[Removal and accumulation of the tetracycline resistance gene in vertical flow constructed wetland].

This paper investigated the efficiency and accumulation of vertical flow constructed wetland on removing tetracycline resistance (tet) genes (tetM, tetO, and tetW) from swine wastewater. The result indicated that all three tet genes were detected in raw wastewater, average absolute abundances of tetW, tetM, and tetO were 1.07 x 10(10), 4.03 x 10(10) and 4.92 x 10(10) gene copies per litre, respectively. Vertical flow constructed wetland could significantly reduce the content of wastewater antibiotics resistance genes, and average elimination rates were 95.73%, 92.21% and 95.05%, respectively. Compare to the content of antibiotics resistance genes in unpolluted soil, the content of that in soil of the system had an obvious increase at the end stage of this study. Meanwhile, absolute abundances and relative abundances of three tet genes in surface layer of soil were higher than that in basement soil. The control condition and structure of construct wetlands would affect the accumulation of tetracycline resistance genes in the system.