School of Environmental Science and Engineering, Shanghai Jiao Tong University, Dong Chuan Road 800, Shanghai, 200240, People's Republic of China.
Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, People's Republic of China.
Environ Sci Pollut Res Int. 2021 Apr;28(14):17878-17890. doi: 10.1007/s11356-020-12177-x. Epub 2021 Jan 5.
Floating treatment wetland (FTW) in restoration of low C/N ratio wastewater was deemed to a frequently used method. However, the nitrate removal performance in floating beds was limited due to insufficient organic carbon sources. Iron scraps as a potential electron donor was beneficial to the NO-N reduction. To research the removal performance and mechanism of denitrification in FTW with iron scraps, FTW with Iris pseudacorus was built, and iron scraps were added as an electron donor to improve nitrogen removal efficiency. The batch experimental results demonstrated that the proper mass ratio of iron scraps to NO-N was 500:1. With iron scraps, the NO-N removal efficiency of FTW and control system increased significantly to 98.04% and 44.42% respectively in 2 weeks, while there was no obvious influence on the removal of NH-N. After adding iron scraps, the proportion of bacteria in the systems related to iron cycle and the relative abundance of nitrifying and denitrifying bacteria have increased obviously. By calculating the nitrogen balance, nitrogen reduction via plant uptake accounted for 8.79%, and the microbial denitrification was the main nitrogen removal pathway in FTW.
浮床湿地（FTW）在修复低 C/N 废水方面被认为是一种常用的方法。然而，由于有机碳源不足，浮床中的硝酸盐去除性能受到限制。铁屑作为一种潜在的电子供体有利于硝酸盐氮的还原。为了研究 FTW 中铁屑的反硝化去除性能和机制，构建了以鸢尾为植物的 FTW，并添加铁屑作为电子供体来提高氮去除效率。批实验结果表明，铁屑与硝酸盐氮的适宜质量比为 500:1。在 2 周内，添加铁屑后，FTW 和对照组的硝酸盐氮去除效率分别显著提高到 98.04%和 44.42%，而对氨氮的去除没有明显影响。添加铁屑后，与铁循环相关的系统中细菌的比例以及硝化和反硝化细菌的相对丰度明显增加。通过计算氮平衡，植物吸收的氮占 8.79%，微生物反硝化是 FTW 中主要的氮去除途径。
