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Effects of Water Vapor on Adsorption Performance of Activated Carbon for Methyl Mercaptan, Toluene and N-Hexane in Fermentation Industrial Waste Gas

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SSRN 2022年

作者： Yao, Xiaolong Shi, Yue Zhou, Jingya Yao, Zhiliang Li, Changmin He, Li Gong, Wenwen School of Ecology and Environment Beijing Technology and Business University Beijing100048 China State Environmental Protection Key Laboratory of Food Chain Pollution Control Beijing Technology and Business University Beijing100048 China Institute of Quality Standard and Testing Technology Beijing Academy of Agriculture and Forestry Science Beijing100097 China

Excessive water vapor in fermentation industrial waste gas complicates the competitive adsorption between water vapor and multicomponent VOCs gases. It is necessary to make an in-depth study on the water vapor-multicomponent VOCs adsorption process on the surface of activated carbon. In this study, a starch-based activated carbon with highly developed microporous structure and rich in oxygen- and nitrogen-containing functional groups was used as the adsorbent. Mixture of three typical VOCs methyl mercaptan, toluene and n-hexane generated in fermentation industrial waste gas was selected as the adsorbate. The adsorption experiments and molecular simulation were used to focus on the adsorption behavior and mechanisms of water vapor and multicomponent VOCs gas on the porous carbon interface. The results indicate that the adsorption energy between water molecules and activated carbon is stronger than that between VOCs and activated carbon. Therefore, toluene, n-hexane and methyl mercaptan are replaced by water molecules at relative humidity 30%. At relative humidity 70%, a water film is formed by capillary condensation on the surface of activated carbon, it reduces the adsorption selectivity of activated carbon for toluene and n-hexane but increases the adsorption selectivity for methyl mercaptan. The water film prevents the adsorption of n-hexane and toluene on the surface of the adsorbent. However, methyl mercaptan can be dissolved in the water film to maintain a relatively stable sorption quantity. Its adsorption changes from the oxidation of oxygen-containing substances on the surface of the adsorbent at relative humidity 0% to the dissolution effect in the water film. © 2022, The Authors. All rights reserved.

关键词： Fermentation

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Identifying key Drivers of Short-Term Abnormally Low Dissolved Oxygen Concentrations at a Trans-Provincial Reservoir in the Dongjiang Headwater Watershed, China

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SSRN 2024年

作者： Yang, Kun Peng, Minggang Liu, Yuxian Zhang, Shixi Weng, Shichuang Zhong, Chao Liu, Shuaishuai Chen, Huaxiang South China Institute of Environmental Sciences Ministry of Ecology and Environment Guangzhou510655 China State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control Guangzhou510655 China School of Public Administration Guangzhou University Guangzhou510006 China School of Environmental Science and Engineering Guangzhou University Guangzhou510006 China Shenzhen Municipality Ecology and Environment Intelligent Control Center Shenzhen518034 China Bureau of Hydrology and Water Resources Pearl River Water Resources Commission of Ministry of Water Resources Guangzhou510611 China Ecology and Environment Bureau of Xunwu County Ganzhou342200 China

Study region: The Douyan Reservoir, South China, under a trans-provincial ecological compensation assessment *** focus: Occasional occurrences of dissolved oxygen (DO) concentrations exceeding the regulatory threshold present challenges to reservoir and river basin management. We examined factors causing short-term abnormally low DO events in the reservoir using hydrological, water quality, aquatic ecosystem, and sediment *** hydrological insights: Significant positive correlations were found between nutrient concentrations (ammonia nitrogen and total nitrogen) in the reservoir and its inflow rivers in 2021. Before abnormally low DO events in 2021, substantial total phosphorus (TP) influx from inflow rivers coincided with historically low inflow and outflow rates and peak temperatures in the reservoir. Allochthonous nutrient inputs (nitrogen and phosphorus), water temperature, and flow rates may have facilitated blooms and subsequent declines of algae, causing sudden DO declines in the reservoir. Moreover, intensified aquatic ecological monitoring in May 2021 (before pH approached its regulatory limit) indicated significant positive correlations: chlorophyll-a with DO and pH, and with total nitrogen (TN) and TP, and pH with DO. These suggest short-term abnormal events resulted from phytoplankton lifecycle activities, driven by an internal-external coupling mechanism, with continuous allochthonous TN inputs and short-term adequate TP influxes acting as primary drivers, and hydrological conditions as inducing factors. This study recommends incorporating TN into ecological compensation assessments for enhanced China’s reservoir and river basin management. © 2024, The Authors. All rights reserved.

关键词： Dissolved oxygen

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Unsteady numerical simulation of flap vibration for 30P30N three-element airfoil

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Journal of Physics: Conference Series 2019年第1期1300卷

作者： Li Ding Zhen Xu State Environmental Protection Key Laboratory of Atmospheric Physical Modeling and Pollution Control National Environmental Protection Research Institute for Electric Power Nanjing China

The pitching motion of NACA0012 airfoil and the flap vibration of 30P30N multi-element airfoil are simulated by using commercial fluid dynamics simulation software Fluent. The influence of flap vibration on lift coefficient and pitch moment coefficient of multi-element airfoil is analyzed. The results show that the influence of flap vibration on pitching moment coefficient of multi-element airfoil is greater. With the increase of flap amplitude, the variation range of lift and moment coefficients gradually increases, while with the increase of frequency, the variation range of lift and moment coefficients gradually decreases, and the hysteresis loop gradually becomes 'thin' and its shape tends to ellipse. With the increase of flap vibration frequency, the unsteady effect of flow field increases, and the hysteresis loop may change in reverse direction.

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Degradation of methylene blue in micro-bubbles activated sodium persulfate system

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IOP Conference Series: Materials Science and Engineering 2018年第1期397卷

作者： Lei Wang Tongtong Li Hui Liu Ningqing Lv Beidou Xi Jinsheng Wang Yuanyuan Xie Ying Zhang State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution Chinese Research Academy of Environmental Sciences Beijing 100012 P. R. China Shenzhen Long Cheng High-tech Environmental protections Co. Ltd. Shenzhen Guangdong 518063

To better understand the promoting effect of the activation process, the performance of micro-bubbles for sodium persulfate activation was evaluated in this study. The degradation rate reached to 91.3% at 90th min in the micro-bubbles activated reactor (MAR), whereas reached to 85.7% at 250th min in the high temperature activated reactor (HTAR). Based on the fitted models, it can be indicated that the reaction rate constant was 2.45 times in the micro-bubbles activated reactor than that in the high temperature activated reactor. It can be concluded that micro-bubbles can effectively strengthen the activation process of sodium persulfate.

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The removal of phosphate in rural domestic wastewater with a SBBR by micro-bubble technology

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IOP Conference Series: Materials Science and Engineering 2018年第1期397卷

作者： Ningqing Lv Tongtong Li Hui Liu Yuanyuan Xie Beidou Xi Jinsheng Wang Lei Wang Ying Zhang State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution Chinese Research Academy of Environmental Sciences Beijing 100012 P. R. China Shenzhen Long Cheng High-tech Environmental protections Co. Ltd. Shenzhen Guangdong 518063

Because of the large content of organic matter as well as nitrogen, the competition between phosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) was serious in wastewater. This phenomenon led to biological phosphate removal in a SBBR with micro-bubble technology was not quite effective. Meanwhile, it can be concluded that the high dissolved oxygen (DO), ammonia nitrogen(NH4+), sludge solubilization affect the biological phosphate removal seriously. This paper was aimed to provide some information's to improve the phosphate removal in the next step.

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Effects of the constructed wetland on dissolved organic matter properties in the drainage channel of domestic sewage treatment plant in winter

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IOP Conference Series: Earth and environmental Science 2021年第1期634卷

作者： Hanxia Yu Xiao Luo Lina Ma Wenbing Tan School of Geographical Sciences Fujian Normal University Fuzhou 350007 China State Key Laboratory of Environmental Criteria and Risk Assessment and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution Chinese Research Academy of Environmental Sciences Beijing 100012 China School of Environmental Science and Engineering Hebei University of Science and Technology Shijiazhuang 050018 China

As a low investment and low energy consumption wastewater treatment technology, the constructed wetland has been gradually accepted by the world. However, there is still a lack of systematic assessment on the impact of the constructed wetland on dissolved organic matter (DOM) properties in the drainage channel of domestic sewage treatment plant in winter. In this study, 3D excitation-emission matrix fluorescence spectroscopy and ultraviolet spectroscopy were combined to reveal the evolution process of DOM properties in the constructed wetland in winter. The results showed that DOC contributed more than 55% of COD in the drainage channels of Shijiazhuang domestic sewage treatment plant in winter, but the COD was significantly decreased after treated by the constructed wetland, which was mainly caused by the more extensive degradation of elements N, H, S and P in DOM. In addition, water DOM in the constructed wetland in winter was mainly contributed by microorganisms, and humus-like components in water DOM were more easily degraded than protein-like components. And humus-like components gradually transformed into protein-like components in the degradation process, and fulvic-like and humic-like components had the same decomposition fate in the constructed wetland in winter.

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A mixed layer height parameterization in a 3-D chemical transport model: Implications for gas and aerosol simulations

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Science of the Total Environment 2024年 955卷 176838页

作者： Kim, Hyeonmin Park, Rokjin J. Hong, Song-you Park, Do-Hyeon Kim, Sang-Woo Oak, Yujin J. Feng, Xu Lin, Haipeng Fu, Tzung-May School of Earth and Environmental Sciences Seoul National University Seoul Korea Republic of Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder United States Physical Sciences Laboratory the National Oceanic and Atmospheric Administration Earth System Research Laboratories Boulder United States Center for Sustainable Environment Research Korea Institute of Science and Technology Seoul Korea Republic of John A. Paulson School of Engineering and Applied Sciences Harvard University CambridgeMA United States State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control School of Environmental Science and Engineering Southern University of Science and Technology Guangdong Shenzhen China Shenzhen Institute of Sustainable Development Southern University of Science and Technology Guangdong Shenzhen China

Vertical mixing within the planetary boundary layer (PBL) is crucial for determining surface-level pollutant concentrations. However, standard PBL schemes in chemical transport models (CTMs) often fail to adequately define the upper bounds of vertical mixing, particularly at night. This limitation frequently results in overestimated nocturnal concentrations of pollutants near the surface. To address this issue, we propose a parameterization of mixed layer height (MLH) derived from the Yonsei University (YSU) PBL scheme and thoroughly evaluate it by comparing simulations with various observations. We utilized the Weather Research and Forecasting model coupled with GEOS-Chem (WRF-GC) to simulate gas and aerosol distributions over South Korea during the Satellite Integrated Joint Monitoring of Air Quality (SIJAQ) campaign in 2021. The WRF-GC simulations incorporating the MLH parameterization improved the excessive titration of O3 and the overproduction of HNO3 and NO3− in the model. Consequently, the model performances in gaseous and aerosol simulations showed a better agreement with observations, with changes in normalized mean biases (NMBs) of NOX (from 50 % to −27 %), O3 (from −49 % to −28 %), NO3− (from 126 % to 91 %), NH4+ (from 113 % to 85 %), BC (from 322 % to 135 %), and PM2.5 (from 58 % to 28 %). © 2024 The Authors

关键词： Air quality

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Fluorescence Characteristics and Source Analysis of DOM in CKDu Zone of the North Central Province in Sri Lanka in Wet Season

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SSRN 2022年

作者： Hu, Dazhou Indika, Suresh Zhong, Hui Weragoda, Sujithra K. Jinadasa, K.B.S.N. Weerasooriya, Rohan Wei, Yuansong State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing100085 China Laboratory of Water Pollution Control Technology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing100085 China University of Chinese Academy of Sciences Beijing100049 China National Water Supply and Drainage Board Katugastota 20800 Sri Lanka Department of Civil Engineering Faculty of Engineering University of Peradeniya Peradeniya20400 Sri Lanka National Institute of Fundamental Studies Hantana Rd Kandy20000 Sri Lanka

Dissolved organic matter (DOM) should be purified for providing safe groundwater-based drinking water. Current research on groundwater in the chronic kidney disease of unknown etiology (CKDu) zone of the North Central Province (NCP) in Sri Lanka has focused mainly on groundwater aquatic chemistry, with limited attention paid to the spatial distribution, compositional sources and factors of DOM in groundwater. Therefore, two kind of groundwater samples from dug well and tube well in the NCP during the wet season were collected, and the structure, composition, source and spatial distribution characteristics of the DOM of these two groundwater types were determined, compared and analyzed by such analytical tools as parallel factor analysis (PARAFAC). Results show that the average concentrations of TOC in the groundwater of the two aquifers are generally greater than 5.0mg/l. The concentration of TOC in the groundwater of the shallow weathered aquifer is higher than that of the deep hard rock aquifer, while its distribution of the two aquifers are on contrary. The DOM in groundwater of shallow weathered aquifer has three types and four components, including humus like component C1(33.36%) and C2(38.60%), protein like component C3(13.09%) and heterogeneous organic component C4(14.95 %). In the deep hard rock aquifer, two types and two components are determined, including humus like component CⅠ(69.80%) widely existing in natural water and soluble microbial by-product CⅡ(30.20%) produced by microbial community activities. In the groundwater of shallow weathered aquifer, DOM is mainly exogenous input, the higher ion concentration in water affected the fluorescence intensity of humus and protein components. In the groundwater of deep hard rock aquifer, DOM has obvious endogenous characteristics, and higher pH value may inhibit the production of protein like fluorescent substances to a certain extent. © 2022, The Authors. All rights reserved.

关键词： Aquifers

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Unique biogeochemical characteristics in coastal ghost forests – The transition from freshwater forested wetland to salt marsh under the influences of sea level rise

Soil and Environmental Health

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Soil and environmental Health 2023年第1期1卷

作者： Chen, Huan Rücker, Alexander Martin Liu, Yina Miller, David Dai, Jia-Ning Wang, Jun-Jian Suhre, Dennis O. Kuo, Li-Jung Conner, William H. Campbell, Barbara J. Rhew, Robert C. Chow, Alex T. Baruch Institute of Coastal Ecology and Forest Science Clemson University 29442 SC United States Department of Environmental Engineering and Earth Science Clemson University 29634 SC United States Department of Biogeochemical Processes Max Planck Institute for Biogeochemistry Jena 07745 Germany Environmental Molecular Sciences Laboratory Pacific Northwest National Laboratory Washington 99354 United States Department of Oceanography Texas A&M University 77843 TX United States Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control School of Environmental Science and Engineering Southern University of Science and Technology Shenzhen 518055 China State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control School of Environmental Science and Engineering Southern University of Science and Technology Shenzhen 518055 China Marine Sciences Laboratory Pacific Northwest National Laboratory Washington 98382 United States Department of Biological Sciences Clemson University 29634 SC United States Department of Geography University of California Berkeley 94720 CA United States

Seawater intrusion by rising sea levels has created large areas of ghost forests along low-lying coastal wetlands in the southeastern USA, but more information is needed to better understand its soil biogeochemistry. Here, we characterized several soil and environmental parameters, including tree litterfall, surface and soil porewater quality, emissions of greenhouse gases, and microbial communities along a forest-to-marsh transect, including a freshwater forested wetland, a salt-impacted degraded ghost forest, and a salt marsh in Winyah Bay, SC, USA. General water quality parameters such as electrical conductivity, dissolved oxygen, temperature and aboveground productivity showed distinct trends along the freshwater forested wetland → degraded ghost forest → salt marsh transect, whereas there were no obvious trends in soil biogeochemical parameters. Concentrations of dissolved organic carbon (DOC) in the degraded ghost forest were generally similar to the freshwater forested wetland, but on average were higher than those in the salt marsh. More labile molecular features observed through Fourier transform ion cyclotron resonance mass spectrometry indicated an increase in the DOC biodegradability along the forest-to-marsh transect. Greater DOC biodegradability in the degraded ghost forest was observed and confirmed through its generation of the highest average electrical currents from sediment microbial fuel cells. The lowest CH₄ and CO₂ fluxes, but the highest degradable DOC, were observed in the degraded ghost forest, suggesting that lateral C export is important in this wetland. Moreover, the degraded ghost forest was dominated by a unique microbial community, including high abundance of Woesearchaeia, which enables carbon metabolism via symbiotic and/or fermentation-based lifestyles. Our study illustrates a ghost forest with very different characteristics compared to its parental freshwater forested wetland and its transitioned salt marsh. D

关键词： Coastal wetland FT-ICR MS Greenhouse gases Microbial community Seawater intrusion Water level

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Vertical Transport of Ultrafine Particles and Turbulence Evolution Impact on New Particle Formation at the Surface & Canton Tower

SSRN

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SSRN 2023年

作者： Wu, Hao Li, Zhanqing Hai, Shangfei Gao, Yang Jiang, Jingkun Zhao, Bin Cribb, Maureen Zhang, Dongmei Pu, Dongyang Liu, Mengqi Wang, Chunling Lan, Jing Wang, Yuying Key Laboratory of China Meteorological Administration Atmospheric Sounding School of Electrical Engineering Chengdu University of Information Technology Chengdu610225 China Department of Atmospheric and Oceanic Science University of Maryland College ParkMD20742 United States College of Oceanic and Atmospheric Sciences Ocean University of China Qingdao266100 China Frontiers Science Center for Deep Ocean Multispheres and Earth System Key Laboratory of Marine Environmental Science and Ecology Ministry of Education Ocean University of China Qingdao266100 China School of Environment State Key Joint Laboratory of Environment Simulation and Pollution Control Tsinghua University Beijing100084 China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing100084 China College of Global Change and Earth System Science Beijing Normal University Beijing100875 China Guangzhou Climate and Agrometeorology Center Guangzhou511430 China Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration Nanjing University of Information Science & Technology Nanjing210044 China

New particle formation (NPF) is a key process occurring in the planetary boundary layer (PBL). Newly formed particles are an important source of aerosols and cloud condensation nuclei (CCN) that influence clouds and climate, while the distribution of these new particles at different altitudes has rarely been studied. In-situ measurements of ultrafine particles (UFP) observed at the ground and at the top of the Canton Tower (454 m) located in downtown Guangzhou in southern China were analyzed using the measurements of multiple meteorological and physicochemical quantities, as both observed during a field campaign and simulated with the WRF-chem model. We found that turbulence and NPF characters vary considerably with heights, with UFP concentration diminishing by half from the surface to the tower top. This indicates the UFP transports upward from the ground in the lower boundary layer. A consistent relationship is established between the occurrences of NPF and the evolution of turbulence. The correlation between the exchange ratio at the tower top has correlated well with nucleation growth, suggesting that turbulence can play an important role in the episodes of NPF growth, whose growth rate is closely related to the turbulence exchange ratio, effectively dictating the ultrafine particle concentration before and during the lockdown period. A new mechanism is thus hypothesized: NPF happens eailer near the surface and grows faster at the upper PBL, attributed to condensable vapors being transported by turbulent vertical mixing in the boundary layer. Model simulations using the WRF-Chem model reveal that the exchange ratio changed the NPF parameters, supporting the proposed mechanism that the evolution of the PBL variation has a significant impact on NPF, which should not be omitted in the NPF research, since this physical factor could be a dominant one in the NPF mechanism. © 2023, The Authors. All rights reserved.

关键词： Turbulence

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