A low-impact nature-based solution for reducing aquatic microplastics from freshwater ecosystems.

Area of Science:

• Environmental Science
• Aquatic Ecology
• Water Treatment Technologies

Background:

• Freshwater microplastic (MP) pollution poses significant ecological and human health risks.
• Effective nature-based solutions (NBS) are needed for in-situ aquatic MP removal.
• Submerged macrophytes show potential for MP retention.

Purpose of the Study:

• To identify and optimize a submerged macrophyte-based NBS for freshwater MP retention.
• To determine the optimal operational parameters for MP removal using Myriophyllum aquaticum.
• To evaluate the efficiency of this NBS in a real lake environment.

Main Methods:

• Screening of various submerged macrophytes for MP retention efficiency.
• Optimization of operational parameters (flow rate, aeration, plant density) using Response Surface Method and Artificial Neural Network modeling.
• In-situ testing of the optimized NBS in a lake environment.

Main Results:

• Myriophyllum aquaticum was identified as a highly effective macrophyte for MP retention.
• Optimal conditions achieved 93.38% MP retention in a lake test.
• The NBS demonstrated high efficiency for MPs >100 μm and reduced total nitrogen and phosphorus by over 78%.

Conclusions:

• Myriophyllum aquaticum offers a feasible NBS for freshwater MP pollution mitigation.
• The optimized strategy provides significant water purification benefits.
• Further research is required for long-term applicability, ecological impact assessment, and harvesting strategies.