower than -140mv; and nitrate nitrogen removal rate is ≥90%.

[0029] According to the present application, preferably, the third culture stage lasts for 12-40h.

[0030] In the present application, the use amount of each component in the Thiobacillus denitrificans growth promoters A, B and C is determined according to the treated water quality.

[0031] In the present application, through the second culture stage, the addition of the Thiobacillus denitrificans growth promoter B can accelerate the formation of Thiobacillus denitrificans microbial membrane on the filler surface.

[0032] In the present application, through the third culture stage, the addition of the growth promoter C of Thiobacillus denitrificans can promote the stable growth of the microbial film of Thiobacillus denitrificans on the surface of the filler.

[0033] The beneficial effects of the technical solutions of the present application are as follows:

[0034] The present application reduces the start-up time of the degradable carrier autotrophic denitrification biofilter, improves the start-up rate of the filter, and achieves the purpose of rapid start-up.

[0035] The present application can achieve rapid start-up of the autotrophic denitrification biofilter without inoculating active sludge, and the fastest start-up time of the autotrophic denitrification biofilter of the present application can be within 96 hours.

[0036] The sodium thiosulfate in the growth promoter A of Thiobacillus denitrificans in the present application can play the role of an oxygen scavenger, reducing the influence of dissolved oxygen on the growth of Thiobacillus denitrificans in the early stage, and also serving as a sulfur source for the growth of Thiobacillus denitrificans to accelerate the growth of sulfur autotrophic denitrifying bacteria.

[0037] The present application combines the growth promoter A of Thiobacillus denitrificans, the growth promoter B of Thiobacillus denitrificans, and the growth promoter C of Thiobacillus denitrificans, which are suitable for different growth stages of Thiobacillus denitrificans.

[0038] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0039] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description of exemplary embodiments of the present application taken in conjunction with the accompanying drawings.

[0040] Figure 1 The nitrate nitrogen removal rate within 15 days of stable operation after the start-up of the rapid start-up method of the degradable carrier autotrophic denitrification biofilter process provided by the embodiment 1 of the present application is shown. DETAILED DESCRIPTION

[0041] The preferred embodiments of the present application will be described in more detail below. Although the preferred embodiments of the present application are described below, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0042] In the following examples:

[0043] The degradable carrier microbial film autotrophic denitrification filler is selected and purchased from Beijing Beipai Technology Co., Ltd.

[0044] Embodiment 1

[0045] The embodiment provides a rapid starting method of a degradable carrier autotrophic denitrification biofilter process, the autotrophic denitrification biofilter is an upflow biofilter, and the water quality conditions of influent of the autotrophic denitrification biofilter are as follows: 7-17 mg / L of nitrate nitrogen, 15-30 mg / L of chemical oxygen demand, 8-18 mg / L of total nitrogen, less than 0.3 mg / L of total phosphorus, 6.8-7.1 of pH, and 3 m / h of design filtration rate of the filter;

[0046] The method comprises the following steps:

[0047] S1: first culture stage

[0048] The autotrophic denitrification biofilter is filled with degradable carrier microbial membrane autotrophic denitrification filler (2.5 m in thickness), a supporting layer of the autotrophic denitrification biofilter supporting the degradable carrier microbial membrane autotrophic denitrification filler is a graded pebble layer, and the thickness of the graded pebble layer is 0.5 m; water is continuously fed into the autotrophic denitrification biofilter, and denitrifying Thiobacillus growth promoter A (including 39 g / L of sodium thiosulfate, 1.5 g / L of ammonium chloride, 0.5 g / L of magnesium sulfate and 20 g / L of ferrous sulfate) is continuously added into the autotrophic denitrification biofilter, the volume ratio of the addition amount of the denitrifying Thiobacillus growth promoter A to the water volume in the autotrophic denitrification biofilter is 1:1000, denitrifying Thiobacillus is enriched and cultured, and the dissolved oxygen concentration (DO) and the oxidation reduction potential (ORP) of the water in the autotrophic denitrification biofilter are monitored; when the dissolved oxygen concentration and the oxidation reduction potential of the water in the autotrophic denitrification biofilter reach first culture condition thresholds, the next culture stage is entered; the first culture condition thresholds comprise that the dissolved oxygen concentration is lower than 0.5 mg / L and the oxidation reduction potential is lower than-150 mv;

[0049] In the embodiment, the DO is 0.27 mg / L and the ORP is-170 mv after 12 h, and the next culture stage is entered;

[0050] S2: second culture stage

[0051] continuously feeding water to the autotrophic denitrification biofilter, and setting the filter speed of the second culture stage to be 0.5 m / h; adding the denitrifying Thiobacillus growth promoter B (including 1 g / L of ammonium chloride, 0.2 g / L of magnesium sulfate, 15 g / L of ferrous sulfate, and 20 g / L of sodium bicarbonate, the volume ratio of the adding amount of the denitrifying Thiobacillus growth promoter B to the water amount in the autotrophic denitrification biofilter being 1:10000) to the autotrophic denitrification biofilter during the continuous feeding of water, accelerating the formation of the denitrifying Thiobacillus microbial membrane on the surface of the filler, and monitoring the dissolved oxygen concentration, the oxidation-reduction potential, and the nitrate nitrogen removal rate of the effluent of the autotrophic denitrification biofilter; when the dissolved oxygen concentration, the oxidation-reduction potential, and the nitrate nitrogen removal rate of the effluent of the autotrophic denitrification biofilter reach the second culture condition threshold, entering the next culture stage; the second culture condition threshold includes that the dissolved oxygen concentration is lower than 0.5 mg / L, the oxidation-reduction potential is lower than -150 mv, and the nitrate nitrogen removal rate is ≥ 90%;

[0052] In this embodiment, the effluent DO is monitored to be 0.44 mg / L after 12 h; the effluent ORP is monitored to be -163 mv, and the nitrate nitrogen removal rate is 93% after 24 h; the effluent ORP is monitored to be -143 mv, the DO is 0.32 mg / L, and the nitrate nitrogen removal rate is 91% after 46 h, and the next culture stage is started;

[0053] S3: third culture stage

[0054] continuously feeding water to the autotrophic denitrification biofilter, and adding the denitrifying Thiobacillus growth promoter C (including 20 g / L of sodium bicarbonate and 1 g / L of ammonium chloride) to the water, the volume ratio of the adding amount of the denitrifying Thiobacillus growth promoter C to the water amount in the autotrophic denitrification biofilter being 1:10000, promoting the rapid growth of the denitrifying Thiobacillus, monitoring the dissolved oxygen concentration, the oxidation-reduction potential, and the nitrate nitrogen removal rate of the effluent of the autotrophic denitrification biofilter; when the dissolved oxygen concentration, the oxidation-reduction potential, and the nitrate nitrogen removal rate of the effluent of the autotrophic denitrification biofilter reach the third culture condition threshold, ending the third culture stage; the third culture condition threshold includes that the dissolved oxygen concentration is lower than 0.5 mg / L, the oxidation-reduction potential is lower than -140 mv, and the nitrate nitrogen removal rate is ≥ 90%;

[0055] In this embodiment, the effluent DO is monitored to be 0.26 mg / L after 14 h; the effluent ORP is monitored to be -143 mv, and the nitrate nitrogen removal rate is 93% after 36 h, the process is successfully started, and enters the stable operation stage, and the adding of the denitrifying Thiobacillus growth promoter C is stopped.

[0056] The nitrate nitrogen removal rate of the autotrophic denitrification biofilter in this embodiment is as follows within 15 days of stable operation Figure 1 as shown by Figure 1It can be seen that the removal rate of nitrate nitrogen can reach more than 90% during stable operation.

[0057] Embodiments of the application have been described above, with the understanding that these descriptions are exemplary only, and are not intended to be exhaustive or to limit the embodiments disclosed to the precise forms disclosed. Many modifications and variations are possible in light of the above teachings.

Claims

1. A method for rapid start-up of a degradable carrier autotrophic denitrification biofilter process, characterized in that, The method comprises the following steps: S1: first culture stage Continuous water feeding in the autotrophic denitrification biofilter filled with degradable carrier microbial film autotrophic denitrification filler; adding denitrifying Thiobacillus growth promoter A into the autotrophic denitrification biofilter, monitoring the dissolved oxygen concentration and oxidation-reduction potential of water in the autotrophic denitrification biofilter; when the dissolved oxygen concentration and oxidation-reduction potential of water in the autotrophic denitrification biofilter reach the first culture condition threshold, entering the next culture stage; The denitrifying Thiobacillus growth promoter A is composed of the following components: sodium thiosulfate, ammonium chloride, magnesium sulfate and ferrous sulfate; The volume ratio of the addition amount of the denitrifying Thiobacillus growth promoter A to the water amount in the autotrophic denitrification biofilter is (0.8-1.2):1000; The first culture condition threshold comprises: the dissolved oxygen concentration is lower than 0.5 mg / L, and the oxidation-reduction potential is lower than -150 mV; The first culture stage lasts for 10-18 h; S2: second culture stage Adding denitrifying Thiobacillus growth promoter B into the autotrophic denitrification biofilter during continuous water feeding, monitoring the dissolved oxygen concentration, oxidation-reduction potential and nitrate nitrogen removal rate of the effluent of the autotrophic denitrification biofilter; when the dissolved oxygen concentration, oxidation-reduction potential and nitrate nitrogen removal rate of the effluent of the autotrophic denitrification biofilter reach the second culture condition threshold, entering the next culture stage; The denitrifying Thiobacillus growth promoter B is composed of the following components: ammonium chloride, magnesium sulfate, ferrous sulfate and sodium bicarbonate; In the second culture stage, the volume ratio of the addition amount of the denitrifying Thiobacillus growth promoter B to the water amount in the autotrophic denitrification biofilter is (0.5-1.0):10000; The second culture condition threshold comprises: the dissolved oxygen concentration is lower than 0.5 mg / L, the oxidation-reduction potential is lower than -150 mV, and the nitrate nitrogen removal rate is ≥90%; The second culture stage lasts for 16-49 h; S3: third culture stage Adding denitrifying Thiobacillus growth promoter C into the autotrophic denitrification biofilter during continuous water feeding, monitoring the dissolved oxygen concentration, oxidation-reduction potential and nitrate nitrogen removal rate of the effluent of the autotrophic denitrification biofilter; when the dissolved oxygen concentration, oxidation-reduction potential and nitrate nitrogen removal rate of the effluent of the autotrophic denitrification biofilter reach the third culture condition threshold, indicating that the process is successfully started and entering the stable operation stage, and stopping the addition of the denitrifying Thiobacillus growth promoter C; The denitrifying Thiobacillus growth promoter C is composed of the following components: sodium bicarbonate and ammonium chloride; In the third culture stage, the volume ratio of the addition amount of the denitrifying Thiobacillus growth promoter C to the water amount in the autotrophic denitrification biofilter is (0.8-1.2):10000; The third culture condition threshold comprises: the dissolved oxygen concentration is lower than 0.5 mg / L; the oxidation-reduction potential is lower than -140 mV; and the nitrate nitrogen removal rate is ≥90%; The third culture stage lasts for 12-40 h; The method does not need to inoculate activated sludge; The influent of the autotrophic denitrification biofilter comprises at least one of domestic sewage, industrial wastewater, secondary effluent of a sewage treatment plant, total effluent of a reclaimed water plant, and landscape water.

2. The method for fast start-up of a degradable carrier autotrophic denitrification biofilter process according to claim 1, wherein, The water temperature of the influent of the autotrophic denitrification biofilter is 10-38℃.

3. The method for fast start-up of a degradable carrier autotrophic denitrification biofilter process according to claim 1, wherein, The autotrophic denitrification biofilter is an upflow or downflow biofilter.

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