A treatment method for progesterone-containing wastewater

Abstract

The present invention discloses a method for treating wastewater containing progesterone. Anaerobic ammonium oxidation granular sludge with the dominant strain of Candidatus Kuenenia is inoculated in an anaerobic ammonium oxidation reactor. Ammonia nitrogen and nitrite nitrogen are provided in the influent to start up the reactor and make it operate stably. Then, wastewater containing ammonia nitrogen, nitrite nitrogen and progesterone is used as the influent for treatment, so as to complete the removal of progesterone without reducing the denitrification performance. The present invention can be used both in the side-stream condition and in the mainstream condition, and is closer to the actual application environment; the operation is simple, no external oxidant is required, the treatment cost is low, and it is easy to be popularized on a large scale; while efficiently removing progesterone, it can ensure a low ammonia nitrogen concentration in the effluent.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment containing environmental progestogens, and particularly relates to a method for treating wastewater containing progesterone. Background Art

[0002] Environmental progestogens are endocrine disruptors that have often been detected in surface waters in recent years because they are not completely removed in sewage treatment systems. Sewage treatment plants (WWTPs) are considered an important source of progestogens, and finding effective treatment processes can reduce the harm of progestogens to the environment. In addition, progestogens have received wide attention due to their potential harm to the environment and organisms, and can have an adverse impact on the reproduction and behavior of aquatic organisms at low concentrations, such as carp and zebrafish.

[0003] Many studies have examined the types and concentrations of progestogens in the influent and effluent of sewage treatment plants. Several main types of progestogens are progesterone (also known as luteosterone, PGT), dydrogesterone (DDG), norethisterone (NTD), dienogest (DNT), and etienolone (ETE). In a survey of 17 sewage treatment plants, it was found that progesterone dominated in the influent, secondary effluent, final effluent, and excess sludge. It is reported that the concentration of PGT in pig farm wastewater is 2.8 - 11900 ng·L -1 , and the concentration in pig farm manure is 14400 ng·g -1 , and the concentration in municipal wastewater is 4.3 - 904 ng·L -1 . PGT and its metabolites have been shown to be harmful to exposed organisms, damaging reproductive ability and inducing the masculinization of aquatic organisms.

[0004] The patent specification with the publication number CN 103159286 A discloses a method for irradiating and degrading the hormone progesterone in wastewater. The wastewater solution containing progesterone pollutants is irradiated by an electron beam accelerator irradiation technology to decompose the progesterone in the wastewater solution; the irradiation dose of the electron beam accelerator is less than 15 kGy.

[0005] Current research has shown that A 2In the O process, the aerobic, anoxic, and anaerobic tanks can all effectively remove PGT, and the aerobic tank is the most important contributor to removing most of the PGT. However, some studies have also shown that PGT is mainly eliminated in the anaerobic and anoxic units, while the confirmed transformation products (TPs) are mainly formed in the anaerobic and anoxic units and then eliminated in the aerobic unit. Activated sludge treatment and ultraviolet photolysis can also effectively remove PGT. The main removal mechanism of PGT in the aerobic tank is biodegradation, while the degradation mechanisms in the anoxic and anaerobic tanks are unclear. Previous studies have shown that the removal efficiency is affected by various factors such as influent quality, temperature, sludge retention time (SRT), treatment process operating parameters, and microbial community structure. Temperature has been proven to be a key factor affecting the removal of PGT.

[0006] The anaerobic ammonium oxidation (anammox) process is an efficient biological nitrogen removal technology, and its system consists of a rich microbial community. Exploring whether it has the potential to treat wastewater containing PGT can help provide a reference for the removal of PGT in the environment. However, different operating parameters for mainstream treatment and sidestream treatment also affect the removal effect of PGT. Therefore, considering both mainstream and sidestream in the experiment can better understand the changing trend of PGT in the system. Summary of the Invention

[0007] The present invention provides a method for treating progesterone-containing wastewater, which uses the anaerobic ammonium oxidation process and utilizes anaerobic ammonium oxidation granular sludge with the dominant strain Candidatus Kuenenia to efficiently remove environmental concentrations of progesterone while maintaining high nitrogen removal performance.

[0008] The specific technical solution is as follows:

[0009] A method for treating progesterone-containing wastewater, inoculate anaerobic ammonium oxidation granular sludge with the dominant strain Candidatus Kuenenia in an anaerobic ammonium oxidation reactor, provide ammonia nitrogen and nitrite nitrogen in the influent, start the reactor and make it operate stably, and then use wastewater containing ammonia nitrogen, nitrite nitrogen, and progesterone as the influent for treatment, achieving progesterone removal without reducing the nitrogen removal performance.

[0010] In a preferred example, for the method for treating progesterone-containing wastewater, the volatile suspended solids concentration (VSS) of the inoculated anaerobic ammonium oxidation granular sludge is 180 - 190 g·L -1 . To a certain extent, the volatile suspended solids concentration reflects the level of microbial content in the sludge. The anaerobic ammonium oxidation granular sludge within the above preferred volatile suspended solids concentration range has high biological activity and is suitable for treating progesterone-containing wastewater in the present invention.

[0011] In a preferred example, for the method for treating progesterone-containing wastewater, the particle size of the inoculated anaerobic ammonium oxidation granular sludge is < 2 mm. The present invention has found through research that when the particle size of the anaerobic ammonium oxidation granular sludge is above 2 mm, the sludge mass transfer capacity is poor, and the microorganisms inside the particles are difficult to contact nutrients, easily forming dead zones, with low microorganism utilization rate and poor treatment effect on progesterone.

[0012] In a preferred example, for the method for treating progesterone-containing wastewater, the volume of the inoculated anaerobic ammonium oxidation granular sludge accounts for 50% - 65% of the volume of the anaerobic ammonium oxidation reactor. The present invention preferably uses an upflow anaerobic sludge bed reactor, and it is recommended that the sludge inoculation volume ratio does not exceed 2 / 3 of the reactor volume. Otherwise, during operation, the water flows upward in a plug flow manner, easily causing sludge overflow and resulting in sludge loss.

[0013] For the method for treating progesterone-containing wastewater, the treatment temperature of the wastewater containing ammonia nitrogen, nitrite nitrogen and progesterone can be 14 - 36 °C. The technical solution of the present invention can efficiently remove progesterone at environmental concentration under both mainstream temperature conditions and side-stream temperature conditions, and does not affect the original denitrification performance.

[0014] For the method for treating progesterone-containing wastewater, in the wastewater containing ammonia nitrogen, nitrite nitrogen and progesterone, the progesterone concentration can be 440 ng·L -1 or higher, such as 440 - 490 ng·L -1 . The technical solution of the present invention can treat progesterone wastewater close to environmental concentration, has a wider application range, and has important guiding significance for the treatment of trace progesterone.

[0015] In a preferred example, for the method for treating progesterone-containing wastewater, the concentrations of ammonia nitrogen and nitrite nitrogen in the wastewater containing ammonia nitrogen, nitrite nitrogen and progesterone are the same as those of ammonia nitrogen and nitrite nitrogen in the influent water during the stage of starting up the reactor and making it operate stably. This can keep the sludge stable and efficient throughout the progesterone wastewater treatment process.

[0016] In a preferred example, for the method for treating progesterone-containing wastewater, during the stage of starting up the reactor and making it operate stably, the concentrations of ammonia nitrogen and nitrite nitrogen provided by the influent water are both 40 - 140 mg·L -1 . The technical solution of the present invention can still maintain high-efficiency removal of high-concentration ammonia nitrogen in the wastewater in the presence of progesterone at environmental concentration.

[0017] The method for treating progesterone-containing wastewater according to the present invention can be used under mainstream conditions, such as 14 - 16 °C, 40 - 50 mg·L -1 ammonia nitrogen and nitrite nitrogen concentrations, or can also be used under side-stream conditions, such as 35 - 56 °C, 130 - 140 mg·L -1 ammonia nitrogen and nitrite nitrogen concentrations, and very good progesterone removal effects can be achieved, without affecting the ammonia nitrogen removal performance of the sludge itself.

[0018] For the treatment method of progesterone-containing wastewater, the index for stable operation of the reactor can be that the total nitrogen removal efficiency (NRE) is greater than 80%.

[0019] As a general inventive concept, the present invention also provides the application of anaerobic ammonium oxidation granular sludge with the dominant strain of Candidatus Kuenenia in the treatment of progesterone-containing wastewater. The anaerobic ammonium oxidation granular sludge can remove progesterone without reducing the original denitrification performance. For the preference of some technical solutions in the above application, reference can be made to the treatment method of progesterone-containing wastewater.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] The present invention can be used in both flow measurement conditions and mainstream conditions, which is closer to the actual application environment; it is simple to operate, without the need for additional oxidants, has a low treatment cost, and is easy to promote on a large scale; while efficiently removing progesterone, it can ensure that the ammonia nitrogen concentration in the effluent meets the discharge requirements of the first-level standard in the Comprehensive Wastewater Discharge Standard of China (GB 8978-1996). Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the anaerobic ammonium oxidation experimental device. In the figure: 1 - water inlet tank; 2 - peristaltic pump; 3 - upflow anaerobic sludge bed reactor; 4 - effluent bucket.

[0023] Figure 2 It is the progesterone concentration of the influent and effluent of reactor A and reactor B. In the figure: Inf represents influent, and Eff represents effluent.

[0024] Figure 3 It is the specific anaerobic ammonium oxidation activity of reactor A and reactor B. Detailed Embodiments

[0025] The present invention will be further described below in conjunction with the drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0026] For the operating methods without specific conditions noted in the following embodiments, they are usually in accordance with conventional conditions or in accordance with the conditions recommended by the manufacturer.

[0027] In this embodiment, two groups of anaerobic ammonium oxidation experimental devices are adopted. Each group of anaerobic ammonium oxidation experimental devices is as Figure 1As shown in the figure, it includes a water inlet tank 1, a peristaltic pump 2, an upflow anaerobic sludge bed reactor 3, and an effluent tank 4 connected in sequence. One set of anaerobic ammonium oxidation experimental device uses an upflow anaerobic sludge bed reactor A, and the other set uses an upflow anaerobic sludge bed reactor B. The volumes of both reactors are 1.5 L, and both are inoculated with 0.8 L of anaerobic ammonium oxidation granular sludge with the dominant strain of Candidatus Kuenenia. The volatile suspended solids concentration of the inoculated anaerobic ammonium oxidation granular sludge is 183.0 g·L -1 , and the particle size of the granular sludge is <2 mm.

[0028] The above inoculated granular sludge was first eluted 3 times with an inorganic salt solution and pure water respectively to remove residual substrates. The composition of the inorganic salt solution is:

[0029]

[0030]

[0031] The two reactors were started up and the load was increased independently, and were carried out at 15 °C (reactor A) and 35 °C (reactor B) respectively. Using nitrogen-containing simulated wastewater as the reactor inlet water, the hydraulic retention time (HRT) of reactor A is 0.99 h, and the HRT of reactor B is 0.875 h. The ammonia nitrogen and nitrite nitrogen concentrations in the influent and effluent of the two reactors were monitored every two days, and the reactor operating conditions were adjusted according to the changes in the ammonia nitrogen and nitrite nitrogen concentrations in the effluent. The composition of the nitrogen-containing simulated wastewater includes:

[0032] NaNO2 and (NH4)2SO4 were used to provide nitrite nitrogen and ammonia nitrogen respectively, and the molar ratio of ammonia salt to nitrite was 1:1; in addition, there are:

[0033]

[0034] And trace element concentrates I and II with a concentration of 1.25 mL·L -1 ;

[0035] Among them, the specific composition of trace element concentrate I is:

[0036] EDTA 5 g·L -1 ,

[0037] FeSO4·7H2O 9.14 g·L -1 ;

[0038] The specific composition of trace element concentrate II is:

[0039]

[0040] First, in the period of 0 - 35 days (d), denoted as Stage I, the influent substrate concentration (nitrite nitrogen concentration and ammonia nitrogen concentration) of Reactor B was 140 mg·L -1 unchanged, and the influent substrate concentration of Reactor A was 40 mg·L -1 unchanged. During this process, the total nitrogen removal load of Reactor A decreased from 38.0 kg N·m -3 ·d -1 to 12.7 kg N·m -3 ·d -1 , and the average total nitrogen removal rate was 97.7%; the total nitrogen removal load of Reactor B was 37.1 kg N·m -3 ·d -1 , and the average total nitrogen removal rate was 98.9%.

[0041] Starting from the 36th day, the influent substrate concentration of Reactor A was maintained at 40 mg·L -1 , and that of Reactor B was 140 mg·L -1 , and progesterone was added to the reactors. Preparation method of progesterone: First, weigh 0.1 g of progesterone (Cas No. 57 - 83 - 0) and dissolve it in 100 mL of methanol. Then, take 1 mL from the 100 mL progesterone - methanol mixture and add it to ultrapure water, with the final volume being 100 mL. The above - mentioned mixture is the mother liquor added to the reactors. During the operation process, the ammonia nitrogen and nitrite nitrogen concentrations in the influent and effluent of the two reactors were monitored every two days. Considering problems such as possible volatilization loss of ammonia nitrogen, the influent in the influent tank was replaced every three days to ensure the stable concentrations of substances such as ammonia nitrogen and progesterone in the influent.

[0042] The initial concentrations of progesterone in the influent of Reactors A and B were controlled at around 450 ng·L -1 , and this process was run for 150 d (i.e., from the 36th day to the 185th day, denoted as Stage II). During this process, the total nitrogen removal loads of Reactors A and B were 12.0 kgN·m -3 ·d -1 and 37.3 kg N·m -3 ·d -1 , and the average total nitrogen removal rates were 100% and 99% respectively. On the 185th day, the progesterone concentration in the influent of Reactor A was measured to be 441.4 ng·L -1 , and the progesterone concentration in the effluent was 121.9 ng·L -1 , with a removal efficiency of 72.3%. The progesterone concentration in the influent of Reactor B was 473.7 ng·L -1 , and the progesterone concentration in the effluent was 24.3 ng·L -1 , with a removal efficiency of 94.8%( Figure 2 ).

[0043] Starting from the 186th day, continue to operate under the conditions of Phase II for 30 days, that is, from the 186th day to the 215th day, and this process is denoted as Phase III. Figure 3 Figure 3 shows the specific anaerobic ammonium oxidation activities in each period of Phase I, Phase II, and Phase III. It can be found that after long-term addition of progesterone, the specific anaerobic ammonium oxidation activities of Reactors A and B are significantly higher than the initial levels, being 432.7 mgN·gVSS -1 ·d -1 and 485.7 mgN·gVSS -1 ·d -1 , indicating that the anaerobic ammonium oxidation granular sludge with the dominant strain Candidatus Kuenenia of the present invention has good adaptability to the wastewater containing progesterone.

[0044] It can be seen that the present invention first proposes to use anaerobic ammonium oxidation granular sludge with the dominant strain Candidatus Kuenenia to treat wastewater containing progesterone. Even under the adverse condition of the mainstream low temperature of 15°C, progesterone in the wastewater can still be removed with high efficiency, and it will not have a negative impact on the original denitrification performance. It is a progesterone wastewater treatment method with great practical application prospects, reflecting the significant advantages of anaerobic ammonium oxidation granular sludge with the dominant strain Candidatus Kuenenia in treating progesterone wastewater.

[0045] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A method for treating wastewater containing progesterone, characterized in that, Inoculate anaerobic ammonium oxidation granular sludge with the dominant strain Candidatus Kuenenia in the anaerobic ammonium oxidation reactor. Provide ammonia nitrogen and nitrite nitrogen in the influent, start the reactor and make it operate stably, and then treat the wastewater containing ammonia nitrogen, nitrite nitrogen and progesterone as the influent to complete the removal of progesterone without reducing the nitrogen removal performance; The volatile suspended solids concentration of the inoculated anaerobic ammonium oxidation granular sludge is 180-190 g·L -1 ; The particle size of the inoculated anaerobic ammonium oxidation granular sludge is <2 mm; The treatment temperature of the wastewater containing ammonia nitrogen, nitrite nitrogen and progesterone is 14 - 36 °C.

2. The treatment method of progesterone-containing wastewater according to claim 1, wherein The volume of the inoculated anaerobic ammonium oxidation granular sludge accounts for 50% - 65% of the volume of the anaerobic ammonium oxidation reactor.

3. The treatment method of progesterone-containing wastewater according to claim 1, wherein In the wastewater containing ammonia nitrogen, nitrite nitrogen and progesterone, the progesterone concentration is 440 ng·L -1 or more.

4. The method for treating progesterone-containing wastewater according to claim 1, wherein The concentrations of ammonia nitrogen and nitrite nitrogen in the wastewater containing ammonia nitrogen, nitrite nitrogen and progesterone are the same as those of ammonia nitrogen and nitrite nitrogen in the influent during the stage of starting the reactor and making it operate stably.

5. The treatment method of progesterone-containing wastewater according to claim 1, characterized in that, In the stage of starting up the reactor and making it operate stably, the concentrations of ammonia nitrogen and nitrite nitrogen provided by the influent water are both 40 - 140 mg·L -1 .

6. Application of anaerobic ammonium oxidation granular sludge with dominant strain Candidatus Kuenenia in treating wastewater containing progesterone, characterized in that, The anaerobic ammonium oxidation granular sludge can remove progesterone without reducing its original nitrogen removal performance; the volatile suspended solids concentration of the inoculated anaerobic ammonium oxidation granular sludge is 180-190 g·L -1 ; the particle size of the inoculated anaerobic ammonium oxidation granular sludge is <2 mm; Take the wastewater containing ammonia nitrogen, nitrite nitrogen and progesterone as the influent, and the treatment temperature of the wastewater containing ammonia nitrogen, nitrite nitrogen and progesterone is 14 - 36 °C.

Images