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Efficient photoelectrochemical oxidation of rhodamine B on metal electrodes without photocatalyst or supporting electrolyte

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Frontiers of environmental Science & Engineering 2018年第6期12卷 113-118页

作者： Xuejiao Wang Xiang Feng Jing Shang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China

We designed photoelectrochemical cells to achieve efficient oxidation of rhodamine B (RhB) without the need for photocatalyst or supporting electrolyte. RhB, the metal anode/cathode, and O2 formed an energy-relay structure, enabling the efficient formation of O2– species under ultraviolet illumination. In a single-compartment cell (S cell) containing a titanium (Ti) anode, Ti cathode, and 10 mg·mL–1 RhB in water, the zero-order rate constant of the photoelectrochemical oxidation (kPEC) of RhB was 0.049 mg·L–1·min–1, while those of the photochemical and electrochemical oxidations of RhB were nearly zero. kPEC remained almost the same when 0.5 mol·L–1 Na2SO4 was included in the reactive solution, regardless of the increase in the photocurrent of the S cell. The kPEC of the illuminated anode compartment in the two-compartment cell, including a Ti anode, Ti cathode, and 10 mg·mL–1 RhB in water, was higher than that of the S cell. These results support a simple, eco-friendly, and energysaving method to realize the efficient degradation of RhB.

关键词： Energy relay structure Energy saving Photocatalyst-free and low-salinity degradation Photoelectrochemical cell

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Distributions of dimethylsulfide in the Bohai Sea and Yellow Sea of China

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Journal of environmental Sciences 2003年第6期15卷 762-767页

作者： HU Min TANG Xiao-yan LI Jin-long MA Qi-ju State Joint Key Laboratory of Environmental Simulation and Pollution Control Center for Environmental Sciences Peking UniversityBeijing 100871China.

Dimethylsulfide(DMS) measurements in the surface seawater of China eastern coastline were conducted during March 9—10, 1993 in Bohai Sea along the cruise from Dalian to Tianjin and during September 24—25, 1994 in Yellow Sea along the cruise from Shanghai to Qingdao. On the cruise in Bohai Sea DMS concentrations varied from 0.11 to 2.63 nmol/L with an average of 1.31 nmol/L, while DMS flux was estimated to be 0.85 μmol/(m 2·d) with the range of 0.04—3.12 μmol/(m 2·d). On the cruise in Yellow Sea DMS concentrations varied from 0.95 to 7.48 nmol/L with an average of 2.89 nmol/L, and DMS flux was estimated to be 7.94 μmol/(m 2·d) with the range of 0.11—18.88 μmol/(m 2·d). Variations in DMS concentrations along the latitude in Yellow Sea were observed larger than those along the longitude in Bohai Sea. DMS concentrations and fluxes had a similar spatial trend both in Bohai Sea and Yellow Sea with the correlation coefficients of 0.75 and 0.64, respectively.

关键词： dimethylsulfide sea-to-air flux China Bohai Sea China Yellow Sea

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Analysis of China’s PM_(2.5)and ozone coordinated control strategy based on the observation data from 2015 to 2020

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Journal of environmental Sciences 2024年第4期138卷 385-394页

作者： Liuwei Kong Mengdi Song Xin Li Ying Liu Sihua Lu Limin Zeng Yuanhang Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China

The coordinated control of PM_(2.5)and ozone has become the strategic goal of national air pollution *** the gradual decline in PM_(2.5)concentration and the aggravation of ozone pollution,a better understanding of the coordinated control of PM_(2.5)and ozone is urgently ***,we collected and sorted air pollutant data for 337 cities from 2015 to 2020 to explore the characteristics of PM_(2.5)and ozone pollution based on China’s five major air pollution *** results show that it is necessary to continue to strengthen the emission reduction in PM_(2.5)and ozone precursors,and control NO_(x) and VOCs while promoting a dramatic emission reduction in PM_(2.5).The primary method of curbing ozone pollution is to strengthen the emission control of VOCs,with a long-term strategy of achieving substantial emission reductions in NO_(x),because VOCs and NO_(x) are also precursors to PM_(2.5);hence,their reductions also contribute to the reduction in PM_(2.5).Therefore,the implementation of a multipollutant emission reduction control strategy aimed at the prevention and control of PM_(2.5)and ozone pollution is the only means to realize the coordinated control of PM_(2.5)and ozone.

关键词： PM_(2.5) Ozone Coordinated control Multipollutant reduction

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Spatial Distribution and environmental Determinants of Denitrification Enzyme Activity in Reed-Dominated Raised Fields

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Chinese Geographical Science 2015年第4期25卷 438-450页

作者： LAN Yan CUI Baoshan HAN Zhen LI Xia LI Fengju ZHANG Yongtao School of Environment State Key Joint Laboratory of Environmental Simulation and Pollution Control Beijing Normal University

Denitrification is an important process of nitrogen removal in lake ***,the importance of denitrification across the entire soil-depth gradients including subsurface layers remains poorly *** study aims to determine the spatial pattern of soil denitrification enzyme activity(DEA) and its environmental determinants across the entire soil depth gradients in the raised fields in Baiyang Lake,North *** two different zones of the raised fields(i.e.,water boundary *** body of the raised fields),the soil samples from 1.0 m to 1.1 m depth were collected,and the DEA and following environmental determinants were quantified:soil moisture,p H,total nitrogen(TN),ammonia nitrogen(NH4+-N),nitrate nitrogen(NO3–-N),total organic carbon(TOC),and rhizome biomass of Phragmites *** results showed that the soil DEA and environmental factors had a striking zonal distribution across the entire soil depth *** soil DEA reached two peak values in the upper and middle soil layers,indicating that denitrification are important in both topsoil and subsurface of the raised *** correlation analysis showed that the DEA is negatively correlated with the soil depth(p < 0.05).However,this phenomenon did not occur in the distance to the water edge,except in the upper layers(from 0.2 m to 0.7 m) of the boundary zone of the raised *** the main body of the raised fields,the DEA level remained high;however,it showed no significant relationship with the distance to the water *** linear regression analysis showed significant positive correlation of the DEA with the soil TN,NO3–-N,NH4+-N,and TOC;whereas it showed negative correlation with soil p *** significant correlations with soil moisture and temperature were observed.A positive correlation was also found between the DEA and rhizome biomass of ***.

关键词： denitrification enzyme activity(DEA) nitrate removal raised fields Baiyang Lake rhizomes

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Ambient photolysis frequency of NO2 determined using chemical actinometer and spectroradiometer at an urban site in Beijing

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Frontiers of environmental Science & Engineering 2016年第6期10卷 73-81页

作者： Qi Zou Keding Lu Yusheng Wu Yudong Yang Zhuofei Du Min Hu State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University Beijing 100871 China

The photolysis frequency of NO2, j（NO2）, is an important analytical parameter in the study of tropospheric chemistry. A chemical actinometer （CA） was built to measure the ambient j（NQ） based on a high precision NOx instrument with 1 min time resolution. Parallel measurements of the ambient j（NO2） by using the CA and a commercial spectroradiometer （SR） were conducted at a typical urban site （Peking University Urban environmental Monitoring Station） in Beijing. In general, good agreement was achieved between the CA and SR data with a high linear correlation coefficient （R2 = 0.977） and a regression slope of 1.12. The regression offset was negligible compared to the measured signal level. Thej（NO2） data were calculated using the tropospheric ultraviolet visible radiation （TUV） model, which was constrained to observe aerosol optical properties. The calculated j（NO2） was intermediate between the results obtained with CA and SR, demonstrating the consistency of all the parameters observed at this site. The good agreement between the CA and SR data, and the consistency with the TUV model results, demonstrate the good performance of the installed SR instrument. Since a drift of the SR sensitivity is expected by the manufacturer, we propose a regular check of the data acquired via SR against those obtained by CA for long-term delivery of a high quality series ofj（NO2） data. Establishing such a time series will be invaluable for analyzing the long-term atmospheric oxidation capacity trends as well as O3 pollution for urban Beijing.

关键词： Photolysis frequency of nitrogen dioxide Chemical actinometer Spectroradiometer Tropospheric ultraviolet visible radiationmodel

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Reinvestigation of the Henry's law constant for hydrogen peroxide with temperature and acidity variation

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Journal of environmental Sciences 2010年第4期22卷 570-574页

作者： Daoming Huang,Zhongming Chen The state key laboratory of environmental simulation and pollution control,College of environmental Sciences and Engineering,Peking University,Beijing 100871,China. [a] The State Key Laboratory of Environmental Simulation Pollution Control College of Environmental Sciences Engineering Peking University Beijing 100871 China

Hydrogen peroxide is not only an important oxidant in itself; it also serves as both sink and temporary reservoir for other important oxidants including HOx （OH and HO2） radicals and O3 in the atmosphere. Its partitioning between gas and aqueous phases in the atmosphere, usually described by its Henry＇s law constant （KH）, significantly influences its role in atmospheric processes. Large discrepancies between the KH values reported in previous work, however, have created uncertainty for atmospheric modelers. Based on our newly developed online instrumentation, we have re-determined the temperature and acidity dependence of KH for hydrogen peroxide at an air pressure of （0.960 ± 0.013） atm （1 atm = 1.01325 × 10^5 Pa）. The results indicated that the temperature dependence of KH for hydrogen peroxide fits to the Van＇t Hoff equation form, expressed as lnKH = a/T - b, and a = -△H/R, where KH is in M/atm （M is mol/L）, T is in degrees Kelvin, R is the ideal gas constant, and AH is the standard heat of solution. For acidity dependence, results demonstrated that the KH value of hydrogen peroxide appeared to have no obvious dependence on decreasing pH level （from pH 7 to pH 1）. Combining the dependence of both temperature and acidity, the obtained a and b were 7024 ± 138 and 11.97 ± 0.48, respectively, AH was （58.40 ± 1.15） kJ/（***）, and the uncertainties represent σ. Our determined KH values for hydrogen peroxide will therefore be of great use in atmospheric models.

关键词： hydrogen peroxide Henry's law constant atmosphere acidity

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

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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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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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