Objective: This study was to assess the influence of interaction of combination of immobilized nitrogen cycling bacteria (INCB) with aquatic macrophytes on nitrogen removal from the eutrophic waterbody, and to get insight into different mechanisms involved in nitrogen removal.
Methods: The aquatic macrophytes used include Eichhornia crassipes (summer-autumn floating macrophyte), Elodea nuttallii (winter-growing submerged macrophyte), and nitrogen cycling bacteria including ammonifying, nitrosating, nitrifying and denitrifying bacteria isolated from Taihu Lake. The immobilization carriers materials were made from hydrophilic monomers 2-hydroxyethyl acrylate (HEA) and hydrophobic 2-hydroxyethyl methylacrylate (HEMA). Two experiments were conducted to evaluate the roles of macrophytes combined with INCB on nitrogen removal from eutrophic water during different seasons.
Results: Eichhornia crassipes and Elodea nuttallii had different potentials in purification of eutrophic water. Floating macrophyte+bacteria (INCB) performed best in improving water quality (during the first experiment) and decreased total nitrogen (TN) by 70.2%, nitrite and ammonium by 92.2% and 50.9%, respectively, during the experimental period, when water transparency increased from 0.5 m to 1.8 m. When INCB was inoculated into the floating macrophyte system, the populations of nitrosating, nitrifying, and denitrifying bacteria increased by 1 to 2 orders of magnitude compared to the un-inoculated treatments, but ammonifying bacteria showed no obvious difference between different treatments. Lower values of chlorophyll a, COD(Mn), and pH were found in the microbial-plant integrated system, as compared to the control. Highest reduction in N was noted during the treatment with submerged macrophyte+INCB, being 26.1% for TN, 85.2% for nitrite, and 85.2% for ammonium at the end of 2nd experiment. And in the treatment, the populations of ammonifying, nitrosating, nitrifying, and denitrifying bacteria increased by 1 to 3 orders of magnitude, as compared to the un-inoculated treatments. Similar to the first experiment, higher water transparency and lower values of chlorophyll a, COD(Mn) and pH were observed in the plant+ INCB integrated system, as compared to other treatments. These results indicated that plant-microbe interaction showed beneficial effects on N removal from the eutrophic waterbody.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1500880 | PMC |
http://dx.doi.org/10.1631/jzus.2006.B0521 | DOI Listing |
Environ Res
January 2025
State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China.
The water-level fluctuation zones (WLFZ) in Three Gorges Reservoir encounter several ecological challenges, particularly potential greenhouse gas (GHG) emissions and water eutrophication due to water level variations. Therefore, to address those challenges, our study explores the relationships between soil properties (Phosphorus cycle), plant conditions, microbial community, and GHG emissions. Our findings reveal that aboveground plants are the key link in the WLFZ ecosystem, which has previously been overlooked.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
Pyrene, a representative polycyclic aromatic hydrocarbon, frequently occurs in aquatic environments and is associated with lethal impacts on humans and wildlife. This study examined the impact of pyrene on , a dinoflagellate responsible for harmful algal blooms, and their capability to bioremove pyrene. In a 96 h exposure experiment, effectively reduced the pyrene concentration in seawater to 50, 100, and 200 μg/L, with a combined removal efficiency of 96% in seawater.
View Article and Find Full Text PDFEcol Evol
January 2025
Tianjin Key Laboratory of Animal and Plant Resistance, Tianjin Key Laboratory of Conservation and Utilization of Animal Diversity, College of Life Science Tianjin Normal University Tianjin China.
Understanding the adaptation of archaea to hypoxia is essential for deciphering the functions and mechanisms of microbes when suffering environmental changes. However, the dynamics and responses of archaea to the sedimentary hypoxia in Bohai Sea are still unclear. In this study, the diversity, composition, and distribution of archaeal community in sediment along an inshore-offshore transect across the oxygen-depleted area in the Bohai Sea were investigated in June, July, and August of 2021 by employing high-throughput sequencing of 16S rRNA gene.
View Article and Find Full Text PDFEnviron Res
January 2025
Shanghai Key Lab for Urban Ecological Processes and Eco-Restorations, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China; Center for Global Change and Ecological Forecasting, Institute of Eco-Chongming, Shanghai, China. Electronic address:
Eutrophication caused by human activities has severely impacted freshwater ecosystems, leading to harmful cyanobacterial blooms that threaten water quality and ecosystem stability. During blooms, denitrification is a key process for nitrogen removal, which can occur both in the sediment and in the waterbody mediated by cyanobacterial aggregate (CA)-associated microorganisms. In this study, the structure, dynamics and assembly mechanisms of CA-associated nirK-, nirS-, and nosZ-encoding denitrifying communities were investigated in the eutrophic Lake Taihu across the bloom season.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Danjiangkou Wetland Ecosystem Field Scientific Observation and Research Station, Chinese Academy of Sciences & Hubei Province, Wuhan, 430074, P.R. China.
Denitrification and anaerobic ammonium oxidation (anammox) are the major microbial processes responsible for global nitrogen (N) loss. Yet, the relative contributions of denitrification and anammox to N loss across contrasting terrestrial and aquatic ecosystems worldwide remain unclear, hampering capacities to predict the human alterations in the global N cycle. Here, a global synthesis including 3240 observations from 199 published isotope pairing studies is conducted and finds that denitrification governs microbial N loss globally (79.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!