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Updated: Feb 14, 2026

Mesocosm-Scale Constructed Wetland Design for Wastewater Treatment
Published on: May 2, 2025
Effects of water flow on submerged macrophyte-biofilm systems in constructed wetlands
Bing Han1, Songhe Zhang2, Peifang Wang3
1Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, College of Environment, Hohai University, Nanjing, 210098, China.
Abstract:
The effects of water flow on the leaf-biofilm interface of Vallisneria natans and Hydrilla verticillata were investigated using artificial plants as the control. Water flow inhibited the growth of two species of submerged macrophytes, reduced oxygen concentrations in plant leaves and changed oxygen profiles at the leaf-biofilm interface. The results from confocal laser scanning microscopy and multifractal analysis showed that water flow reduced biofilm thickness, changed biofilm topographic characterization and increased the percentages of single colony-like biofilm patches. A cluster analysis revealed that the bacterial compositions in biofilms were determined mainly by substrate types and were different from those in sediments. However, water flow increased the bacterial diversity in biofilms in terms of operational taxonomic unit numbers and Shannon Indices. Our results indicated that water flow can be used to regulate the biomass, distribution and bacterial diversities of epiphytic biofilms in constructed wetlands dominated by submerged macrophytes.
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