Influence of pyrene combination state in soils on its treatment efficiency by Fenton oxidation

Remediation of PAH-contaminated sediments by chemical oxidation

“…Hydrogen peroxide can be used alone, but it is considered not kinetically fast enough to degrade most of organic contaminants before its decomposition occurs [19]. In Fenton's reagent, hydrogen peroxide is dosed together with a solution of a transition metal (typically iron) to enhance the radical formation, as the catalyst addition dramatically increases the peroxide oxidative strength [19][20][21][22]29,[31][32][33][34][35][36]. The typical Fenton's reaction is based on the hydrogen peroxide decomposition into hydroxyl radicals in the presence of ferrous iron, according to the reaction:…”

“…Since in environmental conditions iron is mainly found as Fe(III), low pH (optimal range about 3.5-5) or chelating agents (like citric acid, cyclodextrins, ethylene diamine tetra-acetic acid (EDTA), catechol) can be used to increase the availability of iron(II), so as to enhance the Fenton's reactions [19,22,37]. Once hydroxyl radicals have been created, the degradation can be due either to hydrogen abstraction (reaction (4)) or to hydroxyl addition (reaction (5)) [33]:…”

“…Several Authors have in fact reported that the oxidation can enhance the biodegradability of PAHs, the application of chemical pre-oxidation having found to overcome the PAH recalcitrance to biodegradation [8,[20][21][22][23]. In certain conditions, the mineralization effect can be achieved by using a pressurized hot water flux (about 250-300 • C) as extracting or oxidant agent [24,25].…”

Sorption and degradation of carbaryl in soils amended with biochars: influence of biochar type and content

“…Hence, it can be expected that an increase in the contaminant sorption will result in a reduction in biodegradation. Though the impact of sorption on chemical reactivities has been relatively rarely studied, it was found that strong sorption leads to reduced oxidation of pyrene by H 2 O 2 (Sun and Yan 2008).…”

Bioremediation of Pyrene-Contaminated Soils Using Biosurfactant

“…Therefore, a higher efficiency would be more acceptable. Some of the European and North American countries like England, Canada and Holland use the phenanthrene guideline of 40 mg/kg as the PAH standard for soil (33). If this guideline is considered as the base of comparison, removal of pyrene to less than 40 mg/kg was not observed in any of the studied conditions of soil remediation till day 63, but a large portion of pyrene (84.6%) was removed, which cannot be argued due to lack of internal standards.…”