Comparison of conventional and two-stage reversible flow, static-bed biodenitrification reactors

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Microbial Ecology

Background:

• Nitrate contamination in drinking water poses significant health risks.
• Traditional single-stage biodenitrification systems face challenges in removing residual organics.
• Optimizing reactor configuration is crucial for efficient nitrate removal.

Purpose of the Study:

• To compare the efficacy of a two-stage, reversible flow biodenitrification system against traditional single-stage systems.
• To evaluate the removal of nitrates and residual organics in treated water.
• To assess system performance at low hydraulic retention times (HRTs).

Main Methods:

• Comparative analysis of single-stage and two-stage reversible flow biodenitrification reactors.
• Operation in series with periodic flow regime reversal in the two-stage system.
• Monitoring of nitrate and residual organic compound concentrations in effluent.

Main Results:

• Nitrate-nitrogen removal efficiency slightly improved from 98% to 99.5% with the two-stage system.
• The reversible flow system reduced effluent residual organics by approximately two-thirds compared to single-stage units.
• The two-stage system demonstrated resilience to extreme shock loads without sustained loss of treatment efficiency.
• Effective removal of nitrates and organics achieved at HRTs as low as 0.5 hours.

Conclusions:

• Two-stage, reversible flow biodenitrification offers superior removal of nitrates and residual organics in drinking water.
• The reversible flow design provides enhanced stability and efficiency, particularly for residual organic removal.
• This system presents a robust solution for achieving stringent drinking water quality standards.