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Mesocosm-Scale Constructed Wetland Design for Wastewater Treatment
Published on: May 2, 2025
814
Nitrogen removal performance and needed area estimation of surface-flow constructed wetlands using a probabilistic
Pei Luo1, Feng Liu1, Shunan Zhang1
1Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China.
Journal of Environmental Management
|November 29, 2019
Summary
A probabilistic approach improves constructed wetland (CW) performance assessment for fluctuating wastewater. This method accurately estimates needed area for ammonium removal in swine wastewater treatment systems.
Area of Science:
- Environmental Engineering
- Wastewater Treatment Technologies
- Ecological Engineering
Background:
- Constructed wetlands (CWs) face challenges in assessing performance due to highly fluctuating influent pollutant concentrations.
- Directly using influent and effluent concentrations leads to significant uncertainties in removal efficiency calculations.
- A probabilistic approach offers a more robust method for evaluating CW performance and estimating treatment area.
Purpose of the Study:
- To apply a probabilistic approach for assessing the performance and needed area of surface-flow constructed wetlands (SFCWs) treating swine wastewater.
- To compare the probabilistic approach with the deterministic method for removal rate and efficiency estimations.
- To analyze the relationship between removal constants and influent/effluent loading rates in SFCWs.
Main Methods:
- Construction and operation of a three-stage SFCW system for swine wastewater treatment.
- Application of a probabilistic approach to calculate surface removal rates and removal efficiencies of ammonium nitrogen.
- Estimation of the required SFCW area based on varying removal efficiencies and influent ammonium loading rates.
- Statistical analysis of the first-order removal constant in relation to influent and effluent concentrations.
Main Results:
- Probabilistic removal rates (0.27-3.23 g m⁻² d⁻¹) and efficiencies (43.0-99.9%) were consistent with deterministic estimates.
- Required SFCW area varied from 6.6 to 29.7 m² for 40-90% ammonium removal efficiency.
- For 90% removal efficiency, needed areas ranged from 13.9 to 40.8 m² depending on influent loading rates.
- The first-order removal constant decreased logarithmically with increasing loading rates (p < 0.001).
Conclusions:
- The probabilistic approach provides reliable performance evaluation and area estimation for CWs treating wastewater with fluctuating concentrations.
- This method enhances decision-making in wastewater treatment and engineering applications.
- Understanding the impact of loading rates on removal constants is crucial for accurate CW design.
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