Constructed wetland microbial fuel cell coupling system and sewage treatment method

Abstract

The invention discloses a biological cathode strengthened type constructed wetland microbial fuel cell coupling system and a sewage treatment method. The system is characterized in that the system isprovided with a first gravel layer, a positive pole, a second gravel layer, a negative pole and emergent aquatic plants sequentially along the water flow direction, a water inlet and a water outlet are positioned below the first gravel layer and above the second gravel layer respectively, and the positive pole is connected with the negative pole through an external circuit. The dissolved oxygen concentration of a negative pole area is increased by hydraulically driving the negative pole to rotate, the oxygen utilization rate is increased through secretases of microorganisms on the negative electrode, a wetland substrate provides a great place for microorganism growth, microorganism activity is improved by root system sediments and an oxygen secretion function of wetland plants, and accordingly purification effects and power generation performance of the coupling system are improved.

Description

technical field [0001] The invention belongs to the technical field of sewage treatment, and relates to a sewage treatment device and a sewage treatment method, in particular to a hydraulically driven rotating air biological cathode enhanced artificial wetland microbial fuel cell coupling system and an organic sewage treatment method. Background technique [0002] In the traditional constructed wetland microbial fuel cell coupling system, the substrate of the constructed wetland with a large specific surface area is inhabited by rich and diverse microorganisms, which increases the number and biodiversity of microorganisms in the microbial fuel cell; the secreted sediments of plant roots are anode microorganisms The organic carbon source is provided as a co-substrate, which improves the microbial activity and the removal effect of pollutants. The oxygen secretion of the root system and the reoxygenation of the atmosphere provide a good aerobic environment for the degradation o...

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Problems solved by technology

Pratiksha Srivastava et al. used platinum as the cathode catalyst to obtain three times the power density, but its popularization was limited due to the expensive price of platinum.

Non-noble metal oxides have a wide range of sources and low prices. Liu et al. studied the influence of the morphology and size of the MnOx catalyst on its oxygen reduction performance, and the power density can reach 772 mW / m 3 , but the catalyst is prone to poisoning and failure, and the practical application is not long-term effective

Some researchers use algal photosynthesis to generate oxygen to supply oxygen to the cathode area. Compared with traditional mechanical oxygen supply, the concentration of dissolved oxygen in the cathode chamber of algae photosynthetic cathode fuel cell can reach 20 mg / L, but considering the artificial wetland The shading effect of emergent plants, algae cathode is not suitable for promotion in constructed wetlands

Photocatalytic cathodes can significantly improve the power generation performance of microbial fuel cells and completely degrade organic matter in water, but they are also affected by light like algae cathodes, so they are not suitable for promotion in constructed wetlands

Studies have found that microorganisms can secrete some enzymes to improve the utilization rate of oxygen. Some researchers have used biocathodes to provide electricity generation and purification effects, but they cannot increase the concentration of dissolved oxygen in the cathode area.

Some researchers increase the dissolved oxygen concentration of the cathode by means of aeration, electric drive rotating cathode, etc., but additionally increase the consumption of electric energy

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