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

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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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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environmental impact of radionuclide migration in groundwater from a low intermediate level radioactive waste repository

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Journal of environmental Sciences 2001年第2期13卷 180-184页

作者： J S Wang Z F Yang S S Li Z M Wang Institute of Environmental Sciences Beijing Normal University State Key Joint Laboratory of Environmental Simulation and Pollution Control Beijing 100875 China.

The radionuclide migration from a certain Chinese repository with low-intermediate level radioactive solid waste is studied. The migration in groundwater is analyzed and computed in detail. Under presumption of normal releasing, or the bottom of the repository has been marinated for one month with precipitation reaching 600 mm once and a 6 m aerated zone exists, a prediction for 7 radionuclides is conducted. It shows that the aerated zone is the primary barrier for migration. The migration for radionuclides 60Co, 137Cs, 90Sr, 63Ni, etc. will be retarded in it within 500 years. The concentration of 239Pu will be decreased by amount of 6 order. Only 3H and 14C can migrate through the aerated zone. The radionuclides that go through the aerated zone and enter the aquifer will exist in spring, stream and sea. Based on this, the intake dose by residents in different age group resulting from drinking contaminated spring water, eating seafood is calculated. The results showed that the impact of the repository to the key resident group is lower than the limit in national repository regulation standard. This complies with the repository management target.

关键词： intermediate level radioactive waste repository environmental impact of radionuclide migration in groundwater from a low

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Warm-wetting and/or warm-drying tendency over Xinjiang, China?

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Journal of Hydrology 2025年 660卷

作者： Wang, Gang Zhang, Qiang Woolway, R. Iestyn Xu, Lei Ma, Hushuang Yang, Zhifeng Guangdong Basic Research Center of Excellence for Ecological Security and Green Development School of Ecology Environment and Resources Guangdong University of Technology Guangzhou510006 China Advanced Interdisciplinary Institute of Environment and Ecology Guangdong Provincial Key Laboratory of Wastewater Information Analysis and Early Warning Beijing Normal University Zhuhai China School of Ocean Sciences Bangor University Wales Bangor United Kingdom State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing100875 China

Drylands, characterized by fragile ecosystems and severe water shortages, are highly responsive to climatic changes. Recent studies have observed a general wetting trend in Xinjiang, a region covering over one-sixth of China territory and known for its arid climate. However, the spatiotemporal variability of wetting and drying tendencies and their underlying drivers remain poorly understood. Here we utilize the Eulerian moisture tracking model in conjunction with emergent constraining projections to assess trends in moisture dynamics across Xinjiang. Our analysis reveals a prevailing warm-wetting tendency over the past 40 years. We find that moisture influx into Xinjiang predominantly originated from the North Atlantic, traveling through Europe and West Asia, with external sources contributing approximately 89.1 % of the region's total water vapor. The increased moisture input has driven the observed wetting trend. Constraining projections indicate future increases in precipitation, evaporation, and temperature in Xinjiang, with the rate of change being more pronounced under the SSP585 scenario. Spatially, northern Xinjiang and its mountainous regions exhibit a significant warm-wetting trend, while southern Xinjiang shows a tendency towards warm-drying. Restricting global temperature rises to 1.5 °C above pre-industrial levels, as opposed to 2 °C, could mitigate extreme drying and wetting conditions in the region. These findings underscore the partially wetting trend in drylands and highlight the critical need for stringent climate action to limit global warming to 1.5 °C for effective climate change mitigation. © 2025 Elsevier B.V.

关键词： Global warming

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Releasing characteristics of phosphorus and other substances during thermal treatment of excess sludge

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Journal of environmental Sciences 2007年第10期19卷 1153-1158页

作者： XUE Tao HUANG Xia Department of Environmental Science and Engineering State Key Joint Laboratory of Environment Simulation and Pollution Control Tsinghua University Beijing 100084 China

The releasing characteristics of phosphorus, nitrogen compounds, organics, and some metal cations during thermal treatment of excess sludge were investigated. It was found that during heating not only phosphorus, but also nitrogen compounds, organics, and some metal cations could be released in abundance. The maximum orthophosphate （ortho-P） release of about 90 mg/L in concentration was observed at 50℃ in 1 h. Except for volatile fatty acids （VFAs）, comparatively little total nitrogen （TN）, total organic carbon （TOC）, and metal cations were released at the same time. Such results might favor further process of phosphorus recovery. VFAs were considerably released only at 50℃. Acetic, butyric, and propionic acid were the most abundant components in turn and their releasing profiles exhibited good linear relationship with time （R2 = 0.9977, 0.9624, and 0.8908, respectively）. The concentrations of Mg^2＋ and K^＋ increased with time and temperature during thermal treatment, but Ca^2＋ decreased. The release of Mg^2＋ and K^＋ agreed well with TP release （R^2 = 0.9892 and 0.9476, respectively）. Temperature in the experimental range had very little impact on the linear relationships, especially of Mg^2＋. Moreover, the parameter of mixed liquor suspended solids （MLSS） was found to be an important factor for thermal sludge treatment as the released ortho-P and total phosphorus （TP） at 50℃ increased more than one-fold when MLSS was increased from 4000 to 8000 mg/L.

关键词： phosphorus recovery excess sludge volatile fatty acids (VFAs) metal cations

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A review of atmospheric mercury emissions, pollution and control in China

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Frontiers of environmental Science & Engineering 2014年第5期8卷 631-649页

作者： Shuxiao WANG Lei ZHANG Long WANG Qingru WU FengyangWANG Jiming HAO State Key Joint Laboratory of Environmental 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

Mercury, as a global pollutant, has significant impacts on the environment and human health. The current state of atmospheric mercury emissions, pollution and control in China is comprehensively reviewed in this paper. With about 500-800 t of anthropogenic mercury emissions, China contributes 25%-40% to the global mercury emissions. The dominant mercury emission sources in China are coal combustion, non-ferrous metal smelting, cement production and iron and steel production. The mercury emissions from natural sources in China are equivalent to the anthropogenic mercury emissions. The atmospheric mercury concentration in China is about 2-10 times the background level of North Hemisphere. The mercury deposition fluxes in remote areas in China are usually in the range of 10-50μg·m^-2·yr^-1. To reduce mercury emissions, legislations have been enacted for power plants, non-ferrous metal smelters and waste incinerators. Currently mercury contented in the flue gas is mainly removed through existing air pollution control devices for sulfur dioxide, nitrogen oxides, and particles. Dedicated mercury control technologies are required in the future to further mitigate the mercury emissions in China.

关键词： atmospheric mercury emissions pollution,control China

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Synergetic PM_(2.5) and O_(3) control strategy for the Yangtze River Delta,China

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Journal of environmental Sciences 2023年第1期123卷 281-291页

作者： Zhaoxin Dong Jia Xing Fenfen Zhang Shuxiao Wang Dian Ding Hongli Wang Cheng Huang Haotian Zheng Yueqi Jiang Jiming Hao State Key Joint Laboratory of Environmental Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084China State Environmental Protection Key Laboratory of the Formation and Prevention of Urban Air Pollution Complex Shanghai Academy of Environmental SciencesShanghai 200233China

PM_(2.5)concentrations have dramatically reduced in key regions of China during the period 2013-2017,while O_(3)has *** there is an urgent demand to develop a synergetic regional PM_(2.5)and O_(3)control *** study develops an emission-to-concentration response surface model and proposes a synergetic pathway for PM_(2.5)and O_(3)control in the Yangtze River Delta(YRD)based on the framework of the Air Benefit and Cost and Attainment Assessment System(ABaCAS).Results suggest that the regional emissions of NOx,SO_(2),NH3,VOCs(volatile organic compounds)and primary PM_(2.5)should be reduced by 18%,23%,14%,17%and 33%compared with 2017 to achieve 25%and 5% decreases of PM_(2.5)and O_(3)in 2025,and that the emission reduction ratios will need to be 50%,26%,28%,28% and 55%to attain the National Ambient Air Quality *** effectively reduce the O_(3) pollution in the central and eastern YRD,VOCs controls need to be strengthened to reduce O_(3)by 5%,and then NOx reduction should be accelerated for air quality ***,control of primary PM_(2.5)emissions shall be prioritized to address the severe PM_(2.5)pollution in the northern *** most cities in the YRD,the VOCs emission reduction ratio should be higher than that for NOx in Spring and *** control should be increased in summer rather than winter when a strong VOC-limited regime ***,regarding the emission control of industrial processes,on-road vehicle and residential sources shall be prioritized and the joint control area should be enlarged to include Shandong,Jiangxi and Hubei Province for effective O_(3)control.

关键词： PM_(2.5) O_(3) Response surface model Synergistic control pathway Cost-benefit analysis

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