Background: Polycyclic aromatic hydrocarbons (PAHs), which consist of fused conjugated aromatic rings, not only are toxic to humans and other living organisms, but will also pollute groundwater. These compounds can be point source or non-point source and are one of the most widespread organic pollutants. Some of them are suspected carcinogens and are linked to other health problems. This study was carried out to assess the petroleum hydrocarbon phytoremediation potential of the Aeluropus littoralis species. Accumulation of PAHs in roots and upper parts of A. littoralis has been determined. Translocation factor (TF) was also calculated. Methods: In this study, soil samples were taken from the vicinity of Isfahan oil refinery, and the PAHs compounds were analyzed with gas chromatography. One-meter soil columns were prepared from the control and contaminated soil. Unplanted A. littoralis treatments were also prepared to eliminate the effects of environmental factors on the reduction of oil-based contaminants. Seventeen weeks after planting, soil columns were sampled at 25, 50, 75, and 100 cm depths, and the concentration of petroleum hydrocarbons and number of oil-degrading bacteria were counted. Moreover, the roots and shoots of A. littoralis were separated and weighed. Results: Results indicated that A. littoralis reduced the concentration of petroleum hydrocarbons to a significantly higher extent than the control treatment. Increasing depth was associated with improved petroleum hydrocarbon concentrations and decreased number of oil-degrading bacteria. Mostly, the bioaccumulation factor (BAF) of PAHs was <1, which shows A. littoralis could be an excluder of PAHs. The results also showed that the TF of PAHs was less than one, and hence, A. littoralis could be considered as an accumulator of PAHs. Conclusion: It can be concluded that this species is suitable for use in the phytoremediation of PAHS contamination. For further confirmation, an evaluation under field conditions should be undertaken. Keywords: Biodegradation, Soil, Polycyclic aromatic hydrocarbons, Aeluropus littoralis plant Citation: Rafiee M, Jahangiri Rad M, Afshari A. Bioaccumulation and translocation factors of petroleum hydrocarbons in Aeluropus littoralis.

A B S T R AC TThe presence of synthetic dyes in aquatic environments poses potential health and ecological risks. Several techniques are available for dyes' removal. In this study the degradation of an anthraquinone dye, Reactive blue 29 (RB29), using an advanced oxidation process followed by single-wall carbon nanotubes (SWCNTs) was investigated. Advanced oxidation process was optimized over a period of 60 min by varying the ratio of acetic acid to hydrogen peroxide, the compounds which form peroxy acid. Reduction of 20.2-56.4% of RB29 was observed when the ratio of hydrogen peroxide/acetic acid/dye changed from 344/344/1 to 344/344/0.08 at different times (60, 120 and 180 min). Hydrogen peroxide served as controls in all advanced oxidation process and demonstrated minimal degradation over the time course study. The optimum ratio of acetic acid/hydrogen peroxide/dye was found to be 344/344/0.16 over 60 min. The resultant then introduced for further removal by SWCNTs as adsorbent. The adsorption of RB29 onto SWCNTs was also solely investigated. The Langmuir, Freundlich and BET isotherms were determined and the result revealed that the adsorption of RB29 onto SWCNTs well explained by BET model and changed to Freundlich isotherm when SWCNTs used after the application of peroxy acid. The maximum adsorption capacity of RB29 by SWCNTs also decreased from 496 mg/g to 472 mg/g when SWCNTs used solely and in sequence with peroxy acid, respectively. The removal of RB29 using an advanced oxidation process prior to the application of SWCNTs was also optimized over a period of 2 h. Color removal obtained over 2 h was 67.8-84.4% depending on the amount of SWCNTs used. Further studies are needed to identify the effects of peroxy acid degradation intermediates and to investigate their effects on SWCNTs.

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There are about 70% people living in cities in the world, however, urbanization in cities is still in progress. Urban development brings us economic benefits but also results in environmental pollutions. Steps taken to environmental sustainability can lead to the preservation of natural resources while welfare, economic and social dimensions are considered. There are lots of ways to reach sustainability, one of which is through abatement of air pollution which in turn would have direct and indirect impacts on environmental, economic and sociopolitical sustainability. This review outlines the issues concerned in air mitigation such as the use of renewable energies, the role of green lands and sustainable transportation as keys for sustainable development.