三种挺水植物对CW-MFC耦合系统脱氮及产电性能的影响

为探究不同植物类型对人工湿地微生物燃料电池系统(CW-MFC)耦合系统脱氮和产电性能的影响及机制,分别以芦苇(reed)、千屈菜(Lythrum salicaria)和美人蕉(Canna indica)构建3组CW-MFC小试系统,依次标记为CM-R、CM-L及CM-C。结果显示:(1) CW-MFC耦合系统的输出电压和功率密度呈现CM-L>CMC>CM-R;(2) CM-R耦合系统的NH₄⁺-N和TN去除率(76.8±9.9)%;(54.2±8.2)%]显著高于CM-L(61.2±8.0)%;(43.1±6.5)%]高于CM-C(58.9±9.5)%;(42.0±9.8)%], P<0.01;(3)植物生长速率整体表现为CM-R>CM-C>CM-L,并且千屈菜(CM-L)的叶片中MDA含量最高,代表其受损害程度可能较高;(4)地杆菌属(Geobacter)作为典型的产电菌属,在3个耦合系统中均具有较高丰度(4.45%—7.64%),并且其相对丰度大小与输出电压和功率密度大小变化趋势一致,此外, CM-R中...

THREE EMERGENT AQUATIC PLANTS ON NITROGEN REMOVAL AND ELECTRICITY GENERATION PERFORMANCE OF CW-MFC COUPLING SYSTEM

To explore the effects and mechanisms of different wetland plants on nitrogen removal and electricity generation performance of CW-MFC coupling system, three groups of CW-MFC pilot systems were constructed with reed, Lythrum salicaria, and Canna indica, which were recorded as CM-R, CM-L, and CM-C, respectively. The results revealed that: 1) the output voltage and power density of CW-MFC coupling system were CM-L>CM-C>CM-R; 2) the NH₄+-N and TN removal rates of CM-R coupling system (76.8±9.9)%; (54.2±8.2)%] were higher than that of CM-L system (61.2±8.0)%; (43.1±6.5)%], which were higher than that of CM-C system (58.9±9.5)%; (42.0±9.8)%], P<0.01; 3) the overall growth rate of plants was CM-R> CM-C>CM-L, and the MDA content was the highest in the leaves of Lythrum salicaria (CM-L), indicating that the degree of its damage may be higher; 4) Geobacter, as a typical electrogenesis genus, had a high abundance (4.45% to 7.64%) in all three coupling systems, and its abundance was consistent with the change trend of output voltage and power density, whereas the relative abundance of Acinetobacter and Flavobacterium in CM-R was 21.10% and 14.37%, significantly higher than that of the other two systems (CM-L: 0.33% and 0.10%; CM-C: 0.75% and 0.07%), which was the most dominant genus of denitrification bacteria in CM-R; 5) combined with the FACOPTAX predictions, a total of 47 functional groups including chemoheterotrophy, aerobic chemoheterotrophy, iron respiration, nitrate reduction and nitrogen respiration were detected, and the results also showed that the functional groups of the CM-R were quite different from the other two systems, among which the functional groups of chemoheterotrophy and aerobic chemoheterotrophy accounted for a relatively high proportion in CM-R. The results will help to strengthen plant understanding of the effects of electrogenesis and denitrification performance on the CW-MFC coupling system.