2017 Seminars

 

A method for rapidly measuring equilibrium partition coefficients for SVOCs sorbed to clothing

Azin Eftekhari
Ph.D. student

Civil, Architectural & Environmental Engineering
Missouri University of Science and Technology

3:30 PM
Friday May 5, 2017
Room 121 Butler-Carlton Hall
Missouri University of Science and Technology

Abstract:
Semi-volatile organic compounds (SVOCs) as an important class of indoor pollutants are of great health concern. They can be found in a variety of consumer products used indoors. They can enter the human body through ingestion, inhalation and dermal uptake. Recently, dermal uptake from clothing has been shown to be an important contributor to the body burden of some phthalate esters. The cloth-air partition coefficient, Kcloth-air, is a key parameter in estimating dermal uptake from clothing. The partition coefficient is defined at the equilibrium concentration in the fabric divided by the air concentration. Since semi-volatile organic compounds partition very slowly to fabrics, measurements of equilibrium partition coefficients can take many days or months; therefore a method that reduces the time to reach equilibrium is needed for efficient experimental work. In this research, we demonstrated that the partition coefficient, , can be measured very rapidly using the headspace analysis of vials containing cloth with a known area dosed with a known mass of the two SVOC’s considered in this study, diethyl phthalate (DEP) and di-n-butyl phthalate (DnBP). The known mass of SVOCs were applied to the cloth in an appropriate volatile solvent carrier and after evaporation of solvent, the cloth was placed in a 20 ml headspace vial and allowed to equilibrate with the air in the vial. Since the volume of headspace air is small, the total mass required to transfer from cloth to air is small and also the time required is very short (a few minutes). The, partition coefficients for the two phthalate esters, DEP and DnBP, and jean (cotton) were measured at two temperatures of . We found  and  for DEP and  and  for DnBP at , respectively (). These results neatly bound values generated at 25ºC using other, more time consuming methods. This proof of concept for two phthalates suggests that the partition coefficients can be rapidly measured for many compounds, simultaneously for many fabric types.

Biography:
Azin Eftekhari is a PhD student in Dr. Glenn Morrison’s research group in the department of Environmental Engineering at Missouri University of Science & Technology. She received her bachelor’s and master’s in Chemical Engineering in Azad University of North Tehran Branch in 2007 and 2010. Her first interaction with environmental engineering happened when she started her first job in industrial waste water treatment plant and then she became familiar to air pollution researches mainly by starting her job in MATN Research Institute that they studied all environmental pollution effects of 20 power plants in Iran. She joined to Dr. Morrison’s research group on Fall 2015. She has been working on Semi Volatile Organic Compounds and their partitioning with materials present in buildings.


Occurrence and Control of Cyanobacteria and Their Toxins in Water Treatment

Craig Adams, PhD, PE, F.ASCE
Oliver L. Parks Endowed Chair & Professor
Dept. of Civil Engineering
St. Louis University

3:30 PM
Friday April 28, 2017
Room 121 Butler-Carlton Hall
Missouri University of Science and Technology

Abstract:
Controlling cyanotoxins from hazardous algal blooms (HAB) is a significant and increasing challenge for drinking water utilities in Missouri and throughout the nation. The U.S. Environmental Protection Agency promulgated in 2015 new health advisories for microcystins and cylindrospermopsin of 0.3 and 0.7 µg/L, respectively, for infants. Controlling these cyanotoxins as well anatoxin a and saxitoxin, can be complex due to complicating factors. For example, cyanotoxins can enter a water treatment plant in either the intracellular form (within a cyanobacteria) or extracellular form (in the water phase). Oxidation of cyanobacteria with chlorine, ozone and permanganate at the intake or anywhere prior to filtration all can cause the release of these intracellular toxins. A further complication to treatment strategies includes that certain oxidant/cyanotoxin combinations achieve rapid toxin removal for other combinations are very slow. The purpose of this talk is to present critical issues and tools (including the AWWA model Hazen-Adams CyanoTOX Ver. 2) for dealing with HABs and their associated toxins.

Bio:
Dr. Adams is the Oliver Parks Professor of Engineering in the Department of Civil Engineering at Saint Louis University. He is a Fellow of ASCE and a registered professional engineer. Dr. Adams conducts research in the Water Quality and Treatment Laboratory at SLU on the oxidation and sorption processes for drinking water contaminants (including pharmaceuticals, cyanotoxins, taste-and-odor compounds, disinfection byproducts, andother compounds). His research group uses a fundamental approach to address water quality and treatment issues to develop actionable guidance for utilities in Missouri and beyond. His group also focuses on developing point-of-use treatment technology for use in developing nations. Dr. Adams is active in AWWA and other professional organizations.


Prediction of Magnesite Dissolution Rate in Heterogeneous Porous Media using Deep Learning

Peyman Heidari, Ph.D.
Assistant Professor
Petroleum Engineering
Department of Geosciences and Geological and Petroleum Engineering

Missouri University of Science and Technology

3:30 PM
Friday April 14, 2017
Room 121 Butler-Carlton Hall
Missouri University of Science and Technology

Abstract: 
Physical and chemical heterogeneity can significantly affect the dissolution rate of minerals in the subsurface. Two-dimensional representations of porous media were generated using statistical parameters that represent the spatial distribution of mineral. Magnesite dissolution was simulated using reactive transport modeling under various hydrogeochemical conditions. Different realizations of the porous media were generated using mineral abundance, major and minor direction anisotropies. Different permeability ratios and inlet pH were considered during the simulations.  A total of 3257 simulations were carried out. The most significant variable that changed dissolution rate, porosity and concentration of Mg2+ was permeability ratio followed by major direction anisotropy and inlet pH. More homogeneous spatial distributions have smaller anisotropy values. A more homogeneous distribution will result in higher breakthrough concentration of Mg2+ and higher porosity change. At the end, deep learning was used to predict porosity change (reaction rate) based on statistical and hydrogeochemical parameters regardless of the underlying spatial distribution of minerals. Lasso regression was used to select features that were included in the deep learning training. The model was trained using 80% of the data and was tested with the rest. Deep learning captured 89.0% of the variance in the test data, while a linear regression model captured only 73.2% of the variance.


The Nature of Particulate Matter Emissions from Aerospace Sources.
The work of the MS&T COE in CREE

Philip Whitefield, Ph.D.
Professor of Chemistry
Director of CREE
Chairman-Dept. of Chemistry
Missouri University of Science and Technology

3:30 PM
Friday April 21, 2017
Room 121 Butler-Carlton Hall
Missouri University of Science and Technology

Abstract:
The presentation will focus on developing a regulatory certification method out of several research techniques for fundamental PM characterization.  First the research techniques will be described and examples of their application for local air quality impact and for sustainable (alternative) jet fuel emissions characterization studies will be presented.  Second   a reference standard measurement system for emissions certification purposes, based on the research techniques, will be described and its performance assessed.

Bio:
Dr. Philip Whitefield received his BSc and PhD degrees from the University of London, England.  He is a Professor of Chemistry and Director of the Missouri S&T Center for Research in Energy and Environment.  He is also Chairman of the Department of Chemistry at Missouri S&T. Dr. Whitefield is Lead Scientist for Emissions Characterization related projects in ASCENT, the FAA Center of Excellence for Alternative Jet Fuels and Environment. He is a member of Society of Automotive Engineers E-31 committee on aircraft engine exhaust emissions measurements.  Dr. Whitefield has 28 years’ experience in aerospace-related emissions research focusing on the development and application of novel techniques for future recommended standard measurement practices and the measurement and interpretation of aerospace emissions data with aparticularemphasis in particulate matter (PM) characterization and quantification.


Cyanobacteria (Blue-Green Algae)and Related Cyanotoxins Control in Drinking Water Treatment Systems

Haiting Zhang
Doctoral Student

Chemistry Department
Missouri University of Science and Technology

3:30 PM
Friday March 24, 2017
Room 121 Butler-Carlton Hall
Missouri University of Science and Technology

Abstract: 
Algal blooms are increasing problems worldwide and have been observed in the Midwest area of the USA which has increased concern for many drinking water treatment facilities because the blooms cause taste and odor issues and, more importantly, the harmful algal blooms produce algal toxins (cyanotoxins). Microcystins, especially microcystin-LR (MC-LR) and cylindrospermopsin (CYN) are the most common species primarily produced by microcystis aeruginosa and cylindrospermopsis raciborskii. My research focuses on these cyanobacteria and cyanotoxin occurrence screening and bloom control in drinking water system. An ultra-fast liquid chromatography tandem mass spectrometry method was optimized and validated to monitor cyanotoxin in water. The harmful algae species were cultured, introduced into the water samples collected from source water of drinking water systems, and then treated with various disinfectants. Intracellular and extracellular cyanotoxins were monitored to evaluate the efficiencies of cell lysis and toxin destruction. The result demonstrated that low dosage of chlorine with no measureable free chlorine exposure can cause the majority of intracellular toxin to be released from the cyanobacterial cells with little destruction of the total toxin present. Increasing oxidant exposure was shown to cause increased rates for toxin release from cells. The released cyanotoxins can be degraded by high concentration of free chlorine, but not chloramine and peracetic acid. Permanganate affects differently on different cyanobacteria and toxins. These results are important in the developing treatment strategies for water utilities that must continue preoxidation to achieve disinfection and other simultaneous objective during HAB bloom.

Biography:  Haiting Zhang is a senior doctoral student in Dr. Honglan Shi’s research group in the department of Chemistry at Missouri S&T. She received a Master degree in environmental engineering in 2014 from Chinese Academy of Science, China, and published two papers about disinfection byproducts in seawater during that time. Now, her research fields mainly focus on drinking water analysis and improving drinking water quality. Specific areas include cyanobacteria and related cyanotoxins monitoring and control, synergetic effect of nanoparticles and algaecide on control of algal bloom, Drinking water taste and odor source identification and control. She is working closely with water treatment facilities in Missouri to solve their real drinking problems.


Permeable Reactive Concrete

Megan Hart, Ph.D.
Assistant Professor
Civil and Mechanical Engineering
University of Missouri-Kansas City

3:30 PM
Friday March 3, 2017
Room 121 Butler-Carlton Hall
Missouri University of Science and Technology

Abstract:
Reactive materials are a well-known remedial method for stormwater in which industrialized reactive media such as zero-valent iron and activated carbon treat a specific compound. Permeable reactive concrete (PRC) is an alternative reactive medium composed of relatively inexpensive materials such as cement, aggregate, and other agents. A variety of multimodal, simultaneous processes drive remediation of metals, PFAs, nutrients and other contaminants from solution within PRC. Driving mechanisms and rates of removal are due to the complex heterogeneous matrix formed during concrete hydration. This webinar will address how the combinations of aggregate, portland cement, fly ash, additives, and combinations thereof have on the removal of lead, cadmium, zinc, bromate, phosphate, nitrate and others from stormwater. Absorption, adsorption, precipitation, co-precipitation, and internal diffusion are the versatile mechanisms of removal in the matrix. Local aggregates can be used as the coarse component with high removal of metals, however calcareous sources of aggregate are preferred due to improved metals removal. PRC can pass TCLP and LEAF leachability tests for all known contaminants tested and process designs can mitigate chromate leaching and the impact of pH on the discharge effluent. PRC results are comparable to metals removal by activated carbon and are significantly cheaper in a site specific treatment plan.

Biography:
Megan Hart is a nationally recognized expert on environmental geotechnical processes and in-situ remediation techniques and Missouri Registered Geologist. She holds B.S. in Geology from Western Washington University with a minor in chemistry. She holds B.S., M.S. and Ph.D. degrees from Missouri University of Science and Technology in Geological Engineering with graduate work focusing on natural and engineered semi-permeable barrier processes and technology.  Dr. Hart worked as an environmental engineer for the Missouri Department of Natural Resources working in the areas of hazardous waste, groundwater analysis, and water and wastewater treatment and joined the faculty of Saint Louis University in June, 2010 in the department of Civil Engineering and in 2012, she joined the faculty at the University of Missouri – Kansas City. She is currently working on soil stabilization techniques using in-situ streaming potential of clay materials and a passive treatment system for levee stabilization of earthen cores.  Previously Dr. Hart’s clay research led to the creation of passive filter process technics that provide clean drinking water for developing worlds.


St. Louis County Bacteria TMDLS: Creve Coeur, Coldwater, Fishpot, and Watkins Creeks

Jay Hoskins, P.E.
Metropolitan St. Louis Sewer District

Engineering Department – Environmental Compliance

3:30 PM
Friday February 10, 2017
Room 121 Butler-Carlton Hall
Missouri University of Science and Technology

Abstract:
A total maximum daily load, or TMDL, is a "pollutant diet plan" for improving water quality. TMDLs are important to permit holders because they influence permit requirements that they must follow. On July 13, 2016, EPA approved four (E. Coli) bacteria TMDLs for waters in the MSD: Creve Coeur Creek, Fishpot Creek, Watkins Creek, and Coldwater Creek. These are the first approved TMDLs on waters located in the District, but they will not be the last. 

This presentation will review the approach Missouri DNR used to develop these first TMDLs, which have several important provisions. They allocate the allowable waste load (i.e., calories) to the stormwater system, yet recognize the work that MSD is doing to address sewer overflows as the primary activity that will reduce bacteria levels. Regarding stormwater load reduction, the TMDLs state that they will be implemented in MS4 permits by iterative use of best practices (and not end-of-pipe effluent limits). Together, this provides the St. Louis region an opportunity to leverage the investments in sanitary sewer system infrastructure with a sustainable framework for additional stormwater load reductions, all of which improves water quality.

Biography:
Jay Hoskins is Program Manager of Environmental Compliance Programs at the Metropolitan St. Louis Sewer District (MSD). Jay manages the teams that track compliance with a broad range of environmental issues, including the St. Louis region’s MS4 permit, MSD’s wastewater treatment plant operating permits, and MSD’s Title V air permits. He has a BS in Civil Engineering from the Missouri University of Science & Technology (1999), and a MS in Environmental Engineering & Science from Clemson University (2001). (And Jay enjoys fly fishing for trout and smallmouth bass.)


Indoor air chemistry with window-opening behavior

Arun Kumar Reddy Loka, Ph.D.
Post-Doctoral Fellow

Civil, Architectural and Environmental Engineering
Missouri University of Science and Technology

3:30 PM
Friday January 27, 2017
Room 121 Butler-Carlton Hall
Missouri University of Science and Technology

Abstract:
People spend most of their time indoors and therefore the largest share of VOC exposure often results from the indoor environment. VOCs are released by a wide array of sources within the home (e.g., household products, building materials) and also migrate indoors from outdoor sources (e.g., industrial and mobile sources) and therefore, concentrations of many VOCs are consistently higher indoors (up to ten times higher) than outdoors. The impact of infiltration, indoor sources, chemistry and other phenomena are strongly dependent on building factors, especially exchange of air from outdoors to indoors. Air exchange is particularly variable where windows are frequently open. In general, higher ventilation rates reduce the concentration of indoor sources pollutants and increase the concentration of outdoor photochemical pollutants. Indoor chemical reactions between oxidizing compounds such as ozone and other common indoor compounds like terpenes and cooking oils, which are easily oxidized in air or on the surfaces of carpets,  form formaldehyde, acrolein, peroxides and other oxidized VOCs. This study is aimed at determining the impact of window opening on ozone and VOC concentrations inside and outside a residence. Observed changes in reactants (pinene and limonene) and reaction products (carbonyl compounds) were consistent with increased oxidation chemistry occurring with greater window opening and greater photochemical oxidant infiltration.

Biography:
I Dr. Arun Kumar Reddy Loka am a Postdoc fellow in Dr. Glenn Morrison’s research group in the department of Civil, Architectural and Environmental Engineering at Missouri S&T. I earned M.Sc. in Analytical chemistry from Osmania University, Hyderabad- India, and Ph.D. in Environmental chemistry (2013) from Osmania University, Hyderabad- India. My research interests include chemical composition of aerosols, chemistry of indoor air pollution. I worked two years as a Research Fellow on Long range transport of aerosols project at National institute of Environmental Research south korea.1 year as a faculty at Technology de Monterrey, Mexico.