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Linking Management and Riparian Physical Functions to Water Quality and Aquatic Habitat

Journal of Water Resource and Protection 2016年第8期8卷 797-815页

作者： Donald F. Kozlowski Robert K. Hall Sherman R. Swanson Daniel T. Heggem USDA Forest Service Beckwourth Ranger District Plumas National Forest Blairsden CA USA usepa region ix WTR2 San Francisco CA USA Natural Resources & Environmental Sciences University of Nevada Reno NV USA usepa Office of Research & Development NERL Environmental Sciences Division Las Vegas NV USA

Stream and wetland riparian areas are able to sustain a state of resiliency based on the ecosystem’s ability to attain the functions of its ecological potential. This resiliency allows an area to provide and produce desired and valued water quality and aquatic habitat ecosystem services. Maintaining healthy aquatic and riparian habitats depends on “management” allowing for, or facilitating natural recovery of riparian functions. Altering grazing management practices in Maggie Creek lead to changes in riparian functionality, water quality, and aquatic habitat. Maggie Creek basin, historically renowned for its fishery, is one of only a few watersheds in Nevada capable of supporting Lahontan Cutthroat Trout (LCT) (Oncorhynchus clarkia ssp. Henshawi) meta-populations. Prior to 1993, the majority of Maggie Creek was grazed by cattle throughout the growing season. Decades of intensive grazing, water development, and road construction degraded aquatic and riparian habitats. By the early 1990’s, a majority of the Maggie Creek watershed was rated as nonfunctional or functional-at-risk condition with unstable banks, channel incision, loss of riparian vegetation, wide shallow channels, excessive erosion and deposition, reduced stream flows, and increased water temperatures. As mitigation for their 1993 South Operations Area Project mine dewatering, Newmont Mining Company, in cooperation with the Elko District Bureau of Land Management (BLM) and the Elko Land and Livestock Company, developed the Maggie Creek Watershed Restoration Project to enhance LCT habitat. The project was developed to enhance 82 miles of stream, 2000 acres of riparian habitat and 40,000 acres of upland watershed primarily through prescriptive livestock management. Beginning in 1994, grazing systems were implemented for portions of the perennial/intermittent streams. This greatly reduced the frequency and duration of hot season grazing on Maggie Creek and its tributaries. The objective of this paper is to c

关键词： Ecosystem Function Water Quality Non-Point Source Proper Functioning Condition

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Use of Environmental Sequence Stratigraphy (ESS) as an Environmental Forensic Tool to Identify Chlorinated Solvent Sources at a Complex Site in Silicon Valley, California

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Journal of Environmental Protection 2018年第5期9卷 554-566页

作者： Rick Cramer Jun Lu Mike Shultz Colin Plank Herb Levine Burns & McDonnell Brea California USA Hefei University of Technology Hefei China Burns & McDonnell Concord California USA Burns & McDonnell Grand Rapids Michigan USA United States Environmental Protection Agency Region IX San Francisco California USA

This paper presents a case study for a complex contaminated groundwater site impacted by a historical release of chlorinated solvents in Silicon Valley, California. The original conceptual site model (CSM) inferred a contaminant migration pathway based on the groundwater gradient interpreted from groundwater elevation data, which is based on the underlying assumption that the subsurface conditions are homogeneous. However, the buried channel deposits render the underlying geology highly heterogeneous, and this heterogeneity plays a significant role in the subsurface migration of contaminants. Chemical fingerprinting evidence suggested that contamination at the downgradient property boundary was related to an off-site contaminant source. But, this alone was not a compelling argument. However, Environmental Sequence Stratigraphy (ESS), a geology-based environmental forensic technique, was applied to define the permeability architecture or the “plumbing” that controls subsurface fluid flow and contaminant migration. First, the geologic and depositional setting was synthesized based on regional geologic data, and representative facies models were identified for the site. Second, the existing CSM and site lithology data were reviewed and existing lithology data were graphically presented to display vertical grain-size patterns. This analysis focused on the nexus between the depositional environment and the site-specific subsurface data resulting in correlations/interpretations between and beyond data points that are based on established stratigraphic principles. The depositional environment results in buried river channels as the primary control on subsurface fluid flow, which defines hydrostratigraphic units (or HSUs). Finally, a hydrostratigraphic CSM that includes maps and cross sections was constructed to depict the HSUs present as a framework to integrate hydro-geology and chemistry data. This study demonstrates that: 1) Highly per-meable buried river channel deposi

关键词： Environmental Sequence Stratigraphy Hydrostratigraphic Units HSU Contaminant Sources Source Identification Migration Pathways Depositional Environment Chlorinated Solvents Environmental Forensic Tool

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Pesticide and Nutrient Loads of Lake Bosomtwe in the Ashanti region of Ghana

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Journal of Water Resource and Protection 2021年第10期13卷 794-806页

作者： Collins Kuffour David Kofi Essumang Hugh Komla Akotoye Richard Amankwah Kuffour Janice Dwomoh Abraham Department of Environmental Health and Sanitation Education Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development Mampong Ashanti Region Ghana School of Physical Sciences University of Cape Coast Cape Coast Central Region Ghana Department of Environmental Science University of Cape Coast Cape Coast Central Region Ghana Department of Biological Sciences Education Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development Mampong Ashanti Region Ghana

Pollution of Lake Bosomtwe is a major concern in Ghana due to its derived socio-economic benefits such as employment, ecotourism and major protein source to the people in the basin. Besides these benefits, the lake water is used for domestic purposes and has since served as the drinking water source to the people. However, the use of agrochemicals within the basin has intensified within the last decade. The problems associated with fertilizer and pesticide use in the Bosomtwe basin seem to carry with it a higher price, which, if not identified and checked, will overshadow the desired benefits of the lake. This study assesses pesticide and nutrient loads of Lake Bosomtwe in the Ashanti region of Ghana. Fifty-four (54) lake water samples were collected from September 2016 to February 2017. Pesticide samples were extracted using the solid phase extraction method and GCMS to identify the pesticides present in the water samples and determine their loads. The data obtained were analyzed using Statistical Product Service Solutions (SPSS version 20) for descriptive statistics. The concentration of dichlorvos was a bit lower when compared with the WHO/usepa guidelines of 5 ppb for surface water. Diazinon had a mean concentration of 0.28 ± 0.03 ppb which was higher than the WHO 0.05 ppb and usepa 0.04 ppb for surface water bodies. The detection of diazinon confirms the findings from the field survey, which revealed that diazinon, is an active ingredient of a pesticide with a trade name “Akate suro”, which was extensively used by cocoa farmers along the banks of the lake. The mean concentration recorded for nitrate and phosphate were 0.15 ± 0.05 mg/L and 0.40 ± 0.12 mg/L respectively. The pesticides application inventory and implications of pesticide and nutrient loads on the lake are discussed in the paper.

关键词： Organochlorine Organophosphorus Pesticide Fertilizer Bosomtwe

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Optimal Sample Preservation and Analysis of Cr(VI) in Drinking Water Samples by High Resolution Ion Chromatography Followed by Post Column Reaction and UV/Vis Detection

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Journal of Analytical Sciences, Methods and Instrumentation 2012年第2期2卷 74-80页

作者： Prince Ezebuiro Jay Gandhi Chunlong Zhang Johnson Mathew Melvin Ritter Marvelyn Humphrey Metrohm USA Inc. Riverview Florida USA 3U.S. EPA region 6 Laboratory Houston USA U.S. EPA region 6 Laboratory Houston USA University of Houston-Clear Lake Houston USA 2Metrohm USA Inc. Riverview Florida USA University of Houston-Clear Lake Houston USA 2Metrohm USA Inc. Riverview Florida USA 3U.S. EPA region 6 Laboratory Houston USA

A recent study by the Environmental Working Group reported the detection of hexavalent chromium (Cr(VI)) in tap water at 31 out of 35 states investigated in the United States. Even though Cr(III) is an essential element for human diet, Cr(VI) is a potential carcinogen. Previous work has clearly identified a linear trend of increasing risk of lung cancer mortality with increasing cumulative exposure to water soluble Cr(VI). Regardless, Cr(VI) is still not regulated or monitored in drinking water in the U.S. There is an existing method (EPA 218.6) for the analysis of Cr(VI), however, this analytical method does not addresses detailed sample preservation techniques and optimization process to achieve lowest detection limit possible. In this study, five buffer solutions with pH of 9 and above were compared to determine the most suitable buffer to preserve Cr(VI) in drinking water samples for an extended period of time. Results showed that the five buffers responded very differently to Cr(VI)-fortified drinking water. The best preserving reagent was found to be Ammonium Hydroxide + Ammonium Sulfate (pH 9.2) and Sodium Carbonate + Sodium Bicarbonate+ Ammonium Sulfate (pH 9.7), whereas a buffer solution with Sodium Hydroxide + Sodium Carbonate (pH 11.5+) resulted in a poor chromatographic resolution. A controlled study with a fortified Cr(III) at 1 ppb was also conducted to ensure no false positive detection of Cr(VI) due to the potential oxidation of Cr(III) during sample storage. The optimal preserving reagent identified from this study was compatible with the existing EPA method 218.6 using ion chroma-tography followed by post column reaction, with a method quantitation limit of 0.020 ppb and matrix spike recovery of ± 10%.

关键词： Hexavalent Chromium Ion Chromatography usepa Method Sample Preservation

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Development and case study of a new-generation model-VAT for analyzing the boundary conditions influence on atmospheric mercury simulation

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Frontiers of Environmental Science & Engineering 2018年第1期12卷 149-158页

作者： Wenwei Yang Yun Zhu Carey Jang Shicheng Long Che-Jen Lin Bin Yu Zachariah Adelman Shuxiao Wang Jia Xing Long Wang Jiabin Li Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control College of Environment and Energy South China University of Technology Guangzhou Higher Education Mega Center Guangzhou 510006 China State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing 100084 China usepa/Office of Air Quality Planning ＆ Standards RTP NC 27711 USA Guangzhou Urban Environmental Cloud Information Technology R＆D Co. Ltd Guangzhou 510006 China 5 Department of Civil Engineering Lamar University Beaumont TX 77710-0024 USA 6 Guangzhou Environmental Monitoring Center Station Guangzhou 510030 China 7 Institute for the Environment The University of North Carolina at Chapel Hill Chapel Hill NC 27517 USA

Atmospheric models are essential tools to study the behavior of air pollutants. To interpret the complicated atmospheric model simulations, a new-generation Model Visualization and Analysis Tool （Model-VAT） has been developed for scientists to analyze the model data and visualize the simulation results. The Model-VAT incorporates analytic functions of conventional tools and enhanced capabilities in flexibly accessing, analyzing, and comparing simulated results from multi-scale models with diflbrent map projections and grid resolutions. The performance of the Model-VAT is demonstrated by a case study of investigating the influence of boundary conditions （BCs） on the ambient Hg formation and transport simulated by the CMAQ model over the Pearl River Delta （PRD） region. The alternative BC options are taken from （1） default time-independent profiles, （2） outputs from a CMAQ simulation of a larger nesting domain, and （3） concentration files from GEOS-Chem （re-gridded and re-projected using the Model-VAT）. The three BC inputs and simulated ambient concentrations and deposition were compared using the Model-VAT. The results show that the model simulations based on the static BCs （default profile） underestimates the Hg concentrations by --6.5%, dry depositions by -9.4%, and wet depositions by --43.2% compared to those of the model-derived （e. g. GEOS-Chem or nesting CMAQ） BCs. This study highlights the importance of model nesting approach and demonstrates that the innovative functions of Model-VAT enhances the efficiency of analyzing and comparing the model results from various atmospheric model simulations.

关键词： Model and data wsuahzatlonModel and data analysisCMAQBoundary conditionsMercury

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Dynamic performance and parameter optimization of a half-vehicle system coupled with an inerter-based X-structure nonlinear energy sink

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 85-110页

作者： Yong WANG Peili WANG Haodong MENG Liqun CHEN .Automotive Engineering Research Institute Jiangsu UniversityZhenjiang 212013Jiangsu ProvinceChina Guangxi Key Laboratory of Automobile Components and Vehicle Technology Guangxi University of Science and TechnologyLiuzhou 545006Guangxi Zhuang Autonomous RegionChina School of Automotive Engineering Changzhou Institute of TechnologyChangzhou 213032Jiangsu ProvinceChina Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Frontier Science Center of MechanoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200444China

Inspired by the demand of improving the riding comfort and meeting the lightweight design of the vehicle, an inerter-based X-structure nonlinear energy sink(ixNES) is proposed and applied in the half-vehicle system to enhance the dynamic performance. The X-structure is used as a mechanism to realize the nonlinear stiffness characteristic of the NES, which can realize the flexibility, adjustability, high efficiency, and easy operation of nonlinear stiffness, and is convenient to apply in the vehicle suspension, and the inerter is applied to replacing the mass of the NES based on the mass amplification characteristic. The dynamic model of the half-vehicle system coupled with the ix-NES is established with the Lagrange theory, and the harmonic balance method(HBM) and the pseudo-arc-length method(PALM) are used to obtain the dynamic response under road harmonic excitation. The corresponding dynamic performance under road harmonic and random excitation is evaluated by six performance indices, and compared with that of the original half-vehicle system to show the benefits of the ix-NES. Furthermore, the structural parameters of the ix-NES are optimized with the genetic algorithm. The results show that for road harmonic and random excitation, using the ix-NES can greatly reduce the resonance peaks and root mean square(RMS) values of the front and rear suspension deflections and the front and rear dynamic tire loads, while the resonance peaks and RMS values of the vehicle body vertical and pitching accelerations are slightly *** the structural parameters of the ix-NES are optimized, the vehicle body vertical and pitching accelerations of the half-vehicle system could reduce by 2.41% and 1.16%,respectively, and the other dynamic performance indices are within the reasonable ***, the ix-NES combines the advantages of the inerter, X-structure, and NES, which improves the dynamic performance of the half-vehicle system and provides an effective option for vibrati

关键词： inerter X-structure nonlinear energy sink(NES) half-vehicle system dynamic performance

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典型城市臭氧污染源贡献及控制策略费效评估

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环境科学学报 2017年第9期37卷 3306-3315页

作者：盛叶文朱云陶谨陈享华刘可旋 Carey Jang 王书肖朱振华危浩袁颖枝华南理工大学环境与能源学院广东省大气环境与污染控制重点实验室广州510006 国家环境保护大气复合污染来源与控制重点实验室清华大学环境学院北京100084 东莞市环境保护局东莞523009 usepa/Office of Air Quality Planning&Standards RTPNC27711USA 广州城环云信技术研发有限公司广州510006

东莞是珠三角O_3污染最严重的城市,使用RSM/CMAQ(曲面响应模型)法分析了珠三角区域人为排放的NO_x和VOCs对东莞市O_3浓度变化源贡献.2014基准年分析结果表明,扣除模型域外区域传输及天然源排放对O_3本底浓度贡献(41.00%)后,东莞本地VOC... 详细信息

东莞是珠三角O_3污染最严重的城市,使用RSM/CMAQ(曲面响应模型)法分析了珠三角区域人为排放的NO_x和VOCs对东莞市O_3浓度变化源贡献.2014基准年分析结果表明,扣除模型域外区域传输及天然源排放对O_3本底浓度贡献(41.00%)后,东莞本地VOCs排放对O_3贡献最大(18.50%),珠三角区域NO_x减排率>13%时可持续降低东莞市O_3浓度.进一步使用ABa CAS-SE(空气污染控制成本效益与达标评估系统)对2017、2020、2025东莞市3个未来年O_3污染控制情景进行了费效评估.评估结果显示,NO_x和VOCs控制比例相对较低的2017年控制情景人体健康效益/区域控制成本比约为1.1;而控制比例相对较高的2025年东莞O_3达标情景效益成本比仅为0.1.这说明,在高减排率情景下,以末端治理为主的控制措施经济可行性较差,需综合采取产业/能源结构调整、清洁生产等措施实现NO_x和VOCs的大比例减排,实现东莞O_3的稳定达标.今后将进一步研究NO_x和VOCs减排对PM_(2.5)环境浓度及健康效益影响,开展多目标污染物协同控制费效评估.

关键词：臭氧污染曲面响应模型源贡献分析污染控制费效评估

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基于曲面响应建模的PM2.5可控人为源贡献解析

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环境科学学报 2018年第10期38卷 3877-3887页

作者：杨再东朱云陶谨陈享华刘可旋 Carey Jang 王书肖邢佳游志强余美芳华南理工大学环境与能源学院、广东省大气环境与污染控制重点实验室广州510006 清华大学环境学院、国家环境保护大气复合污染来源与控制重点实验室北京100084 东莞市环境保护局东莞523009 usepa/Office of Air Quality Planning&Standards RTPNC27711USA 广州城环云信技术研发有限公司广州510006

以东莞市PM_(2.5)重污染月份为例,使用强力法(Brute Force)和RSM/CMAQ曲面响应模型法分别解析了珠三角地区人为源排放对东莞PM_(2.5)的贡献,以及区域传输的可控人为源SO_2、NO_x和一次颗粒物(PM)在不同控制比例下(25%、50%、75%和100%)... 详细信息

以东莞市PM_(2.5)重污染月份为例,使用强力法(Brute Force)和RSM/CMAQ曲面响应模型法分别解析了珠三角地区人为源排放对东莞PM_(2.5)的贡献,以及区域传输的可控人为源SO_2、NO_x和一次颗粒物(PM)在不同控制比例下(25%、50%、75%和100%)对东莞PM_(2.5)的累积浓度贡献.强力法研究结果表明,2014年1月珠三角地区人为源二次转化对东莞市PM_(2.5)的贡献(约58.10%)大于一次PM排放贡献(约41.90%),其中,人为源NH_3排放贡献最大,约占总量的21.66%.RSM/CMAQ动态源贡献结果显示,东莞市PM_(2.5)的人为可控源排放贡献(SO_2、NO_x和一次PM)占比为82.17%,受本地排放影响较大,且叠加区域排放的影响;一次PM减排对PM_(2.5)环境浓度的贡献高于仅减排SO_2和NO_x.在减排比例较低时,一次PM减排可有效削减东莞市PM_(2.5)浓度;随控制比例加大,二次前体物(SO_2和NO_x)减排对东莞市PM_(2.5)浓度削减率的影响加大.进一步使用HYSPLIT模式和轨迹聚类分析方法研究了2014年1月东莞市PM_(2.5)污染传输过程.结果显示,该时段共有6条长、短距离污染传输路径,污染物主要来自东莞市东、东北及东南方向,途经其上风向区域(惠州、深圳和广州等)传输至东莞;惠州是各主导上风向出现频率最高的城市,因而其区域传输对东莞PM_(2.5)的贡献也较大,深圳次之.

关键词： PM2.5 曲面响应模型源贡献分析人为排放区域传输

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