Determination of mass transfer rates and deposition levels of polycyclic aromatic hydrocarbons (PAHs) using a modified water surface sampler

AbstractThere are different approaches to determine dry deposition velocities (Vd) and mass transfer coefficients (KG) of individual polycyclic aromatic hydrocarbons (PAHs). A modified water surface sampler (MWSS) and a high volume air sampler were concurrently used to determine Vd and KG in this study. Ambient air and deposition samples were collected from August 2004 to May 2005 in Bursa, Turkey. The mean particle-phase dry deposition flux of PAHs was 890±520 ng/m2 d, while the mean gas-phase PAH flux was 5 060±4 260 ng/m2 d. The ratio between fluxes and air concentration values was used in calculation of Vd and KG. The average calculated Vd and KG values for PAH compounds were 0.52±0.36cm/s and 0.69±0.41cm/s, respectively. Despite the fluctuation on seasonal atmospheric concentrations due to regional sources and meteorological conditions, there was no significant difference on deposition velocities and mass transfer rates. KG was also calculated using some models reported in the literature and models developed using the MWSS. The predicted KG determined by models developed using the MWSS was 0.59±0.02cm/s showing a close agreement with the experimentally measured values

Influence of an aerobic selector on copper and hexavalent chromium biosorption by activated sludge

The definitive version may be found at www.wiley.comUfuk Alkan, Siddik Cindoruk, Yücel Tasdemir, Christopher Colb

Existence of SARS-CoV-2 RNA on ambient particulate matter samples: A nationwide study in Turkey

Coronavirus disease 2019 (COVID-19) is caused by the SARS-CoV-2 virus and has been affecting the world since the end of 2019. The disease led to significant mortality and morbidity in Turkey, since the first case was reported on March 11th, 2020. Studies suggest a positive association between air pollution and SARS-CoV-2 infection. The aim of the present study was to investigate the role of ambient particulate matters (PM), as potential carriers for SARS-CoV-2. Ambient PM samples in various size ranges were collected from 13 sites including urban and urban-background locations and hospital gardens in 10 cities across Turkey between 13th of May and 14th of June 2020 to investigate the possible presence of SARS-CoV-2 RNA on ambient PM. A total of 203 daily samples (TSP, n = 80; PM2.5, n = 33; PM2.5-10, n = 23: PM10 mu m, n = 19; and 6 size segregated PM, n = 48) were collected using various samplers. The N1 gene and RdRP gene expressions were analyzed for the presence of SARS-CoV-2, as suggested by the Centers for Disease Control and Prevention (CDC). According to real time (RT)-PCR and three-dimensional (3D) digital (d) PCR analysis, dual RdRP and NI gene positivity were detected in 20 (9.8%) samples. Ambient PM-bound SARS-CoV-2 was analyzed quantitatively and the air concentrations of the virus ranged from 0.1 copies/m(3) to 23 copies/m(3). The highest percentages of virus detection on PM samples were from hospital gardens in Tekirdag, Zonguldak, and Istanbul, especially in PM2.5 mode. Findings of this study have suggested that SARS-CoV-2 may be transported by ambient partides, especially at sites close to the infection hot-spots. However. whether this has an impact on the spread of the virus infection remains to be determined. (C) 2021 Elsevier B.V. All rights reserved