No abstract

This study reports a spatiotemporal characterization of toluene, benzene, ethylbenzene, and xylenes concentrations (BTEX) in an urban hot spot in Iran, specifically at an bus terminal region in Shiraz. Sampling was carried out according to NIOSH Compendium Method 1501. The inverse distance weighting (IDW) method was applied for spatial mapping. The Monte Carlo simulation technique was applied to evaluate carcinogenic and non-carcinogenic risk owing to BTEX exposure. The highest average BTEX concentrations were observed for benzene in the morning (at 7:00–9:00A.M. local time) (26.15±17.65μg/m3) and evening (at 6:00–8:00P.M. local time) (34.44±15.63μg/m3). The benzene to toluene ratios in the morning and evening were 2.02 and 3.07, respectively. The main sources of BTEX were gas stations and a municipal solid waste transfer station. The inhalation lifetime cancer risk (LTCR) for benzene in the morning and evening were 1.96×10−4 and 2.49×10−4, respectively, which exceeds the recommended value by US EPA and WHO. The hazard quotient (HQ) of all these pollutants was less than 1. The results of this work have implications for public health near ‘hot spots’ such as IKBT where large populations are exposed to carcinogenic emissions.

No abstract

No abstract

No abstract

No abstract

No abstract

In this study, the removal of cephalexin (CEX) antibiotic from aqueous solution was examined using a novel green adsorbent without employing any toxic chemicals or capping agents. Nettle and Thyme extracts were used to synthesize novel nano-zero-valent iron (NNZVI and TNZVI) for the adsorption of CEX. The nature and morphology of synthesized adsorbent were characterized by Transmission electron microscopy, scanning electron microscope, X-ray diffraction and Fourier transform infrared spectroscopy spectroscopy. Batch experiments were performed to study the influence of various experimental parameters such as contact time, initial concentration of the CEX, solution pH and adsorbent dosage. The adsorption isotherms of CEX by NNZVI and TNZVI were found to fit well with Freundlich and Langmuir models, respectively. The maximum adsorption capacity of CEX onto NNZVI and TNZVI were observed as 1667 and 1428 mg/g, respectively, based on the Langmuir model. The adsorption trend followed the pseudo-first-order kinetics model and equilibrium could be established in about two hours for both adsorbents. The developed nanoparticles in this study have considerable potential for the removal of CEX and could be considered as a promising adsorbent for the removal of other antibiotics also from aqueous solutions.