Sensors for Biomass Monitoring in Vegetated Green Infrastructure: A Review

Area of Science:

• Environmental Engineering
• Microbiology
• Sensor Technology

Background:

• Bioretention cells (rain gardens) utilize phytoremediation and bioremediation to reduce stormwater contaminants.
• Bacterial communities in soil and root zones are crucial for the bioremediative processes in these systems.
• Accurate monitoring of bioremediation is essential for designing, operating, and maintaining effective bioretention cells.

Purpose of the Study:

• To review available biomass monitoring technologies for quantifying bioremediation in rain gardens.
• To assess the suitability of different methods for in situ, real-time field application.
• To identify promising sensor technologies for effective bioretention cell performance assessment.

Main Methods:

• Review and discussion of microscopical, piezoelectric, fiber-optic, thermometric, and electrochemical monitoring methods.
• Evaluation of methods based on accuracy, calibration needs, in situ potential, real-time capability, and biofilm characterization.
• Focus on methods suitable for media with fluctuating nutrient supply.

Main Results:

• Microscopical methods are vital for calibration but not for field use.
• Piezoelectric, fiber-optic, and thermometric methods have limitations for field deployment.
• Electrochemical methods, particularly impedance-based sensing, show significant promise for in situ monitoring.

Conclusions:

• An impedance-based electrochemical sensor, validated by microscopy, is the most promising technology for real-time bioremediation monitoring in rain gardens.
• Effective monitoring tools are needed to improve bioretention cell design and performance.
• Further development of field-deployable sensors is crucial for advancing stormwater management strategies.