Ozone in polycyclic aromatic hydrocarbon degradation

A review on recent advancements in the treatment of polyaromatic hydrocarbons (PAHs) using sulfate radicals based advanced oxidation process

Polyaromatic hydrocarbons (PAHs) are the most persistent compounds that get contaminated in the soil and water. Nearly 16 PAHs was considered to be a very toxic according US protection Agency. Though its concentration level is low in the environments but the effects due to it, is enormous. Advanced Oxidation Process (AOP) is an emergent methodology towards treating such pollutants with low and high molecular weight of complex substances. In this study, sulfate radical (SO4‾•) based AOP is emphasized for purging PAH from different sources. This review essentially concentrated on the mechanism of SO4‾• for the remediation of pollutants from different sources and the effects caused due to these pollutants in the environment was reduced by this mechanism is revealed in this review. It also talks about the SO4‾• precursors like Peroxymonosulfate (PMS) and Persulfate (PS) and their active participation in treating the different sources of toxic pollutants. Though PS and PMS is used for removing different contaminants, the degradation of PAH due to SO4‾• was presented particularly. The hydroxyl radical (•OH) mechanism-based methods are also emphasized in this review along with their limitations. In addition to that, different activation methods of PS and PMS were discussed which highlighted the performance of transition metals in activation. Also this review opened up about the degradation efficiency of contaminants, which was mostly higher than 90% where transition metals were used for activation. Especially, on usage of nanoparticles even 100% of degradation could be able to achieve was clearly showed in this literature study. This study mainly proposed the treatment of PAH present in the soil and water using SO4‾• with different activation methodologies. Particularly, it emphasized about the importance of treating the PAH to overcome the risk associated with the environment and humans due to its contamination.

Polycyclic aromatic hydrocarbons in soybean grains

During the burning of the organic material (firewood) in the drying, combustion may occur incompletely, thus generating smoke contaminants such as polycyclic aromatic hydrocarbons (PAHs) in the furnaces. This study aimed to identify possible contamination by PAHs in soybean grains from storage units in municipalities in the Midwest region that have undergone drying in a direct-fired furnace with firewood as fuel. The soybean grains were collected in different municipalities of the Midwest region of Brazil, totaling 22 samples. A survey of possible contamination of soybean grains by PAHs was carried out using High-Performance Liquid Chromatography. The experiment was carried out in a completely randomized design with three replicates, and the data were subjected to analysis of variance, with means compared by Tukey test. The sum of the groups was: PAH4 - 1.45 μg kg-1 for Edéia (2), PAH8 - 2.97 μg kg-1 for Catalão (19) and PAHT - 5.06 μg kg-1 for Edéia (2); for benzo(a)pyrene, the sum was below 2.0 μg kg-1, not exceeded by the value of 0.64 μg kg-1 for Edéia (1). The values found of PAHs did not exceed the maximum limits established by the European Union, except for infant food.