Poster Abstracts5th International Conference on Environmental Informatics
August 1-3, 2006, Bowling Green, Kentucky, USA
Poster Abstracts
5th International Conference on Environmental Informatics
August 1-3, 2006, Bowling Green, Kentucky, USA
Stability prediction of the xanthate-stabilized Zn(OH)2 and Cu(OH)2 sludge in simulated landfill environment
Teh-Sheng Su (1), Yi-Kuo Chang (1), Juu-En Chang (2, 3), Ming-Sheng Ko (4) and Yan-Hsuen Chen (2)
(1) Department of Safety Health and Environmental Engineering, Central Taiwan University of Science and Technology, 11, Po-Tze Lane, Takun, Taichung 406, Taiwan.
(2) Department of Environmental Engineering, National Cheng Kung University, 1 Ta-Hsueh Rd., Tainan city 701, Taiwan.
(3) The Sustainable Environment Research Center, National Cheng Kung University, 1 Ta-Hsueh Rd., Tainan city 701, Taiwan.
(4) Department of Materials and Mineral Resources Engineering, National
Taipei University of Technology, No. 1, sec. 3, Jungshiau E Rd., Daan
Chiu, Taipei 106, Taiwan
Abstract. In this work, the long-term stability of the xanthate-stabilized Zn(OH)2 sludge (ZnBX matrices) and Cu(OH)2 sludge (CuBX matrices) under simulated acidic landfill environment was studied. The semi-dynamic leaching test (SDLT) using 1N acetic acid solution as leachant was performed to simulate the landfill age as one SDLT leaching cycle provided the equivalent acidity of a 5-yr landfill period. The SDLT had been performed 10 weeks totally (i.e., 10 leaching cycles), which gives the simulation of the time period for 50 years of landfill age. The leaching and stabilizing characteristics of the ZnBX and CuBX matrices through the SDLT were characterized using pH meter, ORP meter, A.A., UV-vis, XRD and EA techniques.
The result of SDLT after 10 weeks of extractions showed that the leached species were reducing and alkaline materials, and both the metal released rate in ZnBX and CuBX matrices gradually decreased with the increase of extraction time. The cumulative fraction of zinc released was 71.9 %, whereas the copper was 2.6 %. The xanthate treatment was suitable for copper-bearing sludges than zinc-bearing sludges when choosing landfill as final disposal. The rate of containment leaching was controlled by dissolution (diffusion) and surface wash-off. The UV-vis spectra of leaching solutions indicated that the xanthate species were decomposed in the acidic solution. The XRD patterns showed the Cu(BX)2 and ZnS to be the residual phase of the ZnBX and CuBX matrices after SDLT. The long-term stability of the CuBX matrices might be attributed to the formation of Cu(BX)2 complexes.
Keywords: Stability, xanthate, semi-dynamic leaching test, landfill
Drought Induced Dissolved Oxygen Dynamics of an Effluent Dominated Stream Entering a Reservoir Backwater and Implications for Environmental Compliance
R.D. Taylor, K.L. Dickson, and V. Golla
Western Kentucky University, Department of Public Health, Environmental Health Science, 1906 College Heights Blvd., Bowling Green, KY 42104
University of North Texas, Institute for Applied Sciences, P.O. Box 310559, Denton, TX 76203
Corresponding author: ritchie.taylor@wku.edu
Abstract. Compliance with dissolved oxygen standards is the basic means for assessing wastewater treatment plant discharges of oxygen demanding wastes. Methods often consist of collecting water quality samples at or near the critical low flow condition during the summer season, such as the 7-day average flow with a 10-year recurrence interval (7Q10), and developing a water quality model set that adequately represents the empirical data. In the analysis of effluent dominated streams entering reservoirs, the critical event may be defined not only by stream flow conditions but receiving water characteristics, such as the location of the transition zone from stream to reservoir dynamics. This zone is often the stated location for compliance with water quality standards. Drought induced changes in reservoir storage can change the longitudinal extent of stream transition zones. Fluctuating reservoir levels cause concurrent variations in stratified backwater conditions and dissolved oxygen values. By assessing the variability in daily dissolved oxygen values the boundaries of the stream/reservoir transition zone can be identified. The determination of the transition zone is critical to accurately assess compliance with dissolved oxygen water quality standards. Daily variations in dissolved oxygen are used to model the location of the transition zone for water quality compliance, as compared to drought induced reservoir fluctuations. Results indicate that site specific water quality measurements are needed to accurately define environmental compliance monitoring locations in effluent dominated streams entering reservoirs.
Keywords: Wastewater, Dissolved oxygen, Water quality, Effluent, Drought, Effluent dominated stream, Reservoir, Environmental compliance, NPDES
Conflicting Maximum Contaminant Levels and Water Quality Standards:
Data Impairments to Protecting Public Health with Watershed Management
Mary Love Tagert and Jeffery A. Ballweber
Box 9652
Mississippi State, MS 39762
mltagert@gri.msstate.edu
Abstract. The Clean Water Act (CWA) and Safe Drinking Water Act (SDWA) are the nation’s preeminent legal authority for watershed management. Unfortunately, there is a fundamental conflict between the two Acts. The CWA is basically an environmental statute to protect the physical, chemical and biological aspects of the nation’s waters. Alternatively, Congress enacted the SDWA to protect public health. Water quality is critical for a waterbody to meet both environmental and public health requirements; this common feature of both Acts is environmental. However, the philosophical differences between the two Acts have lead to two separate and distinct measures of water quality. The CWA references Water Quality Standards (WQS) for different pollutants based on a waterbody’s designated use. Alternatively, the SDWA references Maximum Contaminant Levels (MCL) for public water supplies. In the field, the split widens as one agency’s water quality monitoring for WQS may ignore another agency’s interest in MCL. Furthermore, a watershed management plan may be spatially developed and approved to satisfy CWA requirements with little or no attention to the SDWA’s similar Source Water Protection program. This presentation suggests opportunities to overcome these differences, acquire more and usually more timely and accurate site specific water quality data, and develop watershed management plans that explicitly integrate Source Water Protection needs.
A Sample Acquisition Concept for Element Detection in Coal-fired Power Plant Emissions via Laser-Induced Breakdown Spectroscopy
W. Collett, L. Kirby, B. Hesson, and J. Kondracki
Department of Engineering, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY 42101
M. Martin
Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
S. Mahajan
Department of Electrical Engineering, Tennessee Technological University, Cookeville, TN 38505
Abstract. A design course sequence in the electrical engineering curriculum at Western Kentucky University is being employed to introduce several EE students to environmental issues by way of a real-world project of interest to the electric power community. The project goal is to address the need to detect and ultimately quantify the presence of mercury in power plant flue gas emissions. An optical technique known as Laser Induced Breakdown Spectroscopy (LIBS) is being evaluated for this purpose. LIBS makes use of a tightly-focused laser beam to spark, or ablate, a chemical sample in either solid, liquid, or gaseous form. The emitted light is then analyzed by a spectrometer to determine constituent elements. Whereas the technique involved in LIBS has been demonstrated time and again in a variety of applications, the challenge at hand is the integration of the technique to on-line power plant flue gas analysis. Current work involves a sample acquisition means by which flue gas might be collected on a substrate, then subjected to LIBS analysis. Challenges to be addressed include exposing the substrate to the appropriate environment and ensuring sufficient elemental concentration for detection. Initial LIBS results with coal and coal ash, in lieu of flue gas, will be presented. Furthermore, pedagogical issues, such as employing a junior level design course to perform real-world engineering on environmental and other problems, will be discussed.
Keywords: LIBS, mercury, coal, power plant, flue gas, engineering pedagogy
Study on the Inverse Method to Permeability Coefficient of
Groundwater System: A Case Study of Uranium Gangue Site in Southern
China
Shuibo Xie, Yi Hu, Ming Jiang and Qi Liu
Institute of Environment Protection, Nanhua University, Hengyang, Hunan 421001, P. R. China
Abstract. Based on the genetic algorithm (GA) and finite element model for simulating groundwater flow, the inverse modeling for permeability coefficient (PC) of groundwater system in uranium gangue site was discussed, and the result of a case to PC of the uranium gangue site in Southern China was presented. This method could express the characteristic of PC in the research field. Comparing with traditional grads optimization methods, GA has no many deficiencies, which include scan velocity slow as series form along with the coefficients increased, getting into local extremum point easily and errors transfer leading to non-convergence and so on. Moreover its convergence speed was satisfying. So it could be employed to optimize coefficients of modeling for heavy metal contamination transfer in uranium gangue site and simulation.
Keywords: GA, finite element, PC, groundwater, inverse method
Sustainability in Higher Education
Travis Kelly Wilson
Assistant Professor
Consumer and Family Sciences
Western Kentucky University
Abstract. The development of modular and prefabricated construction methods has gained popularity among many in the design professions. These processes use a selection of materials of the highest quality which in turn leads to expensive construction. Over the past 5 years, I have developed methods of modular construction that benefits low cost housing. Many of the experimental modules used recycled materials from 1880 church’s to tornado damaged structures. The construction methods are similar, but the use of reclaimed wood and steel provides a lower cost structure with minimal compromise in quality. Several German designers attempted recycled construction using concrete from Soviet housing demolition. However, the cost of transportation and equipment needed far outweighed the traditional methods of construction. The cost benefit ratio was not viable. In the US, housing construction is predominantly wood construction. Materials are small products when dissembled and easily reworked. The US construction industry is focused on new and not reuse construction. There are many structures being burned and razed that could provide materials for low cost housing. This modular construction method’s viability is based on renewable recycled materials.