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Photolysis and photooxidation of typical gaseous VOCs by UV Irradiation： Removal performance and mechanisms

Frontiers of environmental Science & Engineering 2018年第3期12卷 107-120页

作者： In-Sun Kang Jinying Xi Hong-Ying Hu Environmental Simulation and Pollution Control State Key Joint Laboratory School of Environment Tsinghua University Beijing 100084 China

Photodegradation by ultraviolet irradiation （UV） is increasingly applied in volatile organic compound （VOC） and odor gas treatments. In this study, 27 typical VOCs, including 11 hydrocarbons and 16 hydrocarbon derivatives, at 150-200 ppm in air and nitrogen gas were treated by a laboratory-scale UV reactor with 185/254 nm irradiation to systematically investigate their removal and conversion by UV irradiation. For the tested 27 VOCs, the VOC removal efficiencies in air were within the range of 13 %- 97% （with an average of 80%） at a retention time of 53 s, which showed a moderate positive correlation with the -molecular weight of the VOCs （R = 0.53）. The respective contributions of photolysis and photooxidation to VOC removal were identified for each VOC. According to the CO2 results, the mineralization rate of the tested VOCs was within the range of 9%-90%, with an average of 41% and were negatively correlated to the molecular weight （R = -0.63）. Many of the tested VOCs exhibited high concentration particulate matters in the off-gases with a 3-283 mg/m^3 PM10 range and a 2-40 mg/m^3 PM2.5 range. The carbon balance of each VOC during UV irradiation was analyzed based on the VOC, CO2 and PM10 concentrations. Certain organic intermediates and 23-218 ppm ozone were also identified in the off-gases. Although the UV technique exhibited a high VOC removal efficiency, its drawbacks, specifically low mineralization, particulate matters production, and ozone emission, must be considered prior to its application in VOC gas treatments.

关键词： VOCs UV photodegradation Particulate matters Ozone

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In situ monitoring of atmospheric nitrous acid based on multi-pumping flow system and liquid waveguide capillary cell

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Journal of environmental Sciences 2016年第5期28卷 273-284页

作者： Yuhan Liu Keding Lu Huabin Dong Xin Li Peng Cheng Qi Zou Yusheng Wu Xingang Liu Yuanhang Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking University Institute of Energy and Climate Research: Troposphere (IEK-8) Forschungszentrum Juelich GmbH State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University

In the last four decades, various techniques including spectroscopic, wet chemical and mass spectrometric methods, have been developed and applied for the detection of ambient nitrous acid（HONO）. We developed a HONO detection system based on long path photometry which consists of three independent modules i.e., sampling module, fluid propulsion module and detection module. In the propulsion module, solenoid pumps are applied. With solenoid pumps the pulsed flow can be computer controlled both in terms of pump stroke volume and pulse frequency, which enables the attainment of a very stable flow rate. In the detection module, a customized Liquid Waveguide Capillary Cell（LWCC） is used. The customized LWCC pre-sets the optical fiber in-coupling with the liquid wave guide, providing the option of fast startup and easy maintenance of the absorption photometry. In summer 2014, our system was deployed in a comprehensive campaign at a rural site in the North China Plain. More than one month of high quality HONO data spanning from the limit of detection to 5 ppb were collected. Intercomparison of our system with another established system from Forschungszentrum Juelich is presented and discussed. In conclusion, our instrument achieved a detection limit of 10 ppt V within2 min and a measurement uncertainty of 7%, which is well suited for investigation of the HONO budget from urban to rural conditions in China.

关键词： HONO Photometry Field campaign Atmospheric chemistry

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Influence of pore size and membrane surface properties on arsenic removal by nanofiltration membranes

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Frontiers of environmental Science & Engineering 2019年第2期13卷 55-62页

作者： Nathalie Tanne Rui Xu Mingyue Zhou Pan Zhang Xiaomao Wang Xianghua Wen State Key Joint Laboratory of Environmental Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China

Nanofiltration(NF)has a great potential in removing arsenate from contaminated *** performance including arsenate rejection,water permeability and resistance to fouling could however differ substantially among NF *** study was conducted to investigate the influence of membrane pore size and surface properties on these aspects of membrane *** fullyaromatic NF membranes with different physicochemical properties were adopted for this *** results showed that surface charge,hydrophobicity,roughness and pore size could affect water permeability and/or arsenate rejection considerably.A more negative surface charge was desirable to enhance arsenate rejection ***90 and a non-commercialized membrane(M#1)demonstrated the best performance in terms of arsenate rejection and water *** M#1 membrane showed less membrane fouling than NF90 when used for filtration of real arsenic-containing *** was mainly due to its distinct chemical composition and surface properties.A severe membrane fouling could lead to a substantial reduction of arsenic *** M#1 membrane showed the best performance,which indicated that membrane modification could indeed enhance the overall membrane performance for water treatment.

关键词： Arsenate Nanofiltration Drinking water Membrane property Membrane fouling

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Evidence of coal combustion contribution to ambient VOCs during winter in Beijing

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Chinese Chemical Letters 2013年第9期24卷 829-832页

作者： Ming Wang Min Shao Si-Hua Lu Yu-Dong Yang Wen-Tai Chen State Joint Key Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University

Volatile organic compounds （VOCs） play ,an important role in ozone and secondary organic aerosol （SOA） formation, but VOCs sources during winter are not fully understood. To investigate VOCs sources during winter, mixing ratios of C2-C12 VOCs were measured at an urban site in Beijing from December 29, 2011 to January 17, 2012. Correlation analysis of toluene to benzene and i-pentane to n-pentane suggest that coal combustion could also be an important source for VOCs besides vehicular emissions. Source apportionment results show that coal combustion and vehicular emissions contributed 28%-39% and 31%-45% to ambient VOCs during winter, respectively. Backward trajectory analyses demonstrated that contributions from the burning of coal were higher when air masses came from southern regions outside Beijing. Close attention should be paid to VOCs emissions from coal combustion in Beijing city and the vicinity to the South.

关键词： VOC Source apportionment Coal combustion Transport

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Quantifying the ambient formaldehyde sources utilizing tracers

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Chinese Chemical Letters 2014年第11期25卷 1489-1491页

作者： Mei Li Min Shao Ling-Yu Li Si-Hua Lu Wen-Tai Chen Chen Wang State Joint Key Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University

Formaldehyde（HCHO） is one of the most important intermediate products of atmospheric photochemical reactions in the troposphere, therefore understanding of HCHO sources is essential for effective ozone control measures. The objective of this work is to distinguish between primary and secondary sources of HCHO. Based on about one month of online measurements in winter in Ziyang,Sichuan, the multi-linear regression analysis of ambient concentrations of HCHO and possible tracers（acetonitrile, propane and peroxyacetyl nitrate） was performed. The results show that during winter in Ziyang, biomass burning contributed an average of 53.2% to ambient HCHO levels, while secondary processes contributed about 30.1%, and vehicular sources accounted for 7.1%.

关键词： Formaldehyde Sources Tracers Multi-linear regression

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Economic analysis of atmospheric mercury emission control for coal-fired power plants in China

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Journal of environmental Sciences 2015年第7期27卷 125-134页

作者： Maria Pia Ancora Lei Zhang Shuxiao Wang Jeremy Schreifels Jiming Hao State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Collaborative Innovation Center for Regional Environmental Quality Tsinghua University State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex

Coal combustion and mercury pollution are closely linked, and this relationship is particularly relevant in China, the world＇s largest coal consumer. This paper begins with a summary of recent China-specific studies on mercury removal by air pollution control technologies and then provides an economic analysis of mercury abatement from these emission control technologies at coal-fired power plants in China. This includes a cost-effectiveness analysis at the enterprise and sector level in China using 2010 as a baseline and projecting out to 2020 and2030. Of the control technologies evaluated, the most cost-effective is a fabric filter installed upstream of the wet flue gas desulfurization system（FF ＋ WFGD）. Halogen injection（HI） is also a cost-effective mercury-specific control strategy, although it has not yet reached commercial maturity. The sector-level analysis shows that 193 tons of mercury was removed in 2010 in China＇s coal-fired power sector, with annualized mercury emission control costs of 2.7 billion Chinese Yuan. Under a projected 2030 Emission control（EC） scenario with stringent mercury limits compared to Business As Usual（BAU） scenario, the increase of selective catalytic reduction systems（SCR） and the use of HI could contribute to 39 tons of mercury removal at a cost of 3.8 billion CNY. The economic analysis presented in this paper offers insights on air pollution control technologies and practices for enhancing atmospheric mercury control that can aid decision-making in policy design and private-sector investments.

关键词： Atmospheric mercury Coal-fired power plants China Cost-effectiveness Activated carbon and halogen injection

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Effects of culture conditions on ligninolytic enzymes and protease production by Phanerochaete chrysosporium in air

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Journal of environmental Sciences 2008年第1期20卷 94-100页

作者： XIONG Xiaoping WEN Xianghua BAI Yanan QIAN Yi State Key Joint Laboratory of Environmental Simulation and Pollution Control Department of Environmental Science and Engineering Tsinghua University Beifing 100084 China.

The production of ligninolytic enzymes and protease by Phanerochaete chrysosporium was investigated under different culture conditions. Different amounts of medium were employed in free and immobilized culture, together with two kinds of medium with different C/N ratios. Little lignin peroxidase （LIP）（〈 2 U/L） was detected in free culture with nitrogen-limited medium （C/N ratio： 56/2.2, in mmol/L）, while manganese peroxidase （MnP） maximum activity was 231 and 240 U/L in 50 and 100 ml medium culture, respectively. Immobilized culture with 50 ml nitrogen-limited medium gave the highest MnP and LiP production with the maximum values of 410 and 721 U/L separately on the day 5; however, flasks containing 100 ml nitrogen-limited medium only produced less MnP with a peak value of 290 U/L. Comparatively, carbon-limited medium （C/N ratio： 28/44, in mmol/L） was adopted in culture but produced little MnP and LiE Medium type had the greatest impact on protease production. Large amount of protease was produced due to glucose limitation. Culture type and medium volume influence protease activity corporately by affecting oxygen supply. The results implied shallow immobilized culture was a possible way to gain high production of ligninolytic enzymes.

关键词： protease culture conditions ligninolytic enzymes Phanerochaete chrysosporiurn

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Modeling of distributed parameter systems based on independent partial derivative-physics-informed neural network

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Neurocomputing 2025年 642卷

作者： Wang, Lijie Lin, Yangshu Yan, Xinrong Shao, Yuhao Xu, Zuhua Yang, Chao Fan, Haidong Xie, Yurong Zheng, Chenghang State Key Lab of Clean Energy Utilization Institute of Carbon Neutrality State Environmental Protection Engineering Center for Coal-Fired Air Pollution Control Zhejiang University Hangzhou310027 China State Key Laboratory of Industrial Control Technology College of Control Science and Engineering Zhejiang University Hangzhou310027 China Zhejiang Baima Lake Laboratory Co. Ltd. Hangzhou310051 China Huadian Electric Power Research Institute Co. Ltd. Hangzhou310030 China

Physics-informed neural networks (PINNs) have attracted considerable interest due to their capacity to incorporate established physical principles, thus facilitating efficient training with a limited amount of observed data. This approach ensures that the results of supervised learning are in accordance with the governing physical laws of the system, thereby enhancing the interpretability of models. However, existing research predominantly employs a single network architecture to simultaneously learn the information of the partial differential equations (PDEs). Such architectures typically require large network sizes to learn the system characteristics, which leads to prolonged training times and inefficiencies. This paper introduces a novel modeling framework, termed the independent partial derivative-physics-informed neural network (IPD-PINN). In contrast to conventional methodologies, IPD-PINN employs a network comprising multiple subnetworks, with each subnetwork dedicated to the learning of individual partial derivatives in the PDEs. The modular network structure allows for flexible and scalable adjustments to the size of each subnetwork, accommodating modeling tasks of varying complexities. Consequently, the entire network is capable of reducing the required training time while maintaining precise modeling accuracy. The efficacy of the proposed IPD-PINN method is demonstrated through two simulation case studies, which highlight its potential to improve the efficiency and accuracy of IPD-PINN modeling. © 2025

关键词： Wave equations

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Missing in total OH reactivity of VOCs from gasoline evaporation

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Chinese Chemical Letters 2015年第10期26卷 1246-1248页

作者： Ying Wu Yu-Dong Yang Min Shao Si-Hua Lu State Joint Key Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University

Gasoline evaporation is an important anthropogenic source of atmospheric volatile organic compounds（VOCs）. Total OH reactivity for gasoline vapor was measured from 4 kinds of gasoline for the first time by comparative reactivity method（CRM） using proton transfer reaction mass spectrometer（PTR-MS）.Compositions of 56 PAMS（photochemical assessment monitoring station） nonmethane hydrocarbons（NMHCs） were measured for both liquid and headspace of gasoline. We found high abundance of alkenes and aromatics in gasoline. The calculated OH reactivity derived from quantified NMHCs speciation accounted for only 57 ？ 4% of total reactivity obtained from CRM method. N-Alkenes, only 6 wt% in liquid gasoline, contributed to 70% of calculated reactivity. We assume that the undetected branched alkenes are the possible reason for the missing reactivity. We suggest that the priority of gasoline quality improvement is to reduce alkenes content in gasoline in term of reactivity-based control.

关键词： Volatile organic compounds（VOCs） Comparative reactivity method（CRM） Missing OH reactivity Gasoline evaporation

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Influencing factors and prediction of ambient Peroxyacetyl nitrate concentration in Beijing,China

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Journal of environmental Sciences 2019年第3期31卷 189-197页

作者： Boya Zhang Bu Zhao Peng Zuo Zhi Huang Jianbo Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University School of Environment Tsinghua University

Peroxyacyl nitrates(PANs) are important secondary pollutants in ground-level *** prediction of atmospheric pollutant concentrations is crucial to guide effective precautions for before and during specific pollution events. In this study, four models based on the back-propagation(BP) artificial neural network(ANN) and multiple linear regression(MLR) methods were used to predict the hourly average PAN concentrations at Peking University, Beijing, in 2014. The model inputs were atmospheric pollutant data and meteorological parameters. Model 3 using a BP-ANN based on the original variables achieved the best prediction results among the four models, with a correlation coefficient(R) of 0.7089, mean bias error of -0.0043 ppb, mean absolute error of 0.4836?ppb, root mean squared error of 0.5320?ppb, and Willmott's index of agreement of 0.8214. Based on a comparison of the performance indices of the MLR and BP-ANN models, we concluded that the BP-ANN model was able to capture the highly non-linear relationships between PAN concentration and the conventional atmospheric pollutant and meteorological parameters,providing more accurate results than the traditional MLR models did, with a markedly higher goodness of R. The selected meteorological and atmospheric pollutant parameters described a sufficient amount of PAN variation, and thus provided satisfactory prediction results. More specifically, the BP-ANN model performed very well for capturing the variation pattern when PAN concentrations were low. The findings of this study address some of the existing knowledge gaps in this research field and provide a theoretical basis for future regional air pollution control.

关键词： Artificial neural network Conventional atmospheric pollutants Meteorological parameters Concentration prediction Multiple linear regression

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