Bioaerosol emissions from wastewater and wastewater treatment processes are a significant subgroup of atmospheric aerosols. Most previous work has focused on the evaluation of their biological risks. In this study, ho...Bioaerosol emissions from wastewater and wastewater treatment processes are a significant subgroup of atmospheric aerosols. Most previous work has focused on the evaluation of their biological risks. In this study, however, the adsorption method was applied to reduce airborne microorganisms generated from a pilot scale wastewater treatment facility with oxidation ditch. Results showed adsorption on granule activated carbon （GAC） was an efficient method for the purification of airborne microorganisms. The GAC itself had a maximum adsorption capacity of 2217 CFU/g for airborne bacteria and 225 CFU/g for fungi with a flow rate of 1.50 m^3/hr. Over 85% of airborne bacteria and fungi emitted from the oxidation ditch were adsorbed within 80 hr of continuous operation mode. Most of them had a particle size of 0.65-4.7 μm. Those airborne microorganisms with small particle size were apt to be adsorbed. The SEM/EDAX, BET and Boehm＇s titration methods were applied to analyse the physicochemical characteristics of the GAC. Relationships between GAC surface characteristics and its adsorption performance demonstrated that porous structure, large surface area, and hydrophobicity rendered GAC an effective absorber of airborne microorganisms. Two regenerate methods, ultraviolet irradiation and high pressure vapor, were compared for the regeneration of used activated carbon. High pressure vapor was an effective technique as it totally destroyed the microorganisms adhered to the activated carbon. Microscopic observation was also carried out to investigate original and used adsorbents.展开更多
Objective To develop a new sampling medium for detecting of bioaerosols. Methods The sampling media were tested by using Escherichia coli, Staphylococcus aureus and Serratia marcescens under static and active conditio...Objective To develop a new sampling medium for detecting of bioaerosols. Methods The sampling media were tested by using Escherichia coli, Staphylococcus aureus and Serratia marcescens under static and active conditions, preliminary applications were performed using AGI-10 and high volume sampler. Results The average recovery rates were raised to 24.7%, 58.2%, 40.5%, 44.1%, 20.5%, and 15.4%, respectively in six consecutive experiments under static condition for 60 min at room temperature. Four kinds of sampling media were singled out after static experiments, which were referred to as “samplutions” PD1, PX2, TD1, and TX2, respectively. Under the active condition, the protective efficacy of PD1, PX2, TD1, and TX2 was 226% (153/47), 553% (111/17), 150% (120/48), and 268% (419/114), respectively. Conclusion The samplutions have some effects on the subsequent nucleic acid detection, which could be avoided by employing standard nucleic acid extraction procedure. The newly developed samplution can be applied to the detection of bioaerosols.展开更多
Over the past few years, research on the quality of air and microorganisms presen</span><span style="font-family:Verdana;">t in the atmosphere and spore composition of the environment has increas...Over the past few years, research on the quality of air and microorganisms presen</span><span style="font-family:Verdana;">t in the atmosphere and spore composition of the environment has increased significantly, due to concerns over health risks for humans, plants, and animals. This study shows the abundance and diversity of microorganisms </span></span><span style="font-family:Verdana;">and </span><span style="font-family:Verdana;">the</span><span style="font-family:""><span style="font-family:Verdana;"> atmosphere of an urban nucleus, that is, the city of Valladolid (Spain). We considered the conditions of precipitation, humidity </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> wind, and the presence of some atmospheric pollutants such as nitrogen dioxide and nitrogen monoxide (NO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">/NO), carbon monoxide (CO), sulfur dioxide, and particulate matter (</span></span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">PM</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;">10 and </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">PM</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:""><span style="font-family:Verdana;">2.5). After their deposition </span><span style="font-family:Verdana;">present</span><span style="font-family:Verdana;"> at five geographic points with different environmental conditions, differences </span><span style="font-family:Verdana;">were</span><span style="font-family:Verdana;"> observed in the proportion of bacteria growth which </span><span style="font-family:Verdana;">w</span></span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> char</span><span style="font-family:Verdana;">acterized by growth in several specific culture media. Most identified the Gram-negative bacteria ident展开更多
基金supported by the National Natural Science Foundation of China (No.50921064, 50978249)
文摘Bioaerosol emissions from wastewater and wastewater treatment processes are a significant subgroup of atmospheric aerosols. Most previous work has focused on the evaluation of their biological risks. In this study, however, the adsorption method was applied to reduce airborne microorganisms generated from a pilot scale wastewater treatment facility with oxidation ditch. Results showed adsorption on granule activated carbon （GAC） was an efficient method for the purification of airborne microorganisms. The GAC itself had a maximum adsorption capacity of 2217 CFU/g for airborne bacteria and 225 CFU/g for fungi with a flow rate of 1.50 m^3/hr. Over 85% of airborne bacteria and fungi emitted from the oxidation ditch were adsorbed within 80 hr of continuous operation mode. Most of them had a particle size of 0.65-4.7 μm. Those airborne microorganisms with small particle size were apt to be adsorbed. The SEM/EDAX, BET and Boehm＇s titration methods were applied to analyse the physicochemical characteristics of the GAC. Relationships between GAC surface characteristics and its adsorption performance demonstrated that porous structure, large surface area, and hydrophobicity rendered GAC an effective absorber of airborne microorganisms. Two regenerate methods, ultraviolet irradiation and high pressure vapor, were compared for the regeneration of used activated carbon. High pressure vapor was an effective technique as it totally destroyed the microorganisms adhered to the activated carbon. Microscopic observation was also carried out to investigate original and used adsorbents.
文摘Objective To develop a new sampling medium for detecting of bioaerosols. Methods The sampling media were tested by using Escherichia coli, Staphylococcus aureus and Serratia marcescens under static and active conditions, preliminary applications were performed using AGI-10 and high volume sampler. Results The average recovery rates were raised to 24.7%, 58.2%, 40.5%, 44.1%, 20.5%, and 15.4%, respectively in six consecutive experiments under static condition for 60 min at room temperature. Four kinds of sampling media were singled out after static experiments, which were referred to as “samplutions” PD1, PX2, TD1, and TX2, respectively. Under the active condition, the protective efficacy of PD1, PX2, TD1, and TX2 was 226% (153/47), 553% (111/17), 150% (120/48), and 268% (419/114), respectively. Conclusion The samplutions have some effects on the subsequent nucleic acid detection, which could be avoided by employing standard nucleic acid extraction procedure. The newly developed samplution can be applied to the detection of bioaerosols.
文摘Over the past few years, research on the quality of air and microorganisms presen</span><span style="font-family:Verdana;">t in the atmosphere and spore composition of the environment has increased significantly, due to concerns over health risks for humans, plants, and animals. This study shows the abundance and diversity of microorganisms </span></span><span style="font-family:Verdana;">and </span><span style="font-family:Verdana;">the</span><span style="font-family:""><span style="font-family:Verdana;"> atmosphere of an urban nucleus, that is, the city of Valladolid (Spain). We considered the conditions of precipitation, humidity </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> wind, and the presence of some atmospheric pollutants such as nitrogen dioxide and nitrogen monoxide (NO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">/NO), carbon monoxide (CO), sulfur dioxide, and particulate matter (</span></span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">PM</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;">10 and </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">PM</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:""><span style="font-family:Verdana;">2.5). After their deposition </span><span style="font-family:Verdana;">present</span><span style="font-family:Verdana;"> at five geographic points with different environmental conditions, differences </span><span style="font-family:Verdana;">were</span><span style="font-family:Verdana;"> observed in the proportion of bacteria growth which </span><span style="font-family:Verdana;">w</span></span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> char</span><span style="font-family:Verdana;">acterized by growth in several specific culture media. Most identified the Gram-negative bacteria ident
