Carbon source effects on nitrogen transformation processes and the quantitative molecular mechanism in long-term flooded constructed wetlands
| Autor: | Guodong Ji, Shengjie Li, Xianfang Zhu, Zhongxin Luo |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Environmental Engineering
Denitrification 0208 environmental biotechnology food and beverages chemistry.chemical_element 02 engineering and technology 010501 environmental sciences Management Monitoring Policy and Law 01 natural sciences Nitrogen Husk 020801 environmental engineering Denitrifying bacteria chemistry.chemical_compound chemistry Nitrate Environmental chemistry Constructed wetland Sewage treatment Nitrification 0105 earth and related environmental sciences Nature and Landscape Conservation |
| Zdroj: | Ecological Engineering. 123:19-29 |
| ISSN: | 0925-8574 |
| DOI: | 10.1016/j.ecoleng.2018.08.011 |
| Popis: | The effect of adding rice husk as an electron donor on the genetic and metabolic diversity of denitrifying communities in a long-term flooded constructed wetland (D1) was compared with the control group without external carbon source addition (D2). The underlying molecular mechanisms responsible for nitrate removal were quantified under different nitrate loading rates. The results showed that D1 achieved higher and more stable removal efficiencies for NO3−-N (90–97%) and total nitrogen (73–87%) under different nitrate loading rates, which were approximately 10 times higher than those of D2. This corresponded with much higher absolute abundances of bacterial and nitrogen functional genes in D1 than D2. Additionally, the vertical distribution of microbial communities in D1 and D2 showed significant differences. This pattern suggested that adding rice husk in flooded CWs had beneficial effects on the denitrifying community. Quantitative response relationships and network analysis indicated that denitrification was the dominant nitrogen removal pathway. Moreover, the present study indicated that using rice husk as an external carbon source could be conducive to completing the nitrification process, which was first confirmed at the molecular level. The present study indicated that using rice husk as an external carbon source can significantly enhance denitrification rates and thus improve nitrogen removal in CWs for wastewater treatment process. |
| Databáze: | OpenAIRE |
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