Method of improving Fenton oxidation method combined with solid microbial agents to remediate organic matter-contaminated soil

Abstract

The invention discloses a method for improving Fenton's oxidation combined with solid microbial agents to restore organic-contaminated soil, adding sodium pyrophosphate or malic acid to the sieved soil, adding ferric sulfate solution, and then adding hydrogen peroxide; Proteobacteria, β‑proteobacteria, yeasts, Pseudopora cyanicola, Pleurotus pellagra, Trametesmetamorphus, Bacillus subtilis, photosynthetic bacteria and lactic acid bacteria are cultured in liquid medium; then inoculated with straw, peanuts The microbial strain carrier composed of shell, bran and sawdust is cultivated and dried to obtain a solid bacterial agent; the solid bacterial agent is added to the soil to maintain soil moisture for restoration. The method of the present invention adopts the method of improving the Fenton reaction combined with microorganisms, the degradation rate is very high, up to 85-98.5%, and the repair time is short; the reaction can be carried out under the neutral pH condition of the soil, without additional adjustment of the soil pH; Use Fe3+ instead of Fe2+ to avoid the instability of hydrogen peroxide during Fe2+ reaction.

Description

[0001] The invention relates to the field of environmental engineering, and in particular to a method for improving Fenton oxidation combined with solid microbial agents to restore organic-contaminated soil. Background technique [0002] The bioaugmented remediation site test must solve two difficulties: first, due to the complex composition of organic pollutants and their toxic effects on microorganisms, it is difficult for microorganisms to survive, grow and reproduce in soil contaminated by persistent organic compounds; Adsorption and the strong hydrophobicity and "ageing" of POPs in soil make their bioavailability very low; [0003] Fenton oxidation is an advanced oxidation technology that can effectively restore refractory organic matter in soil. The Fenton oxidation reaction produces non-selective hydroxyl radicals to oxidize organic matter, and the final products are water and carbon dioxide, which effectively avoids secondary pollution during the restoration process. ...

AI Technical Summary

Problems solved by technology

However, in practical engineering applications, Fenton oxidation technology is not used frequently

First of all, the Fenton oxidation reaction is rapid, and the reaction is over when the agent is not fully in contact with the soil, resulting in only part of the pollutants being degraded, and because of the special properties of the soil, it is difficult to determine the concentration of undegraded pollutants and untreated soil Quantity; and the Fenton oxidation reaction preferentially oxidizes the easily degradable substances of small molecules in the soil, and finally oxidizes the macromolecules and refractory persistent organic pollutants, so it will increase the dosage of chemicals and increase the repair cost; the traditional Fenton oxidation needs to maintain the soil The pH is between 2-4, but due to the buffering properties of the soil, it is difficult to maintain the pH between 2-4

Secondly, most soil microbial remediation methods use liquid bacterial agents, which infiltrate rapidly after entering the soil, resulting in insufficient nutrients in the early stage of microbial growth, slow biomass growth, and ineffective remediation effects