Research article Degradation of toxic PAHs in water and soil using potassium zinc hexacyanoferrate nanocubes Uma Shanker * , Vidhisha Jassal, Manviri Rani Department of Chemistry, Dr B R Ambedkar National Institute of Technology, Jalandhar, Punjab,144011, India article info Article history: Received 26 June 2017 Received in revised form 26 August 2017 Accepted 5 September 2017 Keywords: Polycyclic aromatic hydrocarbons Water and soil Degradation Potassium zinc hexacyanoferrate nanocubes abstract Polycyclic aromatic hydrocarbons (PAHs) the ubiquitous, persistent and carcinogenic environmental contaminants have raised concern worldwide. Recently, their removal methodologies are advanced after exploring nanomaterials. Therefore, degradation of selected toxic PAHs (3e5 rings) using potassium zinc hexacyanoferrate (KZnHCF) nanocubes was studied. Highly crystalline and sharp KZnHCF nanocubes (~100 nm) were obtained by green route using sapindus mukorossi. In both water and soil, anthracene and phenanthrene were degraded to maximum extent (80e93%), whereas, the degradation of fluorene, chrysene and benzo (a) pyrene were ~70e80%.Because of small size (lower molecular weight), large number of anthracene and phenanthrene molecules were adsorbed on catalyst as compared to other PAHs. Higher degradation of PAHs in water than in the soil is attributed to the easy absorption of PAHs on catalyst in water and slow diffusion of PAHs on organic content of soil. PAHs were degraded at the concentration of 50 mg/L, 25 mg catalyst dose, neutral pH and solar irradiation. Higher proficiency of the catalyst was revealed by degradation of PAHs into small and non-toxic by-products such as mal- ealdehyde, 4-oxobut-2-enoic acid and o-xylene. Overall, the potential KZnHCF nanostructures open future scope for eradication of other pollutants from the environment. © 2017 Elsevier Ltd. All rights reserved. 1. Introduction Polycyclic aromatic hydrocarbons (PAHs), a class of ubiquitous and persistent organic pollutants (POPs), are released into envi- ronment due to natural (volcanic eruptions and forest fires) and anthropogenic (petroleum discharge) sources (Kaushik and Haritash, 2006). They are known to be carcinogenic and their persistence with toxicity increased with increase in molecular weight (Hanazato, 2001; Kaushik and Haritash, 2011). Like other POPs, they may also transformed into more toxic byproducts ((Guptaet al., 2011, 2012a, b, c; Rani, 2012; Rani et al., 2017a; Rani and Shanker, 2017). In recent times, oil-spilling in ocean has drawn attention due to killing of several aquatic species and birds (Stronkhorst et al., 1993; Naf et al., 1992). The Deepwater Horizon drilling rig explosion in the Macondo field of USA on 20 April 2010 was one of the largest oil spill in the history (Suzanne and Terry, 2012). PAHs with estimation of over 80,000 tons are being discharged into the water bodies annually (Manoli and Samara, 1999; Guo et al., 2007). Through biomagnification in tropic or- ganisms, PAHs gets transferred to humans via food consumption (Meador et al., 1995). Several studies reported that the uptake of PAHs through diet (foodstuffs, vegetables and crops) is much higher than the intake through inhalation of air (Menzie et al., 1992). PAHs have tendency to adsorb on the surface of solid particulate rich in organic content (log Ko/w  5.2) and less soluble in water (Tremblay et al., 2005). Consequently, their elevated concentrations were detected in soil, sediments and birds as well as in their eggs and polar organisms and levels are expected to increase with time (Puglisi et al., 2007; WHO, 1998). Due to extensive petroleum trade, the coastal zones of Benin and France are contaminated with pet- rogenic (25 ± 1450 ng g 1 ) and pyrolytic PAHs (4 ± 855 ng g-1), respectively (Soclo et al., 2000). In view of wide contamination, noxiousness and POPs characteristics, 17 unsubstituted PAHs are listed as priority pollutants (US, 1995; Kornmuller et al., 1997; Rockne and Srand, 1998 Bouzige et al., 1999). Therefore, it is a matter of utmost importance to complete eliminate of PAHs as well as their metabolites using efficient and advanced techniques. Nanomaterials with unique properties of high surface area and semiconducting nature are becoming efficient and promising * Corresponding author. E-mail addresses: shankeru@nitj.ac.in, umaorganic29@gmail.com (U. Shanker). Contents lists available at ScienceDirect Journal of Environmental Management journal homepage: www.elsevier.com/locate/jenvman http://dx.doi.org/10.1016/j.jenvman.2017.09.015 0301-4797/© 2017 Elsevier Ltd. All rights reserved. Journal of Environmental Management 204 (2017) 337e348