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A Simulation Experiment on Quality Dynamics of Reclaimed Water under Different Flow Exchanges
Chengzhong Pan1, Zhongfang Guo1, Mingjie Luo1
1College of Water Sciences, Beijing Normal University, No. 19, Xinjiekouwai St., Haidian District, Beijing 100875, China.
International Journal of Environmental Research and Public Health
|October 27, 2022
Summary
Using 100% reclaimed water in urban lakes is not advised. A flow exchange period of 5-10 days can improve water quality and soil microbial diversity, aiding self-purification.
Area of Science:
- Environmental Science
- Water Resource Management
- Ecology
Background:
- Reclaimed water is crucial for urban aquatic ecosystems, especially in water-scarce regions.
- Limited data exists on water quality dynamics and driving mechanisms in reclaimed water bodies.
- Understanding flow exchange impacts is vital for effective water management.
Purpose of the Study:
- To investigate the effects of flow exchange on water quality and soil microbial diversity.
- To compare 100% reclaimed water versus mixed water (50% reclaimed, 50% stream water).
- To determine optimal flow exchange periods for urban water bodies.
Main Methods:
- Simulated experiments with varying flow exchange periods (2-40 days).
- Analysis of water quality parameters like Chemical Oxygen Demand (CODMn) and Ammonia Nitrogen (NH3-N).
- Assessment of soil microbial diversity under different water conditions.
Main Results:
- Degradation coefficients for CODMn and NH3-N were positive in mixed water but negative in 100% reclaimed water.
- Flow exchange had minimal impact on mixed water quality, possibly due to low Total Phosphorus (TP).
- Short or long exchange periods negatively affected water quality dynamics and soil microbial diversity.
Conclusions:
- Isolated urban lakes should not be filled solely with 100% reclaimed water.
- A flow exchange period of 5-10 days is recommended for optimal water self-purification.
- Optimizing flow exchange can enhance water quality and ecological health in urban aquatic systems.
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