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Microbial aerosol chemistry characteristics in highly polluted air

Science China Chemistry 2019年第8期62卷 1051-1063页

作者： Ting Zhang Xinyue Li Minfei Wang Haoxuan Chen Maosheng Yao State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking University

Aerosol chemistry is often studied without considering microbial involvements. Here, we investigated time-and size-resolved bacterial aerosol dynamics in air. Under high particulate matter(PM) polluted episodes, bacterial aerosols exhibited a viability of up to 50%–70% in the 0.56–1 μm size range, at which elevated levels of SO42-, NO3- and NH4+ were concurrently *** or acclimated for both industrial use, bacteria such as Psychrobacter spp., Massilia spp., Acinetobacter lwoffii,Exiguobacteriumaurantiacum and Bacillusmegaterium were shown to have experienced massive abundance shifts in polluted air on early mornings and late afternoons, on which rapid new particle formation events were widely reported. Here, Psychrobacter spp. were shown to account for >96% abundance at a corresponding PM2.5 level of 208 μg/m3. These observed bacterial aerosol changes corresponded to the PM2.5 mass peak shift from 3.2–5.6 μm to the high viability size range of 0.56–1 μm. Additionally,elevated levels of soluble Na, Ca, Mg, K, Al, Fe and P elements, required for bacterial growth, were observed to co-occur with those significant bacterial aerosol structure shifts in the air. For particular time-resolved PM2.5 pollution episodes, Acinetobacter,Psychrobacter and Massilia were shown to alternate in dominating the time-resolved aerosol community structures. The results from a HYSPLIT trajectory model simulation suggested that air mass transport played a minor role in affecting the observed bacterial aerosol structure dynamics. All the data here suggested that airborne bacteria in the size range of 0.56–1 μm could be extensively involved in aerosol chemistry in highly polluted humid air.

关键词： bacterial aerosol dynamics in air particulate matter size-and time-resolved bacterial aerosol aerosol chemistry

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Numerical study of the separation performance of granular sludge and activated sludge in gravity-driven cyclonic field

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Journal of Water Process Engineering 2025年 74卷

作者： Huang, Fei Zhang, Yuantao Tian, Jinyi State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing 100084 China National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery East China University of Science and Technology Shanghai 200237 China State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process East China University of Science and Technology Shanghai 200237 China

The cultivation of aerobic granular sludge (AGS) in a continuous flow process requires an external granular sludge and flocculent activated sludge separator to return the faster settling granular sludge. Experimental studies have confirmed that hydrocyclones are an effective solution for this purpose. This study employed CFD numerical simulations to investigate the operational performance of hydrocyclones at different installation angles. Furthermore, it explored the principles of gravity-driven hydrocyclone-enhanced separation of granular sludge and activated sludge, as well as the hydrocyclone-promoted granulation. The split ratio and separation efficiency are generally proportional to the installation angle, with the optimal angle range identified as −15°~15°. Activated sludge shows a better flow separability with low velocity fluctuations, whereas granular sludge shows more pronounced velocity variations. The results indicate that the inclined gravity-driven hydrocyclone exhibit only a limited difference in separation performance between granular sludge and activated sludge. Therefore, the potential reason for the hydrocyclone-promoted granulation may not be the traditionally considered separative effect, but rather the particle motion induced by the hydraulic shear flow field. © 2025 Elsevier Ltd

关键词： Activated sludge Granular sludge Hydrocyclone Numerical simulation Separation performance

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Fabrication of TiO_2 Nanotube Arrays by Rectified Alternating Current Anodization

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Journal of Materials Science & Technology 2015年第1期31卷 23-29页

作者： Han Song Jing Shang Chen Suo State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking University

Anodization is a popular method of preparing TiO2nanotube array films（TiNTs） by using direct current（DC）power as the driving *** this study,three driving voltage modes,namely,the sine alternating current（sine） mode,the full-wave rectification of sine waves via four diodes（sine-4D,where D means diode） mode,and the DC mode,were used to prepare TiNTs by *** 20 V,TiNTs were formed under sine-4D mode but only irregular porous TiO2films were formed under DC *** 50 V,TiNTs formed under both the sine-4D and DC *** TiNTs formed in the sine mode anodization at either 20 or 50 *** with the DC mode,the sine-4D mode required a lower oxidation voltage for TiNT formation,which suggests that sine-4D is an economical,convenient,and efficient driving voltage for TiNT preparation by *** morphologies and structures of TiNT samples anodized at 50 V in the sine-4D and DC modes at different oxidation time（1,5,10,30,60,and 120 min） were *** growth processes were similar between the studied ***,the growth rate of the films was faster under the sine-4D mode than the DC mode during the first 30 min of anodization.

关键词： TiO2nanotube Anodization Alternating current Growt

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Peroxyacetyl nitrate observed in Beijing in August from 2005 to 2009

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Journal of environmental Sciences 2014年第10期26卷 2007-2017页

作者： Tianyu Gao Li Han Bin Wang Guang Yang Zhenqiang Xu Limin Zeng Jianbo Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking University

Measurements of peroxyacetyl nitrate（PAN） were made at a Beijing urban site each August from2005 to 2009. Over this 5-year period, the average PAN concentration for August in each year increased from 3（2005） to 11.7 μg/m3（2007）; however, it decreased rapidly in 2008（4.1 μg/m3）.Generally, the variation over the 5 years showed a rise in the first part of the study period,followed by a decline. We considered two categories of local and regional air masses in this study, which revealed that the PAN concentration in Beijing was affected mainly by southeastern air masses. The August PAN variation was influenced predominantly by local air masses in 2005,but by 2009 regional air masses had become more important. This study showed the level and variation of PAN in the month of August in 5 consecutive years for the first time, and proved that control measures are useful in decreasing photochemical pollution; hence, these measures are probably feasible for other megacities too. Furthermore, this method of analyzing regional and local impacts might be useful for other studies as well.

关键词： PAN Beijing Transport Local Regional

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Characteristics of volatile organic compounds,NO_2,and effects on ozone formation at a site with high ozone level in Chengdu

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Journal of environmental Sciences 2019年第1期31卷 334-345页

作者： Yuanyuan Deng Jing Li Yaqi Li Rongrong Wu Shaodong Xie College of Environmental Sciences and Engineering State Key Joint Laboratory of Environmental Simulation and Pollution ControlPeking University

Chengdu is a megacity in the southwest of China with high ozone(O_3) mixing *** of volatile organic compounds(VOCs), NO_2 and O_3 with high temporal resolution was conducted in Chengdu to investigate the chemical processes and causes of high O_3 levels. The hourly mixing ratios of VOCs, NO2, and O_3 were monitored by an online system from 28 August to 7 October, 2016. According to meteorological conditions,Chengdu, with relative warm weather and low wind speed, is favorable to O_3 *** of the O_3 in Chengdu may be transported from the downtown area. In O_3 episodes,the average mixing ratios of NO_2 and O_3 were 20.20 ppbv and 47.95 ppbv, respectively. In non-O_3 episodes, the average mixing ratios of NO_2 and O_3 were 16.38 ppbv and 35.15 ppbv,respectively. The average mixing ratio of total VOCs(TVOCs) was 40.29 ppbv in non-O_3 episodes, which was lower than that in O_3 episodes(53.19 ppbv). Alkenes comprised51.7% of the total O_3 formation potential(OFP) in Chengdu, followed by aromatics which accounted for 24.2%. Ethylene, trans-pentene, propene, and BTEX(benzene, ethylbenzene,toluene, m/p-xylene, o-xylene) were also major contributors to the OFP in Chengdu. In O_3 episodes, intensive secondary formations were observed during the campaign. Oxygenated VOCs(OVOCs), such as acetone, Methylethylketone(MEK), and Methylvinylketone(MVK)were abundant. Isoprene rapidly converted to MVK and Methacrolein(MACR) during O_3 episodes. Acetone was mainly the oxidant of C3-C5 hydrocarbons.

关键词： Ozone formation VOCs NO2 OFP Diurnal variation

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Estimating emissions from crop residue open burning in China based on statistics and MODIS fire products

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Journal of environmental Sciences 2016年第6期28卷 158-170页

作者： Jing Li Yu Bo Shaodong Xie College of Environmental Sciences and Engineering State Key Joint Laboratory of Environmental Simulation and Pollution ControlPeking University

With the objective of reducing the large uncertainties in the estimations of emissions from crop residue open burning, an improved method for establishing emission inventories of crop residue open burning at a high spatial resolution of 0.25°× 0.25° and a temporal resolution of1 month was established based on the moderate resolution imaging spectroradiometer（MODIS） Thermal Anomalies/Fire Daily Level3 Global Product（MOD/MYD14A1）. Agriculture mechanization ratios and regional crop-specific grain-to-straw ratios were introduced to improve the accuracy of related activity data. Locally observed emission factors were used to calculate the primary pollutant emissions. MODIS satellite data were modified by combining them with county-level agricultural statistical data, which reduced the influence of missing fire counts caused by their small size and cloud cover. The annual emissions of CO2, CO, CH4,nonmethane volatile organic compounds（NMVOCs）, N2O, NOx, NH3, SO2, fine particles（PM2.5）,organic carbon（OC）, and black carbon（BC） were 150.40, 6.70, 0.51, 0.88, 0.01, 0.13, 0.07, 0.43,1.09, 0.34, and 0.06 Tg, respectively, in 2012. Crop residue open burning emissions displayed typical seasonal and spatial variation. The highest emission regions were the Yellow-Huai River and Yangtse-Huai River areas, and the monthly emissions were highest in June（37%）.Uncertainties in the emission estimates, measured as 95% confidence intervals, range from a low of within ±126% for N2O to a high of within ± 169% for NH3.

关键词： Crop residue open burning Air quality Emission inventory Moderate resolution imaging spectroradiometer(MODIS)

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Investigation of carbonyl compound sources at a rural site in the Yangtze River Delta region of China

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Journal of environmental Sciences 2015年第2期27卷 128-136页

作者： Ming Wang Wentai Chen Min Shao Sihua Lu Limin Zeng Min Hu State Joint Key Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking University

Carbonyl compounds are important intermediates in atmospheric photochemistry, but their primary sources are still not understood well. In this work, carbonyls, hydrocarbons,and alkyl nitrates were continuously measured during November 2011 at a rural site in the Yangtze River Delta region of China. Mixing ratios of carbonyls and hydrocarbons showed large fluctuations during the entire measurement. The average level for total measured volatile organic compounds during the pollution episode from 25 th to 27 th November, 2011 was 91.6 ppb, about 7 times the value for the clean period of 7th–8th, November, 2011. To preliminarily identify toluene sources at this site, the emission ratio of toluene to benzene（T/B） during the pollution episode was determined based on photochemical ages derived from the relationship of alkyl nitrates to their parent alkanes. The calculated T/B was5.8 ppb/ppb, significantly higher than the values of 0.2–1.7 ppb/ppb for vehicular exhaust and other combustion sources, indicating the dominant influence of industrial emissions on ambient toluene. The contributions of industrial sources to ambient carbonyls were then calculated using a multiple linear regression fit model that used toluene and alkyl nitrates as respective tracers for industrial emission and secondary production. During the pollution episode, 18.5%, 69.0%, and 52.9% of measured formaldehyde, acetaldehyde, and acetone were considered to be attributable to industrial emissions. The emission ratios relative to toluene for formaldehyde, acetaldehyde, and acetone were determined to be 0.10, 0.20 and0.40 ppb/ppb, respectively. More research on industrial carbonyl emission characteristics is needed to understand carbonyl sources better.

关键词： Carbonyl compounds Source apportionment Industrial emission Yangtze River Delta

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Country-level antibiotic risk assessment in the multiple environmental matrices based on decennial data

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environmental Research 2025年 279卷 121762页

作者： Zhou, Dafang Chen, Linpeng Huang, Fuyang Yan, Bingshuang Zhou, Zikun Wang, Bin Liu, Fei Dong, Faqin Ren, Dong MOE Key Laboratory of Solid Waste Treatment and Resource Recycle Southwest University of Science and Technology Sichuan Mianyang China Tianfu Institute of Research and Innovation Southwest University of Science and Technology Chengdu China State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution Chinese Research Academy of Environmental Sciences Beijing China Beijing China College of Environmental Science and Engineering China West Normal University Nanchong637009 China

The overuse of antibiotics has led to widespread environmental detection. However, country-level antibiotic risks from a global perspective remain unclear, highlighting a crucial need for antibiotic management worldwide. This study elucidated a global assessment of antibiotic detection frequencies and concentrations across various countries, compared detection levels of antibiotic classifications across compartments in representative countries, and conducted a risk assessment based on predicted no-effect concentrations (PNECs) for antibiotic resistance and minimum inhibitory concentrations (MICs) relevant to microbial nitrogen cycling. A decennial dataset comprising 431,441 records for 137 antibiotics across eight environmental compartments in 45 countries was analyzed. Results showed that Kenya (199 %) had the highest cumulative detection frequencies of four aqueous media. Wastewater from WWTPs (mean: 19.7 ng/L) and animal manure (mean: 2.6 μg/kg) exhibited the highest levels in aqueous and solid media, respectively. From sources to receptors, the highest antibiotic detections and concentrations were found in wastewater from WWTP, where quinolones dominated in France and the USA, and sulfonamides in Kenya (175−357 detections, median: 137−580 ng/L). Similarly, in surface water, sulfonamides were significant in Kenya and Vietnam, quinolones in Kenya (290−2049 detections, median: 32−70 ng/L). From the perspective of cumulative risk, Malaysia, China, and Canada are ranked the top three for both PNECs risk (81 %–191 %) and MICs risk (211 %–236 %). Whether for PNECs or MICs, sulfonamides are the most exceedance-prone antibiotic class across countries and also the highest-risk antibiotic class (median: 33 %). According to the total risk results from different countries, Malaysia (402 %) has the highest risk, followed by Canada (317 %) and China (315 %). The highest antibiotic risks were observed in Asia (medium SDG score), followed by Europe and the Americas (high SDG sco

关键词： Risk assessment

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Evaluating the emission status of light-duty gasoline vehicles and motorcycles in Macao with real-world remote sensing measurement

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Journal of environmental Sciences 2014年第11期26卷 2240-2248页

作者： Yu Zhou Ye Wu Shaojun Zhang Lixin Fu Jiming Hao School of Environment State Key Joint Laboratory of Environment Simulation and Pollution Control Tsinghua University State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex

Roadside remote sensing measurement was used to explore the real-world emission status of light duty gasoline vehicles （LDGVs） and motorcycles in Macao. Both fuel-based and distance-based emission factors were derived using the mass balance method. The emission concentration profile of LDGVs illustrated the benefits of tightening emission standards at the source country or region of import. The distance-based emission factors for CO, HC and NOx of LDGVs registered before 2000 were 8.00, 1.04 and 1.36 g/km, respectively. The distance-based emission factors for CO, HC and NOx of LDGVs registered in or after 2000 were 1.16, 0.15 and 0.18 g/km, respectively. The fuel-based CO emission factors of light duty motorcycles （LDMCs） and heavy duty motorcycles （HDMCs） registered before 2000 were about 10 times higher than those of LDGVs of the same age group. As the emissions of LDGVs decreased more quickly after 2000, the gap widens for newer vehicles. The distance-based HC emission factors of LDMCs and HDMCs registered before 2000 were 4.81 and 2.91 g/km, respectively. The distance-based HC emission factors of LDMCs and HDMCs registered in or after 2000 were 3.52 and 0.93 g/km, respectively. The poor emission performance of motorcycles and their larger share in the traffic flow will cause them to be the major contributor to traffic CO and HC emissions. LDMCs, especially two-stroke models, should be the priority for vehicle emission control efforts in Macao.

关键词： Emission Remote sensing Macao Motorcycle

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Review of technologies and their applications for the speciated detection of RO2 radicals

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Journal of environmental Sciences 2023年第1期123卷 487-499页

作者： Yue Gao Keding Lu Yuanhang Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution ControlCollege of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China

Peroxy radicals(RO_(2)),which are formed during the oxidation of volatile organic compounds,play an important role in atmospheric oxidation ***,the measurement of RO_(2),especially distinct species of RO_(2)radicals,is important and greatly helps the exploration of atmospheric chemistry *** the speciated detection of RO_(2)radicals remains challenging,various methods have been developed to study them in *** methods can be divided into spectroscopy and mass spectrometry *** spectroscopy methods contain laser-induced fluorescence(LIF),UV-absorption spectroscopy,cavity ring-down spectroscopy(CRDS)and matrix isolation and electron spin resonance(MIESR).The mass spectrometry methods contain chemical ionization atmospheric pressure interface time-of-flight mass spectrometry(CI-APi-TOF),chemical ionization mass spectrometry(CIMS),CI-Orbitrap-MS and the third-generation proton transfer reaction-time-of-flight mass spectrometer(PTR3).This article reviews technologies for the speciated detection of RO_(2)radicals and the applications of these *** addition,a comparison of these techniques and the reaction mechanisms of some key species are ***,possible gaps are proposed that could be filled by future research into speciated RO_(2)radicals.

关键词： Speciated RO_(2)radicals Atmospheric chemistry Reaction mechanisms Mass spectrometry

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