Search

CN-122010304-A - Bioelectrochemistry coupled iron-based constructed wetland device and application

CN122010304ACN 122010304 ACN122010304 ACN 122010304ACN-122010304-A

Abstract

The invention discloses a bioelectrochemical coupling iron-based constructed wetland device and application thereof, the device comprises a container, a water supply device is arranged at the top of the container, a supporting layer is paved at the inner bottom of the container, bioelectrochemical units and a gravel layer are paved on the supporting layer in sequence, aquatic plants are planted on the gravel layer, a plurality of water outlets are arranged on the container wall at positions corresponding to the bioelectrochemical units, wherein the bioelectrochemical units are formed by paving an upper cathode layer, an anode layer and a lower cathode layer in sequence from top to bottom, electrodes are horizontally embedded in each layer and are electrically connected with a power supply outside the container, and an aerator is further embedded in the anode layer and connected with an air compressor outside the container through a ventilation pipeline. The device can realize synchronous and efficient removal of various pollutants through coupling of a multi-electrode bioelectrochemical structure, a controllable aerobic environment and iron-based filler chemical catalysis, and simultaneously can quickly respond to water quality change by adjusting voltage and an aeration strategy, and is suitable for treating eutrophication water bodies with complex components.

Inventors

  • SONG NA
  • ZHOU SHENGKAI
  • YANG JINYAN
  • LV WEN
  • LIU SHUAI
  • WANG SICHENG

Assignees

  • 南京师范大学
  • 江苏省水文水资源勘测局苏州分局

Dates

Publication Date
20260512
Application Date
20260116

Claims (10)

  1. 1. The bioelectrochemistry coupling iron-based constructed wetland device is characterized by comprising a container (16), wherein the top of the container is provided with a water supply device (1), a supporting layer (9) formed by gravels or gravels is paved at the inner bottom of the container, bioelectrochemical units and a gravel layer (15) are paved on the supporting layer (9) in sequence, aquatic plants are planted in the gravel layer (15), and a plurality of water outlets (10) are formed in the wall of the container (16) and correspond to the bioelectrochemical units; The bioelectrochemical unit is formed by sequentially paving a lower cathode layer (8) formed by pyrite, an anode layer (7) formed by volcanic and an upper cathode layer (6) formed by iron-based filler from bottom to top, electrodes are horizontally embedded in each layer, a series resistor (5) is connected between the cathode electrode (4) and a power supply (2) outside a container (16) in series, the anode electrode (3) is directly and electrically connected with the power supply (2), an aerator (12) is embedded in the anode layer (7), and the aerator is connected with an air compressor (14) outside the container (16) through a ventilation pipeline (13).
  2. 2. The apparatus of claim 1, wherein the iron-based filler is scrap iron, pyrite, or a scrap iron-biochar mixture.
  3. 3. The device of claim 2, wherein when the iron-based filler is a mixture of iron filings and biochar, the mass ratio of the iron filings to the biochar is 6-10:1.
  4. 4. The device according to claim 1, characterized in that the thickness of the supporting layer (9) is 3-7 cm, the thickness of each layer in the bioelectrochemical cell is 10-20 cm, and the thickness of the gravel layer (15) is 3-7 cm.
  5. 5. The device according to claim 1, wherein the particle size of crushed stone or gravel in the supporting layer (9) is 10-20 mm, the particle size of pyrite ore in the lower cathode layer (8) is 8-10 mm, the particle size of volcanic rock in the anode layer (7) is 6-10 mm, the particle size of iron-based filler in the upper cathode layer (6) is 3-8 mm, and the particle size of gravel in the gravel layer is 10-20 mm.
  6. 6. The device according to claim 1, wherein the cathode electrode (4) and the anode electrode (3) are graphite felt electrodes with a length of 15-20 cm, a width of 5-10 cm and a thickness of 0.3-0.7 cm.
  7. 7. The device according to claim 1, wherein the power supply (2) is a voltage-adjustable power supply, and the resistance value of the resistor (5) is 500-1500 Ω.
  8. 8. The apparatus of claim 1, wherein the aquatic plants comprise any one or more of canna, calamus, reed.
  9. 9. The method for treating the eutrophic sewage is characterized by comprising the following steps: s1, inoculating activated sludge in the bioelectrochemical coupling iron-based constructed wetland device according to any one of claims 1-8, performing microbial domestication, then adding eutrophic sewage until the sewage passes through a gravel layer, standing for 36-60 hours, and then evacuating; s2, continuously supplying the nutrient-rich sewage to be treated through a water supply device (1) for treatment.
  10. 10. The method for treating nutrient-rich sewage as claimed in claim 9, wherein in the step S2, the hydraulic retention time of the nutrient-rich sewage is 24 to 48 hours.

Description

Bioelectrochemistry coupled iron-based constructed wetland device and application Technical Field The invention relates to an artificial wetland, in particular to an iron-based artificial wetland device with bioelectrochemical coupling and application thereof. Background Eutrophic water bodies such as rivers, lakes, offshore areas, aquaculture tail water and the like commonly have the problem of combined pollution of high ammonia nitrogen, high Chemical Oxygen Demand (COD), high phosphorus and residual antibiotics. The constructed wetland technology is widely applied to the treatment of the wastewater due to the advantages of low cost, simple operation and maintenance and the like. The constructed wetland filler, in particular to the iron-based filler plays a key role in the denitrification and dephosphorization of the wetland, can promote autotrophic denitrification through the circulation of iron and sulfur, and has good adsorption effect on phosphorus. Further, there is a study on introducing a bioelectrochemical system into an ecological treatment of an artificial wetland in order to enhance electron transfer and pollutant conversion in the wetland system through electrode reaction. However, constructed wetland systems coupled with conventional two-electrode bioelectrochemical systems are often limited by their single electron transfer path and simple redox environment, and have significant shortcomings in terms of electron utilization efficiency and synergistic removal of various pollutants. Meanwhile, the treatment efficiency is difficult to flexibly adjust according to the water inlet load, so that the adaptability of the system to the change of the running condition is poor, and the practical application is limited. Disclosure of Invention The invention aims to provide an iron-based constructed wetland device coupled with a multi-electrode bioelectrochemical system, which can flexibly adjust treatment efficiency, and the second aim is to provide the application of the device in the treatment of eutrophic sewage. The bioelectrochemical coupling iron-based constructed wetland device comprises a container, wherein a water supply device is arranged at the top of the container, a supporting layer formed by gravels or gravels is paved at the inner bottom of the container, bioelectrochemical units and a gravel layer are paved on the supporting layer in sequence, aquatic plants are planted on the gravel layer, a plurality of water outlets are formed in positions, corresponding to the bioelectrochemical units, on the container wall, of the container, the bioelectrochemical units are formed by paving a lower cathode layer formed by pyrite, an anode layer formed by volcanic and an upper cathode layer formed by iron-based filler in sequence from bottom to top, electrodes are buried horizontally in each layer, the cathode electrodes are electrically connected with a power supply outside the container through series resistors, the anode electrodes are directly and electrically connected with the power supply, and an aerator is buried in the anode layer and connected with an air compressor outside the container through a ventilation pipeline. In the bioelectrochemical unit, the iron pyrite in the lower cathode layer can be further denitrified under anaerobic environment, the oxidation product Fe 2O3 can adsorb phosphorus-containing pollutants, the volcanic in the anode layer has a porous structure, nitrifying bacteria can be attached, an aerator paved in the anode region is combined, a proper aerobic environment is created for the nitrifying bacteria, NH 4+ -N can be promoted to be converted into NO 3- -N, and the iron-based filler in the upper cathode layer can promote the generation of hydroxyl free radicals under aerobic cathode condition, so that antibiotics are degraded. Preferably, the iron-based filler is scrap iron, iron pyrite or a scrap iron-biochar mixture, and further preferably, when the iron-based filler is scrap iron and biochar mixture, the mass ratio of the scrap iron to the biochar is 6-10:1. Preferably, the thickness of the supporting layer is 3-7 cm, the thickness of each layer in the bioelectrochemical unit is 10-20 cm, and the thickness of the gravel layer is 3-7 cm. Preferably, the particle size of gravels or gravels in the supporting layer is 10-20 mm, the particle size of pyrite in the lower cathode layer is 8-10 mm, the particle size of volcanic rocks in the anode layer is 6-10 mm, the particle size of iron-based fillers in the upper cathode layer is 3-8 mm, and the particle size of gravels in the gravel layer is 10-20 mm. Preferably, the cathode electrode and the anode electrode are graphite felt electrodes with the length of 15-20 cm, the width of 5-10 cm and the thickness of 0.3-0.7 cm. Preferably, the power supply is a voltage-adjustable power supply, the resistance value of the resistor is 500-1500Ω, and further preferably, the voltage range of the power supply adjustable is 10-30V,