Porewater, a key reservoir of nutrients, plays a critical role in sediment nutrient release. This study used electrokinetic geosynthetics (EKGs) as electrodes to drain sediment porewater in the presence of 20 cm-deep overlying water and conducted five sets of indoor experiments (one control group and four groups exposed to voltage gradients of 0, 0.5 (intermittent power IP), 0.5 (continuous power CP), 1.0 V/cm (IP)) to investigate the performance and mechanisms of porewater drainage regulating sediment nutrient release and the response of microbial communities. Total nitrogen (TN) release flux dramatically decreased to ≤10% of its maximum within 14 days, while total phosphorus (TP) release flux clearly decreased after fluctuating for nearly 28 days. 0.5 and 1.0 V/cm were more effective for restraining TN and TP release, respectively. For both nitrogen and phosphorus, the drainage of porewater changed the sediment’s role from nutrient source to sink, effectively restraining nutrient accumulation in the overlying water. Physical processes including porewater renewal by overlying water, gravity drainage, and sediment pore compression were the key mechanisms restricting sediment nutrient release, while electromigration and electrochemical oxidation promoted nutrient transformation and separation. The drainage caused a non-significant decline in community abundance indices but not changed the dominant species of the sediment microorganisms.
- Open Access
- Article
Transforming Sediment from Nutrient Source to Sink through Electrokinetic Geosynthetics-Driven Porewater Drainage
- Xianqiang Tang 1, 2, 3, *,
- Rui Li 1, 2, 3,
- Yanping Hu 1, 2, 3,
- Danyang Wang 1, 2, 3,
- Junjun Gu 1, 2, 3,
- Zhenhua Wang 1, 2, 3
Author Information
Received: 04 Aug 2025 | Revised: 22 Sep 2025 | Accepted: 31 Dec 2025 | Published: 12 Jan 2026
Abstract
Keywords
electrokinetic geosynthetics | eutrophication | nitrogen | nutrient | phosphorus | sediment remediation
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