Stabilization/Solidification of Nitrobenzene Contaminated Soil based on Hydrophobilized CaO

Lime, one of the common binders used in Solidification/Stabilization (S/S), is not adequate to immobilize toxic organic compounds of high-concentration released into soil by accidents in petrochemical and chemical industries. CaO, the main composition of lime, was hydrophobilized with stearic acid (SA) and silane coupling agent (KH570) to improve its fixation of nitrobenzene in S/S remediation of contaminated soil in present work, and the effect of hydrophobilized CaO on toxic organic compound encapsulation was evaluated through leaching and volatilization tests. Results showed that the binder composed of 20% SA hydrophobilized CaO together with 10% original CaO could reduce nitrobenzene's volatilization ratio to 0.096% and leaching ratio to 8.79%, while the nitrobenzene's volatilization ratio is 0.413% and leaching ratio is 35.48% with 30% original CaO as the binder.