The novel SARS-CoV-2 outbreak was declared as pandemic by the World Health Organization (WHO) on March 11, 2020. Understanding the airborne route of SARS-CoV-2 transmission is essential for infection prevention and control. In this study, a total of 107 indoor air samples (45 SARS-CoV-2, 62 bacteria, and fungi) were collected from different wards of the Hajar Hospital in Shahrekord, Iran. Simultaneously, bacterial and fungal samples were also collected from the ambient air of hospital yard. Overall, 6 positive air samples were detected in the infectious 1 and infectious 2 wards, intensive care unit (ICU), computed tomography (CT) scan, respiratory patients’ clinic, and personal protective equipment (PPE) room. Also, airborne bacteria and fungi were simultaneously detected in the various wards of the hospital with concentrations ranging from 14 to 106 CFU m −3 and 18 to 141 CFU m −3 , respectively. The highest mean concentrations of bacteria and fungi were observed in respiratory patients’ clinics and ICU wards, respectively. Significant correlation ( p < 0.05) was found between airborne bacterial concentration and the presence of SARS-CoV-2, while no significant correlation was found between fungi concentration and the virus presence. This study provided an additional evidence about the presence of SARS-CoV-2 in the indoor air of a hospital that admitted COVID-19 patients. Moreover, it was revealed that the monitoring of microbial quality of indoor air in such hospitals is very important, especially during the COVID-19 pandemic, for controlling the nosocomial infections. Supplementary Information The online version contains supplementary material available at 10.1007/s11356-021-13628-9.

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This study aims to investigate the biosorption of Pb (II) by living and nonliving biomass of Penicillium notatum. Penicillium notatum PTCC 5074 was purchased from Iran Scientific-Industrial Research Organization in lyophilized form and after culturing in potato dextrose agar was propagated in Sabouraud dextrose broth medium. The highest adsorption by living and nonliving biomass (180.74 and 187.08 mg/g per dry weight of biomass, respectively) was at the Pb (II) concentration of 228 mg/L and ionic strength of 43 mg/L in terms of Ca2+ and 1.2 g/L biomass concentration. The optimum contact time and temperature in nonliving biomass were 37 hours and 32.5°C, respectively. Kinetic studies showed that Pb(II) adsorption in both cases follows a pseudo-second-order reaction. The adsorption process was consistent with the Langmuir model in the nonliving state, whereas the favourite models for the living state were Langmuir and Freundlich. Thermodynamic constants indicated that the adsorption process by nonliving and living biomass were exothermic and endothermic, respectively. The obtained results showed that Penicillium notatum in living and nonliving states is suitable for the development of an efficient and economic biosorbent for the removal of Pb (II) from aqueous environments.

One of the most important environmental pollutants is azo dyes in textile wastewater. In this study, the removal of azo dye Acid Red 18 (AR 18) with initial concentration of 25-100 mg L−1 in aqueous solution by the adsorption process onto activated charcoal prepared from almond shell (AC-AS) was investigated. The effects of initial pH (2-12), contact time (15-120 min), adsorbent (0.2-2 g L-1) and initial concentration of AR 18 (25-100 mg L-1) on the removal efficiency of AR 18 solution were investigated. All experiments were performed on a synthetic wastewater. The efficiency of dye removal and Freundlich and Langmuir adsorption isotherms were compared as a function of decolorization and adsorption and kinetic behavior of AR 18. The maximum removal efficiency of AR 18 (i.e., 90.83%) was occurring with pH 2, contact time of 60 min, initial dye concentration of 75 mg L-1 and the adsorbent dose of 0.8 g L-1. The removal of AR 18 followed the Frundlich isotherm model (r2>0.994). Fitting of obtaining data onto kinetic models showed the pseudo second-order reaction kinetics with respect to the dye concentration. This investigation revealed adsorption onto activated charcoal prepared from almond shell presents good efficiency for solution decolorization.