CN112250188A - Denitrification treatment method and denitrification treatment system for thiourea-containing ammonia nitrogen wastewater - Google Patents

Abstract

The invention discloses a denitrification treatment method and a denitrification treatment system for thiourea-containing ammonia nitrogen wastewater, wherein the denitrification treatment method comprises the following steps: s1, allowing a material containing nitrate and ammonia nitrogen wastewater containing thiourea to be treated to enter a short-cut denitrification reactor for short-cut denitrification reaction; and S2, enabling the reaction liquid obtained in the step S1 after the short-cut denitrification reaction to enter an anaerobic ammonia oxidation reactor for denitrification reaction. The denitrification treatment system comprises a short-cut denitrification reactor and an anaerobic ammonia oxidation reactor, wherein the short-cut denitrification reactor is provided with a short-cut denitrification reaction water outlet pipe, the anaerobic ammonia oxidation reactor is provided with an anaerobic ammonia oxidation reaction water inlet pipe, and the short-cut denitrification reaction water outlet pipe is communicated with the anaerobic ammonia oxidation reaction water inlet pipe. The invention creatively introduces the ammonia nitrogen wastewater containing the sulfur biological inhibitor into the denitrification system, and synchronously achieves the aim of removing COD and ammonia nitrogen by using the short-range denitrification and ammonia oxidation processes.

Description

Denitrification treatment method and denitrification treatment system for thiourea-containing ammonia nitrogen wastewater

Technical Field

The invention relates to the technical field of industrial wastewater treatment, in particular to a denitrification treatment method and a treatment system for thiourea-containing ammonia nitrogen wastewater.

Background

The currently common biological denitrification process for wastewater is nitrification and denitrification process, and the ammonia nitrogen in the water body is converted into nitrogen gas by the synergistic action of autotrophic nitrifying bacteria and heterotrophic denitrifying bacteria, so as to realize the purpose of denitrification. However, once the water contains biological inhibiting substances such as thiourea and derivative organic substrates, the nitrification and denitrification processes cannot be smoothly carried out, so that the effective denitrification cannot be realized.

The thiourea and the derivative organic matrix thereof are intermediates of pesticides such as bactericide carbendazim, flufenacet, buthiuron and the like, and are also raw materials and intermediates of medicines such as thiamine thiazole, sulfonamides and the like. Thiourea substances can generate a serious inhibition effect on a nitrification system in a biological treatment system, and can act on the ammonia oxidase in the nitrification process so as to destroy the process of ammonia nitrogen nitrification. The data show that thiourea and thiosemicarbazide can inhibit the nitrification system by about 75% at the concentrations of 0.076ppm and 0.18ppm respectively. In addition, the presence of thiourea and derived organic substrates etc. in the wastewater reduces the specific growth rate of nitrifying bacteria.

For sulfur-containing biological inhibitor wastewater, the existing treatment method is usually very complex in process and is not suitable for industrial application. The patent CN110255823A provides a high-zinc high-ammonia nitrogen high-thiourea wastewater treatment process, which comprises the steps of sequentially carrying out pretreatment steps of heating, precipitating, removing zinc, evaporating ammonia, carrying out advanced oxidation, deeply removing zinc and the like on high-zinc high-ammonia nitrogen high-thiourea wastewater to remove zinc and thiourea, and then carrying out biochemical treatment on the high-zinc high-ammonia nitrogen high-thiourea wastewater through hydrolytic acidification and AO processes. The process steps are complex, the control parameters are more, the dosage is difficult to master, and secondary pollution is easy to generate. Meanwhile, ammonia nitrogen wastewater containing sulfur biological inhibitors is often generated in the same production process in industrial wastewater of medicines, pesticides and the like, namely, the ammonia nitrogen content in water is high, and sulfur biological nitrification inhibiting substances exist at the same time, but research on the ammonia nitrogen wastewater treatment process of the sulfur biological inhibitors is not reported.

Disclosure of Invention

Therefore, the invention provides a denitrification treatment method and a denitrification treatment system for thiourea-containing ammonia nitrogen wastewater, which aim to solve the problem that ammonia nitrogen cannot be smoothly denitrified in thiourea-containing ammonia nitrogen wastewater due to the inhibition effect of thiourea.

In order to achieve the above purpose, the invention provides the following technical scheme:

according to a first aspect of the invention, the invention provides a denitrification treatment method for thiourea-containing ammonia nitrogen wastewater, which comprises the following steps: s1, enabling a material containing nitrate and ammonia nitrogen wastewater containing thiourea to be treated to enter a short-cut denitrification reactor for short-cut denitrification reaction so as to convert at least part of thiourea into sulfate radicals; and S2, enabling the reaction liquid obtained in the step S1 after the short-cut denitrification reaction to enter an anaerobic ammonia oxidation reactor for denitrification reaction.

Further, the denitrification processing method further comprises a reflux step after the step S2: refluxing the reaction liquid after the denitrification reaction to the short-cut denitrification reactor in step S1 to perform the short-cut denitrification reaction; the reflux ratio of the reflux is 40-75%.

Further, the preparation steps of the material containing nitrate comprise: and (3) allowing the ammonia-containing organic wastewater to enter a carbon oxidation nitration reactor for carbon oxidation nitration reaction to obtain the material containing the nitrate, wherein the ammonia-containing organic wastewater contains ammonium ions and organic nitrogen.

Further, the chemical oxygen demand of the ammonia-containing organic wastewater is 1500mg/L (1000-) -, the ammonia nitrogen concentration is 200mg/L (150-) -, the ratio of the biochemical oxygen demand to the chemical oxygen demand is more than 0.3, and the dissolved oxygen is 2-4 mg/L; the reaction time of the carbon oxidation nitration reaction is 24-48h, the temperature is 20-30 ℃, and the chemical oxygen demand of the reaction liquid containing the nitrate obtained after the nitration reaction is below 100 mg/L; in the carbon oxidation and nitration reaction, sludge containing ammonia oxidizing bacteria and nitrite oxidizing bacteria is added according to the concentration of 3000-5000mg/L, and the nitrate nitrogen concentration in the obtained reaction liquid containing nitrate is 100-200 mg/L.

Further, the content of thiourea in the inlet water in the short-cut denitrification reactor is 50-100mg/L, the chemical oxygen demand is 200-500mg/L, and the concentration of ammonia nitrogen is 50-100 mg/L; before the short-cut denitrification reaction in the step S1, adjusting the pH value of the reaction liquid in the short-cut denitrification reactor to be 7.0-8.5, and adding sludge containing thiobacillus denitrificans into the short-cut denitrification reactor according to 2500-4500mg/L, wherein the content of the thiobacillus denitrificans in the sludge is 10-30 wt%; the time for the short-range denitrification reaction is 12-72h, the reaction temperature is 20-40 ℃, and the concentration of nitrite nitrogen in the reaction liquid obtained through the short-range denitrification reaction is 50-150 mg/L.

Further, in the denitrification reaction in step S2, carbonate is added to the anammox reactor so that the mass concentration ratio of inorganic carbon to total nitrogen is 0.2 to 0.4, and the dissolved oxygen in the anammox reactor is controlled to be 0.2mg/L or less, and the reactor is protected from light, at a reaction temperature of 30 ℃.

According to a second aspect of the invention, the invention provides a denitrification treatment system for thiourea-containing ammonia nitrogen wastewater, which comprises a short-cut denitrification reactor and an anaerobic ammonia oxidation reactor, wherein the short-cut denitrification reactor is provided with a short-cut denitrification reaction water inlet pipe and a short-cut denitrification reaction water outlet pipe, the bottom of the anaerobic ammonia oxidation reactor is provided with an anaerobic ammonia oxidation reaction water inlet pipe, and the short-cut denitrification reaction water outlet pipe is communicated with the anaerobic ammonia oxidation reaction water inlet pipe; the short-cut denitrification reactor is also provided with a short-cut denitrification external reflux water inlet pipe, the anaerobic ammonia oxidation reactor is also provided with an anaerobic ammonia oxidation external reflux water outlet pipe, and the anaerobic ammonia oxidation external reflux water outlet pipe is communicated with the short-cut denitrification external reflux water inlet pipe.

Furthermore, the denitrification treatment system also comprises a carbon oxidation nitration reactor, wherein the carbon oxidation nitration reactor is provided with a carbon oxidation nitration water outlet pipe, and the carbon oxidation nitration water outlet pipe is communicated with the short-distance denitrification reaction water inlet pipe; the nitrogen removal processing system still including set up in carbon oxidation nitration reactor with equalizing basin between the short distance denitrification reactor, the equalizing basin is provided with equalizing basin inlet tube and equalizing basin outlet pipe, carbon oxidation nitration outlet pipe with the equalizing basin inlet tube is linked together, the equalizing basin outlet pipe with the short distance denitrification inlet tube is linked together.

Furthermore, the bottom of the carbon oxidation nitration reactor is provided with a water inlet pipe and a backwashing water inlet pipe, the water inlet pipe is communicated with the backwashing water inlet pipe, a filter brick layer, a supporting layer and a packing layer are sequentially arranged inside the carbon oxidation nitration reactor from bottom to top, and the upper part inside the carbon oxidation nitration reactor is provided with a water outlet weir communicated with the carbon oxidation nitration water outlet pipe; the bottom of the carbon oxidation nitration reactor is also provided with a water distribution channel which is respectively communicated with the water inlet pipe and the backwashing water inlet pipe; the carbon oxidation nitration reactor is also provided with an aeration pipe and a backwashing air inlet pipe.

Furthermore, the short-cut denitrification reactor is also provided with an activated carbon biological filler adding device for adding the activated carbon biological filler into the short-cut denitrification reactor, and the short-cut denitrification reactor is also internally provided with a mechanical stirring device extending from top to bottom; the anaerobic ammoxidation reactor is an up-flow anaerobic sludge bed reactor, a sludge suspension area of the up-flow anaerobic sludge bed reactor is provided with an internal circulation water outlet pipe and an internal circulation pump, and the internal circulation water outlet pipe is communicated with the anaerobic ammoxidation water inlet pipe through the internal circulation pump; the upper part of the upflow anaerobic sludge blanket reactor is sequentially provided with a three-phase separator and a biogas collecting chamber; the anaerobic ammonia oxidation reactor is also provided with an inorganic carbon source adding device and an anaerobic ammonia oxidation water outlet pipe.

The invention has the following advantages:

firstly, the method and the system for treating the ammonia nitrogen wastewater containing thiourea creatively introduce the ammonia nitrogen wastewater containing the sulfur biological inhibitor into a denitrification system, and synchronously remove COD and ammonia nitrogen by using the short-range denitrification and ammonia oxidation processes, so that the final effluent can meet the requirements of more than two levels in the national comprehensive wastewater discharge standard GB 8978-2002;

secondly, the sulfur-containing biological inhibitor ammonia nitrogen wastewater is introduced into a denitrification system, thiobacillus denitrificans is utilized to realize effective degradation of thiourea organic matters, S in C ═ S is oxidized into sulfate, the inhibition effect of the sulfate on biological nitrification is relieved, and the normal and stable operation of a wastewater biochemical system is ensured;

thirdly, the invention can realize the targeted effective treatment of various pollutants in the thiourea-containing ammonia nitrogen wastewater under the conditions of saving energy and reducing energy consumption, synchronously remove COD and ammonia nitrogen, and has good application prospect for treating the sulfur-containing biological inhibitor ammonia nitrogen wastewater;

fourthly, the invention adopts a biochemical method, has simple process, low operation cost and strong impact resistance, and can effectively ensure that the effluent can reach the discharge standard required by the industry. The cost of enterprises is reduced, the environmental protection requirement is met, good economic benefits are generated, and the sustainable development requirement is met.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.

The structures, ratios, sizes, and the like shown in the present specification are only used for matching with the contents disclosed in the specification, so that those skilled in the art can understand and read the present invention, and do not limit the conditions for implementing the present invention, so that the present invention has no technical significance, and any structural modifications, changes in the ratio relationship, or adjustments of the sizes, without affecting the functions and purposes of the present invention, should still fall within the scope of the present invention.

FIG. 1 is a schematic structural diagram of a denitrification system for wastewater containing thiourea and ammonia nitrogen provided in embodiment 7 of the present invention;

FIG. 2 is a schematic structural diagram of a denitrification system for wastewater containing thiourea and ammonia nitrogen provided in embodiments 8-10 of the present invention;

FIG. 3 is a process flow diagram of a denitrification system for wastewater containing thiourea and ammonia nitrogen provided in embodiment 8 of the invention.

In the figure:

100. a carbon oxidation nitration reactor; 101. a water inlet pipe; 102. backwashing the water inlet pipe; 103. a water distribution channel; 104. a brick filtering layer; 105. a support layer; 106. a filler layer; 107. an effluent weir; 108. a carbon oxidation nitration water outlet pipe; 109. an aeration pipe; 110. backwashing the air inlet pipe; 200. a regulating tank; 201. a regulating reservoir water inlet pipe; 202. a water outlet pipe of the regulating tank; 300. a short-cut denitrification reactor; 301. a short-cut denitrification reaction water inlet pipe; 302. a mechanical stirring device; 303. activated carbon biological filler; 304. a short-cut denitrification external reflux water inlet pipe; 305. a short-range denitrification reaction water outlet pipe; 400. an anammox reactor; 401. an anaerobic ammonia oxidation reaction water inlet pipe; 402. an inorganic carbon source adding device; 403. a three-phase separator; 404. a biogas collection chamber; 405. anaerobic ammonia oxidation external reflux water outlet pipe; 406. an internal circulation water outlet pipe; 407. an internal circulation pump; 408. anaerobic ammonia oxidation outlet pipe.

Detailed Description

The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The embodiment provides a denitrification treatment method of thiourea-containing ammonia nitrogen wastewater, which comprises the following steps:

s1, enabling a material containing nitrate and ammonia nitrogen wastewater containing thiourea to be treated to enter a short-cut denitrification reactor for short-cut denitrification reaction so as to convert at least part of thiourea into sulfate radicals;

and S2, enabling the reaction liquid obtained in the step S1 after the short-cut denitrification reaction to enter an anaerobic ammonia oxidation reactor for denitrification reaction.

Before the short-range denitrification reaction in the step S1 is performed, the mixed reaction solution contains nitrate, thiourea substances and ammonium ions (ammonia nitrogen), and through the short-range denitrification reaction in the step S1, nitrate is reduced to nitrite ions, and at the same time, thiourea substances are oxidized to sulfate (sulfate), and ammonium ions remain unchanged; in the short-cut denitrification reaction of the step S1, the thiobacillus denitrificans uses a thiourea organic substrate as an electron donor to oxidize and degrade the thiobacillus denitrificans, and simultaneously uses nitrate as an electron acceptor to perform partial denitrification reaction to generate nitrite; before the denitrification reaction in step S2 is performed, the reaction solution contains ammonium ions (ammonia nitrogen), nitrite ions, and sulfate radicals, and undergoes denitrification reaction in the anammox reactor, the ammonium ions (ammonia nitrogen) and nitrite ions are substantially converted into nitrogen by anammox bacteria, so that denitrification is achieved, and a small amount of nitrate radicals may be generated while being converted into nitrogen.

According to the denitrification treatment method for the thiourea-containing ammonia nitrogen wastewater, the thiourea-containing biological inhibitor ammonia nitrogen wastewater is creatively introduced into a denitrification system, the purpose of removing COD and ammonia nitrogen from the thiourea-containing biological inhibitor ammonia nitrogen wastewater is synchronously achieved by cooperatively utilizing the short-range denitrification and ammonia oxidation processes, and finally the effluent can meet the requirements of more than two levels in the national comprehensive wastewater discharge standard GB 8978-2002.

Example 2

The denitrification treatment method according to embodiment 1, further comprising a reflux step after step S2:

refluxing the reaction liquid after the denitrification reaction to the short-cut denitrification reactor in step S1 to perform the short-cut denitrification reaction;

the reflux ratio of the reflux is 40-75%.

As described in example 1, most of the ammonium ions (ammonia nitrogen) and nitrite ions are converted into nitrogen gas by anammox bacteria and a small amount of nitrate is generated at the same time as the ammonium ions (ammonia nitrogen) and nitrite ions are converted into nitrogen gas by the denitrification reaction of step S2, and the small amount of nitrate is returned to the short-cut denitrification reactor of step S1 by the return flow step of this example, and then reduced into nitrite by the short-cut denitrification reaction of step S1, and then the denitrification reaction of step S2 is continued, and nitrite is converted into nitrogen gas and a small amount of nitrate, and then the return flow is continued at the above-mentioned return flow ratio, and the above-mentioned processes are circulated in sequence.

Through the reflux step of the embodiment, a small amount of nitrate generated in the step S2 can be reduced to nitrite through the reaction of the step S1, and then converted into nitrogen through the step S2, so that the concentration of nitrate ions in the finally discharged water is reduced, and the finally discharged water is safer and more environment-friendly.

Example 3

The denitrification treatment method as described in embodiment 1 or 2, wherein the nitrate containing material is prepared by the steps of:

and (3) allowing the ammonia-containing organic wastewater to enter a carbon oxidation nitration reactor for carbon oxidation nitration reaction to obtain the material containing the nitrate, wherein the ammonia-containing organic wastewater contains ammonium ions and organic nitrogen.

In addition to the preparation of the nitrate-containing material by the method of this example, the nitrate-containing material may be obtained by directly using a method such as a nitrate preparation method.

In a carbon oxidation and nitrification reactor, an aerobic ammonia oxidation strain (AOB strain) converts ammonia nitrogen in ammonia-containing organic wastewater into nitrous acid through the catalytic action of Ammonia Monooxygenase (AMO) and hydroxylamine oxidase (HAO), and is further oxidized into nitrate under the action of nitrous acid oxidizing bacteria (NOB strain).

Before the carbon oxidation and nitration reaction, the ammonia-containing organic wastewater contains ammonium ions and organic nitrogen, the organic nitrogen is firstly converted into ammonia nitrogen through an ammoniation reaction, and then is converted into nitrate radicals with the ammonium ions in the inlet water through the nitration reaction. The ammonia-containing organic wastewater is a wastewater commonly found in the industry, and the wastewater is used as a raw material to obtain the nitrate-containing material required by the step S1 through carbon oxidation and nitration, so that the cost can be reduced to treasure, and the ammonia-containing organic wastewater is utilized by the denitrification treatment method of the embodiment.

Example 4

The denitrification treatment method as described in embodiment 3, wherein the ammonia-containing organic wastewater has a chemical oxygen demand of 1000-;

the reaction time of the carbon oxidation nitration reaction is 24-48h, the temperature is 20-30 ℃, and the chemical oxygen demand of the reaction liquid containing the nitrate obtained after the nitration reaction is below 100 mg/L;

in the carbon oxidation and nitration reaction, sludge containing ammonia oxidizing bacteria and nitrite oxidizing bacteria is added according to the concentration of 3000-5000mg/L, and the nitrate nitrogen concentration in the obtained reaction liquid containing nitrate is 100-200 mg/L.

In this example, parameters such as the concentration of the reaction liquid material, the reaction temperature, the reaction time, and the concentration of the reaction product of the carbon oxidation nitration reaction are defined, so that the ammonia-containing organic wastewater suitable for preparing the nitrate-containing material can be conveniently selected, and the nitrate-containing material can be successfully obtained according to the parameters of this example.

Example 5

The denitrification treatment method as described in embodiment 1 or 4, wherein the feed water thiourea content of the short-cut denitrification reactor is 50-100mg/L, the chemical oxygen demand is 200-500mg/L, and the ammonia nitrogen concentration is 50-100 mg/L;

before the short-cut denitrification reaction in the step S1, adjusting the pH value of the reaction liquid in the short-cut denitrification reactor to be 7.0-8.5, and adding sludge containing thiobacillus denitrificans into the short-cut denitrification reactor according to 2500-4500mg/L, wherein the content of the thiobacillus denitrificans in the sludge is 10-30 wt%;

the time for the short-range denitrification reaction is 12-72h, the reaction temperature is 20-40 ℃, and the concentration of nitrite nitrogen in the reaction liquid obtained through the short-range denitrification reaction is 50-150 mg/L.

In this embodiment, the relationship between the material concentration of the reaction solution and the amount of different materials in the shortcut denitrification reaction described in step S1, the pH value of the reaction solution, the addition amount of active bacteria, the reaction temperature, the reaction time, and the like are defined, and according to the parameters of this embodiment, thiourea-containing substances and nitrate ions in the thiourea-containing ammonia nitrogen wastewater are converted into sulfate and nitrite respectively, so that the nitrite and ammonium ions (ammonia nitrogen) originally contained in the wastewater are not inhibited by the thiourea-containing substances when converted into nitrogen through the anaerobic ammonia oxidation reaction of the subsequent step S2, and the ammonia nitrogen in the thiourea-containing ammonia nitrogen wastewater can be smoothly denitrified through the anaerobic ammonia oxidation reaction of step S2.

Example 6

In the denitrification treatment method of example 5, in the denitrification reaction of step S2, carbonate is added to the anammox reactor so that the mass concentration ratio of inorganic carbon to total nitrogen is 0.2 to 0.4, and dissolved oxygen in the anammox reactor is controlled to be 0.2mg/L or less and protected from light, at a reaction temperature of 30 ℃.

In this embodiment, the material ratio, the reaction temperature, the illumination and other factors of the denitrification reaction of step S2 are limited, and under the limited conditions of this embodiment, the denitrification reaction of step S2 can convert the ammonium ions and nitrite ions generated in step S1 into nitrogen gas, so as to achieve the purpose of denitrification better.

Example 7

The embodiment provides a denitrification treatment system for thiourea-containing ammonia nitrogen wastewater, as shown in fig. 1, the denitrification treatment system comprises a short-cut denitrification reactor 300 and an anaerobic ammonia oxidation reactor 400, wherein the short-cut denitrification reactor 300 is provided with a short-cut denitrification reaction water inlet pipe 301 and a short-cut denitrification reaction water outlet pipe 305, the bottom of the anaerobic ammonia oxidation reactor 400 is provided with an anaerobic ammonia oxidation reaction water inlet pipe 401, and the short-cut denitrification reaction water outlet pipe 305 is communicated with the anaerobic ammonia oxidation reaction water inlet pipe 401;

the short-cut denitrification reactor 300 is further provided with a short-cut denitrification external reflux water inlet pipe 304, the anaerobic ammonia oxidation reactor 400 is further provided with an anaerobic ammonia oxidation external reflux water outlet pipe 405, and the anaerobic ammonia oxidation external reflux water outlet pipe 405 is communicated with the short-cut denitrification external reflux water inlet pipe 304.

The short-cut denitrification reaction of step S1 described in the above embodiment is performed in the short-cut denitrification reactor 300, the material containing nitrate and the thiourea-containing ammonia nitrogen wastewater to be treated enter the short-cut denitrification reactor 300 through the short-cut denitrification reaction water inlet pipe 301, after the short-cut denitrification reaction is completed in the short-cut denitrification reactor 300, nitrate is reduced to nitrite ions, thiourea substances are oxidized to sulfate (sulfate), ammonium ions remain unchanged, and the mixed liquid containing nitrite ions, sulfate (sulfate) and ammonium ions after the short-cut denitrification reaction sequentially enters the anaerobic ammonia oxidation reactor 400 through the short-cut denitrification reaction water outlet pipe 305 and the anaerobic ammonia oxidation reaction water inlet pipe 401; the denitrification reaction of step S2 is performed in the anammox reactor 400, and through the denitrification reaction occurring in the anammox reactor 400, most of the ammonium ions (ammonia nitrogen) and nitrite ions are converted into nitrogen by anammox bacteria while generating a small amount of nitrate, under a certain reflux ratio, the mixed solution after denitrification reaction sequentially flows back through the anammox external reflux water outlet pipe 405 and the short-cut denitrification external reflux water inlet pipe 304 to enter the short-cut denitrification reactor 300 for carrying out short-cut denitrification reaction again, so that a small amount of nitrate can be continuously reduced into nitrite through the reaction of step S1 in the short-cut denitrification reactor 300, and then is converted into nitrogen through step S2 in the anammox reactor 400, thereby reducing the concentration of nitrate ions in the final discharged water, and making the final discharged water safer and more environment-friendly.

Example 8

The denitrification treatment system according to embodiment 7, as shown in fig. 2, further comprising a carbon oxidation nitrification reactor 100, wherein the carbon oxidation nitrification reactor 100 is provided with a carbon oxidation nitrification reaction water outlet pipe 108, and the carbon oxidation nitrification reaction water outlet pipe 108 is communicated with the short-cut denitrification reaction water inlet pipe 301;

as shown in fig. 3, the denitrification treatment system further comprises a regulating reservoir 200 arranged between the carbon oxidation nitration reactor 100 and the short-range denitrification reactor 300, wherein the regulating reservoir 200 is provided with a regulating reservoir water inlet pipe 201 and a regulating reservoir water outlet pipe 202, the carbon oxidation nitration water outlet pipe 108 is communicated with the regulating reservoir water inlet pipe 201, and the regulating reservoir water outlet pipe 202 is communicated with the short-range denitrification water inlet pipe 301.

Firstly, the carbon oxidation nitration reaction as described in example 3 is performed in the carbon oxidation nitration reactor 100, the ammonia-containing organic wastewater enters the carbon oxidation nitration reactor 100 to undergo the carbon oxidation nitration reaction, so as to obtain the nitrate-containing material, and the nitrate-containing material (mixed solution) enters the short-range denitrification reactor 300 through the carbon oxidation nitration reaction water outlet pipe 108 and the short-range denitrification reaction water inlet pipe 301 in sequence to undergo the short-range denitrification reaction.

Secondly, as described in example 5, "the content of thiourea in the thiourea-containing ammonia nitrogen wastewater to be treated is 50-100mg/L, the chemical oxygen demand is 200-500mg/L, and the ammonia nitrogen concentration is 50-100 mg/L;

before the short-cut denitrification reaction in the step S1, adjusting the pH value of the reaction liquid in the short-cut denitrification reactor to be 7.0-8.5, and adding sludge containing thiobacillus denitrificans into the short-cut denitrification reactor according to 2500-4500mg/L, wherein the content of the thiobacillus denitrificans in the sludge is 10-30 wt%. The parameters such as pH value of the reaction need to be adjusted before the short-cut denitrification reaction of step S1, the parameters such as pH value can be conveniently adjusted in the adjusting tank 200 of this embodiment, and after the parameters are adjusted to the ranges described in embodiment 5, the short-cut denitrification reaction is performed in the short-cut denitrification reactor 300, so that the short-cut denitrification reaction can be performed under more suitable conditions.

Example 9

The denitrification treatment system according to embodiment 8, as shown in fig. 2, the bottom of the carbon oxidation nitrification reactor 100 is provided with a water inlet pipe 101 and a backwash water inlet pipe 102, the water inlet pipe 101 is communicated with the backwash water inlet pipe 102, the carbon oxidation nitrification reactor 100 is internally provided with a filter brick layer 104, a support layer 105 and a filler layer 106 in sequence from bottom to top, and the upper part in the carbon oxidation nitrification reactor 100 is provided with a water outlet weir 107 communicated with the carbon oxidation nitrification reactor water outlet pipe 108;

the bottom of the carbon oxidation nitration reactor 100 is also provided with a water distribution channel 103, and the water distribution channel 103 is respectively communicated with the water inlet pipe 101 and the backwashing water inlet pipe 102; the carbon oxidation nitration reactor 100 is also provided with an aeration pipe 109 and a backwash air inlet pipe 110.

The carbon oxidation nitrification reactor 100 can be conveniently aerated by arranging the aeration pipe 109, the carbon oxidation nitrification reaction can be more smoothly and thoroughly carried out, and the liquid inlet flow rate in the water inlet pipe 101 and the backwashing water inlet pipe 102 can be more stable by arranging the water distribution channel 103.

Example 10

The denitrification processing system according to embodiment 9, as shown in fig. 2, the short-cut denitrification reactor 300 is further provided with an activated carbon biological filler adding device for adding an activated carbon biological filler 303 into the short-cut denitrification reactor 300, and the short-cut denitrification reactor 300 is further provided with a mechanical stirring device 302 extending from top to bottom;

the anaerobic ammonia oxidation reactor 400 is an up-flow anaerobic sludge bed reactor, a sludge suspension area of the up-flow anaerobic sludge bed reactor is provided with an internal circulation water outlet pipe 406 and an internal circulation pump 407, and the internal circulation water outlet pipe 406 is communicated with the anaerobic ammonia oxidation reaction water inlet pipe 401 through the internal circulation pump 407; the upper part of the upflow anaerobic sludge blanket reactor is sequentially provided with a three-phase separator 403 and a biogas collecting chamber 404; the anaerobic ammonia oxidation reactor 400 is further provided with an inorganic carbon source adding device 402 and an anaerobic ammonia oxidation water outlet pipe 408.

The short-cut denitrification reactor 300 is internally provided with a mechanical stirring device 302 extending from top to bottom, the mechanical stirring device 302 can be a stirring rod arranged by one or more layers, the reaction liquid in the short-cut denitrification reactor 300 is more uniform in mixing through the mechanical stirring device 302, and the short-cut denitrification reaction in the short-cut denitrification reactor 300 can be more uniform and thorough.

Example 11

A process for treating fumaric acid wastewater of an oil refinery mainly comprises the following steps:

(1) adjusting the pH value of the ammonia-containing organic wastewater to about 7.0, pumping the ammonia-containing organic wastewater into a carbon oxidation nitration reactor through a water pump, and keeping the Dissolved Oxygen (DO) in the reactor at about 3mg/L, the chemical oxygen demand at 1200mg/L, the ammonia nitrogen concentration at 150mg/L, the ratio of the biochemical oxygen demand to the chemical oxygen demand at 0.4 and the Hydraulic Retention Time (HRT) at 48h by adopting microporous aeration. In a carbon oxidation nitration reactor, removing Chemical Oxygen Demand (COD) and ammonia nitrogen simultaneously through activated sludge;

(2) the effluent of the carbon oxidation nitration reactor (the chemical oxygen demand is 90mg/L, the nitrate nitrogen concentration is 100mg/L) and thiourea-containing wastewater (the thiourea content is 187mg/L, the ammonia nitrogen concentration is 168mg/L) are mixed according to the water quantity ratio of 2.6: 1, uniformly mixing for 30min, wherein the concentration of the mixed thiourea is 50mg/L, the concentration of ammonia nitrogen is 80mg/L, the chemical oxygen demand is 300mg/L, and further adjusting the pH value to be kept about 7.5;

(3) preparing a short-range denitrification reactor, and adding a modified activated carbon biological filler and a denitrifying thiobacillus filler into the short-range denitrification reactor;

(4) pumping the uniformly mixed wastewater into a short-range denitrification reactor, carrying out short-range denitrification reaction on thiobacillus denitrificans by using nitrate nitrogen and thiourea, wherein the pH value of reaction liquid in the short-range denitrification reactor is about 7.6, and adding sludge containing thiobacillus denitrificans into the short-range denitrification reactor according to 3000mg/L, wherein the content of the thiobacillus denitrificans in the sludge is 15 wt%. Controlling the Hydraulic Retention Time (HRT) to be 24h, reducing nitrate nitrogen in the wastewater into a nitrite state, and enabling thiourea to enter the microporous structure of the activated carbon biological filler and be oxidized into sulfate by denitrifying thiobacillus attached to the filler;

(5) sending the effluent of the short-cut denitrification reactor (with nitrite nitrogen concentration of 70mg/L) to an upflow anaerobic sludge blanket reactor (UASB reactor) containing 20% anaerobic ammonium oxidation bacteria, adding a proper amount of sodium bicarbonate to supplement an inorganic carbon source, controlling the mass concentration ratio of inorganic carbon to total inorganic nitrogen to be about 0.3, and controlling the dissolved oxygen in the anaerobic ammonium oxidation reactor to be 0.2 mg/L;

(6) the effluent of an upflow anaerobic sludge bed reactor (UASB reactor) is sent to a short-cut denitrification reactor through an external reflux to ensure that nitrate and organic matters continue to participate in the reaction, and the reflux ratio is set to be 55 percent;

(7) and (3) sending the effluent of the upflow anaerobic sludge blanket reactor (UASB reactor) to a discharge tank for discharge, wherein the final effluent reaches the secondary discharge standard in the national Integrated wastewater discharge Standard GB 8978-2002.

Example 12

The process for treating the buthiuron wastewater of a certain pesticide factory mainly comprises the following steps:

(1) adjusting the pH value of the ammonia-containing organic wastewater to about 7.0, pumping the ammonia-containing organic wastewater into a carbon oxidation nitrification reactor through a water pump, and keeping the Dissolved Oxygen (DO) in the reactor to about 4mg/L, the chemical oxygen demand to 1500mg/L, the ammonia nitrogen concentration to 200mg/L, the ratio of the biochemical oxygen demand to the chemical oxygen demand to 0.52, and setting the Hydraulic Retention Time (HRT) to 32h by adopting microporous aeration. In a carbon oxidation nitration reactor, removing Chemical Oxygen Demand (COD) and ammonia nitrogen simultaneously through activated sludge;

(2) thiourea waste water (thiourea content is 414mg/L, ammonia nitrogen concentration is 185mg/L) and carbon oxidation nitrification effluent (chemical oxygen demand is 100mg/L, nitrate nitrogen concentration is 150mg/L) generated in a thiourea synthesis section are mixed according to the ratio of 1: 3, uniformly mixing in a proportion of 3, wherein the mixing time is 40min, the concentration of the mixed thiourea is 100mg/L, the concentration of ammonia nitrogen is 80mg/L, the chemical oxygen demand is 500mg/L, and the pH is further adjusted to be kept at about 7.5;

(3) preparing a short-range denitrification reactor, and adding a modified activated carbon biological filler and a denitrifying thiobacillus filler into the short-range denitrification reactor;

(4) pumping the uniformly mixed wastewater into a short-range denitrification reactor, carrying out short-range denitrification reaction on thiobacillus denitrificans by using nitrate nitrogen and thiourea, wherein the pH value of reaction liquid in the short-range denitrification reactor is about 7.8, and adding sludge containing thiobacillus denitrificans into the short-range denitrification reactor according to 4000mg/L, wherein the content of the thiobacillus denitrificans in the sludge is 20 wt%. Controlling the Hydraulic Retention Time (HRT) to be 36h, reducing nitrate nitrogen in the wastewater into a nitrite state, and enabling thiourea to enter the microporous structure of the activated carbon biological filler and be oxidized into sulfate by denitrifying thiobacillus attached to the filler;

(5) sending the effluent of the short-cut denitrification reactor (the concentration of nitrite nitrogen is 90mg/L) to an upflow anaerobic sludge blanket reactor (UASB reactor) containing 20% anaerobic ammonium oxidation bacteria, adding a proper amount of sodium bicarbonate to supplement an inorganic carbon source, controlling the mass concentration ratio of inorganic carbon to total inorganic nitrogen to be about 0.3, and controlling the dissolved oxygen in the anaerobic ammonium oxidation reactor to be 0.2 mg/L;

(6) the effluent of an upflow anaerobic sludge bed reactor (UASB reactor) is sent to a short-cut denitrification reactor through an external reflux to ensure that nitrate and organic matters continue to participate in the reaction, and the reflux ratio is set to be 50 percent;

(7) and (3) sending the effluent of the upflow anaerobic sludge blanket reactor (UASB reactor) to a discharge tank for discharge, wherein the final effluent reaches the secondary discharge standard in the national Integrated wastewater discharge Standard GB 8978-2002.

Example 13

The process for treating the acylthiourea wastewater of a certain pharmaceutical factory mainly comprises the following steps:

(1) adjusting the pH value of the ammonia-containing organic wastewater to about 7.0, pumping the ammonia-containing organic wastewater into a carbon oxidation nitrification reactor through a water pump, and keeping the Dissolved Oxygen (DO) in the reactor to about 4mg/L, the chemical oxygen demand to 1500mg/L, the ammonia nitrogen concentration to 200mg/L, the ratio of the biochemical oxygen demand to the chemical oxygen demand to 0.47, and setting the Hydraulic Retention Time (HRT) to 48h by adopting microporous aeration. In a carbon oxidation nitration reactor, removing Chemical Oxygen Demand (COD) and ammonia nitrogen simultaneously through activated sludge;

(2) thiourea-containing wastewater (the thiourea content is 820mg/L, the ammonia nitrogen concentration is 980mg/L) is generated in the thiourea and acyl chloride synthesis working section, and the wastewater is diluted by 5 times through circulating cooling water and flows out of a carbon oxidation nitration reactor (the chemical oxygen demand is 100mg/L, the nitrate nitrogen concentration is 180mg/L) according to the proportion of 1: 1, uniformly mixing at a ratio of about 85mg/L, ammonia nitrogen concentration of 100mg/L and chemical oxygen demand of 200mg/L for 40min, and further adjusting pH to about 7.5;

(3) preparing a short-range denitrification reactor, and adding a modified activated carbon biological filler and a denitrifying thiobacillus filler into the short-range denitrification reactor;

(4) pumping the uniformly mixed wastewater into a short-range denitrification reactor, carrying out short-range denitrification reaction on thiobacillus denitrificans by using nitrate nitrogen and thiourea, wherein the pH value of reaction liquid in the short-range denitrification reactor is about 7.2, and adding sludge containing thiobacillus denitrificans into the short-range denitrification reactor according to 3500mg/L, wherein the content of the thiobacillus denitrificans in the sludge is 20 wt%. Controlling the Hydraulic Retention Time (HRT) to be 72h, reducing nitrate nitrogen in the wastewater into a nitrite state, and enabling thiourea to enter the microporous structure of the activated carbon biological filler and be oxidized into sulfate by denitrifying thiobacillus attached to the filler;

(5) sending the effluent of the short-cut denitrification reactor (the concentration of nitrite nitrogen is 120mg/L) to an upflow anaerobic sludge blanket reactor (UASB reactor) containing 30% anaerobic ammonium oxidation bacteria, adding a proper amount of sodium bicarbonate to supplement an inorganic carbon source, controlling the mass concentration ratio of inorganic carbon to total inorganic nitrogen to be about 0.3, and controlling the dissolved oxygen in the anaerobic ammonium oxidation reactor to be 0.2 mg/L;

(6) the effluent of an upflow anaerobic sludge bed reactor (UASB reactor) is sent to a short-cut denitrification reactor through an external reflux to ensure that nitrate and organic matters continue to participate in the reaction, and the reflux ratio is set to be 40 percent;

(7) and (3) sending the effluent of the upflow anaerobic sludge blanket reactor (UASB reactor) to a discharge tank for discharge, wherein the final effluent reaches the secondary discharge standard in the national Integrated wastewater discharge Standard GB 8978-2002.

Example 11-13 the wastewater containing thiourea and ammonia nitrogen was treated and the water discharged to the discharge tank was subjected to index detection, and the data values of the detection are shown in table 1: (Pre-treatment wastewater means wastewater containing thiourea before treatment, and post-treatment wastewater means water discharged into a discharge tank)

TABLE 1

As can be seen from the above examples, the method of the present invention has a thiourea removal rate of 98% or more and an ammonia nitrogen removal rate of 97% or more.

The biological treatment process method of the sulfur-containing biological inhibitor ammonia nitrogen-like wastewater has the advantages of simple process, strong stability and low cost, can be used for large-scale production, improves the treatment efficiency of the wastewater, further has good application prospect in the aspect of sewage treatment, and is suitable for industrial production. Non-limiting applications of thiourea wastewater in this disclosure are: important intermediates, catalysts and stabilizers in the fields of pesticides, medicines, organic synthesis, fine chemical engineering and the like.

Aiming at the problems that the wastewater containing sulfur organisms inhibiting ammonia nitrogen in pesticides and medical products is difficult to effectively denitrify by the traditional biological treatment mode of autotrophic nitrification-heterotrophic denitrification, sulfur-containing biological toxic substances which have an inhibiting effect on a nitrification system exist in water quality, so that the biological nitrification system is inhibited and difficult to stably operate, even the nitrification system is thoroughly destroyed, and finally the effluent ammonia nitrogen and TN cannot reach the discharge standard and the like. The invention adopts the short-range denitrification and ammonia oxidation process to solve the problem of the synergistic degradation of COD and ammonia nitrogen of the wastewater.

The invention provides a denitrification treatment method of sulfur-containing biological inhibitor ammonia nitrogen wastewater, which utilizes front-end ammonia nitrogen-containing organic wastewater to generate nitrate nitrogen through biological nitrification reaction, the nitrate nitrogen enters a denitrification reactor to carry out short-range denitrification, the sulfur-containing biological inhibitor ammonia nitrogen wastewater enters the denitrification reactor, sulfur substances serve as electron donors of thiobacillus denitrificans to strengthen short-range denitrification, and effluent of the short-range denitrification reactor enters an anaerobic ammonia oxidation reactor to carry out synchronous denitrification. The method avoids the problem that the nitrification inhibitor cannot effectively remove ammonia nitrogen due to the inhibition effect of the nitrification inhibitor on a nitrification system, adopts the short-range denitrification and ammonia oxidation combined process to coordinate biological denitrification, can realize the synchronous standard-reaching discharge of COD and ammonia nitrogen in the sulfur-containing biological inhibitor ammonia nitrogen wastewater, can be used for the quality-divided treatment of industrial wastewater and tail water denitrification engineering, and optimizes investment and operation cost.

Although the invention has been described in detail above with reference to a general description and specific examples, it will be apparent to one skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims (10)

1. A denitrification treatment method for thiourea-containing ammonia nitrogen wastewater is characterized by comprising the following steps:

s1, enabling a material containing nitrate and ammonia nitrogen wastewater containing thiourea to be treated to enter a short-cut denitrification reactor for short-cut denitrification reaction so as to convert at least part of thiourea into sulfate radicals;

and S2, enabling the reaction liquid obtained in the step S1 after the short-cut denitrification reaction to enter an anaerobic ammonia oxidation reactor for denitrification reaction.

2. The denitrification processing method according to claim 1, further comprising a reflux step after step S2:

refluxing the reaction liquid after the denitrification reaction to the short-cut denitrification reactor in step S1 to perform the short-cut denitrification reaction;

the reflux ratio of the reflux is 40-75%.

3. The denitrification treatment method according to claim 1 or 2, wherein the step of preparing the nitrate-containing material comprises:

and (3) allowing the ammonia-containing organic wastewater to enter a carbon oxidation nitration reactor for carbon oxidation nitration reaction to obtain the material containing the nitrate, wherein the ammonia-containing organic wastewater contains ammonium ions and organic nitrogen.

4. The denitrification treatment method as claimed in claim 3, wherein the ammonia-containing organic wastewater has a chemical oxygen demand of 1000-1500mg/L, an ammonia nitrogen concentration of 150-200mg/L, a ratio of biochemical oxygen demand to chemical oxygen demand of more than 0.3, and a dissolved oxygen of 2-4 mg/L;

the reaction time of the carbon oxidation nitration reaction is 24-48h, the temperature is 20-30 ℃, and the chemical oxygen demand of the reaction liquid containing the nitrate obtained after the nitration reaction is below 100 mg/L;

in the carbon oxidation and nitration reaction, sludge containing ammonia oxidizing bacteria and nitrite oxidizing bacteria is added according to the concentration of 3000-5000mg/L, and the nitrate nitrogen concentration in the obtained reaction liquid containing nitrate is 100-200 mg/L.

5. The denitrification treatment method according to claim 1 or 4, wherein the feed water thiourea content of the short-cut denitrification reactor is 50-100mg/L, the chemical oxygen demand is 200-500mg/L, and the ammonia nitrogen concentration is 50-100 mg/L;

before the short-cut denitrification reaction in the step S1, adjusting the pH value of the reaction liquid in the short-cut denitrification reactor to be 7.0-8.5, and adding sludge containing thiobacillus denitrificans into the short-cut denitrification reactor according to 2500-4500mg/L, wherein the content of the thiobacillus denitrificans in the sludge is 10-30 wt%;

the time for the short-range denitrification reaction is 12-72h, the reaction temperature is 20-40 ℃, and the concentration of nitrite nitrogen in the reaction liquid obtained through the short-range denitrification reaction is 50-150 mg/L.

6. The method of claim 5, wherein in the denitrification reaction of step S2, carbonate is added to the anammox reactor so that the mass concentration ratio of inorganic carbon to total nitrogen is 0.2 to 0.4, and dissolved oxygen in the anammox reactor is controlled to 0.2mg/L or less and protected from light, at a reaction temperature of 30 ℃.

7. The denitrification treatment system for the thiourea-containing ammonia nitrogen wastewater is characterized by comprising a short-cut denitrification reactor (300) and an anaerobic ammonia oxidation reactor (400), wherein the short-cut denitrification reactor (300) is provided with a short-cut denitrification reaction water inlet pipe (301) and a short-cut denitrification reaction water outlet pipe (305), the bottom of the anaerobic ammonia oxidation reactor (400) is provided with an anaerobic ammonia oxidation reaction water inlet pipe (401), and the short-cut denitrification reaction water outlet pipe (305) is communicated with the anaerobic ammonia oxidation reaction water inlet pipe (401);

the short-cut denitrification reactor (300) is further provided with a short-cut denitrification external reflux water inlet pipe (304), the anaerobic ammonia oxidation reactor (400) is further provided with an anaerobic ammonia oxidation external reflux water outlet pipe (405), and the anaerobic ammonia oxidation external reflux water outlet pipe (405) is communicated with the short-cut denitrification external reflux water inlet pipe (304).

8. The denitrification treatment system according to claim 7, further comprising a carbon oxidation nitrification reactor (100), wherein the carbon oxidation nitrification reactor (100) is provided with a carbon oxidation nitrification reaction water outlet pipe (108), and the carbon oxidation nitrification reaction water outlet pipe (108) is communicated with the short-cut denitrification reaction water inlet pipe (301);

denitrogenation processing system still including set up in carbon oxidation nitration reactor (100) with equalizing basin (200) between short-cut denitrification reactor (300), equalizing basin (200) are provided with equalizing basin inlet tube (201) and equalizing basin outlet pipe (202), carbon oxidation nitration outlet pipe (108) with equalizing basin inlet tube (201) are linked together, equalizing basin outlet pipe (202) with short-cut denitrification inlet tube (301) are linked together.

9. The denitrification treatment system according to claim 8, wherein the bottom of the carbon oxidation nitrification reactor (100) is provided with a water inlet pipe (101) and a backwash water inlet pipe (102), the water inlet pipe (101) is communicated with the backwash water inlet pipe (102), a filter brick layer (104), a supporting layer (105) and a packing layer (106) are sequentially arranged in the carbon oxidation nitrification reactor (100) from bottom to top, and the upper part in the carbon oxidation nitrification reactor (100) is provided with a water outlet weir (107) communicated with the carbon oxidation nitrification reactor water outlet pipe (108);

the bottom of the carbon oxidation nitration reactor (100) is also provided with a water distribution channel (103), and the water distribution channel (103) is respectively communicated with the water inlet pipe (101) and the backwashing water inlet pipe (102); the carbon oxidation nitration reactor (100) is also provided with an aeration pipe (109) and a backwashing air inlet pipe (110).

10. The denitrification processing system according to claim 9, wherein the short-cut denitrification reactor (300) is further provided with an activated carbon biological filler adding device for adding the activated carbon biological filler (303) into the short-cut denitrification reactor (300), and the short-cut denitrification reactor (300) is further provided with a mechanical stirring device (302) extending from top to bottom;

the anaerobic ammonia oxidation reactor (400) is an up-flow anaerobic sludge bed reactor, a sludge suspension area of the up-flow anaerobic sludge bed reactor is provided with an internal circulation water outlet pipe (406) and an internal circulation pump (407), and the internal circulation water outlet pipe (406) is communicated with the anaerobic ammonia oxidation reaction water inlet pipe (401) through the internal circulation pump (407); the upper part of the upflow anaerobic sludge blanket reactor is sequentially provided with a three-phase separator (403) and a biogas collection chamber (404); the anaerobic ammonia oxidation reactor (400) is also provided with an inorganic carbon source adding device (402) and an anaerobic ammonia oxidation water outlet pipe (408).

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