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Application of internal standard method in recombinant luminescent bacteria test

Journal of environmental Sciences 2015年第9期27卷 128-134页

作者： Yong-zhi Wang Dan Li Miao He Environmental Simulation and Pollution Control (ESPC) State Key Joint Laboratory School of Environment Tsinghua University Fudan University Department of Environmental Science & Engineering

Mercury and its organic compounds have been of severe concern worldwide due to their damage to the ecosystem and human health. The development of effective and affordable technology to monitor and signal the presence of bioavailable mercury is an urgent *** Mer gene is a mercury-responsive resistant gene, and a mercury-sensing recombinant luminescent bacterium using the Mer gene was constructed in this study. The mer operon from marine Pseudomonas putida strain SP1 was amplified and fused with prompterless lux CDABE in the p UCD615 plasmid within Escherichia coli cells, resulting in p THE30–E. *** recombinant strain showed high sensitivity and specificity. The detection limit of Hg^2＋was 5 nmol/L, and distinct luminescence could be detected in 30 min. Cd^2＋, Cu^2＋, Zn^2＋, Ca^2＋,Pb^2＋, Mg^2＋, Mn^2＋, and Al^3＋did not interfere with the detection over a range of 10-5–1 m *** of recombinant luminescent bacteria testing in environmental samples has been a controversial issue： especially for metal-sensing recombinant strains, false negatives caused by high cytotoxicity are one of the most important issues when applying recombinant luminescent bacteria in biomonitoring of heavy metals. In this study, by establishing an internal standard approach, the false negative problem was overcome;furthermore, the method can also help to estimate the suspected mercury concentration,which ensures high detection sensitivity of bioavailable Hg2＋.

关键词： Mercury Biomonitoring Recombinant luminescent bacteria p THE30–E.coli Internal standard method False negative

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Mercury mass flow in iron and steel production process and its implications for mercury emission control

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Journal of environmental Sciences 2016年第5期28卷 293-301页

作者： Fengyang Wang Shuxiao Wang Lei Zhang Hai Yang Wei Gao Qingru Wu Jiming Hao State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua UniversityBeijing 100084 China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084 China

The iron and steel production process is one of the predominant anthropogenic sources of atmospheric mercury emissions worldwide. In this study, field tests were conducted to study mercury emission characteristics and mass flows at two iron and steel plants in China. It was found that low-sulfur flue gas from sintering machines could contribute up to41% of the total atmospheric mercury emissions, and desulfurization devices could remarkably help reduce the emissions. Coal gas burning accounted for 17%–49% of the total mercury emissions, and therefore the mercury control of coal gas burning, specifically for the power plant burning coal gas to generate electricity, was significantly important. The emissions from limestone and dolomite production and electric furnaces can contribute29.3% and 4.2% of the total mercury emissions from iron and steel production. More attention should be paid to mercury emissions from these two processes. Blast furnace dust accounted for 27%–36% of the total mercury output for the whole iron and steel production process. The recycling of blast furnace dust could greatly increase the atmospheric mercury emissions and should not be conducted. The mercury emission factors for the coke oven,sintering machine and blast furnace were 0.039–0.047 g Hg/ton steel, and for the electric furnace it was 0.021 g Hg/ton steel. The predominant emission species was oxidized mercury, accounting for 59%–73% of total mercury emissions to air.

关键词： Iron and steel plant Mercury Emission characteristics Mass flow Emission control

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In situ airborne virus inactivation by microwave irradiation

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Chinese Science Bulletin 2014年第13期59卷 1438-1445页

作者： Yan Wu Maosheng Yao State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University

Infectious diseases cause tremendous costs of both human and economy ***,we have studied the bacterial,fungal,and allergen aerosol inactivation by direct microwave ***,we further investigated its effects on airborne ***2 coliphage used as a human model virus was aerosolized and exposed to the direct microwave irradiation for*2 min at three different power levels(700,385,and 119 W).In addition to the survival rate,the viral genes before and after the microwave treatments were also examined using PCR and gel *** exposure of airborne MS2viruses to the microwave irradiation at 700 W for less than2 min was shown to result in more than 90%inactivation efficiency,about 65%at medium power level(385 W),and 50%at the lowest level(119 W).The aerosol inactivation rate followed a linear relationship with the microwave exposure time(R2=0.9889).Scanning electron images revealed visible damages to the viral surface after the *** were also observed to the viral RNA genes coding for coat proteins,among which the A protein gene was completely *** study demonstrated that even without the filtration the direct microwave irradiation could also achieve rapid inactivation of viral *** information obtained can provide useful guidance on the development of microwave-based viral threat mitigation solutions in a closed or semi-closed space.

关键词：病毒灭活微波辐射空气病毒基因微波照射感染性疾病气溶胶大肠杆菌

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Physicochemical analysis of individual atmospheric fine particles based on effective surface-enhanced Raman spectroscopy

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Journal of environmental Sciences 2019年第1期31卷 388-395页

作者： Zhenli Sun Fengkui Duan Kebin He Jingjing Du Liu Yang Hui Li Tao Ma Shuo Yang State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Tsinghua University State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences

Fine particles associated with haze pollution threaten the health of more than 400 million people in China. It is therefore of great importance to thoroughly investigate and understand their composition. To determine the physicochemical properties in atmospheric fine particles at the micrometer level, we described a sensitive and feasible surface-enhanced Raman scattering(SERS) method using Ag foil as a substrate. This novel method enhanced the Raman signal intensities up to 10,000 a.u. for ν(NO_3^-) in fine *** SERS effect of Ag foil was further studied experimentally and theoretically and found to have an enhancement factor of the order of ～10~4. Size-fractionated real particle samples with aerodynamic diameters of 0.4–2.5 μm were successfully collected on a heavy haze day,allowing ready observation of morphology and identification of chemical components, such as soot, nitrates, and sulfates. These results suggest that the Ag-foil-based SERS technique can be effectively used to determine the microscopic characteristics of individual fine particles, which will help to understand haze formation mechanisms and formulate governance policies.

关键词： SERS PM2.5 Individual particle Atmospheric

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A spectrometer for measuring particle size distributions in the range of 3 nm to 10 μm

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Frontiers of environmental Science & Engineering 2016年第1期10卷 63-72页

作者： Jieqiong LIU Jingkun JIANG Qiang ZHANG Jianguo DENG Jiming HAO State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing 100084 China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084 China

A spectrometer combining electrical mobility sizing and aerodynamic sizing was developed to measure aerosol size distributions in the range of 3 nm to 10 μm. It includes three instruments which cover different size ranges （a nano scanning mobility particle sizer （NSMPS, 3 - 60 nm）, a regular scanning mobility particle sizer （RSMPS, 40 - 700nm）, and an aerodynamic particle sizer （APS, 550nm- 10 μm））. High voltage and sheath flow of the NSMPS and RSMPS were supplied using two home-built control boxes. A labVIEW program was developed for spectrometer automatic operation. A linear inversion method was applied to correct particle multiple charging effects and to integrate data from the three instruments into a wide-range size distribution. Experi- ments were conducted to compare distributions in the overlap size ranges measured by three instruments. Good agreement between the NSMPS and RSMPS was achieved after correcting for the difference in counting efficiencies of the two particle counters. Aerodynamic size distribu- tions reported by the APS were converted to mobility size distributions by applying an effective density method. Distributions measured by the RSMPS and APS were consistent in the overlap size range of 550 - 700 nm. A full spectrum in the size range of 3nm to 10~tm was demonstrated by measuring aerosol generated using a mixture of different sized polystyrene latex spheres.

关键词： spectrometer particle size distribution elec-trical mobility aerodynamic diameter linear inversion

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An optimized two-step derivatization method for analyzing diethylene glycol ozonation products using gas chromatography and mass spectrometry

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Journal of environmental Sciences 2017年第3期29卷 313-321页

作者： Ran Yu Lei Duan Jingkun Jiang Jiming Hao State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084China

The ozonation of hydroxyl compounds （e.g., sugars and alcohols） gives a broad range of products such as alcohols, aldehydes, ketones, and carboxylic adds. This study developed and optimized a two-step derivatization procedure for analyzing polar products of aldehydes and carboxylic acids from the ozonation of diethylene glycol （DEG） in a non-aqueous environment using gas chromatography-mass spectrometry. Experiments based on Central Composite Design with response surface methodology were carried out to evaluate the effects of derivatization variables and their interactions on the analysis. The most desirable derivati- zation conditions were reported, i.e., oximation was performed at room temperature overnight with the o-（2,3,4,5,6-pentafluorobenzyl） hydroxyl amine to analyte molar ratio of 6, silylation reaction temperature of 70℃, reaction duration of 70 min, and N,O-bis（trimethylsilyl）- trifluoroacetamide volume of 12.5 μL. The applicability of this optimized procedure was verified by analyzing DEG ozonation products in an ultrafine condensation particle counter simulation system.

关键词： Gas chromatography-massspectrometryResponse surface methodologyCentral Composite DesignDiethylene glycol ozonation

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Heterogeneous reactions on the surface of fine particles in the atmosphere

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Chinese Science Bulletin 2003年第21期48卷 2267-2276页

作者： DING Jie & ZHU Tong state key Joint laboratory of environmental simulation and pollution control, College of environmental Sciences, Peking University, Beijing 100871, China Correspondence should be addressed to Zhu Tong (e-mail:tzhu@ ***) State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences Peking University China

Fine particles play an important role in the atmosphere. Research on heterogeneous reactions on the surface of fine particles is one of the frontier areas of atmospheric science. In this paper, physical and chemical characteristics of fine particles in the atmosphere and the interactions between trace gases and fine particles are described, methods used in heterogeneous reactions research are discussed in detail, progress in the study of heterogeneous reactions on the surface of fine particles in the atmosphere is summarized, existing important questions are pointed out and future research directions are suggested.

关键词：细微颗粒大气科学多相反应空气动力学

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Optimized production of a novel bioflocculant M-C11 by Klebsiella sp. and its application in sludge dewatering

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Journal of environmental Sciences 2014年第10期26卷 2076-2083页

作者： Jiewei Liu Junwei Ma Yanzhong Liu Ya Yang Dongbei Yue Hongtao Wang State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University School of Environment Tsinghua University

The optimized production of a novel bioflocculant M-C11 produced by Klebsiella sp. and its application in sludge dewatering were investigated. The optimal medium carbon source,nitrogen source, metal ion, initial pH and culture temperature for the bioflocculant production were glucose, NaNO3, MgSO4, and pH 7.0 and 25°C, respectively. A compositional analysis indicated that the purified M-C11 consisted of 91.2% sugar, 4.6% protein and 3.9% nucleic acids（m/m）. A Fourier transform infrared spectrum confirmed the presence of carboxyl, hydroxyl,methoxyl and amino groups. The microbial flocculant exhibited excellent pH and thermal stability in a kaolin suspension over a pH range of 4.0 to 8.0 and a temperature range of 20 to 60°*** optimum bioflocculating activity was observed as 92.37% for 2.56 mL M-C11 and 0.37 g/L CaCl2 dosages using response surface methodology. The sludge resistance in filtration（SRF）decreased from 11.6 × 1012 to 4.7 × 1012m/kg, which indicated that the sludge dewaterability was remarkably enhanced by the bioflocculant conditioning. The sludge dewatering performance conditioned by M-C11 was more efficient than that of inorganic flocculating reagents,such as aluminum sulfate and polymeric aluminum chloride. The bioflocculant has advantages over traditional sludge conditioners due to its lower cost, benign biodegradability and negligible secondary pollution. In addition, the bioflocculant was favorably adapted to the specific sludge pH and salinity.

关键词： Bioflocculant Klebsiella sp. Optimized production Response surface methodology Sludge dewatering

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Removal and ecological impact of sulfamethoxazole and N-acetyl sulfamethoxazole in mesocosmic wetlands dominated by submerged plants: Plant tolerance, microbial response, and nitrogen transformation

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Science of the Total Environment 2025年 958卷 178034页

作者： Mu, Xiaoying Chen, Congli Fan, Qinya Zhang, Weihang Liu, Fei Guo, Jiaxun Qi, Weixiao Liu, Huijuan Center for Water and Ecology State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing100085 China School of Environment and Spatial Informatics China University of Mining and Technology Jiangsu Province Xuzhou221116 China Yangtze Eco-Environment Engineering Research Center China Three Gorges Corporation Wuhan430010 China

Sulfamethoxazole (SMX) and its human metabolite N-acetylsulfamethoxazole (N-SMX) are frequently detected in aquatic environments, posing potential threats to freshwater ecosystem health. Constructed wetlands are pivotal for wastewater treatment, with plant species serving as key determinants of pollutant removal efficiency. In this study, wetlands dominated by three submerged plants (Myriophyllum verticillatum, Vallisneria spiralis, Hydrilla verticillata) were respectively constructed to investigate the removal of SMX and N-SMX, and the impact on wetland ecology regarding plant tolerance, microbial response, and nitrogen transformation. Results showed that wetlands removed N-SMX (82.3–99.8 %) more effectively than SMX (54.3–80.2 %), with the wetland dominated by Myriophyllum verticillatum showing the highest removal efficiency. However, high concentrations (5 mg/L) of SMX and N-SMX significantly reduced NH4+-N and TN removal (p © 2024 Elsevier B.V.

关键词： Wastewater treatment

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Negatively and positively charged bacterial aerosol concentration and diversity in natural environments

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Chinese Science Bulletin 2013年第26期58卷 3169-3176页

作者： SHEN FangXia KAI Wei YAO MaoSheng State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University

Bioaerosol charge information is of vital importance for their electrostatic collection. Here, electrostatic means and molecular tools were applied to studying bioaerosol charge dynamics. Positively or negatively charged bioaerosols were collected using an electrostatic sampler operated with a field strength of 1.1 kV cm 1 at a flow rate of 3 L min 1 for 40 min. Those with fewer or no charges bypassing the sampler were also collected using a filter at the downstream of the electrostatic sampler in one environment. The experiments were independently conducted three times in three different environments. The collected bacterial aerosols were cultured directly on agar plates at 26°C, and the colony forming units (CFU) were manually counted. In addition, the CFUs were washed off from the agar plates, and further subjected to polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) for culturable diversity analysis. The results revealed remarkable differences in positively and negatively charged culturable bacterial aerosol concentration and diversity among the studied environments. In the office environment, negatively charged culturable bacterial aerosols appeared to dominate (P = 0.0489), while in outdoor and hotel environments both polarities had similar concentration levels (P = 0.078, P = 0.88, respectively). DGGE patterns for positively charged culturable bacterial aerosols were shown strikingly different from those of negatively charged regardless of the sampling environments. In addition, for each of the environments positively charged culturable bacterial aerosols collected were found to have more band pattern similarity with those positively charged for respective regions of agar plates than those negatively charged, and vice versa. The information developed here is useful for developing efficient electrostatic sampling protocols for bioaerosols.

关键词：气溶胶浓度多样性分析办公环境正电荷细菌生物气溶胶变性梯度凝胶电泳静电收集

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