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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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Cation exchange resin supported nanoscale zero-valent iron for removal of phosphorus in rainwater runoff

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Frontiers of environmental Science & Engineering 2014年第3期8卷 463-470页

作者： Bangmi XIE Jiane ZUO Lili GAN Fenglin LIU Kaijun WANG State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing 100084 China

Self-made cation exchange resin supported nanoscale zero-valent iron （R-nZVI） was used to remove phosphorus in rainwater runoff. 80% of phosphorus in rainwater runoff from grassland was removed with an initial concentration of 0.72 mg. L-1 phosphorus when the dosage of R-nZVl is 8 g per liter rainwater, while only 26% of phosphorus was removed when using cation exchange resin without supported nanoscale zero-valent iron under the same condition. The adsorption capacity of R-nZVI increased up to 185 times of that of the cation exchange resin at a saturated equilibrium phosphorous concentration of 0.42 mg. L-1. Various techniques were implemented to characterize the R-nZVI and explore the mechanism of its removal of phosphate. Scanning electron microscopy （SEM） indicated that new crystal had been formed on the surface of R-nZVI. The result from inductive coupled plasma （ICP） indicated that 2.1% of nZVI was loaded on the support material. The specific surface area was increased after the load of nanoscale zero-valent iron （nZVI）, according to the measurement of BET-N2 method. The result of specific surface area analysis also proved that phosphorus was removed mainly through chemical adsorption process. X-ray photoelectron spectroscopy （XPS） analysis showed that the new product obtained from chemical reaction between phosphate and iron was ferrous phosphate.

关键词： nanoscale zero-valent iron（R-nZVI） cation exchange resin rainwater runoff phosphorus adsorption

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Removing phosphorus from aqueous solutions by using iron- modified corn straw biochar

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Frontiers of environmental Science & Engineering 2015年第6期9卷 1066-1075页

作者： Fenglin LIU Jiane ZUO Tong CHI Pei WANG Bo YANG State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing 100084 China

Iron-modified corn straw biochar was used as an adsorbent to remove phosphorus from agricultural runoff. When agricultural runoffs with a total phosphorus （TP） concentration of 1.86 mg.L-1 to 2.47 mg.L-1 were filtered at a hydraulic retention time of 2 h through a filtration column packed with the modified biochar, a TP removal efficiency of over 99% and an effluent TP concentration of less than 0.02mg.L-1 were achieved. The isotherms of the phosphorus adsorption by the modified biochar fitted the Freundlich equation better than the Langmuir equation. The mechanism of the phosphorus adsorbed by the modified biochar was analyzed by using various technologies, i.e. scanning electron microscopy （SEM）, X-ray diffraction （XRD） analysis, X-ray photoelectron spectroscopy （XPS）, and Fourier transform infrared spectroscopy （FTIR）. The results indicated that the surface of the modified biochar was covered by small iron granules, which were identified as Fe304. The results also showed that new iron oxides were formed on the surface of the modified biochar after the adsorption of phosphorus. Moreover, new bonds of Fe- O-P and P-C were found, which suggested that the new iron oxides tend to be Fe5（PO4）4（OH）3. Aside from removing phosphorus, adding the modified biochar into soil also improved soil productivity. When the modified biochar-to-soil rate was 5%, the stem, root, and bean of broad bean plants demonstrated increased growth rates of 91%, 64%, and 165%, respectively.

关键词： iron-modified biochar phosphorus removal,agricultural waste agricultural runoff

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Efficient Metal Recovery from Industrial Wastewater:Potential Oscillation and Turbulence Mode for Electrochemical System

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Engineering 2024年第7期38卷 184-193页

作者： Li Chen Gong Zhang Huijuan Liu Shiyu Miao Qingbai Chen Huachun Lan Jiuhui Qu Center for Water and Ecology State Key Joint Laboratory of Environment Simulation and Pollution ControlSchool of EnvironmentTsinghua UniversityBeijing 100084China

Efficient metal recovery from industrial wastewater facilitates addressing of the environmental hazards and resource requirements of heavy *** conventional electrodeposition recovery method is hampered by the limitations of interfacial ion transport in charge-transfer reactions,creating challenges for simultaneous rapid and high-quality metal ***,we proposed integrating a transient electric field(TE)and swirling flow(SF)to synchronously enhance bulk mass transfer and promote interfacial ion *** investigated the effects of the operation mode,transient frequency,and flow rate on metal recovery,enabling determination of the optimal operating conditions for rapid and efficient sequential recovery of Cu in TE&SF *** conditions included low and high electric levels of 0 and 4 V,a 50%duty cycle,1 kHz frequency,and 400 L·h^(-1)flow *** kinetic coefficients of TE&SF electrodeposition were 3.5-4.3 and 1.37-1.97 times that of single TE and SF electrodeposition,*** the deposition process under TE and SF conditions confirmed the efficient concurrence of interfacial ion transport and charge transfer under TE and SF synergy,which achieved rapid and highquality metal ***,the combined deposition strategy is considered an effective technique for reducing metal pollution and promoting resource recycling.

关键词： Ion transport Reaction kinetics Transient electric field Swirling flow

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Biodegradation of polycyclic aromatic hydrocarbons in sediments from the Daliao River watershed, China

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Journal of environmental Sciences 2009年第7期21卷 865-871页

作者： QUAN Xiangchun, TANG Qian, HE Mengchang, YANG Zhifeng, LIN Chunye, GUO Wei state key joint laboratory of environmental simulation and pollution control, School of environment, Beijing Normal University, Beijing 100875, China. [a]State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China

The Daliao River, as an important water system in Northeast China, was reported to be heavily polluted by polycyclic aromatic hydrocarbons （PAHs）. Aerobic biodegradations of four selected PAHs （naphthalene, phenanthrene, fluorene and anthracene） alone or in their mixture in river sediments from the Daliao River water systems were studied in microcosm systems. Effects of additional carbon source, inorganic nitrogen and phosphorus, temperature variation on PAHs degradation were also investigated. Results showed that the degradation of phenanthrene in water alone system was faster than that in water-sediment combined system. Degradation of phenanthrene in sediment was enhanced by adding yeast extract and ammonium, but retarded by adding sodium acetate and not significantly influenced by adding phosphate. Although PAHs could also be biodegraded in sediment under low temperature （5~C）, much lower degradation rate was observed. Sediments from the three main streams of the Daliao River water system （the Hun River, the Taizi River and the Daliao River） demonstrated different degradation capacities and patterns to four PAHs. Average removal rates （15 or 19 d） of naphthalene, phenanthrene, fluorene and anthracene by sediment were in the range of 0.062-0.087, 0.005-0.066, 0.008- 0.016 and 0-0.059 mg/（L.d）, respectively. As a result, naphthalene was most easily degraded compound, anthracene was the hardest one. In multiple PAHs systems, the interactions between PAHs influenced each PAH biodegradation.

关键词： biodegradation the Daliao River microcosm polycyclic aromatic hydrocarbon sediment

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simulation and control strategy for the variational influent of WWTP

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Journal of environmental Sciences 2006年第1期18卷 62-68页

作者： LIU Yan-chen FAN Long SHI Han-chang WANG Zhi-qiang State Key Joint Laboratory of Environment Simulation and Pollution Control Department of Environmental Science and Engineering TsinghuaUniversity Beijing 100084 China

With the development of activated sludge model, the simulation software for the design and operation of wastewater treatment plant （WWTP） was produced and has been widely used. The dynamic change of the quality and flow of influent are major factors causing the unstable operation of wastewater treatment process. As a basic model, ASMI model was used for the simulation of activated sludge process, and double exponential model was selected for the simulation of secondary sedimentation tank. The influences of influent change to the aeration tank and secondary sedimentation tank were investigated, and the relationship among influent change, the quality of effluent and the level of sludge blanket in secondary sedimentation tank was established. On the basis of the simulation results, the operation of the WWTP could be adjusted under the dynamic change of the influent. Furthermore, the controlling strategy combined the feed-forward on the influent flow and the feedback on the level of sludge blanket in the secondary sedimentation tank was studied.

关键词： modeling dynamic simulation static simulation controlling strategy influent

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Antimicrobial activity of silver loaded MnO_2 nanomaterials with different crystal phases against Escherichia coli

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Journal of environmental Sciences 2016年第3期28卷 112-120页

作者： Lian Wang Hong He Changbin Zhang Li Sun Sijin Liu Shaoxin Wang State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of Sciences

Silver-loaded MnO_2 nanomaterials（Ag/MnO_2）,including Ag/α-MnO_2,Ag/β-MnO_2,Ag/γ-MnO_2and Ag/δ-MnO_2 nanorods,were prepared with hydrothermal and impregnation *** bactericidal activities of four types of Ag/MnO_2 nanomaterials against Escherichia coli were investigated and an inactivation mechanism involving Ag~＋ and reactive oxygen species（ROS）was also *** bactericidal activities of Ag/MnO_2 depended on the MnO_2 crystal *** these nanomaterials,Ag/β^-MnO_2 showed the highest bactericidal *** was a 6-log decrease in *** survival number after treatment with Ag/β^-MnO_2 for120 *** results of 5,5-dimethyl-l-pyrroline-N-oxide spin-trapping measurements by electron spin resonance indicate OH and O_2^- formation with addition of Ag/β-MnO_2,Ag/γ-MnO_2 or Ag/δ-MnO_*** strongest peak of OH appeared for Ag/β-MnO_2,while no OH or ·O_2^-signal was found over Ag/α-MnO_*** analysis of electron spin resonance（ESR） and Ag＋elution results,it could be deduced that the toxicity of Ag~＋ eluted from Ag/MnO_2 nanomaterials and ROS played the main roles during the bactericidal *** showed the highest dispersion on the surface of β-MnO_2,which promoted ROS formation and the increase of bactericidal *** results also indicated that Ag/MnO_2 induced the production of intracellular ROS and disruption of the cell wall and cell membrane.

关键词： Silver MnO_2 Bactericidal activity Escherichia coli ROS

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Evidence of sewage discharge on the coalescence mechanism of aquatic microbial communities during high amplitude hydrological periods

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Science of the Total environment 2025年 959卷 178223页

作者： Kou, Xin Huang, Shier Bian, Rui Tang, Qingwen Wang, Hui Liu, Song Wang, Li Qi, Weixiao Cao, Xiaofeng Lan, Huachun Liu, Huijuan Qu, Jiuhui Center for Water and Ecology State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China Center for Ecological Civilization Tsinghua University Beijing100084 China Center of Tsinghua Think Tanks Tsinghua University Beijing100084 China School of Environment Northeast Normal University Changchun130117 China Co. Ltd. Zunyi564501 China Chishui River Middle Basin Watershed ecosystem Observation and Research Station of Guizhou Province Zunyi564501 China

Microbial community coalescence is a ubiquitous ecological process in various ecosystems. However, limited research has addressed the effects of the coalescence on microbial ecological processes and network structure, particularly in the context of sewage discharge during high amplitude hydrological periods. Employing 16S rRNA sequencing and species source tracking analysis, we investigated the coalescence pattern of bacterioplankton in the Chishui river and sewage across various hydrological periods. The results demonstrated that the downstream bacterioplankton mainly originated from the upstream water body, and the sewage discharge from the wastewater treatment plants (WWTPs) had less impact on the downstream bacterioplankton. In the low-water period, the bacterioplankton community showed significant coalescence, and the specialist species and functional taxa gathered in the downstream. Bacterioplankton displayed distinct ecological succession patterns after community coalescence, with notable variations in the abundance of dominant group. Bacterioplankton community assembly was dominated by stochastic processes in river and the sewage over different hydrological periods. The ecological networks exhibited the highest complexity in the high-water period, whereas their stability was most pronounced in the low-water period. Species diversity, as opposed to functional and phylogenetic diversity, might be a more accurate indicator to predict changes in microbial network structure. Our findings will provide new perspectives on the mechanisms of aquatic microbial community coalescence in natural environments. © 2024 Elsevier B.V.

关键词： Anthropogenic

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Land use and landscape pattern changes in Nenjiang River basin during 1988-2002

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中国高等学校学术文摘·地球科学 2010年第1期4卷 33-41页

作者： Sihui WANG Yanwei ZHAO Xinan YIN Lei YU Fei XU State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentBeijing Normal University Beijing 100875 China

Based on the Landsat TM data in 1988 and 2002, the GIS technique and Fragstats software were used to calculate the land use conversion matrix and eight landscape metrics at landscape and patch class levels in upstream, midstream, and downstream regions of Nenjiang River basin. The characteristics of land use and landscape pattern changes in each region during 1988-2002 were analyzed. The results show the followings: 1) During the period from 1988 to 2002, farmland and construction land area increased, while the areas of forestland, grassland, and unutilized land decreased in all three regions. The conversion trends from forestland and grassland to farmland were obvious. The conversion from forestland to farmland mainly occurred in the upstream region, whereas the conversion from grassland to farmland primarily occurred in the midstream and downstream regions. 2) The water area in the upstream and midstream regions enlarged, mainly due to the increase of water impounded area as a result of the construction of reservoirs. Comparatively, the water area in the downstream region decreased, and it mainly occurred in the east part of downstream region with concentrated lakes and swamps. 3) The degree of landscape fragmentation increased in each region. The controlling ability of forestland was weakened, and its patch shape became more complicated. In contrast, the controlling ability of farmland was reinforced, and the connectivity among patches increased. 4) The landscape pattern shows some gradient features. From the upstream to downstream regions, the disturbance of human activities on dominant patches was intensified, and consequently, the landscape fragmentation extent and heterogeneity were enhanced.[PUBLICATION ABSTRACT]

关键词： land use landscape pattern Nenjiang River basin

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Effects of elevated atmospheric carbon dioxide to Microcystis aeruginosa under different forms of phosphorus sources

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Chemosphere 2025年 374卷 144210页

作者： Zhang, Juanjuan Xu, Wenxuan Zhang, Qingquan Deng, Lin Ai, Fuxun Yin, Ying Guo, Hongyan State Key Laboratory of Pollution Control and Resource Reuse School of the Environment Nanjing University Nanjing210023 China Joint International Research Centre for Critical Zone Science-University of Leeds and Nanjing University Nanjing University Nanjing210023 China Jiangsu Academy of Environmental Industry and Technology Corp. Nanjing210000 China

Human activities have led to an increase in atmospheric carbon dioxide (CO2) concentration, which can enhance the flux of CO2 from air to water, thus impacting algal growth. Phosphorus (P) is a key factor influencing the formation of cyanobacteria blooms. Nutrient utilization is closely related to carbon (C) metabolism, but the effects of elevated CO2 on microalgae under different P sources are rarely studied. In this study, we investigated the growth and physiological and biochemical responses of Microcystis aeruginosa (M. aeruginosa) under ambient (400 ppm) and elevated (550 ppm) CO2 levels in P-free, dissolved inorganic P (DIP, 1 mg P/L), and dissolved organic P (DOP, 1 mg P/L) groups. The bioavailability of DIP to M. aeruginosa was greater than that of DOP, and elevated CO2 increased both the uptake of DIP and DOP. Elevated CO2 promoted the growth (increasing by 9.0%–14.2%), photosynthesis, and CO2 fixation of M. aeruginosa under different P sources (P-free, DIP, DOP), and increased total microcystin-LR content (increasing by 5.4%–12.6%), which increased the risk of microcystin-LR release into the environment. Furthermore, elevated CO2 aggravated the stress effect of DOP, leading to an increase in protein content and proportion of humic acid substances in the extracellular polymeric substances. Our study provides a theoretical basis for understanding the impact of elevated CO2 on cyanobacteria bloom under different P sources, and provides a new insight for the control of eutrophic waters under the background of climate change. © 2025 Elsevier Ltd

关键词： Carbon stable isotope Elevated carbon dioxide Microcystin-LR Microcystis aeruginosa Phosphorus

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