Archives: Monthly Archives: May 2016
Engineering Centennial Lecture Series: Micobial Ecology and Metabolic Pathways of the Re-engineered Nitrogen Cycle
Engineering Centennial Lecture Series
Friday, April 29, 2016 • 11:15AM – 12PM • CAST 212
Micobial Ecology and Metabolic Pathways of the Re-engineered Nitrogen Cycle
Dr. Kartik Chandran
Assoc. Professor, Dept. of Earth and Environmental Engineering, Columbia University
Abstract: Engineered wastewater treatment systems can provide an interesting framework to pose and answer questions relating to the structure and metabolic function of the microbes involved in the nitrogen cycle. While the traditional approach to wastewater treatment has involved nitrification and denitrification using wastewater organic carbon, increasingly stringent effluent limits coupled with the need for energy efficiency have given rise to approaches such as partial nitrification and nitritation followed by either denitrification using external organic electron donors or even autotrophic nitrogen removal via anaerobic ammonia oxidation. These developments have resulted in a drastically different version of the engineered N-cycle in advanced wastewater treatment systems, with increased acknowledgment of both aqueous and gaseous nitrogenous discharges. In this presentation, some recent findings related to the impact of engineering strategies on the microbial ecology, metabolic pathways and community genomics of nitrification, denitrification and anammox based wastewater treatment systems are presented.
Bio: A 2015 MacArthur Fellow, Kartik Chandran leads the Columbia University Biomolecular Environmental Science program and the Wastewater Treatment and Climate Change program. Under his stewardship, the research directions of biological wastewater treatment and biological nitrogen removal were established for the first time ever in the history of Columbia University. Dr. Chandran is keenly interested in developing novel models for sustainable sanitation and wastewater treatment, with a specific focus on managing the global nitrogen cycle and linking it to the carbon cycle, the food cycle, the water cycle and the energy cycle. Dr. Chandran is a 2016 UConn Engineering Academy of Distinguished Engineers inductee.
CEE & ENVE COLLOQUIUM SERIES: Understanding the Information Embedded in Observations and Regional Air Quality Model Outputs
ENVIRONMENTAL ENGINEERING SPRING 2016 COLLOQUIUM SERIES
Friday, April 22, 2016 • 12:15 PM • CAST 212
Understanding the Information Embedded in Observations and Regional Air Quality Model Outputs
Huiying Luo
Ph.D. Candidate, Environmental Engineering Program, University of Connecticut
Abstract: In the United States (U.S.), regional scale air quality models are being used to determine the emission reductions needed to comply with the national ambient air quality standards (NAAQS). The uncertainties associated with deterministic air quality model predictions have been researched by many scientists in the past, yet the biases and errors in the predicted air pollutant concentrations are still not negligible. The different timescales captured by modeled values and observations (intraday, synoptic, baseline) is one manifestation of the problem that could result in an uncertain estimate of the efficiency of the envisioned emission control strategies. In this work, we use air quality model simulations and observations from the Environmental Protection Agency (EPA) that span a 21-year long period (1990-2010) to assess the distinguishable scales of variations in pollutant concentration time series for both model and observed ozone concentrations. The Kolmogorov-Zurbenko (KZ) filtering technique is used to separate different scales imbedded in time series of observed and simulated ozone concentrations. Preliminary results for the NE U.S. have shown that the model is more skillful in representing the changes in the concentrations rather than the absolute values (exceedances). In this presentation, we will present the applied technique and the first results for NE U.S.
CEE & ENVE COLLOQUIUM SERIES: Trace Element Bioaccumulation and Trophic Transfer at the Base of Aquatic Food Webs
ENVIRONMENTAL ENGINEERING SPRING 2016 COLLOQUIUM SERIES
Friday, April 15, 2016 • 12:15 PM • CAST 212
Trace Element Bioaccumulation and Trophic Transfer at the Base of Aquatic Food Webs
David Buchwalter
Associate Professor, Department of Biological Sciences, North Carolina State University
Abstract: Many human activities result in trace element contamination in aquatic ecosystems. Water quality criteria (WQC) designed to protect aquatic ecosystems from trace element toxicity are typically based on toxicity tests in which only direct exposure through water is evaluated, while dietary exposure pathways are ignored. Moreover, the species that often dominate freshwater ecosystems (aquatic insects) are generally under-represented in lab based toxicity tests, creating a disconnect between different aspects of the Clean Water Act (the setting of WQC and biomonitoring programs designed to evaluate biological integrity). This seminar will give an overview of research efforts in the Buchwalter lab to better understand trace element bioaccumulation and trophic transfer in a test system utilizing natural periphyton assemblages and a lab-reared mayfly. The seminar will focus on trace elements (arsenic and selenium) associated with coal ash and discuss issues associated with the wet storage of coal combustion products.
CEE & ENVE COLLOQUIUM SERIES: Ecophysiological Controls and Precipitation Seasonality in Amazonia
ENVIRONMENTAL ENGINEERING SPRING 2016 COLLOQUIUM SERIES
Friday, April 8, 2016 • 12:15 PM • CAST 212
Ecophysiological Controls and Precipitation Seasonality in Amazonia
Jung-Eun Lee
Assistant Professor of Earth, Environmental and Planetary Sciences, Brown University
Abstract: It is unclear to what extent seasonal water stress impacts on plant productivity over Amazonia. Using new Greenhouse gases Observing SATellite (GOSAT) satellite measurements of sun-induced chlorophyll fluorescence, we show that midday fluorescence varies with water availability, both of which decrease in the dry season over Amazonian regions with substantial dry season length, suggesting a parallel decrease in gross primary production (GPP). Using additional SeaWinds Scatterometer onboard QuikSCAT satellite measurements of canopy water content, we found a concomitant decrease in daily storage of canopy water content within branches and leaves during the dry season, sup- porting our conclusion. The strong relationship between GOSAT and model fluorescence (r2 = 0.79) was obtained using a fixed leaf area index, indicating that GPP changes are more related to environmental conditions than chlorophyll contents over tropical evergreen forests. We have also incorporated equations coupling SIF to photosynthesis in a land surface model, the National Center for Atmospheric Research Community Land Model version 4 (NCAR CLM4) to use it as a diagnostic tool for evaluating the calculation of photosynthesis.
CEE & ENVE COLLOQUIUM SERIES: Removal of Neutral and Ionic Organic Contaminants by Polymeric Resins – Predictive Modeling and Catalytic Reduction
ENVIRONMENTAL ENGINEERING SPRING 2016 COLLOQUIUM SERIES
Friday, April 1, 2016 • 12:15 PM • CAST 212
Removal of Neutral and Ionic Organic Contaminants by Polymeric Resins – Predictive Modeling and Catalytic Reduction
Huichun (Judy) Zhang, Ph.D.
Assistant Professor, Department of Civil and Environmental Engineering, Temple University
Abstract: Emerging organic contaminants are a growing concern for water treatment as their presence in the environment continues to grow. The focus of this work was to develop technologies to selectively remove neutral and ionic organic contaminants from water using polymeric resins. Three neutral resins (MN200, XAD-4, and XAD-7), three anion exchange resins (Amberlite IRA-910 and IRA-96, and Purolite A860), and two cation exchange resins (Amberlite 200 and MN500) were examined for the removal mechanisms of various neutral and ionic organic contaminants. The sorption isotherms demonstrated that the ion exchange resins have affinity for compounds in the following order: aromatic ions > aliphatic ions > neutral compounds. This preference is due to the differences in non-electrostatic interactions of the compounds such as their H-bonding capability, affinity for Van der Waals and p-p interactions, and the size of the molecular cavity in solution. Resins’ ion exchange capacity and hydrophilicity are mainly responsible for the observed different sorption behavior of various resins. With the above findings and the development of poly-parameter linear free-energy relationships (pp-LFERs), predictive models were developed to accurately estimate the sorption of various compounds onto all the resins under changing pH conditions. Moreover, predictive models for adsorption of multi-solute mixtures were successfully developed; novel resin-Pd composite materials were synthesized and optimized to achieve selective removal of contaminants and in-situ regeneration of the spent catalyst.
CEE & ENVE COLLOQUIUM SERIES: Technical Entrepreneurship: A New Paradigm in Engineering Education
ENVIRONMENTAL ENGINEERING SPRING 2016 COLLOQUIUM SERIES
Friday, March 25, 2016 • 12:15 PM • CAST 212
Technical Entrepreneurship: A New Paradigm in Engineering Education
Christos Christodoulatos
Professor and Vice Provost of Innovation & Entrepreneurship, Stevens Institute of Technology
Abstract: There is a general perception that academic entrepreneurship (AE) and innovation refers mainly to the creation of commercializable output from a university’s intellectual property by creating new ventures also called spin-offs. This perspective is too limited, as the university as a whole can serve as catalyst to the output; therefore, a holistic culture has to be created to involve and motivate all stakeholders, particularly students, to create innovations. Thus, academic entrepreneurship is conceived to span across research and education. Implementation of basic principles of innovation and entrepreneurship in a university setting will be discussed along with challenges, opportunities, required resources and commitment from key stakeholders. It is widely recognized that it is not possible to implement AE successfully if it operates outside the academic structure. Furthermore, institutionalization of AE through proper policies and processes built into the university’s governance structure is the fastest and most efficient way to affect cultural change and gain acceptance of AE by all stakeholders.
CEE & ENVE COLLOQUIUM SERIES: Surfactant Enhanced In-Situ Chemical Oxidation for Soil and Groundwater Remediation
ENVIRONMENTAL ENGINEERING SPRING 2016 COLLOQUIUM SERIES
Friday, March 4, 2016 • 12:15 PM • CAST 212
Surfactant Enhanced In-Situ Chemical Oxidation for Soil and Groundwater Remediation
Geeta Dahal
EthicalChem
Abstract: During In situ chemical oxidation (ISCO) oxidant solutions are typically delivered into the subsurface for contaminant destruction. Contaminants available to the oxidants, however, are limited by the mass transfer of hydrophobic contaminants into the aqueous phase. ISCO treatments therefore often leave sites with temporarily clean groundwater which is subject to contaminant rebound when sorbed and free phase contaminants leach back into the aqueous phase. Using a combined oxidant-surfactant solution, contaminant delivery to the oxidants can be optimized via desorption and emulsification of the contaminants by the surfactants. EthicalChem’s patented Surfactant Enhanced Product Recovery (SEPRTM) and Surfactant-enhanced In Situ Chemical oxidation (S-ISCO®) are green-chemistry technologies developed to address the source of contamination and effectively treat sorbed, hydrophobic, and free phase contaminants. SEPR is implemented for bulk NAPL (Non-Aqueous Phase Liquid) removal by extraction, where surfactants are injected with low doses of hydrogen peroxide. S-ISCO implementation addresses residual NAPL and soil sorbed contamination by significantly enhancing contaminant contact with the oxidant. This presentation will provide an overview of the SEPR and S-ISCO technologies, followed by an implementation case studies at a coal tar contaminated site in Queens, New York and a creosote site in Delaware.
CEE & ENVE COLLOQUIUM SERIES: Integrating Ecosystem Engineering into Ecological Restoration
ENVIRONMENTAL ENGINEERING SPRING 2016 COLLOQUIUM SERIES
Friday, March 11, 2016 • 12:15 PM • CAST 212
Integrating Ecosystem Engineering into Ecological Restoration
Beth Lawrence
Assistant Professor, Natural Resources and the Environment, University of Connecticut
Abstract:Ecosystem engineers are organisms whose presence or activity alters their physical surroundings or changes the flow of resources, thereby creating or modifying habitats. These high leverage species can have desirable or problematic consequences on the structure and function of ecological systems. Dr. Beth Lawrence will highlight how understanding the feedbacks that sustain ecosystem engineers can enhance environmental management, and discuss her research in wetland restoration investigating the carbon dynamics of a tussock forming sedge and a problematic invasive cattail.
CEE & ENVE COLLOQUIUM SERIES: Climate Change Effects on Soils: Molecular and Microscale Reactions and Processes
ENVIRONMENTAL ENGINEERING SPRING 2016 COLLOQUIUM SERIES
Friday, February 26, 2016 • 12:15 PM • CAST 212
Climate Change Effects on Soils: Molecular and Microscale Reactions and Processes
Nikolla Qafoqu
Chief Scientist, Earth Science Division, Pacific Northwest National Lab
Abstract: Climate change (i.e., high atmospheric carbon dioxide (CO2) concentrations (1400 ppm); increasing air temperatures (2–4 °C or greater); significant and/or abrupt changes in daily, seasonal, and interannual temperature; changes in the wet/dry cycles; intensive rainfall and/or heavy storms; extended periods of drought; extreme frost; heat waves and increased fire frequency) is and will significantly affect soil properties and fertility, water resources, food quantity and quality, and environmental quality. Biotic processes that consume atmospheric CO2 and create organic carbon (C) that is either reprocessed to CO2 or stored in soils, are the subject of active current investigations with great concern over the influence of climate change. In addition, abiotic C cycling and its influence on the inorganic C pool in soils is a fundamental global process in which acidic atmospheric CO2 participates in the weathering of carbonate and silicate minerals, ultimately delivering bicarbonate and Ca2+ or other cations that precipitate in the form of carbonates in soils or are transported to the rivers, lakes, and oceans. Soil responses to climate change will be complex, and there are many uncertainties and unresolved issues. The objective of the presentation is to initiate and further stimulate a discussion about some important and challenging aspects of climate-change effects on soils, such as accelerated weathering of soil minerals and resulting C and elemental fluxes in and out of soils, soil/geo-engineering methods used to increase C sequestration in soils, soil organic matter (SOM) protection, transformation and mineralization, and SOM temperature sensitivity. This presentation will also discuss recent research effort and identifies key research needs required to understand the effects of climate change on soils.
CEE & ENVE COLLOQUIUM SERIES: Mercury Redox Transformations in Groundwater
ENVIRONMENTAL ENGINEERING SPRING 2016 COLLOQUIUM SERIES
Friday, February 19, 2016 • 12:15 PM • CAST 212
Mercury Redox Transformations in Groundwater
Nathan Yee
Associate Professor, Department of Environmental Sciences, Earth and Planetary Sciences, Rutgers University
Abstract: The disposal of mercury (Hg) containing wastes has contaminated large areas of sediment and groundwater in the United States. When released into the environment, Hg undergoes redox transformations that strongly affect its solubility and sorption characteristics. Dissolved gaseous elemental mercury [Hg(0)] is mobile in groundwater, while oxidized ionic mercury [Hg(II)] readily sorbs onto mineral surfaces and natural organic matter. Furthermore, Hg(II) is the substrate for methylation and uptake of Hg(II) by anaerobic methylating bacteria leads to the production of neurotoxic methylmercury [MeHg]. Critical to predicting the impacts of subsurface Hg contamination is a mechanistic understanding of the biogeochemical processes that control mercury reduction and methylation along hydrological flow paths. In this presentation, I will discuss our research on Hg reduction and oxidation in groundwater. I will describe our recent discovery of a new pathway in the subsurface mercury cycle, whereby neurotoxic methylmercury is formed from dissolved elemental mercury by anaerobic bacteria.
Currently the redox interactions between Hg(0) and microbial biomass are poorly understood. In this study, we conducted laboratory experiments to determine if subsurface microorganisms can oxidize Hg(0) to Hg(II) under anoxic conditions.
