Effects of Aeration Mode on the Composting of Diesel- Contaminated Soil

Aeration is a critical operational parameter for aerobic composting processes. Three intermittent aeration modes were compared with the continuous aeration mode with respect to the degradation rate of diesel oil in a composting process for contaminated soil. Intermittent aerations were more effective treatment methods for the degradation of both total petroleum hydrocarbons (TPH) and normal alkanes than was continuous aeration. The most active degradation of diesel oil (as TPH) among the intermittent aeration experiments occurred for the 1 h aeration/3 h rest experiment. Until day 15, which is a commonly practiced composting period, the first-order kinetic constants of the 1 h aeration/3 h rest experiment and continuous aeration were 0.134/day and 0.121/day, respectively. As a result of an ANOVA test (p ≤ 0.05), there was no significant difference observed in the first-order degradation rate constants between the continuous and intermittent aeration modes. Considering its energy efficiency, intermittent aeration is preferable over continuous aeration. A sufficient oxygen concentration (> 5 %) for the aerobic degradation of diesel oil was supplied in each of the intermittent aeration modes tested in this study.