Percarbonate as a Hydrogen Peroxide Carrier in Soil Remediation Processes

Abstract

Use of sodium percarbonate (SPC) as a hydrogen peroxide (H 2 O 2 ) 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 H 2 O 2 decomposition kinetics. Soil mass exerts a positive effect in terms of H 2 O 2 abatement rate. An order of 2/3 in H 2 O 2 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 H 2 O 2 decomposition prevailed over the beneficial effects of increasing temperature and SPC concentration.

Benzene depletion by Fe2+-catalyzed sodium percarbonate in aqueous solution

“…Recent studies have shown that peroxymonocarbonate ion (HCO 4 À , E 0 = 1.8 V vs. SHE) can be generated through the equilibrium between HCO 3 À and H 2 O 2 in aqueous solution, as shown in Eq. (11), and other active species are further generated by the decomposition of HCO 4 À [27]. HCO 4 À itself can be a potent oxidant and be capable of oxidizing a variety of organic compounds [27].…”

“…Sodium percarbonate (2Na 2 CO 3 Á3H 2 O 2 , SPC), as an adduct of 32.5% hydrogen peroxide and 67.5% sodium carbonate (based on weight) [10], has recently been used as another oxidant for ISCO [11]. Compared with liquid H 2 O 2 , SPC comes in a solid form that can be used as a dry carrier of H 2 O 2 and as a granulated powder is easier to transport.…”

“…Besides, some researchers reported the application of SPC to replace liquid H 2 O 2 in the remediation of soil or groundwater contaminated by chlorinated aromatic hydrocarbons [14], trichloroethylene [15] and polycyclic aromatic hydrocarbon (PAHs) [11], with significant contaminant removal efficiency. However, to our best knowledge, there are a paucity of literatures related to the degradation of BTEX by Fe 2+ -catalyzed SPC system (SPC/ Fe 2+ ).…”

An efficient catalytic degradation of trichloroethene in a percarbonate system catalyzed by ultra-fine heterogeneous zeolite supported zero valent iron-nickel bimetallic composite

“…Thus, in contrast to peroxide, a major advantage of using SPC for ISCO application is that it is effective over a relatively wide range of pHs [13, 14]. In addition, the SPC decomposition products are non-toxic to micro-organisms owing to its compatibility with bioremediation.…”

Enhancement effects of chelating agents on the degradation of tetrachloroethene in Fe(III) catalyzed percarbonate system

“…However, most of these studies were conducted by applying Fenton-like processes. To the best of our knowledge, few studies to date have investigated Fe(III) catalyzed SPC oxidation of chlorinated-solvent compounds [22]. And the issue of Fe(III) stability in catalyzed SPC system has not been addressed.…”