Effects of Loading Type and Temperature on Performance, Transient Operation, and Kinetics of n-Hexane Vapor Removal in a Biofilter

Zamir, Seyed Morteza; Ferdowsi, Milad; Halladj, Rouein

Effects of Loading Type and Temperature on Performance, Transient Operation, and Kinetics of n-Hexane Vapor Removal in a Biofilter

2014

Zamir, Seyed Morteza | Ferdowsi, Milad | Halladj, Rouein

In this research, different inlet concentrations of n-hexane vapor (1–11 g m⁻³) corresponds to the inlet loading rates of 9–598 g m⁻³ h⁻¹at different temperatures (35–45 °C) were eliminated from air under continuous and intermittent loading (10-h feeding per day) in a biofilter packed with compost and lava rock. Loading type had minor effect on the n-hexane removal at 35 °C and the removal efficiency (RE) was in the range of 70 to 100 % at an inlet concentration of 11 gm⁻³. On the contrary, RE dropped significantly to 25 % at 40 °C under intermittent loading while it was 77 % under continuous loading with the inlet concentration of 9 g m⁻³and empty bed residence time (EBRT) of 2 min. Increasing the temperature to 45 °C significantly reduced the RE at both types of loading at both EBRTs of 2 and 1.3 min; however, intermittent loading was led to a slightly greater removal. According to transient-state experiment under intermittent loading at EBRT of 2 min, the biochemical reaction became the dominant mechanism, after an initial short period, every day to remove n-hexane rather than adsorption on bed. Kinetic modeling showed that the biodegradation rates changed linearly with increase in the logarithmic mean n-hexane concentration during intermittent loading at different temperatures while the order of reaction was higher at continuous loading.

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