LIMeng,TIANTeng-fei,HUANGPeng,et al.Submerged Macrophytes Induced Negative Variation between Dissolved Oxygen and Oxidation-Reduction Potential in Water: Phenomenon and Mechanism Exploration[J].China Water & Wastewater,2025,41(23):1-7.
Submerged Macrophytes Induced Negative Variation between Dissolved Oxygen and Oxidation-Reduction Potential in Water: Phenomenon and Mechanism Exploration
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第23期
Page:
1-7
Column:
Date of publication:
2025-12-01
- Keywords:
- dissolved oxygen (DO); oxidation-reduction potential (ORP); submerged macrophyte; C. demersum; photosynthesis; weight model
- Abstract:
- Conventional water quality management assumes a positive correlation between dissolved oxygen (DO) and oxidation-reduction potential (ORP). Here, we report a previously unrecognized negative correlation pattern between DO and ORP in submerged macrophyte-dominated waters: ORP decreases during daytime DO elevation, whereas ORP rebounds during nighttime DO depletion. Comparative experiments across different systems demonstrated that this phenomenon was mechanistically driven by macrophyte photosynthesis. Changes in light illuminance and duration, plant density, and pH only changed the range of DO and ORP variations, without altering their intrinsic negative correlation. The presence or absence of submerged macrophytes constituted the determinant of this inverse relationship. Mechanistic analysis integrating mass balance and potential theory suggested that oxygen release and reducing metabolite secretion by plants might induce the imbalance of redox state. The discovery and confirmation of this phenomenon will provide a new scientific perspective for urban water body quality monitoring and ecosystem health assessment.
Last Update:
2025-12-01