CN113735377B

CN113735377B - Copper ammonia complex wastewater treatment method for copper removal and denitrification by coupling with sulfide ions

Info

Publication number: CN113735377B
Application number: CN202111074500.6A
Authority: CN
Inventors: 张炜铭; 牛志华; 汪林; 花铭; 吕振华
Original assignee: Jiangsu Nju Environmental Technology Co ltd; Nanjing University
Current assignee: Jiangsu Nju Environmental Technology Co ltd; Nanjing University
Priority date: 2021-09-14
Filing date: 2021-09-14
Publication date: 2022-06-03
Anticipated expiration: 2041-09-14
Also published as: CN113735377A

Abstract

The invention discloses a copper ammonia complex wastewater treatment method for copper removal and denitrification by coupling with sulfide ions, and belongs to the technical field of wastewater treatment. Sequentially carrying out precipitation treatment and denitrification treatment on the wastewater; the precipitation treatment is to add sulfide ions into the wastewater to remove copper, and the molar concentration of the sulfide ions added into the wastewater is determined by the concentration of nitrate in the effluent of anaerobic ammonia oxidation; the denitrification treatment is to sequentially carry out short-cut nitrification and denitrification treatment, anaerobic ammonia oxidation, sulfur autotrophic short-cut denitrification and sulfur autotrophic denitrification treatment on the effluent water after the precipitation treatment. The method can reduce the copper concentration in the copper ammonia complex wastewater to 0.3mg/L, the ammonia nitrogen concentration to 10mg/L and the total nitrogen concentration to 30mg/L, and simultaneously solves the problem of secondary pollution caused by sulfides in the wastewater treatment process.

Description

Copper ammonia complex wastewater treatment method for copper removal and denitrification by coupling with sulfide ions

Technical Field

The invention belongs to the technical field of wastewater treatment, and particularly relates to a copper ammonia complex wastewater treatment method for copper removal and denitrification by coupling with sulfide ions.

Background

With the rapid development of electronic information industry and the increasing requirements for environmental protection, a large amount of dark blue copper ammonia complex wastewater containing copper and ammonia nitrogen with higher concentration is generated in the chemical corrosion plate making process of a circuit board, wherein the copper content is 100 mg/L-3000 mg/L, the ammonia nitrogen content is 500 mg/L-5000 mg/L, and copper ions in the wastewater and a ligand NH are mixed₃Combine to form stable soluble [ Cu (NH) ]₃)₄]²⁺Complexes, in comparison with free form of copper or ammonium ionsThe difficulty of removal is higher. The circuit board waste water is increasingly becoming an important problem influencing the development of the industry, and the key of the circuit board waste water treatment lies in the treatment of the complex copper waste water. The method for treating the copper ammonia complex wastewater comprises two processes, namely firstly removing copper by breaking the complex and secondly removing ammonia. Common treatment methods of copper ammonia complex wastewater include a sulfide precipitation method, a heavy metal collector method, a reduction method and an electrolysis method, wherein the sulfide precipitation method reacts a copper ammonia complex into a more stable CuS precipitate, the treatment effect is better than that of reagents such as sodium hydroxide and sodium hypochlorite, although the copper removal effect of the sulfide precipitation method is obvious, due to the lack of accurate and reliable sulfide and copper online monitoring equipment, excessive sulfide is often added in the industry, the sulfide is usually added according to an S/Cu molar ratio (1.0-1.5:) 1, the amount of the sulfide cannot be accurately added, so that the effluent contains more sulfide, and new pollution is caused. However, common ammonia removal processes such as steam stripping/stripping, magnesium ammonium phosphate method, electrolysis, breakpoint chlorination and the like have no obvious effect on removing sulfides, and simultaneously consume a large amount of reagents/energy consumption, increase the wastewater treatment cost, and neglect the influence of sulfides on the water environment in the existing sulfide precipitation treatment process of copper ammonia complex wastewater.

Through retrieval, the Chinese invention patent CN102923853A discloses a wastewater treatment method of sulfur autotrophic denitrification-anaerobic ammonia oxidation coupling desulfurization and denitrification, which utilizes sulfur autotrophic denitrification bacteria to reduce nitrate into nitrite and oxidize sulfide into elemental sulfur under anaerobic condition; then nitrite and ammonia nitrogen are autotrophically denitrified under the action of anaerobic ammonium oxidation bacteria to generate nitrogen. Selecting an EGSB reactor, inoculating heterotrophic granule methanogen or denitrifying bacteria, and controlling the temperature to be between 25 and 35 ℃. Gradually domesticating anaerobic granular sludge with the coupling characteristic of sulfur autotrophic denitrification and anaerobic ammonia oxidation, and firstly starting an EGSB reactor by using wastewater with low COD concentration; then, by taking nitrite and ammonia nitrogen as inflow water, anaerobic ammonium oxidation bacteria are enriched in the reactor; then, sulfide, nitrate and ammonia nitrogen are used as inflow water, sulfur autotrophic denitrifying bacteria are gradually enriched, the reaction type is guided by controlling the proportion between the vitamine sulfide and the nitrate nitrogen, namely the molar ratio of sulfur to nitrogen, and the products are controlled to be elemental sulfur and nitrite, so that the coupling with anaerobic ammonia oxidation is realized. The patent realizes the coupling of the sulfur autotrophic denitrification and the anaerobic ammonia oxidation by regulating and controlling reaction substrates and process conditions, but the method only has the synergistic treatment effect of removing sulfur and nitrogen for a system without other impurity ions, and is difficult to apply to the copper ammonia complex wastewater containing a large amount of copper ions. For example, in the prior art, sodium sulfide is usually used to precipitate copper ions, and a large amount of sodium sulfide needs to be added to effectively remove the copper ions, at this time, a large amount of residual sulfur ions have certain toxicity to biological bacteria and enter a subsequent reaction system to affect the biological nitrogen removal efficiency, and if the addition content of sodium sulfide is reduced, the copper ions cannot be effectively removed, and the copper ions as heavy metal ions still cause serious pollution.

Therefore, how to effectively remove copper and ammonia nitrogen in wastewater in a targeted manner, reduce wastewater treatment cost and biological sludge yield, and feed sulfides in real time under the condition of no secondary pollution becomes a difficult problem, and a sewage treatment method capable of effectively treating copper ammonia complex wastewater is urgently needed to be designed at present.

Disclosure of Invention

1. Problems to be solved

Aiming at the problem that copper and nitrogen in copper ammonia complex wastewater are difficult to effectively remove in a synergistic manner in the prior art, the invention provides a copper ammonia complex wastewater treatment method for coupling copper removal and denitrification by sulfide ions; through the reaction system of rational design processing copper ammonia complex waste water, to the interpolation content of different waste water system design sulphide ion, the copper element content in the simultaneous control waste water to effectively solve the problem that copper and nitrogen in the copper ammonia complex waste water are difficult to get rid of in coordination effectively.

2. Technical scheme

In order to solve the problems, the technical scheme adopted by the invention is as follows:

according to the copper ammonia complex wastewater treatment method coupling the copper removal and the denitrification of the sulfide ions, when the molar concentration of a copper element in the copper ammonia complex wastewater is 0-6.25 mmol/L, the wastewater is subjected to precipitation treatment and denitrification treatment in sequence; when said waste is exhaustedWhen the molar concentration of the copper element in the water is 6.25 mmol/L-62.5 mmol/L, sequentially carrying out pretreatment, precipitation treatment and denitrification treatment on the wastewater, wherein the molar concentration of the copper element in the pretreated effluent is 0-6.25 mmol/L; the precipitation treatment is to add sulfide ions into the wastewater to remove copper, and the molar concentration of the sulfide ions after being added into the wastewater is C (S)^2-) (ii) a The denitrification treatment is to carry out short-cut nitrification and denitrification, anaerobic ammonia oxidation, sulfur autotrophic short-cut denitrification and sulfur autotrophic denitrification treatment on the effluent water after the precipitation treatment in sequence, wherein the molar concentration of nitrate nitrogen in the effluent water after the anaerobic ammonia oxidation treatment is C (NO)₃ ^--N) 2.85 to 36.36 mmol/L; the C (S)^2-)＝k*C(NO₃ ^--N) + b, wherein k is-0.173 to 0.117 and b is 3.1 to 9.38 mmol/L.

Preferably, the effluent after the precipitation treatment is divided in proportion and is respectively introduced into a regulating reservoir and a shortcut nitrification and denitrification unit, the effluent of the shortcut nitrification and denitrification unit enters the regulating reservoir, the effluent of the regulating reservoir is sequentially subjected to anaerobic ammonia oxidation treatment, sulfur autotrophic shortcut denitrification treatment and sulfur autotrophic denitrification treatment, and finally the effluent is discharged; part of effluent water of the sulfur autotrophic short-cut denitrification treatment flows back to the regulating tank, and the flow rate of the backflow is Q₃(ii) a The concentration ratio of ammonia nitrogen to nitrite nitrogen in the regulating tank is 1: (1.2-1.5); the inflow rate of the wastewater is Q, and the reflux ratio is R ═ Q₃0.5 to 1. The effluent of the precipitation treatment enters a shortcut nitrification and denitrification unit and an adjusting tank respectively according to a certain proportion, the shortcut nitrification and denitrification effluent, the chemical precipitation effluent and the sulfur autotrophic shortcut denitrification effluent are uniformly mixed according to a certain proportion, the ammonia nitrogen and the nitrite nitrogen in the adjusting tank are maintained within the specific concentration range, the effluent of the adjusting tank is sequentially subjected to anaerobic ammonia oxidation treatment, sulfur autotrophic shortcut denitrification treatment and sulfur autotrophic denitrification treatment, nitrate generated by anaerobic ammonia oxidation is used as a substrate of the sulfur autotrophic shortcut denitrification, the sulfur autotrophic shortcut denitrification unit is filled with a special microorganism carrier, and residual S in the wastewater is utilized^2-Converting nitrate to nitrite and simultaneously converting S^2-Conversion to SO₄ ^2-Sulfur autotrophic shortcutThe effluent of denitrification enters a sulfur autotrophic denitrification unit, the sulfur autotrophic denitrification unit is filled with composite filler based on sulfur simple substance to generate sulfur autotrophic denitrification effect, and nitrate nitrogen, nitrite nitrogen and residual S in the wastewater are removed^2-(ii) a Therefore, the invention can utilize the sulfur ions to carry out a synergistic reaction with nitrate nitrogen and nitrite nitrogen, thereby ensuring the copper removal effect, realizing the high-efficiency and low-cost denitrification, simultaneously realizing the desulfurization and solving the potential safety hazard problem of sulfides.

Preferably, the molar concentration of copper element in the inlet water of the precipitation treatment is C (Cu);

when the C (Cu) is 0-2.06 mmol/L, if 2.85 ≦ C (NO)₃ ^--N) < 8.52mmol/L, then said C (S)^2-)＝0.1*C(NO₃ ^--N) +3.1 mmol/L; if C (NO)₃ ^-N) is not less than 8.52mmol/L, then the C (S)^2-)＝-0.173*C(NO₃ ^--N)+9.38mmol/L；

When the C (Cu) is 2.06 mmol/L-6.25 mmol/L, if 2.85 is not more than C (NO)₃ ^--N) < 8.52mmol/L, then said C (S)^2-)＝0.117*C(NO₃ ^--N) +6.24 mmol/L; if C (NO)₃ ^--N) is not less than 8.52mmol/L, then the C (S)^2-)＝0.0275*C(NO₃ ^--N)+8.38mmol/L。

Preferably, the flow rates of the effluent of the precipitation treatment entering the regulating tank and the short-cut nitrification and denitrification unit are respectively Q₁And Q₂Said Q is₁：Q₂：Q₃＝(0.1～0.4)：(0.6～0.9)：(0.5～1)。

Preferably, the DO concentration in the shortcut nitrification and denitrification unit is 0.5-1.5 mg/L, the sulfide concentration is 0.39-6.5 mmol/L, the conversion rate of ammonia nitrogen to nitrite nitrogen is 20-90%, the generation rate of nitrate nitrogen is 2-6%, and the removal rate of N is 4-78%.

Preferably, the sulfur autotrophic short-cut denitrification treatment is carried out in a sulfur autotrophic short-cut denitrification unit, and the sulfur autotrophic short-cut denitrification unit is filled with a carrier loaded with thiobacillus denitrificans and a pyrite filler; the sulfur autotrophic denitrification treatment is carried out in a sulfur autotrophic denitrification treatment unit, sulfur autotrophic denitrification filler is filled in the sulfur autotrophic denitrification treatment unit, the filling rate of the filler is 75-85%, the treatment pH is 7.5-8.5, and the treatment HRT is 4-16 h. The nitrosobacteria, the anaerobic ammonium oxidation bacteria and the thiobacillus denitrificans used in the method are autotrophic bacteria, and an additional organic carbon source is not needed, so that the operation cost is effectively reduced.

Preferably, the temperature of the anaerobic ammonia oxidation treatment is 28-36 ℃, the pH value is 7.5-8.5, and the HRT value is 6-24 h.

Preferably, the ammonia nitrogen concentration in the wastewater is 200 mg/L-3000 mg/L, and the COD is_CrThe concentration is 100 mg/L-1000 mg/L, and the wastewater comes from but is not limited to metallurgy, electroplating and circuit board industries.

Preferably, the pretreatment method comprises a coagulating sedimentation method and/or a redox method and/or an adsorption method, and is used for reducing the concentration of copper ions in the wastewater and controlling the concentration of copper elements in the pretreated effluent water within the range of 0-6.25 mmol/L; the invention carries out pretreatment by optimizing a coagulating sedimentation method and an oxidation reduction method aiming at copper ions in the high-concentration copper ammonia complex wastewater, carries out pretreatment by optimizing a coagulating sedimentation method or an oxidation reduction method aiming at the medium-low concentration copper ammonia complex wastewater, removes most copper ions in the copper ammonia complex wastewater by utilizing the pretreatment, and the pretreated effluent contains a large amount of ammonia nitrogen and residual copper ions and enters a precipitation unit for treatment, the concentration of copper element in the inlet water of the precipitation treatment is controlled within the optimized range of the invention, so that the wastewater can be effectively treated, and the salt content of the wastewater after the chemical precipitation treatment can be controlled within 1% by a dilution method.

3. Advantageous effects

Compared with the prior art, the invention has the beneficial effects that:

(1) according to the copper ammonia complex wastewater treatment method for coupling copper removal and denitrification of the sulfide ions, when the molar concentration of a copper element in wastewater is 0-6.25 mmol/L, the wastewater is subjected to precipitation treatment and denitrification treatment in sequence; when the molar concentration of the copper element in the wastewater is 6.25 mmol/L-62.5 mmol/L, the wastewater is sequentially pretreated, precipitated and denitrified, and the pretreated wastewater is subjected to the pretreatmentThe molar concentration of copper element in the treated effluent is 0-6.25 mmol/L; the precipitation treatment is to add sulfide ions into the wastewater to remove copper, and the molar concentration of the sulfide ions added into the wastewater is C (S)^2-) (ii) a The denitrification treatment is to carry out short-cut nitrification and denitrification treatment, anaerobic ammonia oxidation, sulfur autotrophic short-cut denitrification and sulfur autotrophic denitrification treatment on the effluent water after the precipitation treatment in sequence, wherein the molar concentration of nitrate nitrogen in the effluent water after the anaerobic ammonia oxidation treatment is C (NO)₃ ^--N) 2.85 to 36.36 mmol/L; the C (S)^2-)＝k*C(NO₃ ^--N) + b, wherein k is-0.173 to 0.117 and b is 3.1 to 9.38 mmol/L; by the method, a reaction system of the copper ammonia complex wastewater is reasonably designed, and the concentration of the added sulfur ions is adjusted according to the concentration of nitrate nitrogen in effluent of anaerobic ammonia oxidation treatment so as to enable the concentration to be C (S)^2-) The sulfur ions can be effectively precipitated when reacting with the copper ions, the residual sulfur ions participate in the denitrification reaction, not only can not cause toxicity to biological bacteria, but also can react with nitrate nitrogen and nitrite nitrogen to remove sulfur and nitrogen, thereby achieving the effect of removing the copper and the nitrogen in a synergic manner, and simultaneously effectively consuming the added sulfur ions; therefore, the method can reduce the copper concentration in the copper ammonia complex wastewater to 0.3mg/L, the ammonia nitrogen concentration to 10mg/L and the total nitrogen concentration to 30mg/L, and simultaneously solves the problem of secondary pollution caused by sulfides in the wastewater treatment process.

(2) The invention relates to a copper ammonia complex wastewater treatment method for coupling cupric ion removal and denitrification, wherein the molar concentration of copper element in inlet water subjected to precipitation treatment is C (Cu); when the C (Cu) is 0-2.06 mmol/L, if 2.85 is not more than C (NO)₃ ^--N) < 8.52mmol/L, then said C (S)^2-)＝0.1*C(NO₃ ^--N) +3.1 mmol/L; if C (NO)₃ ^--N) is more than or equal to 8.52mmol/L, then the C (S)^2-)＝-0.173*C(NO₃ ^--N) +9.38 mmol/L; when the C (Cu) is 2.06 mmol/L-6.25 mmol/L, if 2.85 is not more than C (NO)₃ ^--N) < 8.52mmol/L, then said C (S)^2-)＝0.117*C(NO₃ ^--N) +6.24 mmol/L; if C (NO)₃ ^--N) is not less than 8.52mmol/L, then the C (S)^2-)＝0.0275*C(NO₃ ^--N) +8.38 mmol/L; the invention designs C (S) aiming at nitrate nitrogen of effluent of anaerobic ammonia oxidation treatment with different concentrations^2-) And C (NO)₃ ^--N) so as to accurately adjust the sulfur ion content required by the copper ammonia complex wastewater reaction system, and further improve the efficiency of copper removal, nitrogen removal and sulfur removal.

Drawings

FIG. 1 is a schematic diagram of the process flow of the method for treating the copper ammine complex wastewater of the present invention when the concentration of copper element in the copper ammine complex wastewater is 6.25mmol/L to 62.5 mmol/L;

FIG. 2 is a schematic diagram of a process flow of the method for treating the copper ammine complex wastewater, when the concentration of copper element in the copper ammine complex wastewater is 0-6.25 mmol/L.

Detailed Description

The detection method of each parameter in the invention is as follows:

GB 6920 glass electrode method for determining pH value of water

GB 7475 atomic absorption spectrophotometry for measuring copper, zinc, lead and cadmium in water

Methylene blue spectrophotometry for measuring GB/T16489 hydrosulfide in water

Spectrophotometric method for measuring ammonia nitrogen in HJ 535 water quality by using Nassner reagent

Alkaline potassium persulfate digestion ultraviolet spectrophotometry for determining total nitrogen in HJ 636 water

Dichromate method for determining chemical oxygen demand of HJ 828 water

HJ/T346 water quality nitrate nitrogen determination ultraviolet spectrophotometry and/or water quality nitrate concentration-online nitrate tester for determination of portable analyzer.

C (mmol/L) ═ mxc (mg/L), where C represents the molar concentration of the substance mmol/L, M represents the molecular weight of the substance, and the mass concentration of the substance C is mg/L.

The following detailed description of exemplary embodiments of the invention refers to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration exemplary embodiments in which the invention may be practiced, and in which features of the invention are identified by reference numerals. The following more detailed description of the embodiments of the invention is not intended to limit the scope of the invention, as claimed, but is presented for purposes of illustration only and not limitation to describe the features and characteristics of the invention, to set forth the best mode of carrying out the invention, and to sufficiently enable one skilled in the art to practice the invention. It will, however, be understood that various modifications and changes may be made without departing from the scope of the invention as defined in the appended claims. The detailed description and drawings are to be regarded as illustrative rather than restrictive, and any such modifications and variations are intended to be included within the scope of the present invention as described herein. Furthermore, the background is intended to be illustrative of the state of the art as developed and the meaning of the present technology and is not intended to limit the scope of the invention or the application and field of application of the invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; the terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention; as used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The invention is further described with reference to specific examples.

Example 1

As shown in FIG. 1, this example provides a method for treating copper ammine complex wastewater by coupling copper removal and denitrification of sulfide ions, the amount of the treated copper ammine complex wastewater is 1m³The concentration of each component in the wastewater is as follows: the concentration of copper ions is 4000mg/L, the concentration of ammonia nitrogen is 3000mg/L, and the COD is_CrThe concentration is 1000 mg/L; the method comprises the following specific steps:

(1) the copper ammonia complex wastewater enters a pretreatment unit to be pretreated by a combined process of coagulating sedimentation and Fenton oxidation reduction, wherein the coagulation process conditions are that the pH is 8 and Fe²⁺Standing and precipitating for 30min at the concentration of 500mg/L to obtain water with copper ion concentration of 1200 mg/L; the water obtained by coagulating sedimentation enters a Fenton oxidation unit for further copper removal, wherein the Fenton process condition is that the pH is 4, and Fe²⁺＝200mg/L，H₂O₂＝400mg/L，Fenton reaction time is 30min, coagulation reaction pH is 8, coagulant Fe²⁺Standing for 30min, wherein 350mg/L of flocculant PAM is 1.0 mg/L; the concentration of copper ions in the final effluent after pretreatment is reduced to 400 mg/L;

(2) the effluent of the pretreatment unit enters a sodium sulfide precipitation unit for precipitation treatment, sodium sulfide solution is added for deep copper removal, the concentration of copper ions in the effluent of the sodium sulfide precipitation unit is 0.15mg/L, the effluent contains a large amount of ammonia nitrogen and residual sodium sulfide, and the effluent is 0.8m³/h、0.2m³Distributing the water/hour to a short-cut nitrification and denitrification unit and a regulating tank; c (NO) in effluent due to anammox₃ ^--N) 36.36mmol/L, thus the C (S)^2-)＝9.38mmol/L；

(3) In the short-cut nitrification and denitrification unit, the DO concentration in the short-cut nitrification and denitrification unit is controlled to be 0.5 mg/L-1.5 mg/L, the unit inlet water sulfide concentration is 100mg/L, the short-cut nitrification and denitrification unit outlet water ammonia nitrogen is controlled to be 15.3mg/L, nitrite nitrogen is controlled to be 950mg/L, nitrate nitrogen is controlled to be 80mg/L, and S^2-18.1mg/L, and the removal rate of TN is 73 percent; by the specific operation condition and the action of residual sulfides, the shortcut nitrification and denitrification of the ammonia nitrogen wastewater are realized, the content of N in the wastewater is reduced, and meanwhile, the accumulation of nitrite nitrogen can also be realized;

(4) regulating and controlling the short-cut nitrification and denitrification effluent, sodium sulfide precipitation effluent and anaerobic ammonia oxidation reflux wastewater of the inlet water of the regulating tank according to the water quantity ratio, wherein the reflux quantity is 1m³And h, maintaining the ammonia nitrogen concentration of 406mg/L and the nitrite nitrogen concentration of 568mg/L in the regulating tank, wherein the concentration ratio of the ammonia nitrogen to the nitrite nitrogen is 1: 1.4;

(5) the effluent of the regulating reservoir enters an anaerobic ammonia oxidation unit and a sulfur autotrophic short-cut denitrification unit to firstly carry out denitrification and desulfurization, the effluent of the sulfur autotrophic short-cut denitrification area flows back to the regulating reservoir to provide nitrite nitrogen required in the anaerobic ammonia oxidation denitrification process, sulfate radicals in the wastewater can be converted into sulfides and/or elemental sulfur in the anaerobic ammonia oxidation process, and an electron donor for sulfur autotrophic short-cut denitrification is provided; the temperature of the anaerobic ammonia oxidation treatment is 32 ℃, the pH value is 8.0, the HRT value is 24h, and the sulfur autotrophic short-cut denitrification unit is filled with a carrier loaded with denitrobacillus and pyrite filler.

(6) The effluent of the sulfur autotrophic short-cut denitrification unit enters the sulfur autotrophic denitrification unit, nitrate nitrogen in the anaerobic ammonia oxidation effluent further reacts with sulfur ions in the sulfur autotrophic denitrification unit, the removal of the sulfur ions, the nitrate nitrogen and nitrite nitrogen in the wastewater is realized, and simultaneously sulfides in the wastewater are converted into sulfate radicals, so that the risk of secondary pollution caused by adding the sulfides is eliminated; the sulfur autotrophic denitrification treatment unit is filled with sulfur autotrophic denitrification filler, the filling rate of the filler is 85 percent, the treatment pH is 8.0, and the treatment HRT is 16 h.

After the treatment by the method, the effluent quality parameters of the treated copper ammonia complex wastewater are detected, and the treated water quality parameters are recorded in table 1.

TABLE 1 comparison of effluent quality parameters (in mg/L) for each example and comparative example

Example 2

As shown in fig. 1, this embodiment provides a method for treating copper ammine complex wastewater by coupling copper removal and denitrification of sulfide ions, and the concentrations of the components in the treated copper ammine complex wastewater are as follows: the copper ion concentration is 2160mg/L, the ammonia nitrogen concentration is 2535mg/L, and the COD is_CrThe concentration is 324 mg/L; the concentration of copper ions in the effluent after the coagulation sedimentation and Fenton oxidation pretreatment is 180 mg/L. The specific steps of the processing method of this embodiment are basically the same as those of embodiment 1, and the main differences are as follows: c (NO) in effluent due to anammox₃ ^--N) 5.1mmol/L, thus the C (S)^2-) 6.86 mmol/L; the flow rates of the partial nitrification and denitrification effluent, the sodium sulfide precipitation effluent and the anaerobic ammonia oxidation reflux wastewater of the inlet water of the regulating tank are respectively 0.9m³/h、0.1m³/h、0.8m³And h, regulating the ammonia nitrogen concentration of the pond to 385mg/L and the nitrite nitrogen concentration to 548 mg/L.

After the treatment by the method, the water quality parameters of the treated copper ammonia complex wastewater are detected, and the treated water quality parameters are recorded in the table 1.

Example 3

As shown in fig. 1, this embodiment provides a method for treating copper ammine complex wastewater by coupling copper removal and denitrification with sulfide ions, wherein the concentrations of components in the treated copper ammine complex wastewater are as follows: the concentration of copper ions is 1160mg/L, the concentration of ammonia nitrogen is 1821mg/L, and the COD is_CrThe concentration is 200 mg/L; the concentration of copper ions in the effluent after the pre-treatment of coagulating sedimentation is 86 mg/L. The specific steps of the processing method of this embodiment are basically the same as those of embodiment 1, and the main differences are as follows: c (NO) in effluent due to anammox₃ ^--N) 4.12mmol/L, thus the C (S)^2-) 3.51 mmol/L; the flow rates of the partial nitrification and denitrification effluent, the sodium sulfide precipitation effluent and the anaerobic ammonia oxidation reflux wastewater of the inlet water of the regulating tank are respectively 0.6m³/h、0.4m³/h、0.5m³And h, adjusting the ammonia nitrogen concentration of 294mg/L and the nitrite nitrogen concentration of 425mg/L in the pond.

Example 4

As shown in fig. 1, this embodiment provides a method for treating copper ammine complex wastewater by coupling copper removal and denitrification of sulfide ions, and the concentrations of the components in the treated copper ammine complex wastewater are as follows: the copper ion concentration is 551mg/L, the ammonia nitrogen concentration is 828mg/L, and the COD is_CrThe concentration is 236 mg/L; the concentration of copper ions in the effluent after the coagulation sedimentation and Fenton oxidation pretreatment is 50 mg/L. The specific steps of the processing method of this embodiment are basically the same as those of embodiment 1, and the main differences are as follows: c (NO) in effluent due to anammox₃ ^--N) 9.1mmol/L, thus the C (S)^2-) 7.8 mmol/L; the flow rates of the partial nitrification and denitrification effluent, the sodium sulfide precipitation effluent and the anaerobic ammonia oxidation reflux wastewater of the inlet water of the regulating tank are respectively 0.6m³/h、0.4m³/h、0.5m³And h, adjusting the ammonia nitrogen concentration of 166mg/L and the nitrite nitrogen concentration of 243mg/L in the tank.

Example 5

As shown in fig. 2, this embodiment provides a method for treating copper ammine complex wastewater by coupling copper removal and denitrification with sulfide ions, wherein the concentrations of the components in the treated copper ammine complex wastewater are as follows: the copper ion concentration is 30mg/L, the ammonia nitrogen concentration is 150mg/L, and the COD is_CrThe concentration was 186 mg/L. The specific steps of the processing method of this embodiment are basically the same as those of embodiment 1, and the main differences are as follows: since the concentration of copper ions in the copper ammonia complex wastewater is in the range of 0-6.25 mmol/L, the wastewater is directly subjected to precipitation treatment and denitrification treatment, and C (NO) in effluent of anaerobic ammonia oxidation₃ ^--N) 3.52mmol/L, thus the C (S)^2-) 3.45 mmol/L; the flow rates of short-cut nitrification and denitrification effluent, sodium sulfide precipitation effluent and anaerobic ammonia oxidation reflux wastewater of the inlet water of the regulating tank are respectively 0.6m³/h、0.4m³/h、0.5m³And h, regulating the ammonia nitrogen concentration of the pond to be 14mg/L and the nitrite nitrogen concentration to be 20.1 mg/L.

Example 6

(1) the copper ammonia complex wastewater enters a pretreatment unit to be pretreated by a combined process of coagulating sedimentation and Fenton oxidation reduction, wherein the coagulation process conditions are that the pH is 8 and Fe²⁺Standing and precipitating for 30min at the concentration of 500mg/L to obtain water with copper ion concentration of 1200 mg/L; the water obtained by coagulating sedimentation enters a Fenton oxidation unit for further copper removal, wherein the Fenton process condition is that the pH is 4, and Fe²⁺＝200mg/L，H₂O₂400mg/L, Fenton reaction time of 30min, coagulation reaction pH of 8 and coagulant Fe²⁺Standing for 30min, wherein 350mg/L of flocculant PAM is 1.0 mg/L; copper ion in pretreated final effluentThe sub-concentration is reduced to 400 mg/L;

(2) the effluent of the pretreatment unit enters a sodium sulfide precipitation unit for precipitation treatment, and sodium sulfide solution is added for deep copper removal, wherein the method is mainly different from the method in the embodiment 1 in that: the adding concentration of the sodium sulfide solution is C (S)^2-)＝k*C(NO₃ ^--N) + b, where k is 0 and b is 8.75mmol/L, i.e. C (S)^2-) 8.75 mmol/L; the copper concentration of the effluent of the sodium sulfide precipitation unit is 0.27mg/L, S^2-The concentration is 20.8mg/L, and the effluent is 0.8m³/h、0.2m³Distributing the water/hour to a short-cut nitrification and denitrification unit and a regulating tank; c (NO) in effluent of anammox₃ ^--N)＝20.25mmol/L；

(3) In the shortcut nitrification and denitrification unit, the DO concentration in the shortcut nitrification and denitrification unit is controlled to be 0.5 mg/L-1.5 mg/L, the ammonia nitrogen in the effluent of the shortcut nitrification and denitrification unit is controlled to be 32.8mg/L, the nitrite nitrogen is controlled to be 768.1mg/L, the nitrate nitrogen is controlled to be 826.3mg/L, and S is controlled to be^2-The removal rate of the catalyst is 2.1mg/L, and the removal rate of TN is 59.3%; through the specific operation working condition, the content of N in the wastewater is reduced, and nitrate nitrogen is obviously accumulated;

(4) regulating and controlling the short-cut nitrification and denitrification effluent, sodium sulfide precipitation effluent and anaerobic ammonia oxidation reflux wastewater of the inlet water of the regulating tank according to the water quantity ratio, wherein the reflux quantity is 1m³And h, regulating the ammonia nitrogen concentration in the pond to be 350.3mg/L and the nitrite nitrogen concentration to be 470.6mg/L, wherein the concentration ratio of the ammonia nitrogen to the nitrite nitrogen is 1: 1.34;

Comparative example 1

As shown in fig. 2, this embodiment provides a method for treating copper ammine complex wastewater by coupling copper removal and denitrification with sulfide ions, wherein the concentrations of the components in the treated copper ammine complex wastewater are as follows: the concentration of copper ions is 30mg/L, the concentration of ammonia nitrogen is 150mg/L, and the COD is_CrThe concentration was 186 mg/L. The specific steps of the processing method of this embodiment are basically the same as those of embodiment 5, and the main differences are as follows: the sulfide is not added according to the method for adding the sulfide ions, but is added according to 1.1 times of the conventional molar concentration of the copper ions in the embodiment, namely C (S)^2-) The molar concentration of sulfide in the chemically precipitated water is 0.05mmol/L, and the sulfide concentration of the short-cut nitrification and denitrification unit which is not required in the invention is in the range of 0.39 mmol/L-6.5 mmol/L; the ammonia nitrogen concentration in the regulating tank is 27.6mg/L, and the nitrite nitrogen concentration in the regulating tank is 30.2 mg/L.

Comparative example 2

As shown in fig. 1, this embodiment provides a method for treating copper ammine complex wastewater by coupling copper removal and denitrification of sulfide ions, and the concentrations of the components in the treated copper ammine complex wastewater are as follows: the copper ion concentration is 2160mg/L, the ammonia nitrogen concentration is 2535mg/L, and the COD is_CrThe concentration is 324 mg/L; the concentration of copper ions in the effluent after the coagulation sedimentation and Fenton oxidation pretreatment is 180 mg/L. The specific steps of the processing method of this embodiment are basically the same as those of embodiment 2, and the main differences are thatThe method comprises the following steps: the sulfide is not added according to the method for adding the sulfide ions, but is added according to 1.2 times of the conventional molar concentration of the copper ions in the embodiment, namely C (S)^2-) 3.38 mol/L; the molar concentration of sulfide in the effluent of the chemical precipitation unit is 0.2mmol/L, and the denitrification effect cannot reach the expectation, wherein the ammonia nitrogen concentration of the regulating tank is 365mg/L, and the nitrite nitrogen concentration is 356 mg/L.

Comparative example 3

The comparative example provides a copper ammonia complex wastewater treatment method for coupling copper removal and denitrification of sulfide ions, and the concentration of each component in the treated copper ammonia complex wastewater is as follows: copper ion concentration of 20mg/L, ammonia nitrogen concentration of 65mg/L, COD_CrThe concentration was 102 mg/L. The specific steps of the processing method of this embodiment are basically the same as those of embodiment 1, and the main differences are as follows: the sulfur ions are added with C (S) in two times^2-) When the concentration of the sulfur ions in the effluent of the regulating reservoir is 0.4mmol/L and the concentration of the sulfur ions in the effluent of the regulating reservoir is 3.5mg/L, the accumulation phenomenon of nitrite in the short-cut nitrification and denitrification unit is difficult to occur.

More specifically, although exemplary embodiments of the invention have been described herein, the invention is not limited to these embodiments, but includes any and all embodiments modified, omitted, combined, e.g., between various embodiments, adapted and/or substituted, as would be recognized by those skilled in the art from the foregoing detailed description. The limitations in the claims are to be interpreted broadly based the language employed in the claims and not limited to examples described in the foregoing detailed description or during the prosecution of the application, which examples are to be construed as non-exclusive. Any steps recited in any method or process claims may be executed in any order and are not limited to the order presented in the claims. The scope of the invention should, therefore, be determined only by the appended claims and their legal equivalents, rather than by the descriptions and examples given above.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control. When "pH, concentration, temperature, time, or other value or parameter is expressed as a range, preferred range, or as a range defined by a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, a range of 1 to 50 should be understood to include any number, combination of numbers, or subrange selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50, and all fractional values between the above integers, e.g., 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, and 1.9. With respect to sub-ranges, specifically consider "nested sub-ranges" that extend from any endpoint within the range. For example, nested sub-ranges of exemplary ranges 1-50 may include 1-10, 1-20, 1-30, and 1-40 in one direction, or 50-40, 50-30, 50-20, and 50-10 in another direction. "

Claims

1. The method for treating the copper ammino wastewater by coupling the copper removal and the denitrification of the sulfide ions is characterized in that when the molar concentration of a copper element in the copper ammino wastewater is 0-6.25 mmol/L, the wastewater is subjected to precipitation treatment and denitrification treatment in sequence; when the molar concentration of the copper element in the wastewater is 6.25-62.5 mmol/L, sequentially carrying out pretreatment, precipitation treatment and denitrification treatment on the wastewater, wherein the molar concentration of the copper element in the pretreated effluent is 0-6.25 mmol/L;

the precipitation treatment is to add sulfide ions into the wastewater to remove copper, and the molar concentration of the sulfide ions added into the wastewater is C (S)^2-)；

The denitrification treatment is to sequentially carry out short-cut nitrification and denitrification, anaerobic ammonia oxidation, sulfur autotrophic short-cut denitrification and sulfur autotrophic denitrification treatment on the effluent water after the precipitation treatment, wherein the molar concentration of nitrate nitrogen in the effluent water after the anaerobic ammonia oxidation treatment is C (NO)₃ ^--N) =2.85 mmol/L-36.36 mmol/L; the C (S)^2-)=k*C(NO₃ ^--N) + b, k = -0.173 to 0.117, b =3.1mmol/L to 9.38 mmol/L;

the molar concentration of copper element in the inlet water of the precipitation treatment is C (Cu);

when the C (Cu) = 0-2.06 mmol/L, if 2.85 is not more than C (NO)₃ ^--N) < 8.52mmol/L, then said C (S)^2-)=0.1*C(NO₃ ^--N) +3.1 mmol/L; if C (NO)₃ ^-N) is not less than 8.52mmol/L, then the C (S)^2-)=-0.173*C(NO₃ ^--N)+9.38mmol/L；

When the C (Cu) =2.06 mmol/L-6.25 mmol/L, if 2.85 is not more than C (NO)₃ ^--N) < 8.52mmol/L, then said C (S)^2-)=0.117*C(NO₃ ^--N) +6.24 mmol/L; if C (NO)₃ ^--N) is not less than 8.52mmol/L, then the C (S)^2-)=0.0275*C(NO₃ ^--N)+8.38mmol/L。

2. The method for treating the cuprammonia wastewater by coupling the copper removal and the nitrogen removal of the sulfide ions, according to claim 1, is characterized in that the effluent of the precipitation treatment is divided in proportion and is respectively introduced into a shortcut nitrification and denitrification unit and a regulating reservoir, the effluent of the shortcut nitrification and denitrification unit enters the regulating reservoir, and the effluent of the regulating reservoir is sequentially subjected to anaerobic ammonia oxidation treatment, sulfur autotrophic shortcut denitrification treatment and sulfur autotrophic denitrification treatment, and finally is discharged; part of effluent water of the sulfur autotrophic short-cut denitrification treatment flows back to the regulating tank, and the flow rate of the backflow is Q₃(ii) a The concentration ratio of ammonia nitrogen to nitrite nitrogen in the regulating tank is 1: (1.2-1.5); the inflow of the wastewater is Q, and the reflux ratio is R = Q₃/Q=0.5~1。

3. The method for treating the cuprammonium wastewater by coupling the copper removal and the nitrogen removal of the sulfide ions as claimed in claim 2, wherein the flow rates of the effluent of the precipitation treatment which is divided into the regulating tank and the short-cut nitrification and denitrification unit are respectively Q₁And Q₂Said Q is₁：Q₂：Q₃=（0.1~0.4）：（0.6~0.9）：（0.5~1）。

4. The method for treating the cuprammonium wastewater by coupling the copper removal and the nitrogen removal of the sulfide ions as claimed in claim 2, wherein the DO concentration in the short-cut nitrification and denitrification unit is 0.5mg/L to 1.5mg/L, the sulfide concentration is 0.39mmol/L to 6.5mmol/L, the conversion rate of ammonia nitrogen to nitrite nitrogen is 20% to 90%, the generation rate of nitrate nitrogen is 2% to 6%, and the removal rate of N is 4% to 78%.

5. The method for treating the cuprammonium wastewater by coupling the copper removal and the nitrogen removal of the sulfide ions, according to claim 2, wherein the sulfur autotrophic short-cut denitrification treatment is performed in a sulfur autotrophic short-cut denitrification unit, and the sulfur autotrophic short-cut denitrification unit is filled with a carrier loaded with thiobacillus denitrificans and a pyrite filler; the sulfur autotrophic denitrification treatment is performed in a sulfur autotrophic denitrification treatment unit, sulfur autotrophic denitrification fillers are filled in the sulfur autotrophic denitrification treatment unit, the filling rate of the fillers is 75-85%, the treatment pH = 7.5-8.5, and the treatment HRT = 4-16 h.

6. The method for treating the cuprammonium wastewater by coupling the copper removal and the denitrification of the sulfide ions according to claim 1, wherein the temperature of the anaerobic ammonia oxidation treatment is 28-36 ℃, the pH is = 7.5-8.5, and the HRT is = 6-24 h.

7. The method for treating the cuprammonium wastewater by coupling the copper removal and the denitrification of the sulfide ions according to claim 1, wherein the concentration of ammonia nitrogen in the wastewater is 200-3000 mg/L, and the COD is_CrThe concentration is 100 mg/L-1000 mg/L.

8. The method for treating the cuprammonium complex wastewater coupled with the copper removal and denitrification of the sulfide ions according to any one of claims 1 to 7, wherein the pretreatment method comprises a coagulating sedimentation method, an oxidation-reduction method and/or an adsorption method, and is used for reducing the concentration of the copper ions in the wastewater and controlling the concentration of copper elements in pretreated effluent to be in a range of 0 to 6.25 mmol/L.