人工湿地（CW）和微生物燃料电池（MFC）的结合形成了CW-MFC系统，该系统能够充分利用两者的优势，具有构造成本低、运行维护简单、没有二次污染等优点。CW-MFC具有处理重金属废水的功能，湿地植物的引入不仅为微生物提供了更好的生存场所，同时对提升系统产电性能和重金属去除起到重要作用。通过植物根部的泌氧（ROL）向CW-MFC系统的阴极区域输送氧分子，有助于提高产电，从而促进铜离子定向迁移和阴极还原去除。本项研究设置了四组实验，分别为：M1（未种植任何植物的对照组）、M2（种植风车草）、M3（种植美人蕉）和M4（种植鸢尾），深入探究植物类型及根系氧气释放对铜离子废水处理和电能的提升作用及其相关机制。实验主要研究结果如下：

（1）CW-MFC中的3种植物展现了差异化的金属耐受性。当暴露于铜离子浓度为100 mg/L的环境中时，美人蕉与鸢尾的叶子出现了黄化和枯萎现象。相比之下，风车草即使在同等浓度的铜污染水质中，也展示了显著的适应能力。这种差异可能源自于风车草根部表皮细胞的松散排布，这一结构有助于氧气更有效地分散，从而增强了其在恶劣环境下的生存能力。

（2）植物类型对CW-MFC处理含Cu²⁺的废水具有显著影响，不同植物CW-MFC系统对Cu²⁺的去除效率表现为M2> M3> M4> M1。湿地植物可以显著促进湿地对水体中Cu²⁺的去除，而植物ROL是根表铁膜形成的主要因素之一，根表铁膜中Fe含量的增加有利于促进Cu²⁺在根表沉积，在一定程度上可以抑制Cu²⁺进入植物体内，但ROL促进植物吸收Cu²⁺的强度远大于根表铁膜抑制植物吸收Cu²⁺的强度。在较低的Cu²⁺浓度（15 mg/L和50 mg/L）环境下时，观察到风车草展现出优异的Cu²⁺去除能力，主要归因于其较高的ROL含量。当Cu²⁺浓度提升至100 mg/L，风车草相较于其他种植物表现出更强的金属耐受性，这一特性不仅源于其较高的ROL含量，并且ROL会提高阴极电势，增加植物的产电并且促进Cu²⁺的去除。

（3）在CW-MFC系统中加入植物之后，系统的电化学性质受到了ROL的正面影响。实验结果表明，种植植物的CW-MFC系统在产电电压、功率密度和极化性能方面均显著超越了无植物对照系统，展示了植物对提升CW-MFC性能的关键作用。比较了不同植物对CW-MFC性能的影响，当Cu²⁺浓度为50 mg/L时，风车草因其较高的ROL值而达到最优的电压表现（530 mV），最大产电功率密度为48.6 mW/m²，而种植美人蕉和鸢尾的CW-MFC系统的最大的电压为523 mV和489 mV，对应的最大功率密度为42.3 mW/m²和31.9 mW/m²。极化和功率密度曲线的表现也呈现出一致的上升趋势，这进一步说明了ROL对系统电化学性能的改善和增强。

（4）植物根系效应显著增强了CW-MFC系统阴极区的微生物群落多样性，特别是在植入风车草的CW-MFC系统中更为明显。表明了植物ROL在促进CW-MFC内部微生物环境平衡中的重要作用，Proteobacteria、Bacteroidetes、Actinobacteria以及Chloroflexi等微生物的相对丰富度远超过空白对照组。阳极样本中的比较也显示，风车草系统的微生物组成丰富度最为突出。

The combination of constructed wetland and microbial fuel cell forms the CW-MFC system, which can make full use of the advantages of both, and has the advantages of low construction cost, simple operation and maintenance, and no secondary pollution. Microbial fuel cells have the function of treating heavy metal wastewater. The introduction of wetland plants not only provides a better living place for microorganisms, but also plays an important role in improving the electrical production performance of the system and removing heavy metals. By providing oxygen to the cathode region of CW-MFC through ROL, plants can significantly enhance the activity of aerobic microbial communities,and promote the effective removal of copper ion (Cu²⁺) in wastewater. In this study, four different reactors were designed: M1 (blank control group, non-planted plants), M2 (Cyperus involucratus Rottboll), M3 (Canna indica L), and M4 (Iris tectorum) to further investigate the effect of plant ROL on simultaneously removing Cu²⁺ wastewater and promoting voltage generation and the mechanism behind it. The main research contents and results are as follows:

(1) The three species of plants in the wetland ecosystem showed differentiated resistance. When exposed to copper concentrations up to 100mg/L, the leaves of canna and iris showed yellowing and wilting. In contrast, pinmill grass showed remarkable resilience even in water contaminated with the same concentration of copper. The difference may be due to the loose arrangement of epidermal cells in the root of the windmill, a structure that helps distribute oxygen more efficiently, enhancing its ability to survive harsh environments.

(2) Plant type has a significant effect on the treatment of Cu²⁺ containing wastewater by CW-MFC, and the removal efficiency of CW-MFC system for different plants is M2> M3> M4> M1. ROL of wetland plants can significantly promote Cu²⁺ absorption by wetland plants, and is one of the main factors for the formation of iron film on root surface. The increase of Fe content in iron film on root surface is conducive to promoting the deposition of Cu²⁺ on root surface, and can inhibit the entry of Cu²⁺ into plants to a certain extent. The effect of ROL on Cu²⁺ absorption was much greater than the effect of iron membrane on Cu²⁺ absorption. At low Cu²⁺ concentrations (15 mg/L and 50 mg/L), it was observed that Cyperus involucratus Rottboll exhibited excellent Cu²⁺ removal ability, mainly due to its high ROL content. When Cu²⁺ concentration is increased to 100 mg/L, Cyperus involucratus Rottboll exhibits stronger metal tolerance than other plants, which is not only due to its higher ROL content, but also because ROL can increase the cathode potential, increase plant electricity production and promote Cu²⁺ directed removal.

(3) After the addition of plants to the CW-MFC system, the electrochemical properties of the system are significantly positively affected by plant root oxygen secretion (ROL). The experiments show that the CW-MFC system with plants significantly outperforms the control system without plants in terms of voltage, power density and polarization performance, demonstrating the key role of plants in improving the performance of CW-MFC. When comparing the effects of different species of plants on CW-MFC performance, when Cu²⁺ concentration is 50 mg/L, Cyperus involucratus Rottboll achieves the optimal voltage performance (530 mV) and power density performance (48.6 mW/m²) due to its higher ROL value, while the maximum voltage of Cannas and iris is 523 mV and 489 mV. The corresponding maximum power densities are 42.3 mW/m² and 31.9 mW/m². The polarization and power density curves also show a consistent upward trend, which further explains the improvement and enhancement of the electrochemical performance of the system.

(4) Plant root oxygen secretion (ROL) significantly enhanced the microbial community diversity in the cathode region of CW-MFC system, especially in the CW-MFC system implanted with Cyperus involucratus Rottboll. This indicates that ROL plays an important role in promoting the balance of microbial environment in CW-MFC.The relative abundance of Proteobacteria, Bacteroidetes, Actinobacteria and Chloroflexi is much higher than that of the blank control group. The comparison of the anode samples also showed that the microbial composition of the Cyperus involucratus Rottboll system was the most prominent.