A method for treating polyene and polyamine-based high-salt organic wastewater

Abstract

This invention relates to the field of wastewater treatment technology, specifically a method for treating high-salt organic wastewater containing polyenes and polyamines. This invention overcomes the problems of high toxicity of polyenes and polyamines, easy complexation with catalysts, and low biochemical efficiency under high-salt conditions in wastewater treatment. First, this invention utilizes copper-supported cross-linked chitosan to achieve specific complexation and sedimentation of macromolecules, significantly reducing toxicity. Then, it uses oxygen-rich vacancy titanium dioxide particle electrodes combined with ultrasound to efficiently break stubborn C-N bonds. Next, bimetallic catalytic ozone completely eliminates residual biotoxicity. Finally, iron-modified biochar provides a salt-resistant microenvironment and electron shuttle effect for salt-tolerant bacteria, achieving deep mineralization and denitrification of pollutants. This effectively solves the biochemical treatment problem under the dual stress of high salt and high toxicity, resulting in stable effluent quality.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically a method for treating polyene and polyamine-based high-salt organic wastewater. Background Technology

[0002] Polyene polyamines are widely used in the synthesis processes of pesticides, pharmaceuticals, surfactants, and epoxy resin curing agents. During their production and application, large quantities of high-salt polyene polyamine-based organic wastewater are inevitably generated. This type of wastewater exhibits three typical water quality characteristics: First, extremely high salt concentration, with high osmotic pressure leading to dehydration and death of conventional microbial cells; second, polyene polyamine molecules are rich in primary and secondary amine groups, possessing strong metal complexing ability and significant biotoxicity, capable of disrupting microbial enzyme systems; third, the wastewater exhibits high COD and total nitrogen concentrations, and the high molecular weight polyene polyamines are typical recalcitrant organic compounds.

[0003] Currently, traditional treatment methods for this type of wastewater mainly include incineration, distillation and concentration, traditional Fenton oxidation, and conventional biochemical methods. Incineration and evaporation face problems such as high energy consumption, severe equipment corrosion, and secondary pollution. In the traditional Fenton process, the strong complexation of polyenes and polyamines with iron ions leads to rapid deactivation of the Fenton reagent, resulting in large amounts of iron sludge and incomplete degradation. Conventional biochemical methods, under the dual stress of high salinity and high toxicity, cause activated sludge to easily disintegrate, failing to achieve stable removal of organic matter and nitrogen. Therefore, how to efficiently break down the complexation network of polyenes and polyamines, significantly reduce biotoxicity, and construct a highly efficient degradation system adapted to high-salt environments are core technical challenges that urgently need to be solved in this field.

[0004] Therefore, a method for treating polyene-polyamine high-salt organic wastewater is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a method for treating polyene and polyamine-based high-salt organic wastewater.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for treating high-salt organic wastewater containing polyenes and polyamines, the method being as follows: S1 Complex Flocculation Pretreatment: High-salt organic wastewater containing polyenes and polyamines is introduced into the reaction tank, the pH is adjusted to 8.0, and a composite flocculant is added at a dosage of 3 g / L. At 25°C, the mixture is first stirred at 250 rpm for 10 min, then the stirring speed is adjusted to 50 rpm for 30 min. After settling for 60 min, the supernatant is collected. The composite flocculant is prepared from chitosan, dialdehyde starch solution, and copper sulfate solution. By utilizing the specific complexation effect of copper ions and polyene polyamines in the modified composite material, combined with the high molecular weight flocculation of cross-linked chitosan, the large molecular weight polyene polyamines in the water are initially settled, reducing toxicity and lowering the subsequent oxidative load. S2 Ultrasonic-Assisted Three-Dimensional Electrocatalytic Oxidation: The supernatant from S1 is introduced into a three-dimensional electrocatalytic reactor, which is filled with particle electrodes at a density of 50-100 g / L. An ultrasonic generator and a DC power supply are then turned on for processing. The particle electrodes are made of TiO2 sol and activated carbon. Under the synergistic effect of ultrasonic cavitation and particle electrodes, the CN bonds of polyene polyamines are efficiently broken, degrading them into small molecule organic acids and short-chain amines; S3 Catalytic Ozone Deep Oxidation: The effluent from S2 is introduced into the catalytic ozone contact tower, and a bimetallic doped diatomaceous earth catalyst is added at a dosage of 3 g / L. Ozone is introduced from the bottom of the catalytic ozone contact tower to carry out the reaction. The bimetallic doped diatomaceous earth is prepared from pretreated diatomaceous earth, ferric nitrate and manganese nitrate. Further, the short-chain amines and recalcitrant organic acids after chain breakage are oxidized into carbon dioxide, water and nitrates, thus completely eliminating their biotoxicity to subsequent biochemical treatments; S4 Immobilized Specific Biochemical Treatment: The effluent from S3 is introduced into the equalization tank, the pH value is adjusted to 7.5, and then pumped into the membrane bioreactor. Iron-modified biochar is added to the membrane bioreactor at a dosage of 4 g / L, and simultaneously acclimated salt-tolerant sludge is inoculated at a dosage of 3000 mg / L to obtain effluent that can be discharged.

[0007] The rich pores of iron-modified biochar provide a microenvironment that protects salt-tolerant bacteria from the impact of high salt osmotic pressure. At the same time, the electron shuttle effect of surface iron species accelerates the complete mineralization of residual short-chain amines and the removal of total nitrogen, and effectively alleviates MBR membrane fouling.

[0008] Preferably, the composite flocculant is prepared as follows: 10g of chitosan (degree of deacetylation ≥85%, average molecular weight 400,000 Da) is dissolved in 2wt% acetic acid solution, and 20mL of 10% dialdehyde starch solution (dialdehyde starch oxidation degree is 90%; at 25℃, its 10wt% aqueous solution has a dynamic viscosity of 30mPa·s) is added dropwise at 50-70℃. The mixture is stirred at 300rpm for 3-5h to generate a cross-linked hydrogel. 50mL of 0.5mol / L copper sulfate solution is added dropwise to the cross-linked hydrogel. The free amino and hydroxyl groups in the cross-linked network are used to complex copper ions. The pH is adjusted to neutral to allow the product to precipitate. After filtration, washing, and vacuum drying at 60℃ for 12h, the product is ground and passed through a 200-mesh standard sieve to obtain the composite flocculant.

[0009] Preferably, the particle electrode is prepared as follows: 10 mL of tetrabutyl titanate is dissolved in 40 mL of anhydrous ethanol, and a mixture of 2 mL of deionized water, 10 mL of anhydrous ethanol and 1 mL of glacial acetic acid (as a hydrolysis inhibitor) is added dropwise. The mixture is stirred continuously for 2 h to form a sol, and then aged for 24 h to form a TiO2 sol. Activated carbon (C668476, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.) is impregnated in the TiO2 sol and coated with a film. 25 g of activated carbon is impregnated for every 100 mL of TiO2 sol, and the impregnation time is 2 h. The film coating rate is controlled at 3 cm / min. After drying at 105 °C, the film is placed in a tube furnace and heated to 500-600 °C at a heating rate of 5 °C / min in an atmosphere of argon and hydrogen mixed gas (volume ratio 9:1). The film is calcined for 3 h. The hydrogen reduction process generates a large number of oxygen vacancies (TiO2-x) in the TiO2 lattice. The film is then cooled to room temperature to obtain the particle electrode.

[0010] Preferably, the preparation method of the bimetallic doped diatomite catalyst is as follows: 50g of pretreated diatomite is impregnated in a mixed aqueous solution (200mL) containing 0.1mol / L ferric nitrate and 0.1mol / L manganese nitrate, and stirred at 150rpm in an 80℃ water bath until the water evaporates to dryness to obtain a precursor; the precursor is placed in a muffle furnace and calcined at 550-650℃ for 4h at a rate of 10℃ / min under air atmosphere to obtain the bimetallic doped diatomite catalyst.

[0011] Preferred method for preparing iron-modified biochar is as follows: Corn cobs are washed, dried, and pulverized into particles with an average particle size of 1 mm. 100 g of particles are immersed in 500 mL of ferric chloride solution with a concentration of 0.3-0.8 mol / L, and stirred at a constant temperature of 150 rpm for 12 h at room temperature. After filtration, the solid product is placed in an oven at 105 °C and dried for 24 h to obtain a precursor. The precursor is placed in a tube furnace and heated to 500-700 °C at a heating rate of 10 °C / min under a nitrogen protective atmosphere. It is then pyrolyzed at a constant temperature for 2 h, cooled to room temperature, washed with deionized water until the eluent is neutral, and dried to obtain iron-modified biochar.

[0012] Preferably, in the ultrasound-assisted three-dimensional electrocatalytic oxidation, the reaction temperature is 30℃, the ultrasound frequency is 40kHz, and the ultrasound power density is 0.5W / cm³. 2 The apparent current density of the main electrode is controlled to be 30-45 mA / cm². 2 The reaction time is 90-120 min.

[0013] Preferably, in step S3, the ozone dosage is 15-25 mg / L, the reaction temperature is maintained at 25°C, and the reaction is carried out continuously for 45-60 min.

[0014] Preferably, in step S4, the dissolved oxygen in the membrane bioreactor is controlled at 3.0 mg / L, the water temperature is maintained at 30℃, the hydraulic retention time is 24-36 h, and the sludge age is controlled at 20 d.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention modifies and crosslinks chitosan with dialdehyde starch to construct a three-dimensional polymer network structure with high mechanical strength and stability. At the same time, the loaded copper ions can undergo specific strong coordination complexation with the amino groups of polyenes and polyamines in wastewater. This dual synergistic effect of "specific complexation" and "macromolecular network trapping" breaks the thermodynamic stability of high concentrations of polyenes and polyamines in the aqueous phase. This process not only achieves rapid sedimentation and separation of highly toxic and difficult-to-degrade amino-containing macromolecular organic matter, significantly reducing the overall toxicity of water bodies, but also greatly reduces the organic matter load for subsequent advanced oxidation and biochemical treatment.

[0016] 2. This invention develops a modified titanium-based oxygen-vacancy-rich titanium dioxide particle electrode in an electrocatalytic system. By reducing and calcining it under a specific hydrogen-imine mixed atmosphere, a large number of oxygen vacancies are artificially introduced into the lattice of titanium dioxide. The introduction of oxygen vacancy defects significantly shortens the band gap of the semiconductor material, greatly improving the intrinsic conductivity of the electrode and the efficiency of electrocatalytic generation of hydroxyl radicals. This modification effectively overcomes the problem that traditional three-dimensional particle electrodes are prone to surface passivation and deactivation in high-salinity wastewater, ensuring the system's long-term and stable oxidative degradation capability for organic matter.

[0017] 3. This invention constructs a synergistic coupling process of ultrasound and three-dimensional electrocatalytic oxidation. The acoustic cavitation effect induced by ultrasound in water can generate local high temperature and high pressure and microjets, which can not only continuously physically clean the electrode surface and prevent high salt scaling, but also induce violent fluid disturbance. This disturbance greatly accelerates the mass transfer process of large polyene and polyamine molecules in wastewater to the particle electrode surface, overcoming the steric hindrance effect. The two work together to significantly improve the breaking efficiency of stable CN bonds in macromolecules, and rapidly degrade complex polymers into easily treatable small molecules.

[0018] 4. In the deep oxidation stage, this invention couples an iron-manganese bimetallic doped diatomaceous earth catalyst with ozone oxidation technology. The naturally abundant porous structure of diatomaceous earth provides a huge specific surface area for the reaction, while the uniformly doped iron-manganese bimetallic active sites exhibit excellent electron transfer capabilities. When ozone molecules come into contact with the catalyst surface, the bimetallic sites can efficiently induce the rapid decomposition of dissolved ozone, generating hydroxyl radicals with extremely high oxidation potentials. This synergy between the material and the process completely mineralizes the short-chain amines and stubborn organic acids generated in the early chain breaking stage, eliminating the final biotoxicity and significantly improving ozone utilization.

[0019] 5. This invention introduces a synergistic system of iron-modified biochar coupled with a membrane bioreactor in the final biochemical stage. Addressing the challenge of sludge disintegration caused by high-salt wastewater, the abundant pores of biochar provide a natural buffer refuge for salt-tolerant microorganisms, effectively resisting the impact of high osmotic pressure. Simultaneously, the iron-containing active species loaded on the biochar surface act as excellent redox mediators, significantly accelerating the electron transfer rate during microbial degradation of residual organic matter and denitrification. Furthermore, the suspended, hard carbon particles provide continuous physical scrubbing of the membrane module, fundamentally slowing down the membrane fouling process in high-salt membrane bioreactors. Attached Figure Description

[0020] Figure 1 The graphs show the final effluent COD and TN detection data for Examples 1-4 of this invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figure 1 This invention provides a method for treating high-salt organic wastewater containing polyenes and polyamines, the technical solution of which is as follows: Example 1 10g of chitosan was dissolved in 400mL of 2wt% acetic acid solution. 20mL of 10% dialdehyde starch solution was added dropwise at 50℃, and the mixture was stirred at 300rpm for 3h to generate a cross-linked hydrogel. 50mL of 0.5mol / L copper sulfate solution was added dropwise to the cross-linked hydrogel, and the pH was adjusted to neutral using 1mol / L sodium hydroxide solution to precipitate the product. After filtration, washing, and vacuum drying at 60℃ for 12h, the product was ground and passed through a 200-mesh standard sieve to obtain a composite flocculant.

[0023] 10 mL of tetrabutyl titanate was dissolved in 40 mL of anhydrous ethanol. A mixture of 2 mL of deionized water, 10 mL of anhydrous ethanol, and 1 mL of glacial acetic acid was added dropwise. The mixture was stirred continuously for 2 h to form a sol, which was then aged for 24 h to form a TiO2 sol. Activated carbon was impregnated in the TiO2 sol and coated with a pull-coating film. 25 g of activated carbon was impregnated in every 100 mL of TiO2 sol for 2 h. The pull-coating rate was controlled at 3 cm / min. After drying at 105 °C, the film was placed in a tube furnace and heated to 500 °C at a heating rate of 5 °C / min under an atmosphere of argon and hydrogen mixed gas (volume ratio 9:1) for 3 h. The film was then cooled to room temperature to obtain the particle electrode.

[0024] Commercially available diatomaceous earth (D858223, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.) was passed through a 100-mesh sieve and added to a 15wt% sulfuric acid solution. The mixture was mixed at a solid-liquid ratio of 1:5 (g / mL) and mechanically stirred and acid-washed in a 60℃ water bath for 4 hours. Subsequently, it was filtered and repeatedly washed with deionized water until the pH of the eluent was neutral. It was then dried in a 105℃ oven for 12 hours to obtain pretreated diatomaceous earth. 50g of the pretreated diatomaceous earth was impregnated in a mixed aqueous solution (200mL) containing 0.1mol / L ferric nitrate and 0.1mol / L manganese nitrate. The mixture was stirred at a constant temperature of 150rpm in an 80℃ water bath until the water evaporated to dryness to obtain the precursor. The precursor was placed in a muffle furnace and calcined at 550℃ for 4 hours in an air atmosphere at a rate of 10℃ / min to obtain a bimetallic doped diatomaceous earth catalyst.

[0025] Corn cobs were washed, dried, and crushed into particles with an average particle size of 1 mm. 100 g of the particles were immersed in 500 mL of 0.3 mol / L ferric chloride solution and stirred at 150 rpm for 12 h at room temperature. After filtration, the solid product was dried in an oven at 105 °C for 24 h to obtain the precursor. The precursor was placed in a tube furnace and heated to 500 °C at a heating rate of 10 °C / min under a nitrogen atmosphere. It was then pyrolyzed at a constant temperature for 2 h, cooled to room temperature, washed with deionized water until the eluent was neutral, and dried to obtain iron-modified biochar.

[0026] The following are methods for treating high-salt organic wastewater containing polyenes and polyamines: S1 complex flocculation pretreatment: Polyene and polyamine high-salt organic wastewater is introduced into the reaction tank, the pH value is adjusted to 8.0, and composite flocculant is added at a dosage of 3g / L. At 25℃, the mixture is first stirred at a speed of 250rpm for 10min, then the stirring speed is adjusted to 50rpm for 30min. After standing and settling for 60min, the supernatant is taken. S2 Ultrasonic-Assisted Three-Dimensional Electrocatalytic Oxidation: The supernatant from S1 was introduced into a three-dimensional electrocatalytic reactor, which was filled with particle electrodes at a density of 50 g / L. An ultrasonic generator and DC power supply were then activated for processing. The reaction temperature was 30℃, the ultrasonic frequency was 40 kHz, and the ultrasonic power density was 0.5 W / cm³. 2 The apparent current density of the main electrode is controlled to be 30 mA / cm². 2 The reaction time is 90 minutes; S3 Catalytic Ozone Deep Oxidation: The effluent from S2 is introduced into the catalytic ozone contact tower, and a bimetallic doped diatomaceous earth catalyst is added at a dosage of 3 g / L. Ozone is introduced from the bottom of the catalytic ozone contact tower to carry out the reaction; the ozone dosage is 15 mg / L, the reaction temperature is maintained at 25℃, and the reaction is carried out continuously for 45 min. S4 Immobilized Specific Biochemical Treatment: The effluent from S3 is introduced into the equalization tank, the pH is adjusted to 7.5, and then pumped into the membrane bioreactor. Iron-modified biochar is added to the membrane bioreactor at a dosage of 4 g / L, and acclimated salt-tolerant sludge is inoculated at a dosage of 3000 mg / L to obtain effluent that can be discharged. The dissolved oxygen in the membrane bioreactor is controlled at 3.0 mg / L, the water temperature is maintained at 30℃, the hydraulic retention time is 24 h, and the sludge age is controlled at 20 days.

[0027] Sludge acclimation method: The obtained activated sludge (taken from the secondary sedimentation tank return sludge of a wastewater treatment plant treating amine-containing chemical wastewater) was placed in the SBR, and the initial inoculum sludge concentration was controlled at 3000 mg / L; a gradient acclimation method was adopted, and the single operation cycle of the SBR was set to 12 hours, including 1 hour of influent, 8 hours of aeration, 2 hours of sedimentation, and 1 hour of effluent discharge; in the initial stage, glucose, ammonium chloride, and potassium dihydrogen phosphate were used as carbon, nitrogen, and phosphorus sources, and the influent C:N:P mass ratio was controlled at 100:5:1; subsequently, a 3-day cycle was adopted, with 10 The proportion of high-salt polyene and polyamine wastewater in the influent was gradually increased (from 10% to 100%), while the salt content in the system was gradually increased to 50 g / L. During this period, the reaction temperature was controlled at 25-30℃, the pH was adjusted to 7.0 using sodium hydroxide or dilute sulfuric acid, and the dissolved oxygen was controlled at 3.0 mg / L. The sludge settling ratio and COD removal rate were continuously monitored. When the COD removal rate remained stable above 85% for one week, the sludge volume index remained stable between 100-120 mL / g, and the turbidity of the supernatant was less than 15 NTU, the salt-tolerant sludge acclimatization was completed. In this application, sodium hydroxide or dilute sulfuric acid was used to adjust the pH value.

[0028] Example 2 The preparation method and parameters were the same as in Example 1, except that the crosslinking temperature of the flocculant preparation was 60℃ and the time was 4h; the reduction and calcination temperature of the particle electrode was 550℃; the air calcination temperature of the catalyst was 600℃; the concentration of the biochar-modified ferric chloride was 0.5mol / L and the pyrolysis temperature was 600℃; in S2, the particle electrode filling amount was 75g / L, the apparent current density was 35mA / cm², and the reaction time was 100min; in S3, the ozone dosage was 20mg / L and the reaction time was 50min; and in S4, the hydraulic retention time was 30h.

[0029] Example 3 The preparation method and parameters were the same as in Example 1, except that the crosslinking temperature of the flocculant preparation was 65℃ and the time was 4.5h; the reduction and calcination temperature of the particle electrode was 580℃; the air calcination temperature of the catalyst was 620℃; the concentration of the biochar-modified ferric chloride was 0.6mol / L and the pyrolysis temperature was 650℃; in S2, the particle electrode filling amount was 85g / L, the apparent current density was 40mA / cm², and the reaction time was 110min; in S3, the ozone dosage was 22mg / L and the reaction time was 55min; and in S4, the hydraulic retention time was 32h.

[0030] Example 4 The preparation method and parameters were the same as in Example 1, except that the crosslinking temperature of the flocculant preparation was 70°C and the time was 5 h; the reduction and calcination temperature of the particle electrode was 600°C; the air calcination temperature of the catalyst was 650°C; the concentration of the biochar-modified ferric chloride was 0.8 mol / L and the pyrolysis temperature was 700°C; in S2, the particle electrode filling amount was 100 g / L, the apparent current density was 45 mA / cm², and the reaction time was 120 min; in S3, the ozone dosage was 25 mg / L and the reaction time was 60 min; and in S4, the hydraulic retention time was 36 h.

[0031] Comparative Example 1 The preparation method and parameters of Example 1 are the same, except that in step S1, the composite flocculant is replaced with chitosan that has not been cross-linked with dialdehyde starch.

[0032] Comparative Example 2 The preparation method and parameters of Example 1 are the same, except that in step S1, the composite flocculant is replaced with unloaded copper sulfate dialdehyde starch crosslinked chitosan.

[0033] Comparative Example 3 Referring to the preparation method and parameters of Example 1, the difference is that in the preparation of the particle electrode in step S2, "calcination in a mixed atmosphere of argon and hydrogen" is changed to "calcination in a pure air atmosphere".

[0034] Comparative Example 4 The preparation method and parameters of Example 1 are the same, except that in step S2, activated carbon without TiO2 coating modification is used directly as filler.

[0035] Comparative Example 5 The preparation method and parameters of Example 1 are the same, except that in step S2, the ultrasonic generator is turned off and only the three-dimensional electrocatalytic oxidation system is retained.

[0036] Comparative Example 6 The preparation method and parameters of Example 1 are the same, except that in step S3, the bimetallic doped diatomaceous earth catalyst is replaced with commercially available diatomaceous earth that has not been doped with any metal.

[0037] Comparative Example 7 The preparation method and parameters of Example 1 are the same, except that in step S3, only 0.2 mol / L ferric nitrate is used for doping during catalyst preparation, and manganese nitrate is not used.

[0038] Comparative Example 8 The preparation method and parameters are the same as in Example 1, except that no biochar is added in the S4 biochemical treatment step, allowing the acclimatized sludge to directly face the effluent from step S3.

[0039] Comparative Example 9 The preparation method and parameters of Example 1 are the same, except that in step S4, ordinary corn cob biochar that has not been impregnated with ferric chloride solution is added.

[0040] Experimental Example 1 Initial wastewater test data: Chemical oxygen demand (COD) 15500 mg / L, total nitrogen (TN) 2450 mg / L, salinity (as NaCl and Na2SO4) 105000 mg / L, biodegradability 0.08, pH value 10.5; COD testing: The dichromate method was used, in accordance with the national environmental protection standard HJ 828-2017. TN detection: Alkaline potassium persulfate digestion ultraviolet spectrophotometry was used, in accordance with the national environmental protection standard HJ 636-2012; BOD5 detection: The dilution and inoculation method was used, in accordance with the national environmental protection standard HJ 505-2009; Membrane flux decay detection: Record the steady-state membrane flux after the MBR reactor has been running continuously for 30 days, with the initial flux set at 20 LMH; The results are shown in Table 1; the biodegradability is the B / C (BOD5 / COD) ratio of the S3 effluent.

[0041] Table 1. Detection data of effluent content in Examples 1-4 and Comparative Examples 1-9 ; In Comparative Example 1, the composite flocculant was replaced with ordinary chitosan without dialdehyde starch crosslinking. Ordinary chitosan underwent a "salting out" effect in a high-salt environment, with its molecular chains coiling and completely losing their entrapment and bridging capabilities. This resulted in the failure of large polyene polyamines in the S1 stage to settle, allowing extremely high concentrations of toxic substances to directly impact subsequent systems. The B / C ratio of the S3 effluent was only 0.15, and the final effluent COD reached as high as 940 mg / L. In Comparative Example 2, the composite flocculant was replaced with dialdehyde starch crosslinked chitosan without copper sulfate loading. Lacking the specific strong coordination complexation between copper ions and the amino groups in the polyene polyamines, the physical entrapment of crosslinked chitosan alone could not effectively break the thermodynamic stability of the polyene polyamines in the aqueous phase. The flocculation removal rate decreased significantly, leading to subsequent... The high-level oxidation load was excessive, resulting in a total nitrogen (TN) in the effluent reaching 190 mg / L. In Comparative Example 3, the particle electrode was not reduced by hydrogen, resulting in a lack of oxygen vacancies in the crystal lattice. This led to poor conductivity of titanium dioxide and easy recombination of electron-hole pairs, causing rapid electrode passivation in the high-salt system. The production of hydroxyl radicals decreased sharply, and CN bonds could not be effectively broken, ultimately leading to a sharp increase in COD in the effluent. In Comparative Example 4, activated carbon without TiO2 coating modification was used as the filler. Pure activated carbon only has physical adsorption function and has almost no ability to electrocatalyze the generation of active free radicals. It becomes ineffective after adsorption saturation, rendering the S2 stage ineffective. As a result, the polyene and polyamine matrix structure was not destroyed, and all indicators of the effluent deteriorated. In Comparative Example 5, the ultrasonic generator was turned off, and only the three-dimensional electrocatalytic oxygenation was retained. In Comparative Example 6, the lack of ultrasonic cavitation microjets and acoustic flow effects drastically increased the mass transfer resistance of large molecular pollutants to the particle electrode surface. Furthermore, the electrode surface was easily covered by high-concentration salt scale, limiting mass transfer and causing a decrease in electrocatalytic chain scission efficiency, leading to increased COD in the effluent. In Comparative Example 7, the lack of manganese synergy resulted in a bottleneck in the electron transfer rate of the iron single active site, limiting the efficiency of ozone catalysis. Bimetallic doping could form Fe-Mn redox couples, but lacked the ability to catalyze ozone decomposition. The undoped pure diatomaceous earth in Comparative Example 6 did not possess the ability to catalyze ozone decomposition. Ozone could only react with organic matter through direct oxidation (high selectivity, low potential), failing to generate a large amount of highly active hydroxyl radicals, leading to incomplete mineralization of short-chain amines and increased COD in the effluent. The loss of biochar slowed down the reaction rate and increased the total nitrogen (TN) of the effluent. In Comparative Example 8, no biochar was added in the S4 biological treatment step, completely losing the synergy between the material and the process. Under the direct impact of high salt osmotic pressure, the salt-tolerant sludge cells were severely dehydrated and disintegrated, and the system completely collapsed. The disintegrated extracellular polymers and dead bacteria quickly blocked the MBR membrane, causing a sharp drop in membrane flux and deterioration of the effluent quality. In Comparative Example 9, ordinary corn cob biochar that had not been impregnated with ferric chloride solution was added. Although ordinary biochar provided some space and pressure protection to maintain the basic survival of the microbial community, the lack of iron-active species on the surface as electron shuttles hindered electron transfer during the degradation of residual short-chain amines and denitrification, resulting in slow biochemical metabolism and ultimately failing to meet the TN standard for the effluent.

[0042] In summary, based on Table 1 and Figure 1 As can be seen from Examples 1-4, this application overcomes the limitations of traditional biochemical and physicochemical processes under the dual stress of "high salt + high toxicity". Significant synergistic effects are achieved through material modification and deep coupling of multiple processes, with each step closely linked. Comparing Example 1 with Comparative Examples 1-2, it can be seen that the specifically modified "copper-supported dialdehyde starch crosslinked chitosan" is irreplaceable. Its specific complexation and trapping are the prerequisites for eliminating the primary toxicity of the system. Comparing Example 1 with Comparative Examples 3-7 confirms that oxygen-rich vacancy titanium-based modification, ultrasonic field introduction, and Fe-Mn bimetallic catalysis solve the problems of electrode passivation and low ozone utilization in high-salt environments from three dimensions: "mass transfer-chain severance-mineralization". Comparing Example 1 with Comparative Examples 8-9 highlights the key role of iron-modified biochar at the end of biochemical processes. It not only acts as a physical barrier to resist salt impact, but also acts as an electron shuttle to significantly improve the biological denitrification rate and delay membrane fouling.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for treating high-salt organic wastewater containing polyenes and polyamines, characterized in that: The processing method is as follows: S1 Complex Flocculation Pretreatment: The polyene-polyamine high-salt organic wastewater is introduced into a reaction tank, the pH value is adjusted, a composite flocculant is added, and after stirring, the supernatant is collected after standing and settling. The composite flocculant is prepared from chitosan, dialdehyde starch solution and copper sulfate solution. S2 Ultrasonic-assisted three-dimensional electrocatalytic oxidation: The supernatant from S1 is introduced into a three-dimensional electrocatalytic reactor, which is filled with particle electrodes. An ultrasonic generator and a DC power supply are turned on for processing. The particle electrodes are made of TiO2 sol and activated carbon. S3 Catalytic Ozone Deep Oxidation: The effluent from S2 is introduced into the catalytic ozone contact tower, a bimetallic doped diatomaceous earth catalyst is added, and ozone is introduced from the bottom of the catalytic ozone contact tower to carry out the reaction; the bimetallic doped diatomaceous earth is prepared from pretreated diatomaceous earth, ferric nitrate and manganese nitrate. S4 Immobilized Specific Biochemical Treatment: The effluent from S3 is introduced into the equalization tank, the pH value is adjusted, and then pumped into the membrane bioreactor. Iron-modified biochar is added, and acclimatized salt-tolerant sludge is inoculated at the same time to obtain effluent that can be discharged.

2. The method for treating polyene- and polyamine-based high-salt organic wastewater according to claim 1, characterized in that: The composite flocculant is prepared as follows: chitosan is dissolved in acetic acid solution, and dialdehyde starch solution is added dropwise. The mixture is stirred to generate a cross-linked hydrogel. Copper sulfate solution is added dropwise to the cross-linked hydrogel, and the pH is adjusted to neutral to allow the product to precipitate. The product is then filtered, washed, vacuum dried, and ground to obtain the composite flocculant.

3. The method for treating polyene-polyamine high-salt organic wastewater according to claim 1, characterized in that: The particle electrode is prepared as follows: Tetrabutyl titanate is dissolved in anhydrous ethanol, and a mixture of deionized water, anhydrous ethanol and glacial acetic acid is added dropwise. The mixture is stirred to form a sol, and aged to form the TiO2 sol. The activated carbon is impregnated in the TiO2 sol and coated with a film. After drying, the film is placed in a tube furnace for calcination and cooled to room temperature to obtain the particle electrode.

4. The method for treating polyene- and polyamine-based high-salt organic wastewater according to claim 1, characterized in that: The preparation method of the bimetallic doped diatomite catalyst is as follows: the pretreated diatomite is impregnated in a mixed aqueous solution containing the ferric nitrate and the manganese nitrate and stirred to obtain a precursor; the precursor is placed in a muffle furnace and calcined to obtain the bimetallic doped diatomite catalyst.

5. The method for treating polyene- and polyamine-based high-salt organic wastewater according to claim 1, characterized in that: The method for preparing iron-modified biochar is as follows: corn cobs are washed, dried, and then crushed to obtain granules; the granules are immersed in ferric chloride solution, stirred and impregnated, then filtered, and the solid product is dried to obtain a precursor; the precursor is placed in a tube furnace, heated under a nitrogen protective atmosphere, pyrolyzed at a constant temperature, cooled to room temperature, washed, and dried to obtain the iron-modified biochar.

6. The method for treating polyene-polyamine high-salt organic wastewater according to claim 1, characterized in that: In S2, the apparent current density of the main electrode is controlled to be 30-45 mA / cm². 2 The reaction time is 90-120 min.

7. The method for treating polyene-polyamine high-salt organic wastewater according to claim 1, characterized in that: The ozone dosage in step S3 is 15-25 mg / L, and the reaction is carried out continuously for 45-60 min.

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