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Qin Z, Zhao Z, Xia L, Adam A, Li Y, Chen D, Mela SM, Li H. The dissipation and risk alleviation mechanism of PAHs and nitrogen in constructed wetlands: The role of submerged macrophytes and their biofilms-leaves. Environ Int 2019; 131:104940. [PMID: 31284108 DOI: 10.1016/j.envint.2019.104940] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/18/2019] [Accepted: 06/16/2019] [Indexed: 06/09/2023]
Abstract
The role of submerged macrophytes (Vallisneria natans, Hydrilla verticillata and artificial plant) and their biofilms-leaves for the dissipation and risk alleviation mechanism of PAHs (phenanthrene and pyrene) and nitrogen in constructed wetland systems with PAH-polluted sediments were investigated. Biofilms-leaves/surface might contribute to PAHs degradation, which was positively correlated with PAHs degrading bacteria. Nitrogen-fixing bacteria in biofilms on surface might cause total nitrogen in sediment (TNs) increasing by 4% from 14th d to 28th d indirectly when suffering PAHs pollution. The relative abundance of nitrogen-fixing bacteria significantly increased with the increase of PAHs concentrations in early period (p < 0.01), which might lead to risk of nitrogen accumulation further. Heat maps showed that the relative abundance of functional bacteria were influenced in order of attached surface > incubation time > spiking concentration of PAHs. Interestingly, differences of deduced bacterial functions were affected in order of incubation time > attached surface > spiking concentration. Thus, submerged macrophytes and their biofilms on leaves not only played an important role in PAHs degradation, but also regulated the nitrogen cycling in constructed wetland systems, which could reduce these pollutants risk for natural environment, organisms and human health.
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Affiliation(s)
- Zhirui Qin
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Zhenhua Zhao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China; Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA.
| | - Liling Xia
- Nanjing Institute of Industry Technology, Nanjing 210016, PR China
| | - Abduelrahman Adam
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Yong Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Deqiang Chen
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Sara Margaret Mela
- Department of Geography and Earth Sciences, Aberystwyth University, Penglais, Aberystwyth, Ceredigion, SY23 3DB, UK
| | - Hui Li
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA
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