Open Access. Powered by Scholars. Published by Universities.®

Civil and Environmental Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Marquette University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 181 - 210 of 440

Full-Text Articles in Civil and Environmental Engineering

Semicoupled Modeling Of Interaction Between Deformable Tires And Pavements, Jaime Hernandez, Imad L. Al-Qadi Apr 2017

Semicoupled Modeling Of Interaction Between Deformable Tires And Pavements, Jaime Hernandez, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

The interaction between deformable tires and pavements was studied using finite-element modeling and a semicoupled approach. Three finite-element models were used: (1) a hyperelastic tire rolling on an infinitely rigid surface; (2) a three-dimensional pavement model; and (3) a hyperelastic tire rolling on a deformable viscoelastic body. The tire and pavement models have been successfully compared with experimental measurements. Tire interaction with a rigid surface provided contact stresses to excite the pavement model, and results of the pavement model defined the boundary conditions of the tire rolling on the deformable body. After that, the pavement loaded with the contact stresses …

Go to article

Evaluating The Bond Behavior Between Frp And Grooved Concrete Specimens Using Single Shear Pull Out Test, John Omboko Apr 2017

Evaluating The Bond Behavior Between Frp And Grooved Concrete Specimens Using Single Shear Pull Out Test, John Omboko

Master's Theses (2009 -)

Surface preparation affects the bond behavior between Fiber Reinforcing Polymer (FRP) composite material and concrete. In this research, a special type of surface preparation known as grooving, which involves cutting transverse grooves, is conducted on concrete blocks (specimens) that are categorized as either Unfilled (U) or Filled (F). This idea is to ascertain how the grooves affect the strength of FRP-bonded-concrete specimen. These two categories are then benchmarked to control (C) specimens which do not have grooves on them. Category U specimens only have the epoxy applied on the concrete surface while category F specimens have epoxy applied on both …

Go to article

Biosolids-Derived Biochar For Micropollutant Removal From Wastewater, Lee Kimbell Apr 2017

Biosolids-Derived Biochar For Micropollutant Removal From Wastewater, Lee Kimbell

Master's Theses (2009 -)

Trace organic compounds including antibiotics, hormones, pharmaceuticals and personal care products are discharged to the environment with liquid and solid effluent streams from water resource recovery facilities. These compounds are referred to as micropollutants, and can have negative impacts in receiving waters. Current wastewater treatment processes are not specifically designed to remove micropollutants, and many of these compounds are recalcitrant to conventional treatment technologies. Triclosan (TCS) was selected as a representative micropollutant in this study due to frequent detection in liquid effluents, residual biosolids, and surface waters. Pyrolysis - the thermochemical decomposition of organic matter at elevated temperatures in the …

Go to article

Correlating Methane Production To Microbiota In Anaerobic Digesters Fed Synthetic Wastewater, Kaushik Venkiteshwaran, K. Milferstedt, M. Fujimoto, M. Johnson, Daniel Zitomer Mar 2017

Correlating Methane Production To Microbiota In Anaerobic Digesters Fed Synthetic Wastewater, Kaushik Venkiteshwaran, K. Milferstedt, M. Fujimoto, M. Johnson, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

A quantitative structure activity relationship (QSAR) between relative abundance values and digester methane production rate was developed. For this, 50 triplicate anaerobic digester sets (150 total digesters) were each seeded with different methanogenic biomass samples obtained from full-scale, engineered methanogenic systems. Although all digesters were operated identically for at least 5 solids retention times (SRTs), their quasi steady-state function varied significantly, with average daily methane production rates ranging from 0.09 ± 0.004 to 1 ± 0.05 L-CH4/LR-day (LR = Liter of reactor volume) (average ± standard deviation). Digester microbial community structure was analyzed using more …

Go to article

The Effect Of Plant Water Storage On Water Fluxes Within The Coupled Soil–Plant System, Cheng-Wei Huang, Jean-Christopher Domec, Eric J. Ward, Tomer Duman, Gabriele Manolia, Anthony J. Parolari, Gabriel Katul Feb 2017

The Effect Of Plant Water Storage On Water Fluxes Within The Coupled Soil–Plant System, Cheng-Wei Huang, Jean-Christopher Domec, Eric J. Ward, Tomer Duman, Gabriele Manolia, Anthony J. Parolari, Gabriel Katul

Civil and Environmental Engineering Faculty Research and Publications

In addition to buffering plants from water stress during severe droughts, plant water storage (PWS) alters many features of the spatio-temporal dynamics of water movement in the soil–plant system. How PWS impacts water dynamics and drought resilience is explored using a multi-layer porous media model.

Go to article

Fate And Impacts Of Triclosan, Sulfamethoxazole, And 17Β-Estradiol During Nutrient Recovery Via Ion Exchange And Struvite Precipitation, Yiran Tong, Patrick J. Mcnamara, Brooke K. Mayer Jan 2017

Fate And Impacts Of Triclosan, Sulfamethoxazole, And 17Β-Estradiol During Nutrient Recovery Via Ion Exchange And Struvite Precipitation, Yiran Tong, Patrick J. Mcnamara, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Increasing emphasis on resource recovery from wastewater highlights the importance of capturing valuable products, e.g., nutrients such as nitrogen and phosphorus, while removing contaminants, e.g., organic micropollutants. The objective of this research was to evaluate the fate of the micropollutants triclosan (present as a mixture of neutral and anionic species at neutral pH), 17β-estradiol (neutral at neutral pH), and sulfamethoxazole (anionic at neutral pH) during nutrient recovery using ion exchange-precipitation. Adsorption of the three micropollutants to the phosphate-selective ion exchange resins LayneRT and DOW-HFO-Cu ranged from 54% to 88% in Milli-Q water tests and 50% to 71% in …

Go to article

Curriculum Innovation: Incorporating The Kern Engineering Entrepreneurial Network (Keen) Framework Into Online Discussions, Lisa Bosman, Brooke K. Mayer, Patrick J. Mcnamara Jan 2017

Curriculum Innovation: Incorporating The Kern Engineering Entrepreneurial Network (Keen) Framework Into Online Discussions, Lisa Bosman, Brooke K. Mayer, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

The purpose of this study was to respond to the following research question: How does the Kern Engineering Entrepreneurial Network (KEEN) framework build interest in technical topic areas, impact student learning outcomes, and develop the entrepreneurial mindset when applied to the engineering classroom? The KEEN framework was developed to combine the entrepreneurial mindset with engineering education to produce a more valuable, strategically prepared engineer, rather than simply an “obedient engineer”. The framework proposes that the entrepreneurial mindset of students is increased by promoting curiosity, encouraging connections, and creating value. The results from this work provide insight into the impact and …

Go to article

Virtual Reality Of Earthquake Ground Motions For Emergency Response, Ting Lin Jan 2017

Virtual Reality Of Earthquake Ground Motions For Emergency Response, Ting Lin

Civil and Environmental Engineering Faculty Research and Publications

Ground motions interface earthquake science and engineering to advance understanding of seismic hazards and risk. Virtual reality provides an attractive tool to extend knowledge of the research community to a larger audience. This work visualizes emergency response under extreme motions, in the CAVE of the MARquette Visualization Laboratory. The visualization (a) displays ground motions (from the science community), (b) inputs these motions to structural models (from the engineering community) and illustrates the resulting responses, (c) translates structural responses to damage states of building elements, (d) creates a virtual room subjected to the perception associated with such earthquake shaking, and (e) …

Go to article

Editorial" Fibre Reinforced Polymer Composites For Structural Applications In Construction, Jun Deng, Marcus M.K. Lee, Baolin Wan, Giuseppina Amato Jan 2017

Editorial" Fibre Reinforced Polymer Composites For Structural Applications In Construction, Jun Deng, Marcus M.K. Lee, Baolin Wan, Giuseppina Amato

Civil and Environmental Engineering Faculty Research and Publications

No abstract provided.

Go to article

Baseline Rolling Resistance For Tires’ On-Road Fuel Efficiency Using Finite Element Modeling, Jaime Hernandez, Imad L. Al-Qadi, Hasan Ozer Jan 2017

Baseline Rolling Resistance For Tires’ On-Road Fuel Efficiency Using Finite Element Modeling, Jaime Hernandez, Imad L. Al-Qadi, Hasan Ozer

Civil and Environmental Engineering Faculty Research and Publications

Calculation of truck tires rolling resistance, using the finite element method and considering variables such as incompressible visco-hyperelastic rubber materials, accurate tire geometry and steady temperature distribution, is presented. The model was validated using experimentally measured contact area and contact stresses. Rolling resistance was calculated for three values of axle load, tire inflation pressure, temperature and speed. In addition, regression analysis was used to propose a mathematical expression for predicting rolling resistance as a function of the considered variables. Finally, the contribution of tire’s rubber components to the internal energy was quantified, and it was found that sidewall and subtread …

Go to article

Autocatalytic Pyrolysis Of Wastewater Biosolids For Product Upgrading, Zhongzhe Liu, Patrick J. Mcnamara, Daniel Zitomer Jan 2017

Autocatalytic Pyrolysis Of Wastewater Biosolids For Product Upgrading, Zhongzhe Liu, Patrick J. Mcnamara, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

The main goals for sustainable water resource recovery include maximizing energy generation, minimizing adverse environmental impacts, and recovering beneficial resources. Wastewater biosolids pyrolysis is a promising technology that could help facilities reach these goals because it produces biochar that is a valuable soil amendment as well as bio-oil and pyrolysis gas (py-gas) that can be used for energy. The raw bio-oil, however, is corrosive; therefore, employing it as fuel is challenging using standard equipment. A novel pyrolysis process using wastewater biosolids-derived biochar (WB-biochar) as a catalyst was investigated to decrease bio-oil and increase py-gas yield for easier energy recovery. WB-biochar …

Go to article

Tire-Pavement Interaction Modeling: Hyperelastic Tire And Elastic Pavement, Jaime Hernandez, Imad L. Al-Qadi Jan 2017

Tire-Pavement Interaction Modeling: Hyperelastic Tire And Elastic Pavement, Jaime Hernandez, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

The interaction between deformable tire and pavement was studied using the validated finite element model; the full understanding of tire–pavement contact has implications for pavement damage prediction and pavement life-cycle assessment (fuel consumption estimation). The tire’s rubber and reinforcement were considered hyperelastic and linear elastic, respectively, with material constants obtained from the tire manufacturer (rubber) and laboratory testing (reinforcement). On the other hand, the pavement was assumed linear elastic supported by linear elastic springs. This assumption was made as a first step to examine the impact of using a deformable-on-deformable tire–pavement system to predict energy in the tire and contact …

Go to article

Triclosan: An Instructive Tale, Patrick J. Mcnamara, Stuart B. Levy Dec 2016

Triclosan: An Instructive Tale, Patrick J. Mcnamara, Stuart B. Levy

Civil and Environmental Engineering Faculty Research and Publications

The Food and Drug Administration (FDA) recently released a final rule to ban triclosan and 18 other antimicrobial chemicals from soaps. We applaud this rule specifically because of the associated risks that triclosan poses to the spread of antibiotic resistance throughout the environment. This persistent chemical constantly stresses bacteria to adapt, and behavior that promotes antibiotic resistance needs to be stopped immediately when the benefits are null.

Go to article

Contact Phenomenon Of Free-Rolling Wide-Base Tires: Effect Of Speed And Temperature, Jaime Hernandez, Imad L. Al-Qadi Dec 2016

Contact Phenomenon Of Free-Rolling Wide-Base Tires: Effect Of Speed And Temperature, Jaime Hernandez, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

The finite-element method was used to quantify the effect of temperature and speed on contact area, deflection, and three-dimensional contact stresses of a free-rolling wide-base tire. The tire model comprised material properties identified in the laboratory and/or provided by the tire manufacturer (hyperviscoelastic rubber and linear elastic reinforcement) and accurate geometry. The model was validated using measured deflection and contact area. The analysis matrix consisted of 81 cases resulting from a combination of three loads, tire-inflation pressures, speeds, and temperatures. Four criteria were used to compare contact stresses: range, average, root-mean-square error, and coefficient of determination. Speed and temperature influence …

Go to article

Pyrolysis Of Wastewater Biosolids Significantly Reduces Estrogenicity, T. C. Hoffman, Daniel Zitomer, Patrick J. Mcnamara Nov 2016

Pyrolysis Of Wastewater Biosolids Significantly Reduces Estrogenicity, T. C. Hoffman, Daniel Zitomer, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Most wastewater treatment processes are not specifically designed to remove micropollutants. Many micropollutants are hydrophobic so they remain in the biosolids and are discharged to the environment through land-application of biosolids. Micropollutants encompass a broad range of organic chemicals, including estrogenic compounds (natural and synthetic) that reside in the environment, a.k.a. environmental estrogens. Public concern over land application of biosolids stemming from the occurrence of micropollutants hampers the value of biosolids which are important to wastewater treatment plants as a valuable by-product. This research evaluated pyrolysis, the partial decomposition of organic material in an oxygen-deprived system under high temperatures, as …

Go to article

Altered Antibiotic Tolerance In Anaerobic Digesters Acclimated To Triclosan Or Triclocarban, Daniel Elliott Carey, Patrick J. Mcnamara Nov 2016

Altered Antibiotic Tolerance In Anaerobic Digesters Acclimated To Triclosan Or Triclocarban, Daniel Elliott Carey, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Bench-scale anaerobic digesters were amended to elevated steady-state concentrations of triclosan (850 mg/kg) and triclocarban (150 mg/kg) using a synthetic feed. After more than 9 solids retention time (SRT) values of acclimatization, biomass from each digester (and a control digester that received no antimicrobials) was used to assess the toxicity of three antibiotics. Methane production rate was measured as a surrogate for activity in microcosms that received doses of antibiotics ranging from no-antibiotic to inhibitory concentrations. Biomass amended with triclocarban was more sensitive to tetracycline compared to the control indicating synergistic inhibitory effects between this antibiotic and triclocarban. In contrast, …

Go to article

Anaerobic Digester Bioaugmentation Influences Quasi Steady State Performance And Microbial Community, Kaushik Venkiteshwaran, K. Milferstedt, J. Hamelin, Daniel Zitomer Nov 2016

Anaerobic Digester Bioaugmentation Influences Quasi Steady State Performance And Microbial Community, Kaushik Venkiteshwaran, K. Milferstedt, J. Hamelin, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

Nine anaerobic digesters, each seeded with biomass from a different source, were operated identically and their quasi steady state function was compared. Subsequently, digesters were bioaugmented with a methanogenic culture previously shown to increase specific methanogenic activity. Before bioaugmentation, different seed biomass resulted in different quasi steady state function, with digesters clustering into three groups distinguished by methane (CH4) production. Digesters with similar functional performance contained similar archaeal communities based on clustering of Illumina sequence data of the V4V5 region of the 16S rRNA gene. High CH4 production correlated with neutral pH and high Methanosarcina abundance, whereas …

Go to article

High-Affinity Phosphate-Binding Protein (Pbp) For Phosphorous Recovery: Proof Of Concept Using Recombinant Escherichia Coli, Yu Yang, Wendy Ballent, Brooke K. Mayer Oct 2016

High-Affinity Phosphate-Binding Protein (Pbp) For Phosphorous Recovery: Proof Of Concept Using Recombinant Escherichia Coli, Yu Yang, Wendy Ballent, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Phosphorus (P) is a critical, non-renewable nutrient; yet excess discharges can lead to eutrophication and deterioration of water quality. Thus, P removal from water must be coupled with P recovery to achieve sustainable P management. P-specific proteins provide a novel, promising approach to recover P from water. Bacterial phosphate-binding proteins (PBPs) are able to effectively remove phosphate, achieving extremely low levels in water (i.e. 0.015 mg-P L−1). A prerequisite of using PBP for P recovery, however, is not only removal, but also controlled P release, which has not yet been reported. Phosphate release using recombinant PBP-expressing Escherichia coli …

Go to article

Recovery Of Agricultural Nutrients From Biorefineries, Daniel Elliott Carey, Yu Yang, Patrick J. Mcnamara, Brooke K. Mayer Sep 2016

Recovery Of Agricultural Nutrients From Biorefineries, Daniel Elliott Carey, Yu Yang, Patrick J. Mcnamara, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

This review lays the foundation for why nutrient recovery must be a key consideration in design and operation of biorefineries and comprehensively reviews technologies that can be used to recover an array of nitrogen, phosphorus, and/or potassium-rich products of relevance to agricultural applications. Recovery of these products using combinations of physical, chemical, and biological operations will promote sustainability at biorefineries by converting low-value biomass (particularly waste material) into a portfolio of higher-value products. These products can include a natural partnering of traditional biorefinery outputs such as biofuels and chemicals together with nutrient-rich fertilizers. Nutrient recovery not only adds an additional …

Go to article

Pyrolysis Of Dried Wastewater Biosolids Can Be Energy Positive, Patrick J. Mcnamara, Jon Koch, Zhongzhe Liu, Daniel Zitomer Sep 2016

Pyrolysis Of Dried Wastewater Biosolids Can Be Energy Positive, Patrick J. Mcnamara, Jon Koch, Zhongzhe Liu, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

Pyrolysis is a thermal process that converts biosolids into biochar (a soil amendment), py-oil and py-gas, which can be energy sources. The objectives of this research were to determine the product yield of dried biosolids during pyrolysis and the energy requirements of pyrolysis. Bench-scale experiments revealed that temperature increases up to 500 °C substantially decreased the fraction of biochar and increased the fraction of py-oil. Py-gas yield increased above 500 °C. The energy required for pyrolysis was approximately 5-fold less than the energy required to dry biosolids (depending on biosolids moisture content), indicating that, if a utility already uses energy …

Go to article

Framework For Event-Based Semidistributed Modeling That Unifies The Scs-Cn Method, Vic, Pdm, And Topmodel, Mark Bartlett, Anthony J. Parolari, Jeffrey Mcdonnell, Amilcare Porporato Sep 2016

Framework For Event-Based Semidistributed Modeling That Unifies The Scs-Cn Method, Vic, Pdm, And Topmodel, Mark Bartlett, Anthony J. Parolari, Jeffrey Mcdonnell, Amilcare Porporato

Civil and Environmental Engineering Faculty Research and Publications

Hydrologists and engineers may choose from a range of semidistributed rainfall-runoff models such as VIC, PDM, and TOPMODEL, all of which predict runoff from a distribution of watershed properties. However, these models are not easily compared to event-based data and are missing ready-to-use analytical expressions that are analogous to the SCS-CN method. The SCS-CN method is an event-based model that describes the runoff response with a rainfall-runoff curve that is a function of the cumulative storm rainfall and antecedent wetness condition. Here we develop an event-based probabilistic storage framework and distill semidistributed models into analytical, event-based expressions for describing the …

Go to article

Influent Wastewater Microbiota And Temperature Influence Anaerobic Membrane Bioreactor Microbial Community, Matthew Seib, K. J. Berg, Daniel Zitomer Sep 2016

Influent Wastewater Microbiota And Temperature Influence Anaerobic Membrane Bioreactor Microbial Community, Matthew Seib, K. J. Berg, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

Sustainable municipal wastewater recovery scenarios highlight benefits of anaerobic membrane bioreactors (AnMBRs). However, influences of continuous seeding by influent wastewater and temperature on attached-growth AnMBRs are not well understood. In this study, four bench-scale AnMBR operated at 10 and 25 °C were fed synthetic (SPE) and then real (PE) primary effluent municipal wastewater. Illumina sequencing revealed different bacterial communities in each AnMBR in response to temperature and bioreactor configuration, whereas differences were not observed in archaeal communities. Activity assays revealed hydrogenotrophic methanogenesis was the dominant methanogenic pathway at 10 °C. The significant relative abundance of Methanosaeta at 10 °C concomitant …

Go to article

Framework For Incorporating Probabilistic Building Performance In The Assessment Of Community Seismic Resilience, Henry V. Burton, Gregory Deierlein, David Lallemant, Ting Lin Aug 2016

Framework For Incorporating Probabilistic Building Performance In The Assessment Of Community Seismic Resilience, Henry V. Burton, Gregory Deierlein, David Lallemant, Ting Lin

Civil and Environmental Engineering Faculty Research and Publications

A framework is presented for incorporating probabilistic building performance limit states in the assessment of community resilience to earthquakes. The limit states are defined on the basis of their implications to postearthquake functionality and recovery. They include damage triggering inspection, occupiable damage with loss of functionality, unoccupiable damage, irreparable damage, and collapse. Fragility curves are developed linking earthquake ground motion intensity to the probability of exceedance for each of the limit states. A characteristic recovery path is defined for each limit state on the basis of discrete functioning states, the time spent within each state, and the level of functionality …

Go to article

Government Motivation-Embedded Return Guarantee For Urban Infrastructure Projects Based On Real Options, Qingpeng Man, Chengshuang Sun, Yuesheng Fei, Martin Skitmore, Yong Bai, Weizhuo Lu Jul 2016

Government Motivation-Embedded Return Guarantee For Urban Infrastructure Projects Based On Real Options, Qingpeng Man, Chengshuang Sun, Yuesheng Fei, Martin Skitmore, Yong Bai, Weizhuo Lu

Civil and Environmental Engineering Faculty Research and Publications

Governments usually guarantee the amount of investment income to private sector partners to encourage their participation in Public-Private Partnership urban infrastructure development projects, with the ‘float return on investment guarantee’ being the main method in use by the Chinese government today. The current problems with the float return on investment guarantee are analysed and a guarantee approach with embedded motivational behaviour is presented as an alternative. A pricing method option is then introduced as the motivation-embedded return guarantee has similar characteristics to real options. From this, a valuation model is developed that provides the basis of a new systematic method …

Go to article

Bioaugmentation And Correlating Anaerobic Digester Microbial Community To Process Function, Kaushik Venkiteshwaran Jul 2016

Bioaugmentation And Correlating Anaerobic Digester Microbial Community To Process Function, Kaushik Venkiteshwaran

Dissertations (1934 -)

This dissertation describes two research projects on anaerobic digestion (AD) that investigated the relationship between microbial community structure and digester function. Both archaeal and bacterial communities were characterized using high-throughput (Illumina) sequencing technology with universal 16S rRNA gene primers. In the first project, bioaugmentation using a methanogenic, aerotolerant propionate enrichment culture was investigated as a possible method to increase digester methane production. Nine anaerobic digesters, seeded with different biomass, were operated identically and their quasi steady state function was compared. Before bioaugmentation, different seed biomass resulted in different quasi steady state function, with digesters clustering into high, medium or low …

Go to article

Forest Soil Carbon And Nitrogen Cycles Under Biomass Harvest: Stability, Transient Response, And Feedback, Anthony J. Parolari, Amilcare Porporato Jun 2016

Forest Soil Carbon And Nitrogen Cycles Under Biomass Harvest: Stability, Transient Response, And Feedback, Anthony J. Parolari, Amilcare Porporato

Civil and Environmental Engineering Faculty Research and Publications

Biomass harvest generates an imbalance in forest carbon (C) and nitrogen (N) cycles and the nonlinear biogeochemical responses may have long-term consequences for soil fertility and sustainable management. We analyze these dynamics and characterize the impact of biomass harvest and N fertilization on soil biogeochemistry and ecosystem yield with an ecosystem model of intermediate complexity that couples plant and soil C and N cycles. Two harvest schemes are modeled: continuous harvest at low intensity and periodic clear-cut harvest. Continuously-harvested systems sustain N harvest at steady-state under net mineralization conditions, which depends on the C:N ratio and respiration rate of decomposers. …

Go to article

Removal Of Trace Metal Contaminants From Potable Water By Electrocoagulation, Joe Heffron, Matt Marhefke, Brooke K. Mayer Jun 2016

Removal Of Trace Metal Contaminants From Potable Water By Electrocoagulation, Joe Heffron, Matt Marhefke, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

This study investigated the effects of four operational and environmental variables on the removal of trace metal contaminants from drinking water by electrocoagulation (EC). Removal efficiencies for five metals (arsenic, cadmium, chromium, lead and nickel) were compared under varying combinations of electrode material, post-treatment, water composition and pH. Iron electrodes out-performed aluminum electrodes in removing chromium and arsenic. At pH 6.5, aluminum electrodes were slightly more effective at removing nickel and cadmium, while at pH 8.5, iron electrodes were more effective for these metals. Regardless of electrode, cadmium and nickel removal efficiencies were higher at pH 8.5 than at pH …

Go to article

Beyond The Scs-Cn Method: A Theoretical Framework For Spatially Lumped Rainfall-Runoff Response, Mark Bartlett, Anthony J. Parolari, Jeffrey Mcdonnell, Amilcare Porporato Jun 2016

Beyond The Scs-Cn Method: A Theoretical Framework For Spatially Lumped Rainfall-Runoff Response, Mark Bartlett, Anthony J. Parolari, Jeffrey Mcdonnell, Amilcare Porporato

Civil and Environmental Engineering Faculty Research and Publications

Since its introduction in 1954, the Soil Conservation Service curve number (SCS-CN) method has become the standard tool, in practice, for estimating an event-based rainfall-runoff response. However, because of its empirical origins, the SCS-CN method is restricted to certain geographic regions and land use types. Moreover, it does not describe the spatial variability of runoff. To move beyond these limitations, we present a new theoretical framework for spatially lumped, event-based rainfall-runoff modeling. In this framework, we describe the spatially lumped runoff model as a point description of runoff that is upscaled to a watershed area based on probability distributions that …

Go to article

Emerging Investigators Series: Virus Mitigation By Coagulation: Recent Discoveries And Future Directions, Joe Heffron, Brooke K. Mayer May 2016

Emerging Investigators Series: Virus Mitigation By Coagulation: Recent Discoveries And Future Directions, Joe Heffron, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Waterborne viruses are widespread and persistent in the environment. Coagulation is an effective process for mitigating viruses in drinking water. This review examines recent studies of virus mitigation by coagulation processes in the context of the latest scientific advances. Virus sorption is impacted by electrostatic forces, as well as the hydrophobic effect, steric hindrance, hydrodynamics and interactions with the water matrix. Organic matter in the water may hinder or enhance sorption, depending on virus structure and environmental factors. In addition to physical separation in flocs, coagulation processes have been shown to inactivate viruses. This review evaluates reports of virus inactivation …

Go to article

Relating Anaerobic Digestion Microbial Community And Process Function, Kaushik Venkiteshwaran, Benjamin T.W. Bocher, James Maki, Daniel Zitomer Apr 2016

Relating Anaerobic Digestion Microbial Community And Process Function, Kaushik Venkiteshwaran, Benjamin T.W. Bocher, James Maki, Daniel Zitomer

Biological Sciences Faculty Research and Publications

Anaerobic digestion (AD) involves a consortium of microorganisms that convert substrates into biogas containing methane for renewable energy. The technology has suffered from the perception of being periodically unstable due to limited understanding of the relationship between microbial community structure and function. The emphasis of this review is to describe microbial communities in digesters and quantitative and qualitative relationships between community structure and digester function. Progress has been made in the past few decades to identify key microorganisms influencing AD. Yet, more work is required to realize robust, quantitative relationships between microbial community structure and functions such as methane production …

Go to article

First Prev Next Last