Modulating phytoremediation: How drip irrigation system affect performance of active green wall and microbial...

Area of Science:

• Environmental Science
• Microbiology
• Horticultural Engineering

Background:

• Active green walls utilize biofiltration and mechanical ventilation for air phytoremediation.
• The impact of irrigation on soil moisture and microbial communities in these systems remains largely unstudied.

Purpose of the Study:

• To investigate the influence of drip irrigation techniques on the performance of active green walls.
• To assess how different irrigation flow rates affect substrate moisture, airflow, and microbial communities.

Main Methods:

• A modular green wall system with 7 plant species and a substrate-only control was tested.
• Measurements included water distribution, water-carrying capacity, substrate airflow, and microbial phospholipid fatty acids (PLFA).
• Drip irrigation at low and high flow rates was compared.

Main Results:

• Lower-speed drip irrigation reduced water consumption and improved moisture distribution compared to rapid systems.
• High flow rates caused a water pathway phenomenon, leading to uneven moisture, especially with fibrous roots.
• Drip irrigation did not alter overall microbial community composition but increased fungi by 6% and decreased bacteria by 56.67% at high flow rates.

Conclusions:

• Low flow rate drip irrigation is more beneficial for active green wall performance, supporting both plant growth and microbial community composition.
• Drip irrigation significantly affects substrate airflow and microbial density, crucial factors for effective air cleaning.