Oxidant selection to treat an aged PAH contaminated soil by in situ chemical oxidation

Abstract

This work is a part of the OXYSOL project aiming at the conception of a global treatment pathway including In Situ Chemical Oxidation to clean up soils of former metallurgical sites.It deals with the selection of the most adapted oxidants. Batch experiments were performed with aged contaminated soil samples of a former steel-making plant to degrade the 16 US 1 EPA PAHs. In this research, hydrogen peroxide, modified Fenton's reaction, potassium permanganate, sodium percarbonate and sodium persulfate were compared at high and moderate doses. Hydrogen peroxide, modified Fenton's reagent, percarbonate and activated persulfate led to a maximum degradation ratio of 45%. A higher ratio (70%) was obtained with a high dose of permanganate. Except for permanganate, increasing oxidant dose did not improve degradation rates, especially with radical-based oxidative systems probably due to radical scavenging. Oxidant doses had an effect on pH that drastically increased or dropped in some cases, which was a drawback. Permanganate efficacy was mainly assigned to its persistence. In all cases, the low availability of PAHs, partly sequestrated in the aged soil, was identified as the most limiting factor for degradation performance. Oxidants were ranked according to their efficiency for PAH oxidation in soils. Efficiency was not correlated to the doses.

Application of chemical oxidation to remediate HCH-contaminated soil under batch and flow through conditions

“…Similarly, no significant improvement in degradation efficiency was reported beyond an optimum oxidant dose during radical based oxidation of polycyclic aromatic hydrocarbons in contaminated soils that was correlated to the radical scavenging (Lemaire et al 2013). It is worthy to note that both oxidants when applied without iron activation also effectively degrade both β-HCH (37% and 30% by H2O2 and Na2S2O8 respectively) and lindane (75% and 89% by H2O2 and Na2S2O8 respectively).…”

Selection of oxidant doses for in situ chemical oxidation of soils contaminated by polycyclic aromatic hydrocarbons (PAHs): A review

“…Similarly, soil organic matter content is often measured but also seldom considered in oxidant dose selection. Moreover, even if TOC is the most common indicator (Figure 3), it may have been quantified by a number of methods [244]: dry combustion at 440 °C [94], 680 °C [47] or 900 °C [41,49,50,56,57,163,203,240,241], wet oxidation with dichromate [205,[234][235][236][237] or a mix of both methods [54]. The measurement method may be not specified [30,150,194,206,213,216,221,222,232,233].…”

“…The present review focuses on the unsaturated zone of industrial soils, especially soils of former coking plants [31,39,41,[47][48][49][50][51], manufactured gas plant (MGP) sites and wood preservation sites [24,34,36,37,39,43]. For example, the estimated number of MGP sites ranges from 3 000 to 5 000 in the United States, from 4 000 to 5 000 in Europe and several thousands of MGP sites are likely to exist in large developing countries such as Russia, China and India [46].…”

“…The reagent is then referred to as "modified Fenton's reagent" or "Fenton-like reagent" [42,49,50,56,[162][163][164][165]. Persulphate can be activated with iron (II), hydrogen peroxide, temperature increase or alkaline conditions.…”

Application of surfactant Tween 80 to enhance Fenton oxidation of polycyclic aromatic hydrocarbons (PAHs) in soil pre-treated with Fenton reagents

“…They are wide-spread environmental contaminants that are mainly formed during the incomplete combustion of fossil fuels (Antizar-Ladislao et al, 2004;Jonsson et al, 2007;Rivas, 2006). Industrial sites associated with petroleum refining, manufactured gas plants, wood treatment facilities, steel-making factories, coking plants and thermal power plants are often highly contaminated with PAHs (Jonsson et al, 2007;Lemaire, Buès, Kabeche, Hanna, & Simonnot, 2013). PAHs are very persistent in soils due to their properties, such as low volatility, low water solubility and low biodegradability (López-Vizcaíno, Sáez, Cañizares, & Rodrigo, 2012).…”