In-situ combined remediation method for petroleum contaminated site soil

Abstract

The invention discloses an in-situ combined remediation method for petroleum contaminated site soil and relates to a soil remediation method. According to the in-situ combined remediation method, a chemical oxidation reagent is prepared from the following components including sodium persulfate as an oxidant, sodium hydroxide or calcium peroxide as an activator and sodium thiosulfate as a sustained-release agent; a microorganism simulation nutrient is prepared from the following components including sodium phosphate and ammonium sulfate; the molar ratio of the sodium persulfate and the activator is 5:1; the quantity of the sustained-release agent is 1-5 percent of the quantity of the oxidant and the activator; the molar ratio of C, N and P as the nutrients for promoting growth of microorganisms is 120: 10: 1; a phosphorus source is the sodium phosphate (Na3PO4.12H2O); a nitrogen source is the ammonium sulfate ((NH4)2SO4); and a carbon source is petroleum pollutants and is estimated according to the actual pollutant degree. The in-situ combined remediation method for the petroleum contaminated site soil can reach the purpose of completely remediating the long-term petroleum contaminated site soil, and thus solving the problems of difficulty in remediating aged contaminated soil microorganisms, higher chemical oxidation cost and larger environmental influence and lowering the remediation cost.

Description

technical field [0001] The invention relates to a soil restoration method, in particular to an in-situ joint restoration method for oil-contaminated soil. Background technique [0002] Petroleum pollutants (TPH, Totalpetroleumhydrocarbons) refers to the 4 dissolved, and at wave number 3030cm -1 (≡CH1 aromatic ring), 2960cm -1 (-CH3 methyl) and 2930cm -1 (=CH2 methylene) Any substance with characteristic absorption. Mainly hydrocarbons (according to the structure can be divided into alkanes, cycloalkanes, aromatic hydrocarbons, olefins), followed by a small number of non-hydrocarbon components (containing O, S, N compounds, colloids and asphaltenes). Different components migrate and transform in soil through dispersion, molecular diffusion, volatilization, adsorption, chemical reaction and degradation, and exist in the underground environment in free state (NAPL), volatile state, dissolved state and adsorbed state. Due to the toxicity of petroleum pollutants and their mi...

AI Technical Summary

Problems solved by technology

[0006] For the long-term oil-contaminated site soil that needs in-situ remediation, it is difficult to remove it by conventional remediation techniques. Gas-phase extraction is only effective for volatile organic compounds, and the actual effect of introducing exogenous microorganisms is poor. Phytoremediation takes a long time and can only be remediated Specific pollutants, thermal desorption and other technologies are costly, and leaching technology is difficult to implement in situ

The sodium persulfate oxidation method has strong adaptability to pollutants and good oxidation effect, but there is secondary pollution of sulfate to the environment

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