Study On Degradation Of Petroleum Contaminants In Soil By Chemicai Oxidation Technology

The oxidation technology removing light-oil in soil was simulated. A study was conducted to degrade heavily diesel-contaminated soil with hydrogen peroxide oxidation to achieve the optimized treatment condition influencing removal efficiency. The factors influencing reactions such as initial oil content of soil, H2O2 dosage, pH-value of soil, catalyst and so on and the functions of these factors were investigated.The main results of the study are as follows:⑴Research on treatment conditions of remediation of diesel -contaminated soil by hydrogen peroxide oxidation technology①It is economical and efficient to add 4ml H2O2 to 10g diesel-contaminated soil. The removal efficiency of 20000mg/kg (low oil content ) diesel-contaminated soil achieves more than 70% .②pH-value of soil about 5~8 has little effect on the oxidation technology. The removal efficiency of 50000mg/kg (high oil content ) diesel-contaminated soil achieves more than 96%③When 50000mg/kg (high oil content ) diesel-contaminated soil were degraded by Fenton Reagent, more than 85% diesel were removed when adding 1ml or 2ml H2O2 only to 10g diesel-contaminated soil.④The removal efficiencies of diesel-contaminated soil saturated with water and unsaturated with water are different. The former are better than the latter.⑤pH-value of soil changed during hydrogen peroxide oxidation and Fenton Reagent oxidation. The Fenton Reagent oxidation technology changed acidity and alkalescence of soil.⑥Degradation of diesel in soil was simulated by first-degree kinetics model. The degradation experiment of different pH-values of soil indicate that half-life of three models is 5.50h,6.13h and 6.66h respectively; the degradation experiment of different ratios of Fenton Reagent indicate that half-life of three models is 20.75h,15.30h and 10.07h respectively, which are longer than the former models.⑵Research on remediation of diesel -contaminated soil in soil-column by hydrogen peroxide oxidation technology①50000mg/kg (high oil content ) diesel-contaminated soil was treated respectively by hydrogen peroxide oxidation technology and Fenton Reagentoxidation technology. Correspondingly, the removal efficiencies are 51.89% and 42.68%, and the absolute removal content are 25946mg/kg and 21342mg/kg in 83h.②Degradation of diesel in soil was simulated by first-degree kinetics model. The half-life of two technologies is 123.78h and 192.54h respectively, which are longer than the former models.③pH-value of soil declined by 1.11 and 6.20 respectively during hydrogen peroxide oxidation and Fenton Reagent oxidation. The Fenton Reagent oxidation technology changed character of soil.