The effect of temperature on sorption, biodegradation, and transport of monochlorobenzene in soil

The effect of temperature on the sorption, biodegradation, and transport of monochlorobenzene (MCB) in soil was investigated through batch sorption, microcosm and column tests conducted under aerobic and abiotic conditions. The Freundlich distribution coefficients and retardation values estimated for a sandy soil with moderate organic content decreased over 40% from 22°C to 55°C under equilibrium sorption conditions. However, this effect was not observed in subsequent column tests where rate-limited conditions dominated. An aerobic consortium cultivated from aerobic sludge was enriched on MCB. Degradation rates evaluated from microcosm and column studies operating at 22°C and O2 rich conditions indicated a half-life for MCB around 1 to 2 hours. Degradation rates were significantly reduced from 1.04hr -1 at 22°C to 0.03hr-1 at 55°C as demonstrated in both microcosm and column studies. The results of this investigation indicate thermally enhanced bioremediation will inhibit MCB degradation and thus should not be applied for MCB remediation.