Assessing biofiltration repeatability: statistical comparison of two identical toluene removal systems

Area of Science:

• Environmental biotechnology
• Chemical engineering
• Process control

Background:

• Biofiltration is an emerging technology for treating volatile organic compounds (VOCs).
• The reliability and intrinsic repeatability of biofiltration systems remain under-investigated.
• Lack of data hinders the widespread adoption and trust in biofiltration technology.

Purpose of the Study:

• To comprehensively compare two identically operated toluene biofiltration systems over 129 days.
• To assess the process intrinsic repeatability and reliability of biofiltration for VOC removal.
• To evaluate the variability of key performance indicators and operational parameters.

Main Methods:

• Long-term operation (129 days) of two identical toluene biofiltration systems.
• Comprehensive comparison of system responses during transient and steady-state conditions.
• Statistical analysis, including paired samples Student's t-test, to determine repeatability.
• Monitoring of elimination capacities, CO2 and biomass production, pH, leachate organic content, and moisture content.

Main Results:

• Both biofiltration systems exhibited highly similar responses, even under transient conditions.
• Maximum elimination capacities reached up to 99 g m⁻³ h⁻¹, with no statistically significant differences between systems.
• Repeatability was confirmed for CO2 production, biomass production, pH, leachate organic content, and moisture content.
• While pH showed low variability (1.4%), leachate organic content exhibited higher variability (30.6%) due to hydrodynamic factors.

Conclusions:

• Biofiltration systems demonstrate high intrinsic repeatability and reliability for volatile organic compound removal.
• Fluctuations in elimination capacity between identical biofilter setups are expected to be less than 10%.
• The study provides crucial data supporting the reliability of biofiltration as a viable treatment technology.