Tratabilidade de solo contaminado com fenantreno utilizando persulfato de sódio ativado por quelante de ferro

Abstract

Aromatic polycyclic hydrocarbons (APHs) are constituents of toxic petroleum derivatives. Phenanthrene is an example of HPA, cited on the US Environmental Protection Agency (US EPA) list of priority pollutants. In the event of leaks of petroleum products, the contaminant load can spread over large extensions, damaging the soil and seeping into the water table. Advanced oxidative processes (AOP) are one of the alternatives for remediation of APH-contaminated soils using strong oxidizing agents. The objective of this work was to evaluate treatability assays through the application of chemical oxidation in artificially contaminated soil with phenanthrene. Persulfate was used as oxidizing agent and activated by iron ions complexed in the structure of a chelating agent. The experiments were performed in batch, based on two factorial designs 23 + 4 central points, considering the variables: oxidant concentration, iron concentration and citric acid concentration. The best degradation obtained was 81.76%, resulting in a residual phenanthrene concentration in the soil of 48.94 mg kg-1, below the intervention value determined by CONAMA for industrial zones. The kinetic assays fit a second order model (R2= 0.91), indicating proportionality between the degradation of PHE in the medium and the reaction time.