Percarbonate as a Hydrogen Peroxide Carrier in Soil Remediation Processes

Use of sodium percarbonate (SPC) as a hydrogen peroxide (H2O2) carrier in polycyclic aromatic hydrocarbon (PAH)-contaminated soil remediation has been assessed. A series of SPC decomposition runs in PAH-free soil were conducted in the presence of different soil amounts and temperatures. Results suggest the development of first-order H2O2 decomposition kinetics. Soil mass exerts a positive effect in terms of H2O2 abatement rate. An order of 2/3 in H2O2 decomposition was calculated regarding soil dose. The apparent activation energy of the process was found to be in the proximity of 60 kJ/mol. The second objective of this work was to evaluate the effect of the continuous addition of a SPC solution to an artificially PAH-contaminated soil (acenaphthene, phenanthrene, anthracene, and fluoranthene). The process led to the complete oxidation of acenaphthene. Elimination levels achieved for the rest of PAHs depended on operating conditions. Temperature and SPC concentration in the stream fed to the reactor seem to be the most influential parameters. These two variables positively affected the soil-cleaning process until reaching an optimum value. Thereafter, inefficient H2O2 decomposition prevailed over the beneficial effects of increasing temperature and SPC concentration.