Experimental Study On The Different Ways And Optimal Activation Parameters For Sodium Persulfate Remediation Of Petroleum Contaminated Soil

Persulfate oxidizing agent is just up the development of the heat, light, transition metal ion activation environment can produce strong oxidizing sulfate radical?SO₄^-·?. This paper will examine three kinds of activation methods(thermal activation, activation of Fe²⁺ and Fe²⁺ under UV activated persulfate) on the removal efficiency of oil pollutants in soil, choose the suitable activation technology; secondly, the influence of various factor activation methods, such as the effects of p H value, temperature and persulfate salt concentration, Fe²⁺ concentration, UV light time of oil pollutants sulfate degradation in soil, optimize and determine the key technical parameters, and the effects of Fe²⁺ activated persulfate treatment of petroleum hydrocarbon in soil apparent kinetic equation and four factors using response surface method of UV activation method of Fe²⁺ is optimized; and a comparative analysis of the content of soil before and after treatment in the treatment of soil n-alkanes.?1? heat/S₂O₈^2- system in the acidic environment of petroleum hydrocarbon removal rate is higher; the increase of temperature and the persulfate concentration can make persulfate to produce SO₄^-· of petroleum pollutants in soil degradation, but high or excessive investment and sodium persulfate will reduce the effective utilization rate of SO₄^-·, so that the degradation of petroleum hydrocarbon rate affected.Comprehensive consideration, the best repair parameters of heat/S₂O₈^2- system: p H=2, T=50 C,Na₂S₂O₈=1mol/L, reaction time is 5 days.?2? Fe²⁺/S₂O₈^2- system affected by pH value is more complex, strongly acidic, neutral or alkaline environment is not conducive to the degradation of organic pollutants; concentration of Fe²⁺ and the concentration of sulfate directly impacts the degradation rate of petroleum hydrocarbon. However,excessive investment and Fe²⁺ or Persulfate will enable system of SO₄^-·interaction, cause free radical quenching, not only can not improve the petroleum hydrocarbon removal rate but will make the petroleum hydrocarbon removal rate decreased. Comprehensive consideration, the best repair parameters of Fe²⁺/S₂O₈^2- system: pH=4, Na₂S₂O₈=1mol/L, Fe²⁺=1mol/L, reaction time is 5 days. On Fe²⁺/S₂O₈^2-processing system of petroleum hydrocarbons were apparent kinetic study of and the apparent kinetic equation for V=101.4011·P0.1139·A0.2922·B0.67291. The total count of reaction for 1.07901. In the reaction system of Fe²⁺ concentration play main role.?3? the UV activated persulfate oxidation can also produce good sulfate radical, so together in the UV and Fe²⁺ conditions can increase the rate of degradation of petroleum hydrocarbon in soil. The best repair parameters of UV/ Fe²⁺/S₂O₈^2- system: pH=4, Na₂S₂O₈=1mol/L, Fe²⁺=1mol/L, UV light for 4 days. Using box Behnken design. Through response surface method to establish the pH value, the concentration of sodium persulfate, ferrous sulfate concentration, UV time four factors quadratic regression model, and has carried on the variance analysis and response surface analysis. According to the analysis results, it is showed that the interaction of /Fe²⁺ concentration, Fe²⁺ concentration and Na₂S₂O₈ concentration can significantly affect the removal rate of petroleum hydrocarbons.?4? the gas phase analysis of normal paraffin hydrocarbons in the treated soil and three kinds of activation methods. According to the gas phase analysis results show that, by three activation processing method of soil in the normal paraffin alkane content decreased, of which the photo assisted Fe²⁺ activation method of n-alkanes reduce the maximum degree and Fe²⁺ activation method of thermal activation processing method of n-alkanes decreases with the degree of minimum, and the three activation ofpetroleum hydrocarbon degradation rate. In summary, the order of degradation effect of the three activation methods was: UV/Fe²⁺/S₂O₈^2->Fe²⁺/S₂O₈^2->heat/S₂O₈^2-.