Electrolytic enhanced bioremediation reactor for sludge disposal of water plant and application thereof

Abstract

The present application belongs to the field of sludge disposal of sewage treatment plant, and particularly relates to an electrically enhanced bioremediation reactor for sludge disposal of water plant and application thereof. The reactor is provided with an organic biological oxidation chamber in the device, a cation heavy metal collection chamber, an anode chamber, an anion heavy metal collection and biological attenuation chamber are arranged between the outer wall of the organic biological oxidation chamber and the reactor; a cathode is arranged in the cation heavy metal collection chamber, and an anode is arranged in the anode chamber; the electrodes are respectively connected with a direct current power supply through wires and are electrified. The present application strengthens the microbial metabolism of organic matter and the electromigration process of heavy metal ions through the electric process, has a strong application potential for the disposal of sludge mixture, is a feasible remediation strategy, meets the needs of coupling application of the existing disposal methods, avoids increasing the difficulty of technical development, and realizes efficient and rapid disposal of sludge.

Description

Technical Field

[0001] This invention belongs to the field of sludge disposal in wastewater treatment plants, and specifically relates to an electro-enhanced bioremediation reactor for sludge disposal in water plants and its application. Background Technology

[0002] Currently, the most common method for treating urban domestic and industrial wastewater is still to transport it to wastewater treatment plants via pipelines, where it undergoes secondary or tertiary treatment using processes such as activated sludge. Consequently, large amounts of bottom sludge are typically generated within wastewater treatment plant structures, creating new solid waste disposal problems. Sludge usually contains significant amounts of adsorbed organic matter, heavy metals, and pathogens, and the accumulation of large quantities of sludge poses a significant ecological risk, urgently requiring treatment. Treatment methods for wastewater treatment plant sludge include dewatering, composting, incineration, anaerobic fermentation, and stabilization. However, while existing technologies either degrade organic matter or passivate heavy metals in the sludge, they have not effectively achieved the simultaneous removal of both organic and inorganic pollutants, particularly the reduction of heavy metals in the sludge.

[0003] To address this, a multi-process combined treatment approach can be adopted to separately treat organic and inorganic pollutants in sludge. For example, the sludge can first be dewatered to remove water-soluble organic matter and unadsorbed heavy metal ions to a certain extent, then incinerated to remove adsorbed organic matter, and finally, stabilizing agents can be applied to stabilize residual heavy metals in the sludge. However, this common combined treatment process involves the transportation of the sludge and multiple feeding and discharging processes, prolonging the treatment cycle, increasing treatment costs, and introducing the risk of secondary pollution. To achieve a more convenient and economical simultaneous removal of organic and inorganic pollutants from sludge, the process design can organically combine the degradation of organic matter in the sludge mixture with the separation and detoxification of heavy metals, thereby simplifying process connections, shortening the treatment cycle, reducing process costs, and ensuring sludge purification.

[0004] Electro-enhanced bioremediation processes are widely used in the remediation of organic and compound contaminated soils. However, in the treatment of sludge from wastewater treatment plants, the extremely high water content of sludge makes it difficult to apply in situ. Moreover, in the application of ex-situ sludge treatment, it is mostly presented in the form of sludge reactors, which mainly treat organic pollutants. The development and application of devices that can simultaneously remove heavy metals and organic pollutants from sludge are still rarely reported. Summary of the Invention

[0005] The purpose of this invention is to provide an electro-enhanced bioremediation reactor for the treatment of sludge in water plants and its application.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An electro-enhanced bioremediation reactor for the treatment of sludge in water plants is provided. The reactor (1) is equipped with an organic biological oxidation chamber (5). Between the outer wall of the organic biological oxidation chamber (5) and the reactor (1), there are a cation heavy metal collection chamber (2), an anode chamber (3), and an anion heavy metal collection and biological detoxification chamber (4).

[0008] A cathode (20) is installed in the cation heavy metal collection chamber (2), and an anode (19) is installed in the anode chamber (3). The electrodes are connected to a DC power supply (10) through wires.

[0009] Between the organic biological oxidation chamber (5) and the reactor (1), there is a cation heavy metal collection chamber (2), an anode chamber (3) and two anion heavy metal collection and biological detoxification chambers (4); wherein, the cation heavy metal collection chamber (2) and the anode chamber (3) are arranged opposite each other on both sides of the organic biological oxidation chamber (5);

[0010] The organic biological oxidation chamber (5) and the cation heavy metal collection chamber (2) are separated by a cation exchange membrane partition (7);

[0011] The organic bio-oxidation chamber (5) and the anode chamber (3) are separated by a stainless steel sealing partition (8);

[0012] The organic biological oxidation chamber (5) and the anion heavy metal collection and biological detoxification chambers (4) on both sides are separated by anion exchange membrane partitions (23);

[0013] The anode chamber (3) and the anion heavy metal collection and biological detoxification chamber (4) are separated by a cation exchange membrane partition (7);

[0014] The cationic heavy metal collection chamber (2) and the anionic heavy metal collection and biological detoxification chambers (4) on both sides are separated by stainless steel sealing partitions (8).

[0015] The top of the cation heavy metal collection chamber (2) and the anode chamber (3) are uncovered and electrolyte solution is added inside. The bottom of the reactor side wall of any one of the anion heavy metal collection and biological detoxification chambers (4) is provided with a drain hole (26) (that is, each chamber (including 2, 3, 4) is provided with a drain hole (26)).

[0016] The organic biological oxidation chamber (5) is a biodegradation chamber for organic pollutants in sludge by electric field enhancement. It is equipped with an aeration disc (17) at the bottom and an aeration hole (18) on the aeration disc (17). The aeration disc (17) is connected to the air supply source through the air passage (13) of the biological oxidation chamber that passes through the outer wall of the organic biological oxidation chamber (5) and the anion heavy metal collection and biological detoxification chamber (4) and is distributed along the outer wall of the reactor (3). The bottom of the organic biological oxidation chamber (5) is equipped with a sludge discharge pump (25) to assist in the discharge of sludge. The sludge discharge pump (25) is connected to the sludge discharge pipe (24) to discharge the treated sludge. The sludge discharge pipe (24) is connected to the organic biological oxidation chamber (5) and the reactor (1) chamber.

[0017] The bio-oxidation chamber ventilation duct (13) is equipped with a bio-oxidation chamber ventilation pump (15) that provides gas supply power.

[0018] The anion heavy metal collection and biological detoxification chamber (4) is symmetrically distributed on both sides of the organic biological oxidation chamber (5) to collect anions and heavy metal anions in sludge. The top of the anion heavy metal collection and biological detoxification chamber (4) is designed with a biological detoxification chamber sealing cover (6). The biological detoxification chamber sealing cover (6) is provided with a pH adjustment hole (11) and an automatic venting valve (12). A pH detector (9) is designed on the side wall of the anion heavy metal collection and biological detoxification chamber (4). A drain hole (26) is provided at the bottom of the side wall. The anion heavy metal collection and biological detoxification chamber ventilation channel (14) is distributed upward along the outer wall of the reactor (1) and connected to the N2 source.

[0019] The ventilation duct (14) of the anion heavy metal collection and biological detoxification chamber is equipped with an anion heavy metal collection and biological detoxification chamber ventilation pump (16) to provide power for the introduction of nitrogen into the anion heavy metal collection and biological detoxification chamber (4) for deoxygenation.

[0020] Iron-reducing bacteria were inoculated in the anionic heavy metal collection and biological attenuation chamber (4), with an initial inoculation abundance of 10. 7 CFU·mL -1 above.

[0021] An application of the electro-enhanced bioremediation reactor for the treatment of sludge in wastewater treatment plants, wherein the reactor is used for electro-enhanced bioremediation of organic pollutants and / or inorganic heavy metal ions in sludge from wastewater treatment plants.

[0022] The sludge from the wastewater treatment plant to be treated is added to the organic biological oxidation chamber (5) of the device. An external current controls the gradual and continuous degradation of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons by microorganisms in the organic biological oxidation chamber (5). Heavy metal cations in the organic biological oxidation chamber (5) migrate through the cation exchange membrane partition (7) to the cation heavy metal collection chamber (2). Heavy metal anions in the organic biological oxidation chamber (5) migrate through the anion exchange membrane partition (23) to the anion heavy metal collection and biological detoxification chamber (4). Simultaneously, the stainless steel anode (19) in the anode chamber (3) continuously releases Fe into the solution in the anode chamber (3) through an electro-corrosion oxidation process in the presence of electrolyte. 3+ Fe 3+ Under the influence of an electric field, the heavy metals migrate through the cation exchange separator (7) into the anion heavy metal collection and biological detoxification chamber (4), and gather there to participate in the iron-reducing bacteria's action on heavy metal anions AsO4 under anaerobic conditions. 3- The reduction and detoxification reaction is used to achieve electrodynamic enhanced bioremediation of organic pollutants and / or inorganic heavy metal ions in sewage treatment plant sludge.

[0023] The advantages and beneficial effects of this invention are:

[0024] 1. The electro-enhanced bioremediation reactor described in this invention can simultaneously treat organic pollutants and heavy metals in sludge from wastewater treatment plants, thereby purifying the sludge; moreover, it can degrade organic pollutants aerobically or anaerobically, and the current can also stimulate the metabolic degradation activity of microorganisms on organic pollutants.

[0025] 2. The degradation of organic matter in sludge by the electro-enhanced bioremediation reactor described in this invention can be enhanced by the stimulation of functional microorganisms by electric current;

[0026] 3. In the electro-enhanced bioremediation reactor of the present invention, the organic biological oxidation chamber (5) can carry out both anaerobic biological oxidation degradation and aerobic biological oxidation degradation, and can also carry out anaerobic degradation first and then aerobic degradation, thus having a stronger degradation advantage for large molecular recalcitrant organic matter in sludge;

[0027] 4. The electro-enhanced bioremediation reactor in this invention utilizes cation exchange membranes and anion exchange membranes to assist electromigration and guide the flow of cations and anions, thereby collecting and stabilizing heavy metals, achieving the removal of heavy metals from sludge and the collection of heavy metals in water;

[0028] 5. In the present invention, Fe(III) is supplied to the anionic heavy metal collection and biological detoxification chamber (4) in the anode chamber (3) of the electro-enhanced bioremediation reactor through corrosion of the metal iron electrode. Thus, under anaerobic conditions, Fe(III) is oxidized to As(V) in synergy with iron-reducing bacteria, thereby playing a detoxification role. Attached Figure Description

[0029] Figure 1 This is a three-dimensional schematic diagram of an electro-enhanced bioremediation reactor provided in an embodiment of the present invention;

[0030] Figure 2 A top view of an electro-enhanced bioremediation reactor provided in an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the migration and distribution of ions and organic matter in an electro-enhanced bioremediation reactor provided in an embodiment of the present invention;

[0032] Figure 4 The changes in the content of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons in the organic bio-oxidation chamber of the electro-enhanced bioremediation reactor provided in the embodiments of the present invention;

[0033] Figure 5 The variation of aliphatic hydrocarbon content in different carbon number ranges in the organic bio-oxidation chamber of the electro-enhanced bioremediation reactor provided in the embodiments of the present invention;

[0034] Figure 6 The content variation of each single polycyclic aromatic hydrocarbon in the organic bio-oxidation chamber of the electro-enhanced bioremediation reactor provided in the embodiments of the present invention;

[0035] Figure 7 The variation in bacterial microbial abundance in the organic bio-oxidation chamber of the electro-enhanced bioremediation reactor provided in this embodiment of the invention;

[0036] Figure 8 The variation of heavy metal cation content in the organic bio-oxidation chamber of the electro-enhanced bioremediation reactor provided in this embodiment of the invention;

[0037] Figure 9 The variation of heavy metal cation content in the cation heavy metal collection chamber of the electro-enhanced bioremediation reactor provided in this embodiment of the invention;

[0038] Figure 10 The variation of heavy metal anion content in the organic bio-oxidation chamber of the electro-enhanced bioremediation reactor provided in this embodiment of the invention;

[0039] Figure 11 The anionic heavy metal collection and the change of heavy metal anion content in the bio-attenuation chamber of the electro-enhanced bioremediation reactor provided in this embodiment of the invention;

[0040] 1. Electro-enhanced bioremediation reactor; 2. Cation heavy metal collection chamber; 3. Anode chamber; 4. Anion heavy metal collection and bio-detoxification chamber; 5. Organic bio-oxidation chamber; 6. Bio-detoxification chamber sealing cover; 7. Cation exchange membrane partition; 8. Stainless steel sealing partition; 9. pH detector; 10. DC power supply; 11. pH adjustment port; 12. Automatic vent valve; 13. Aeration duct for bio-oxidation chamber; 14. Aeration duct for anion heavy metal collection and bio-detoxification chamber; 15. Aeration pump for bio-oxidation chamber; 16. Aeration pump for anion heavy metal collection and bio-detoxification chamber; 17. Aeration disc; 18. Aeration hole; 19. Anode; 20. Cathode; 21. Cathode wire; 22. Anode wire; 23. Anion exchange membrane partition; 24. Sludge discharge pipe; 25. Sludge discharge pump; 26. Liquid discharge hole. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] The device of this invention removes organic matter from sludge through an anaerobic or aerobic biological oxidation chamber combined with the enhanced effect of electric current on functional microorganisms; a cation heavy metal collection chamber collects cations from the sludge and stabilizes them through an alkaline precipitation reaction; an anion heavy metal collection and biological detoxification chamber collects heavy metal anions from the sludge; and an anode chamber generates Fe(III) and transports it to the anion heavy metal collection and biological detoxification chamber to assist iron-reducing bacteria therein in oxidizing arsenate ions. The application of the electro-enhanced bioremediation reactor effectively achieves the degradation of organic pollutants in sludge and the collection and detoxification of heavy metals.

[0043] This invention enhances the microbial metabolism of organic matter and the electromigration of heavy metal ions through an electrochemical process, which has great application potential for the treatment of sludge mixtures and is a feasible remediation strategy. It meets the need to couple existing treatment methods and achieves efficient and rapid treatment of sludge without increasing the difficulty of technical development.

[0044] Example: Aerobic treatment of sediment sludge from the secondary sedimentation tank of a municipal wastewater treatment plant

[0045] Sludge samples were collected from a wastewater treatment plant located in the suburbs of a city in northern my country. This plant uses the aerobic activated sludge process to treat domestic and industrial wastewater. The plant has a daily wastewater treatment capacity of 1.3 million tons, with sludge production in the secondary sedimentation tank reaching 700,000 tons per year. This significant sludge production has become a major environmental burden, posing a threat to environmental safety as solid waste. During operation, as the treatment cycle lengthens, the sludge accumulates and ages, leading to a decrease in microbial activity, partial death of microorganisms, and enlargement of activated sludge flocs with a loose structure, losing their metabolic degradation activity for pollutants. However, they retain the ability to adsorb pollutants from the wastewater, resulting in a significant increase in pollutant concentration in the sludge. Consequently, the environmental hazard risk of the sludge increases dramatically, necessitating effective treatment. The collected sludge samples were partially dewatered sludge-sewage mixtures, with sludge dry weight comprising 50% (w / v). Pollutant content analysis was performed on the collected sludge samples, focusing on major pollutant categories including aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and heavy metals. GC-MS, HPLC, and ICP-MS were used to determine the aliphatic hydrocarbons, PAHs, and heavy metals, respectively. The results showed that the initial total aliphatic hydrocarbon content in the sludge was 12087 mg·kg⁻¹. -1 The initial total amount of polycyclic aromatic hydrocarbons (PAHs) was 4612 mg·kg. -1 The initial total heavy metal content was 9954.1 mg·Kg. -1 Component analysis of aliphatic hydrocarbons with different carbon numbers revealed that the detectable carbon number range was C6–C35, with initial concentrations of 1963 mg·kg⁻¹ for each range. -1 (C6~C10), 2692 mg·Kg -1 (C11~C15), 3081 mg·Kg -1 (C16~C20), 2298 mg·Kg -1 (C21~C25), 1293 mg·Kg -1 (C26~C30), 760 mg·Kg -1 (C31~C35); the initial content of each detectable monocyclic polycyclic aromatic hydrocarbon was 43.42 mg·Kg. -1 (fluorene), 217.46 mg·Kg -1 (Philippines), 77.02 mg·Kg -1 (Anthracene), 855.58 mg·Kg -1 (Fluoranthracene), 722.23 mg·Kg -1 (Pyrene), 448.56 mg·Kg -1 (Benzo[a]anthracene), 383.84 mg·Kg -1(䓛), 366.73 mg·Kg -1 (Benzo[b]fluoranthene), 223.70 mg·Kg -1 (Benzo[k]fluoranthene), 488.62 mg·Kg -1 (Benzo[a]pyrene), 122.91 mg·Kg -1 Dibenzo[a,h]anthracene, 348.25 mg·Kg -1 Benzo[g,h,i]perylene, 313.70 mg·Kg -1 Indene[1,2,3-cd]pyrene. The heavy metal composition includes heavy metal cations comprising 412 mg·Kg. -1 Cr 3+ 2981 mg·Kg -1 Cu 2 + 758 mg·Kg -1 Pb 2+ 687 mg·Kg -1 Cd 2+ 4809 mg·Kg -1 Zn 2+ 39 mg·Kg -1 Ni 2+ Heavy metal anions included 46.9 mg·Kg. -1 AsO4 3- 15.2 mg·Kg -1 AsO2 - .

[0046] A mixture sample containing 50% sludge dry weight was filled into the organic biological oxidation chamber (5) of the reactor. Figure 1 Nutrient solids are added to the sludge mixture in a predetermined ratio and stirred until dissolved; the final concentration of the added nutrient substances is 0.8 g·L⁻¹. -1 NaCl, 0.3 g·L -1 MgSO4, 0.5 g·L -1 (NH4)2SO4, 1.0 g·L -1 K2HPO4, 0.6 g·L -1 KH2PO4, 0.06 g·L -1 CaCl2, 0.03 g·L -1FeSO4. Simultaneously, nutrient solution of equal volume to the sludge mixture was added to the cation heavy metal collection chamber (2) and the anode chamber (3), respectively, with the final concentration of each ion in the nutrient solution being consistent with that in the organic biological oxidation chamber (5). Sludge samples were taken, and chloroform was used as the organic extractant to extract the adsorbed residual hydrophobic organic pollutants from the sludge mixture. Sludge samples were then placed in a nutrient solution culture medium at a ratio of 3%, with the composition of various inorganic salts in the medium being the same as the final concentration of the aforementioned nutrient substances in the sludge mixture. The extracted organic pollutants were then added to the nutrient solution culture medium at a ratio of 5%, and 5 g·L⁻¹ was added to the culture medium. -1 Glucose was used as a supplementary carbon source, and cathode and anode electrodes were inserted into the culture system, with an application of 1.0 V·cm⁻¹. -1 The voltage gradient was used to culture the bacteria under aerobic conditions for 21 days. The bacteria were then collected and inoculated into the sludge mixture in the organic biological oxidation chamber (5). After inoculation, the abundance of microorganisms in the sludge mixture reached 10. 7 CFU·g -1 above.

[0047] Anaerobic iron-reducing bacteria ( ) were added to the anionic heavy metal collection and biological attenuation chamber (4). Fontibacter ferrireducens (This strain was purchased from Mingzhou Biotechnology Co., Ltd., product number B64156) bacterial suspension, the bacterial suspension was tested in the above inorganic salt system at 5 g·L⁻¹ -1 Glucose was used as the carbon source substrate and anaerobic fermentation was carried out at 30±2 °C for 32 days to obtain the fermentation broth. The fermentation broth was collected in an anaerobic chamber, and the bacterial cells were collected by centrifugation and resuspended in a nutrient solution with the same nutrient concentration as described above, so that *Ischemic iron-reducing bacillus* (IFF) could be anaerobic. Fontibacter ferrireducens The final concentration reached 2.6 × 10⁻⁶. 7 CFU·L -1 Add anaerobic iron-reducing bacillus ( ). Fontibacter ferrireducens After the bacterial culture is completed, quickly place the sealing cap (6) of the biological attenuation chamber on top of the anion heavy metal collection and biological attenuation chamber (4) and keep it sealed. Connect the reactor electrodes (19, 20) to the DC power supply (10) through the cathode and anode wires (21, 22). Figure 2 Air and nitrogen are introduced into the organic biological oxidation chamber (5) and the anion heavy metal collection and biological attenuation chamber (4) respectively by the biological oxidation chamber ventilation pump (15) and the anion heavy metal collection and biological attenuation chamber ventilation pump (16). The entire system starts operation after being powered on.

[0048] During the operation of the electro-enhanced bioremediation reactor, aliphatic hydrocarbons and polycyclic aromatic hydrocarbons in the organic bio-oxidation chamber (5) are gradually and continuously degraded; heavy metal cations in the organic bio-oxidation chamber (5) migrate to the cation heavy metal collection chamber (2) through the cation exchange membrane partition (7); heavy metal anions in the organic bio-oxidation chamber (5) migrate to the anion heavy metal collection and bio-detoxification chamber (4) through the anion exchange membrane partition (23); at the same time, the stainless steel anode (19) in the anode chamber (3) continuously releases Fe into the solution in the anode chamber (3) through the oxidation process of electro-corrosion. 3+ Fe 3+ Under the influence of an electric field, the heavy metals migrate through the cation exchange separator (7) into the anion heavy metal collection and biological detoxification chamber (4), and gather there to participate in the iron-reducing bacteria's action on heavy metal anions AsO4 under anaerobic conditions. 3- Reduction and attenuation reaction ( Figure 3 In addition, H generated in the anode chamber (3) + It also enters the anion heavy metal collection and biological detoxification chamber (4) through electromigration. Therefore, during the operation of the reactor, the pH change in the anion heavy metal collection and biological detoxification chamber (4) is monitored in real time by pH detector (9), and 2 M NaOH solution is added to the anion heavy metal collection and biological detoxification chamber (4) through pH adjustment hole (11) to adjust the pH of the mixed solution and keep the pH change range of the reactor in the range of 5-9 during operation.

[0049] After power was switched on, the treatment process began. Samples were taken from the organic biological oxidation chamber (5), the cationic heavy metal collection chamber (2), and the anionic heavy metal collection and biological attenuation chamber (4) at 5, 15, 30, 45, and 60 days of treatment, and the contents of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, and heavy metals in the organic pollutants were monitored. The results showed that with the extension of treatment time, the contents of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons in the organic biological oxidation chamber (5) showed a continuous decrease. Figure 4 After 60 days of treatment, the total aliphatic hydrocarbon and polycyclic aromatic hydrocarbon contents decreased to 3735 mg·Kg, respectively. -1 and 579 mg·Kg -1 The degradation rates reached 69.1% and 87.4%, respectively. Significant reductions were observed in all carbon number ranges of aliphatic hydrocarbons, particularly in the recalcitrant macromolecular components in the C31-C35 range, where the degradation rate reached 62.5%. Figure 5 ); Each individual substance in polycyclic aromatic hydrocarbons also exhibits significant degradation characteristics, especially 3-5 ring polycyclic aromatic hydrocarbon molecules, which show significant degradation characteristics. Figure 6 In addition, the abundance of bacteria in the sludge mixture within the biological attenuation chamber (4) was measured and analyzed. The bacterial abundance increased from an initial 7.8 × 10⁻⁶. 7CFU·g -1 (0 days) decreased to 4.78×10 7 CFU·g -1 (60 days) Figure 7 This shows that although the degradation rate of organic pollutants decreased slightly in the later stages ( Figure 4 However, the overall abundance of bacteria and microorganisms remained at a similar high level initially, reflecting the good sustainability of the reactor in this claim for the removal of organic pollutants. Furthermore, the heavy metal cations (Cr) in the biological attenuation chamber (4) 3+ Cu 2+ Pb 2+ Cd 2+ Zn 2+ Ni 2+ ) and heavy metal anions (AsO4) 3- AsO2 - The removal rates of Cr showed a significant decreasing trend with prolonged treatment time, reaching 45.1% (Cr 3+ ), 82.0% (Cu 2+ ), 87.2% (Pb 2+ ), 95.3% (Cd 2+ ), 77.5% (Zn 2+ ), 82.1% (Ni 2+ ), 80.9% (AsO4) 3- ), 66.3% (AsO2) - () Figure 8 and Figure 10 ).

[0050] The aforementioned heavy metals in the cationic heavy metal collection chamber (2) and the anionic heavy metal collection and bio-attenuation chamber (4) were detected respectively. The content of each heavy metal ion in the cationic heavy metal collection chamber (2) reached 193 mg·Kg. -1 Cr 3+ 2498 mg·Kg -1 Cu 2+ 709 mg·Kg -1 Pb 2+ 673 mg·Kg -1 Cd 2+ 3819 mg·Kg -1 Zn 2+ 41 mg·Kg -1 Ni 2+ ( Figure 9 ); Anion heavy metal collection and bio-detoxification chamber (4) AsO4 3- and AsO2 - The concentrations reached 41.6 mg·kg⁻¹.-1 and 6.2 mg·Kg -1 And AsO4 3- and AsO2 - The concentration ratio (AsO4) 3- / AsO2 - The value gradually increased, rising from an initial 3.73 (5 days) to 6.71 (60 days). Figure 11 This reflects the iron-reducing bacteria in the anionic heavy metal collection and biological detoxification chamber (4) utilizing Fe under the stimulation of electric current. 3+ AsO2 - Anaerobic oxidation has a good detoxification effect.

[0051] In summary, the electro-enhanced bioremediation reactor provided by this invention has a good treatment effect on sludge from sewage treatment plants, and is particularly suitable for the degradation of organic pollutants and the removal, collection and detoxification of heavy metal ions in sludge, and has good engineering application potential.

Claims

1. An electro-enhanced bioremediation reactor for wastewater sludge treatment, characterized in that: The device consists of an organic biological oxidation chamber (5) inside the reactor (1), and a cation heavy metal collection chamber (2), an anode chamber (3), and an anion heavy metal collection and biological detoxification chamber (4) between the outer wall of the organic biological oxidation chamber (5) and the reactor (1). A cathode (20) is installed in the cation heavy metal collection chamber (2), and an anode (19) is installed in the anode chamber (3). The electrodes are connected to a DC power supply (10) through wires. Between the organic biological oxidation chamber (5) and the reactor (1), there is a cation heavy metal collection chamber (2), an anode chamber (3) and two anion heavy metal collection and biological detoxification chambers (4); wherein, the cation heavy metal collection chamber (2) and the anode chamber (3) are arranged opposite each other on both sides of the organic biological oxidation chamber (5); The organic biological oxidation chamber (5) and the cation heavy metal collection chamber (2) are separated by a cation exchange membrane partition (7); The organic bio-oxidation chamber (5) and the anode chamber (3) are separated by a stainless steel sealing partition (8); The organic biological oxidation chamber (5) and the anion heavy metal collection and biological detoxification chambers (4) on both sides are separated by anion exchange membrane partitions (23); The anode chamber (3) and the anion heavy metal collection and biological detoxification chamber (4) are separated by a cation exchange membrane partition (7); The cationic heavy metal collection chamber (2) and the anionic heavy metal collection and biological detoxification chambers (4) on both sides are separated by stainless steel sealing partitions (8); The top of the cation heavy metal collection chamber (2) and the anode chamber (3) are not covered, and electrolyte solution is added inside both. Iron-reducing bacteria were inoculated in the anionic heavy metal collection and biological detoxification chamber (4); The stainless steel anode (19) inside the anode chamber (3) continuously releases Fe into the solution inside the anode chamber (3) through an oxidation process of electro-corrosion in the presence of electrolyte. 3+ Fe 3+ Under the influence of an electric field, the metals migrate through the cation exchange membrane septum (7) into the anion heavy metal collection and biological detoxification chamber (4), where they gather to participate in the oxidation of arsenate ions by iron-reducing bacteria under anaerobic conditions.

2. The electro-enhanced bioremediation reactor for sludge treatment in water plants according to claim 1, characterized in that: A drain hole (26) is provided at the bottom of the reactor side wall of any one of the anionic heavy metal collection and biological detoxification chambers (4).

3. The electro-enhanced bioremediation reactor for sludge treatment in water plants according to claim 1, characterized in that: The organic biological oxidation chamber (5) is a biodegradation chamber for organic pollutants in sludge by electric field enhancement. It is equipped with an aeration disc (17) at the bottom and an aeration hole (18) on the aeration disc (17). The aeration disc (17) is connected to the air supply source through the air passage (13) of the biological oxidation chamber that passes through the outer wall of the organic biological oxidation chamber (5) and the anion heavy metal collection and biological detoxification chamber (4) and is distributed along the outer wall of the reactor (1). The bottom of the organic biological oxidation chamber (5) is equipped with a sludge discharge pump (25) to assist in the discharge of sludge. The sludge discharge pump (25) is connected to the sludge discharge pipe (24) to discharge the treated sludge. The sludge discharge pipe (24) is connected to the outer chamber of the organic biological oxidation chamber (5) and the reactor (1).

4. The electro-enhanced bioremediation reactor for sludge treatment in water plants according to claim 3, characterized in that: The bio-oxidation chamber ventilation duct (13) is equipped with a bio-oxidation chamber ventilation pump (15) that provides gas supply power.

5. The electro-enhanced bioremediation reactor for sludge treatment in water plants according to claim 1, characterized in that: The anion heavy metal collection and biological detoxification chamber (4) is symmetrically distributed on both sides of the organic biological oxidation chamber (5) to collect anions and heavy metal anions in sludge. The top of the anion heavy metal collection and biological detoxification chamber (4) is designed with a biological detoxification chamber sealing cover (6). The biological detoxification chamber sealing cover (6) is provided with a pH adjustment hole (11) and an automatic venting valve (12). A pH detector (9) is designed on the side wall of the anion heavy metal collection and biological detoxification chamber (4). A drain hole (26) is provided at the bottom of the side wall. The anion heavy metal collection and biological detoxification chamber ventilation channel (14) is distributed upward along the outer wall of the reactor (1) and connected to the N2 source.

6. The electro-enhanced bioremediation reactor for sludge treatment in water plants according to claim 5, characterized in that: The anion heavy metal collection and biological detoxification chamber ventilation duct (14) is equipped with an anion heavy metal collection and biological detoxification chamber ventilation pump (16) to provide power for the introduction of nitrogen into the anion heavy metal collection and biological detoxification chamber (4) for deoxygenation.

7. The electro-enhanced bioremediation reactor for sludge treatment in water plants according to claim 1, characterized in that: The initial inoculation abundance of iron-reducing bacteria reached 10. 7 CFU·mL -1 above.

8. The application of the electro-enhanced bioremediation reactor for sludge treatment in water plants as described in claim 1, characterized in that: The reactor is used for electrodynamically enhanced bioremediation of organic pollutants and / or inorganic heavy metal ions in sludge from wastewater treatment plants.

9. The application of the electro-enhanced bioremediation reactor for sludge treatment in water plants according to claim 8, characterized in that: Sludge from the wastewater treatment plant to be treated is added to the organic biological oxidation chamber (5) of the device described in claim 1. The sludge is then subjected to gradual and continuous degradation of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons by microorganisms within the organic biological oxidation chamber (5) via an external current. Heavy metal cations in the organic biological oxidation chamber (5) migrate through the cation exchange membrane partition (7) to the cation heavy metal collection chamber (2). Heavy metal anions in the organic biological oxidation chamber (5) migrate through the anion exchange membrane partition (23) to the anion heavy metal collection and biological detoxification chamber (4). Simultaneously, the stainless steel anode (19) in the anode chamber (3) continuously releases Fe into the solution within the anode chamber (3) through an electro-corrosion oxidation process in the presence of electrolyte. 3+ Fe 3+ Under the action of an electric field, the cation exchange membrane septum (7) migrates into the anion heavy metal collection and biological detoxification chamber (4) and gathers here to participate in the oxidation of arsenate ions by iron-reducing bacteria under anaerobic conditions, thereby realizing the electrodynamic enhanced biological remediation of organic pollutants and / or inorganic heavy metal ions in the sludge of the sewage treatment plant.

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