Enhanced nitrogen removal using solid carbon source in constructed wetland with limited aeration

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Microbial Ecology

Background:

• Constructed wetlands are crucial for wastewater treatment.
• Nitrogen removal is a key challenge in wastewater management.
• Solid carbon sources offer potential for enhanced microbial activity in wetlands.

Purpose of the Study:

• To investigate the performance of nitrogen removal in constructed wetlands using a solid carbon source with limited aeration.
• To evaluate the impact of limited aeration on microbial communities and effluent quality.

Main Methods:

• Utilized blends of poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) and polyacetic acid (PLA) as a combined carbon source and biofilm support.
• Compared nitrogen removal efficiencies, microbial abundance, and community structure between a limited aeration system (System A) and a non-aerated system (System NA).
• Employed pyrosequencing for microbial community analysis.

Main Results:

• System A achieved higher ammonia (91.00%) and total nitrogen (97.03%) removal efficiencies compared to System NA.
• Limited aeration reduced Chemical Oxygen Demand (COD) concentrations in the effluent.
• System A exhibited higher microbial abundance than System NA.
• Pyrosequencing identified Brevinema as dominant in System NA and Thiothrix in System A.

Conclusions:

• Limited aeration in constructed wetlands with solid carbon sources enhances nitrogen removal and microbial activity.
• PHBV/PLA blends are effective as a dual-function carbon source and biofilm support.
• Limited aeration is a promising strategy for optimizing constructed wetland performance.