Next Article in Journal
Predictive Uncertainty Estimation on a Precipitation and Temperature Reanalysis Ensemble for Shigar Basin, Central Karakoram
Previous Article in Journal
Micro Radar Surface Velocimetry for Hydrologic Signal Processing Using a Bandpass Filtering Approach
Previous Article in Special Issue
Evaluation of Phytodesalination Potential of Vegetated Bioreactors Treating Greenhouse Effluent
Article Menu

Export Article

Open AccessArticle
Water 2016, 8(6), 265; doi:10.3390/w8060265

Flume Experiments for Optimizing the Hydraulic Performance of a Deep-Water Wetland Utilizing Emergent Vegetation and Obstructions

1
Hydrotech Research Institute, National Taiwan University, Taipei City 106, Taiwan
2
Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei City 106, Taiwan
*
Author to whom correspondence should be addressed.
Academic Editor: Alan Howard
Received: 23 March 2016 / Revised: 10 June 2016 / Accepted: 17 June 2016 / Published: 21 June 2016
(This article belongs to the Special Issue Constructed Wetlands Systems and Management)
View Full-Text   |   Download PDF [3467 KB, uploaded 21 June 2016]   |  

Abstract

Constructed ponds and wetlands are widely used in urban areas for stormwater management, ecological conservation, and pollution treatment. The treatment efficiency of these systems is strongly related to the hydrodynamics and hydraulic residence time. In this study, we developed a physical model and used rhodamine-WT as a tracer to conduct flume experiments. An equivalent Reynolds number was assumed, and the flume was a 1/25-scale model. Emergent obstructions (EOs), submerged obstructions (SOs), and high- and low-density emergent vegetation were placed along the sides of the flume, and 49 tracer tests were performed. We altered the density, spatial extent, aspect ratio, and configurations of the obstructions and emergent vegetation to observe changes in the hydraulic efficiency of a deep-water wetland. In the cases of low-aspect-ratio obstructions, the effects of the EOs on the hydraulic efficiency were significantly stronger than those of the SOs. In contrast, in the cases of high-aspect-ratio obstructions, the improvement effects of the EOs were weaker than those of the SOs. The high-aspect-ratio EOs altered the flow direction and constrained the water conveyance area, which apparently caused a short-circuited flow phenomenon, resulting in a decrease in hydraulic efficiency. Most cases revealed that the emergent vegetation improved the hydraulic efficiency more than the EOs. The high-density emergent vegetation (HEV) improved the hydraulic efficiency more than the low-density emergent vegetation (LEV). Three cases involving HEV, two cases involving LEV, and one case involving EOs attained a good hydraulic efficiency (λ > 0.75). To achieve greater water purification, aquatic planting in constructed wetlands should not be overly dense. The HEV configuration in case 3-1 achieved optimum hydraulic performance for compliance with applicable water treatment standards. View Full-Text
Keywords: constructed wetland; hydraulic efficiency; flume experiment; similarity; Reynolds number; tracer constructed wetland; hydraulic efficiency; flume experiment; similarity; Reynolds number; tracer
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Shih, S.-S.; Hong, S.-S.; Chang, T.-J. Flume Experiments for Optimizing the Hydraulic Performance of a Deep-Water Wetland Utilizing Emergent Vegetation and Obstructions. Water 2016, 8, 265.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Water EISSN 2073-4441 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top