Anthracene decomposition in soils by conventional ozonation

Anthracene decomposition in solid phase by conventional ozonation was investigated employing model and real soil samples. Reaction in a two-phase system (soil-ozone) and a three-phase system (soil-water-ozone) was studied. The total anthracene decomposition in the two studied systems (sand-ozone and burned soil-ozone) was obtained at 15 and 30 min of treatment by ozone, respectively, and the efficiency of ozonation was depended on the water content in treated soil samples. The anthracene degradation in an agricultural soil (free water) was carried up slower (only 30% after 90 min of ozonation), because the real solid samples content organic matter that provokes the additionally ozone consuming. The pre-ozonation of free anthracene agricultural soil depicts the content of the organic matter fraction, which have the ozone reactivity orders as aromatic > aliphatic > polar. In all cases, the ozonation by-products were identified partiality; the majority of by-products formatted react with ozone. Actually some of them were decomposed totally, while others were accumulated. Some products identified in all systems such as anthrone, 9,10-anthraquinone and phthalic acid, are less toxic than the anthracene.

► Ozone was proposed for the anthracene degradation in model and real soil. ► The ozonation in baked and moist sand, and real soil was carried out in the reactor (12 × 3.0 cm) by the “fluid bed” principle to 90 min. ► The formation of OH radicals in the presence of water (20% w/w) is reflected in a similar decomposition of all by-products. ► In real soil the decomposition degree depended on the physicochemical soil characteristics and the water and organic matter content.