Ammoniacal Nitrogen Stripping From Landfill Leachate at Open Horizontal Flow Reactors

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Waste Management

Background:

• Landfill leachate poses environmental challenges due to high ammonia nitrogen concentrations.
• Conventional ammonia removal methods can be costly or energy-intensive.
• Open horizontal flow reactors offer a potential low-cost alternative for ammonia stripping.

Purpose of the Study:

• To evaluate the efficacy of ammonia nitrogen stripping using open horizontal flow reactors.
• To assess the process's performance in reducing ammonia and chemical oxygen demand (COD) in landfill leachate.
• To determine the influence of superficial loading rates on removal efficiencies.

Main Methods:

• Experimental setup with four open horizontal flow reactors fed with raw landfill leachate.
• Application of varying superficial loads: 650 kgN/ha/day (Phase 1), 750 kgN/ha/day (Phase 2), and 850 kgN/ha/day (Phase 3).
• Monitoring of ammonia nitrogen and total COD concentrations with corresponding hydraulic retention times.

Main Results:

• Ammonia nitrogen removal efficiencies consistently exceeded 99% across all phases (99.0% to 99.5%).
• COD removal efficiency decreased with increasing superficial load, from 69.20% (Phase 1) to 29.23% (Phase 3).
• Ammonia removal efficiency demonstrated a direct proportionality to the applied superficial load.

Conclusions:

• Open horizontal flow reactors are a highly effective and promising technology for ammonia nitrogen reduction in landfill leachate.
• The process is economically viable due to the absence of chemical reagent costs and electricity requirements.
• Optimal performance is expected in regions with sufficient land availability and ambient temperatures above 25°C.