1. Study on the purification mechanism for ammonia nitrogen in micro-polluted rivers by herbaceous plant - Rumex japonicus Houtt.
- Author
-
Zhang, Xiangyang, Wang, Huiliang, Zhang, Wei, Lv, Hong, and Lin, Xiaoying
- Subjects
- *
HERBACEOUS plants , *RUMEX , *AMMONIA , *NITRITES , *NITRIFYING bacteria , *NITROGEN - Abstract
Water eutrophication caused by nitrogen pollution is an urgent global issue that requires attention. The Qingyi River is a typical micro-polluted river in China. In this study, we took this river as the research object to investigate the nitrogen pollution purification capacity of a herbaceous plant, Rumex japonicus Houtt. (RJH). Compared to nitrate nitrogen (NO 3 −-N) and nitrite nitrogen (NO 2 −-N), RJH showed better purification performance on total nitrogen (TN), total phosphorus (TP) and ammonia nitrogen (NH 4 +-N), with a highest removal rate of 37.22%, 52.13%, and 100%, respectively. RJH could completely remove ammonia nitrogen and exhibit excellent resistance to pollutant interference when the initial concentration of ammonia nitrogen in the cultivation devices increased from 1 mg/L to 10 mg/L or in the actual river. This indicated the great application potential of RJH in ammonia nitrogen removal from natural micro-polluted rivers. In addition, combined effects of nitrification of roots, absorption of self-growth, stripping, and others contributed to nitrogen removal by RJH. Particularly, the nitrification of roots played a dominant role, accounting for 73.85% ± 8.79%. High-throughput sequencing results indicate that nitrifying bacteria accounted for over 75% of all bacterial species in RJH. Furthermore, RJH showed good growth status and strong adaptability. The correlation coefficients of its relative growth rate with chlorophyll A and the degradation rate of absorption were 0.9677 and 0.9594, respectively. Our research demonstrates that RJH is one of the excellent varieties for ammonia removal. This provides a very promising and sustainable method for purifying micro-polluted rivers. [Display omitted] • A Rumex japonicus Houtt.(RJH)-based phytoremediation technology was proposed. • Nitrification, absorption, stripping and other effects influenced ammonia removal. • Nitrification of roots accounted for 73.85% ± 8.79% of the total degradation rate. • The good growth status and strong purification ability of RJH were verified. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF