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

Engineering Commons

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

Articles 1 - 30 of 30

Full-Text Articles in Engineering

In-Plane Vibration Of Hammerhead Resonators For Chemical Sensing Applications, Luke A. Beardslee, Christopher Carron, Kemal S. Demirci, Jonathan Lehman, Steven Schwartz, Isabelle Dufour, Stephen M. Heinrich, Fabien Josse Phd, Oliver Brand Dec 2019

In-Plane Vibration Of Hammerhead Resonators For Chemical Sensing Applications, Luke A. Beardslee, Christopher Carron, Kemal S. Demirci, Jonathan Lehman, Steven Schwartz, Isabelle Dufour, Stephen M. Heinrich, Fabien Josse Phd, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

Thermally excited and piezoresistively detected in-plane cantilever resonators have been previously demonstrated for gas- and liquid-phase chemical and biosensing applications. In this work, the hammerhead resonator geometry, consisting of a cantilever beam supporting a wider semicircular “head”, vibrating in an in-plane vibration mode, is shown to be particularly effective for gas-phase sensing with estimated limits of detection in the sub-ppm range for volatile organic compounds. This paper discusses the hammerhead resonator design and the particular advantages of the hammerhead geometry, while also presenting mechanical characterization, optical characterization, and chemical sensing results. These data highlight the distinct advantages of the hammerhead …


Electrocoagulation As A Pretreatment For Electroxidation Of E. Coli, William Lynn, Joe Heffron, Brooke Mayer Dec 2019

Electrocoagulation As A Pretreatment For Electroxidation Of E. Coli, William Lynn, Joe Heffron, Brooke Mayer

Civil and Environmental Engineering Faculty Research and Publications

Insufficient funding and operator training, logistics of chemical transport, and variable source water quality can pose challenges for small drinking water treatment systems. Portable, robust electrochemical processes may offer a strategy to address these challenges. In this study, electrocoagulation (EC) and electrooxidation (EO) were investigated using two model surface waters and two model groundwaters to determine the efficacy of sequential EC-EO for mitigating Escherichia coli. EO alone (1.67 mA/cm2, 1 min) provided 0.03 to 3.9 logs mitigation in the four model waters. EC alone (10 mA/cm2, 5 min) achieved ≥1 log E. coli mitigation in all …


Power Law Growth And Delayed Feedbacks In Socio‐Hydrological Systems, Anthony J. Parolari, Gabriele Manolia Nov 2019

Power Law Growth And Delayed Feedbacks In Socio‐Hydrological Systems, Anthony J. Parolari, Gabriele Manolia

Civil and Environmental Engineering Faculty Research and Publications

Water infrastructure dynamics result from coupled social and physical hydrological processes embedded in “socio‐hydrological systems” (SHSs). Freshwater fuels socioeconomic activity, which in turn exerts pressure on water resources through increased water demand and water quality degradation. Many factors emphasize the need for quantitative tools to predict the future of these systems, including SHS failures due to growing water scarcity from population growth and climate change. However, unfolding the interactions between social and hydrological factors continues to resist theoretical treatment, impeding progress toward a predictive framework. To resolve this issue, we propose and evaluate time delays as surrogates for the social …


Stormwater Management Actions Under Regulatory Pressure: A Case Study Of Southeast Wisconsin, Walter M. Mcdonald, Joseph Naughton Nov 2019

Stormwater Management Actions Under Regulatory Pressure: A Case Study Of Southeast Wisconsin, Walter M. Mcdonald, Joseph Naughton

Civil and Environmental Engineering Faculty Research and Publications

In the United States, new legislation has given regulatory authorities greater oversight of municipal stormwater management programs. However, estimating the impact of greater oversight on municipal actions is difficult due to the uncertainty in current compliance efforts and their associated costs. This paper seeks to fill this gap through a case study of NPDES stormwater runoff permit reports from municipalities in Southeast Wisconsin. Specifically, this study evaluates the reported actions and expenditures against socioeconomic variables to identify the relationships between cost, socioeconomics, and the best management practices (BMPs) used for compliance. Results indicate that there are distinct differences between municipalities …


Mechanisms Of Virus Mitigation And Suitability Of Bacteriophages As Surrogates In Drinking Water Treatment By Iron Electrocoagulation, Joe Heffron, Brad Mcdermid, Emily Maher, Patrick J. Mcnamara, Brooke K. Mayer Oct 2019

Mechanisms Of Virus Mitigation And Suitability Of Bacteriophages As Surrogates In Drinking Water Treatment By Iron Electrocoagulation, Joe Heffron, Brad Mcdermid, Emily Maher, Patrick J. Mcnamara, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Emerging water treatment technologies using ferrous and zero-valent iron show promising virus mitigation by both inactivation and adsorption. In this study, iron electrocoagulation was investigated for virus mitigation in drinking water via bench-scale batch experiments. Relative contributions of physical removal and inactivation, as determined by recovery via pH 9.5 beef broth elution, were investigated for three mammalian viruses (adenovirus, echovirus, and feline calicivirus) and four bacteriophage surrogates (fr, MS2, P22, and ΦX174). Though no one bacteriophage exactly represented mitigation of the mammalian viruses in all water matrices, bacteriophage ΦX174 was the only surrogate that showed overall removal comparable to that …


Impact Of Hurricane Harvey On The Results Of Regional Flood Frequency Analysis, Walter M. Mcdonald, Joseph Naughton Oct 2019

Impact Of Hurricane Harvey On The Results Of Regional Flood Frequency Analysis, Walter M. Mcdonald, Joseph Naughton

Civil and Environmental Engineering Faculty Research and Publications

Hurricane Harvey was an unprecedented event that resulted in immense damage to life and property. As a result, it is important to determine how this event, as well as past and future events like it, will impact engineering design equations that are based upon historical data, such as flood frequency analysis equations. This study seeks to contribute to this discussion by evaluating the extent to which Harvey influenced estimations of instantaneous peak discharges in rural ungauged basins in southeast Texas. Results indicate that Harvey significantly increased the computations of design floods using Log‐Pearson Type III analysis (e.g., 3–55% for 2‐year …


Sequential Electrocoagulation-Electrooxidation For Virus Mitigation In Drinking Water, Joe Heffron, Donald R. Ryan, Brooke K. Mayer Sep 2019

Sequential Electrocoagulation-Electrooxidation For Virus Mitigation In Drinking Water, Joe Heffron, Donald R. Ryan, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Electrochemical water treatment is a promising alternative for small-scale and remote water systems that lack operational capacity or convenient access to reagents for chemical coagulation and disinfection. In this study, the mitigation of viruses was investigated using electrocoagulation as a pretreatment prior to electrooxidation treatment using boron-doped diamond electrodes. This research is the first to investigate a sequential electrocoagulation-electrooxidation treatment system for virus removal. Bench-scale, batch reactors were used to evaluate mitigation of viruses in variable water quality via: a) electrooxidation, and b) a sequential electrocoagulation-electrooxidation treatment train. Electrooxidation of two bacteriophages, MS2 and ΦX174, was inhibited by natural organic …


Communication Of Recommendations For The Disposal Of Unused Prescription Opioid Medications By Stakeholders In The News Media, Megan Lynn Petrik, Patrick J. Mcnamara, Susan M. Moeschler, Benjamin D. Blair Sep 2019

Communication Of Recommendations For The Disposal Of Unused Prescription Opioid Medications By Stakeholders In The News Media, Megan Lynn Petrik, Patrick J. Mcnamara, Susan M. Moeschler, Benjamin D. Blair

Civil and Environmental Engineering Faculty Research and Publications

Objective

The opioid epidemic is a national public health emergency that requires a comprehensive approach to reduce opioid-related deaths. Proper and timely disposal of unused prescription opioids is one method to deter improper use of these medications and prevent overdose. The objective of this study was to understand how recommendations for disposing of unused prescription opioids, including both take-back programs and toilet disposal, are communicated to the public.

Methods

Two hundred sixty-three US newspaper articles published between January 1, 2014, and June 30, 2017, containing information on opioids and take-back programs were found using LexisNexis. Using content analysis, articles were …


Methane Yield And Lag Correlate With Bacterial Community Shift Following Bioplastic Anaerobic Co-Digestion, Kaushik Venkiteshwaran, Nicholas Benn, Saba Seyedi, Daniel Zitomer Sep 2019

Methane Yield And Lag Correlate With Bacterial Community Shift Following Bioplastic Anaerobic Co-Digestion, Kaushik Venkiteshwaran, Nicholas Benn, Saba Seyedi, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

Past plastic management practices have resulted in pollution. An improved management scenario may involve adding used bioplastic to anaerobic digesters to increase methane for renewable energy. In this work, effects of polyhydroxybutyrate (PHB) bioplastic anaerobic co-digestion with synthetic primary sludge on operation and microbial communities were investigated. Co-digesters treating sludge were co-fed 20% untreated or pretreated (55 °C, pH 12) PHB. Pretreatment resulted in shorter lag (5 d shorter) before methane production increased after co-digestion. At steady-state, co-digesters converted 86% and 91% of untreated and pretreated PHB to methane, respectively. Bacterial communities were different before and after bioplastic co-digestion, whereas …


An Analytical Approach To Ascertain Saturation-Excess Versus Infiltration-Excess Overland Flow In Urban And Reference Landscapes, Ryan D. Stewart, Aditi S. Bhaskar, Anthony J. Parolari, Dustin L. Herrmann, Jinshi Jian, Laura A. Schifman, William D. Shuster Aug 2019

An Analytical Approach To Ascertain Saturation-Excess Versus Infiltration-Excess Overland Flow In Urban And Reference Landscapes, Ryan D. Stewart, Aditi S. Bhaskar, Anthony J. Parolari, Dustin L. Herrmann, Jinshi Jian, Laura A. Schifman, William D. Shuster

Civil and Environmental Engineering Faculty Research and Publications

Uncontrolled overland flow drives flooding, erosion, and contaminant transport, with the severity of these outcomes often amplified in urban areas. In pervious media such as urban soils, overland flow is initiated via either infiltration‐excess (where precipitation rate exceeds infiltration capacity) or saturation‐excess (when precipitation volume exceeds soil profile storage) mechanisms. These processes call for different management strategies, making it important for municipalities to discern between them. In this study, we derived a generalized one‐dimensional model that distinguishes between infiltration‐excess overland flow (IEOF) and saturation‐excess overland flow (SEOF) using Green–Ampt infiltration concepts. Next, we applied this model to estimate overland flow …


Syntroph Diversity And Abundance In Anaerobic Digestion Revealed Through A Comparative Core Microbiome Approach, Masanori Fujimoto, Daniel Elliott Carey, Daniel Zitomer, Patrick J. Mcnamara Aug 2019

Syntroph Diversity And Abundance In Anaerobic Digestion Revealed Through A Comparative Core Microbiome Approach, Masanori Fujimoto, Daniel Elliott Carey, Daniel Zitomer, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Anaerobic digestion is an important biotechnology treatment process for conversion of waste to energy. In this study, a comparative core microbiome approach, i.e., determining taxa that are shared in functioning digesters but not shared in non-functioning digesters, was used to determine microbial taxa that could play key roles for effective anaerobic digestion. Anaerobic digester functions were impaired by adding the broad-spectrum antimicrobial triclosan (TCS) or triclocarban (TCC) at different concentrations, and the core microbiomes in both functioning and non-functioning anaerobic digesters were compared. Digesters treated with high (2500 mg/kg) or medium (450 mg/kg) TCS and high (850 mg/kg) …


Evaluating The Variability Of Urban Land Surface Temperatures Using Drone Observations, Joseph Naughton, Walter M. Mcdonald Jul 2019

Evaluating The Variability Of Urban Land Surface Temperatures Using Drone Observations, Joseph Naughton, Walter M. Mcdonald

Civil and Environmental Engineering Faculty Research and Publications

Urbanization and climate change are driving increases in urban land surface temperatures that pose a threat to human and environmental health. To address this challenge, we must be able to observe land surface temperatures within spatially complex urban environments. However, many existing remote sensing studies are based upon satellite or aerial imagery that capture temperature at coarse resolutions that fail to capture the spatial complexities of urban land surfaces that can change at a sub-meter resolution. This study seeks to fill this gap by evaluating the spatial variability of land surface temperatures through drone thermal imagery captured at high-resolutions (13 …


Bacteriophage Inactivation As A Function Of Ferrous Iron Oxidation, Joe Heffron, Brad Mcdermid, Brooke K. Mayer Jul 2019

Bacteriophage Inactivation As A Function Of Ferrous Iron Oxidation, Joe Heffron, Brad Mcdermid, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Iron-based disinfection has been promoted as a potential low-cost, low-byproduct means of virus mitigation. This research is the first to establish that virus inactivation due to ferrous iron is impacted both by the extent of iron oxidation (from ferrous to ferric iron) and the rate of iron oxidation. Log inactivation of bacteriophages increased linearly with ferrous iron concentration at low doses (< 3 mg/L Fe), but higher doses limited disinfection, likely due to floc formation. The rate of iron oxidation was controlled by independently varying pH and dissolved oxygen concentration. Bacteriophage inactivation increased with the inverse of ferrous oxidation rate, suggesting that slower iron oxidation rates allow better contact between viruses and reactive ferrous iron. Ferrous iron showed potential for disinfection in conditions of low pH and dissolved oxygen, though these conditions preclude effective iron coagulation/flocculation.


Ion Exchange Nutrient Recovery From Anaerobic Membrane Bioreactor Permeate, Patrick Mullen, Kaushik Venkiteshwaran, Daniel Zitomer, Brooke K. Mayer Jul 2019

Ion Exchange Nutrient Recovery From Anaerobic Membrane Bioreactor Permeate, Patrick Mullen, Kaushik Venkiteshwaran, Daniel Zitomer, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Nutrient recovery from municipal wastewater was evaluated using anion exchange media loaded with hydrated ferric oxide (HFO) and copper (Cu2+) (Dow‐HFO‐Cu resin) to selectively capture phosphate, followed by clinoptilolite for ammonium removal and recovery. Nutrients were concentrated in the regenerants and recovered as precipitated struvite. Media exchange capacity after multiple ion exchange cycles was determined using permeate from an anaerobic membrane bioreactor (AnMBR) treating synthetic or actual municipal wastewater from a full‐scale water reclamation facility. Regeneration through five ion exchange cycles using relatively low concentration regenerant solution (2% NaCl and 0.5% NaOH) resulted in the highest phosphate exchange …


Experimental Study Of Hybrid Strengthening Technique Using Carbon Fiber Laminates And Steel Plates For Reinforced Concrete Slabs, Xiaohong Zheng, Baolin Wan, Peiyan Huang, Jinlin Huang Jun 2019

Experimental Study Of Hybrid Strengthening Technique Using Carbon Fiber Laminates And Steel Plates For Reinforced Concrete Slabs, Xiaohong Zheng, Baolin Wan, Peiyan Huang, Jinlin Huang

Civil and Environmental Engineering Faculty Research and Publications

External bonding (EB) technique has been used widely to strengthen reinforced concrete (RC) structures in civil engineering over several decades. Steel and fiber reinforced polymers (FRP) are the two most common materials used for strengthening RC structures. Although each material has its advantages for EB application, they also have their own weaknesses. Steel plates are heavy and poor in corrosion resistance, and the thickness of steel plates is also limited due to lack of shape flexibility for strengthening RC structures. The EB-FRP technique is restricted for broader applications because the bond interface is the weakest link in such retrofitted or …


Improved Reliability Of Stormwater Detention Basin Performance Through Water Quality Data-Informed Real-Time Control, Sazzad Sharior, Walter M. Mcdonald, Anthony J. Parolari Jun 2019

Improved Reliability Of Stormwater Detention Basin Performance Through Water Quality Data-Informed Real-Time Control, Sazzad Sharior, Walter M. Mcdonald, Anthony J. Parolari

Civil and Environmental Engineering Faculty Research and Publications

Stormwater detentions basins are designed to capture stormwater to reduce and delay peak flows and to improve water quality. A novel technology proposed to improve basin performance is real-time, active control of the basin outflow, in so-called “smart” stormwater systems. Existing studies demonstrate the performance of active controls that respond in real-time to basin water level, detention time, and rainfall forecast for one or a small number of rainfall events. We hypothesize that the performance of these active controls can be improved by incorporating real-time water quality data into the control algorithm. In addition, we hypothesize that active control performance …


Effect Of Specimen Thicknesses On Water Absorption And Flexural Strength Of Cfrp Laminates Subjected To Water Or Alkaline Solution Immersion, Xue Zhang, Yanlei Wang, Baolin Wan, Gaochuang Cai, Yuan Qu May 2019

Effect Of Specimen Thicknesses On Water Absorption And Flexural Strength Of Cfrp Laminates Subjected To Water Or Alkaline Solution Immersion, Xue Zhang, Yanlei Wang, Baolin Wan, Gaochuang Cai, Yuan Qu

Civil and Environmental Engineering Faculty Research and Publications

In this paper, an experimental research was undertaken to investigate the effect of specimen thicknesses on water absorptions and flexural strengths of wet lay-up CFRP laminates subjected to distilled water or alkaline solution immersion up to 180 days. Test results showed that the water uptake and flexural strength retention of CFRP laminates were significantly affected by the adopted specimen thickness. For the same aging time, the water uptake of CFRP laminates decreased in the early stage of immersion and increased in the later stage of immersion with the increase of specimen thickness. Meanwhile, the flexural strength retention generally increased as …


A Microfluidic Platform For The Simultaneous Quantification Of Methanogen Populations In Anaerobic Digestion Processes, Prince Peter Mathai, Hannah M. Dunn, Kaushik Venkiteshwaran, Daniel Zitomer, James Maki, Satoshi Ishii, Michael J. Sadowsky May 2019

A Microfluidic Platform For The Simultaneous Quantification Of Methanogen Populations In Anaerobic Digestion Processes, Prince Peter Mathai, Hannah M. Dunn, Kaushik Venkiteshwaran, Daniel Zitomer, James Maki, Satoshi Ishii, Michael J. Sadowsky

Civil and Environmental Engineering Faculty Research and Publications

Methanogens are a diverse group of archaea that play a critical role in the global carbon cycle. The lack of appropriate molecular tools to simultaneously quantify numerous methanogenic taxa, however, has largely limited our ability to study these communities in a wide variety of habitats, such as anaerobic digesters (ADs). In this study, 34 probe-based quantitative PCR (qPCR) assays were designed to target all known methanogenic genera within the archaeal phylum Euryarchaeota. These qPCR assays were adapted to a high-throughput microfluidic platform, which allowed for the simultaneous detection and absolute quantification of numerous taxa in a single run. The …


Adsorption Of Organic Micropollutants To Biosolids-Derived Biochar: Estimation Of Thermodynamic Parameters, Yiran Tong, Brooke K. Mayer, Patrick J. Mcnamara Apr 2019

Adsorption Of Organic Micropollutants To Biosolids-Derived Biochar: Estimation Of Thermodynamic Parameters, Yiran Tong, Brooke K. Mayer, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

This research quantified thermodynamic parameters to better understand the use of wastewater biosolids-derived biochar as an adsorbent to remove micropollutants. The objective of this research was to quantify adsorption capacity; isosteric heat; and change of enthalpy, entropy, and free energy characterizing adsorption reactions between biochar and micropollutants. Adsorption isotherms were developed using a range of temperatures for the micropollutants benzyldimethyldecylammonium chloride (BAC-C10) Carbamazepine (CBZ), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), and triclosan (TCS). The thermodynamic parameters derived from the isotherm data were used to assist in characterizing binding affinity, spontaneity, and mechanisms of adsorption. More polar compounds such as BAC-C10 and CBZ …


Probability Of Failure In Infrastructure Project Unbalanced Bidding, Yuhan Jiang, Yong Bai, Sisi Han, Ting Lin Apr 2019

Probability Of Failure In Infrastructure Project Unbalanced Bidding, Yuhan Jiang, Yong Bai, Sisi Han, Ting Lin

Civil and Environmental Engineering Faculty Research and Publications

Design-Bid-Build infrastructure projects with Unit-Price Contracts have a high risk of quantity and price deviations. Those deviations might be the result of contractors' unbalanced bidding. At the same time, contractors' performance was unknown under unbalanced bidding situations. The researchers utilized the First Order Reliability Method and Statistical Analysis to evaluate contractors' bidding performances and engineers' estimating performances with bidding and settlement data of 163 NDDOT projects. Results showed that contractors adopted unbalanced bidding strategies as follows: if quantities were overestimated, then they underrated unit price; if quantities were underestimated, then they overrated unit price to maintain projects' Bid Total Amount …


Comment On “Patented Blunderings, Efficiency Awareness, And Self-Sustainability Claims In The Pyrolysis Energy From Waste Sector”, Patrick J. Mcnamara, Daniel Zitomer, Zhongzhe Liu Apr 2019

Comment On “Patented Blunderings, Efficiency Awareness, And Self-Sustainability Claims In The Pyrolysis Energy From Waste Sector”, Patrick J. Mcnamara, Daniel Zitomer, Zhongzhe Liu

Civil and Environmental Engineering Faculty Research and Publications

No abstract provided.


Analysis Of Operational Parameters, Reactor Kinetics, And Floc Characterization For The Removal Of Estrogens Via Electrocoagulation, Emily K. Maher, Kassidy N. O'Malley, Joe Heffron, Jingwan Huo, Brooke K. Mayer, Yin Wang, Patrick J. Mcnamara Apr 2019

Analysis Of Operational Parameters, Reactor Kinetics, And Floc Characterization For The Removal Of Estrogens Via Electrocoagulation, Emily K. Maher, Kassidy N. O'Malley, Joe Heffron, Jingwan Huo, Brooke K. Mayer, Yin Wang, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Estrogenic compounds can cause human and ecological health issues and have been detected in surface and drinking water. In this research a reactor analysis determined the impact of operational parameters, the best fit kinetic model for the removal of estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-ethynylestradiol (EE2) using a bench-top iron electrocoagulation reactor, and characterized the floc generated in-situ. The parameters investigated were current density, conductivity, stir rate, and polarity reversal. Estrogen removal correlated well with an increase in current density, while conductivity did not impact removal but did reduce potentials. High stir rates and frequent polarity reversal …


Global Opportunities To Increase Agricultural Independence Through Phosphorus Recycling, Stephen M. Powers, R. B. Chowdhury, G. K. Macdonald, A, H.W. Beusen, A. F. Bouwman, S. E. Hampton, Brooke Mayer, M. L. Mccracklin, D. A. Vaccari Apr 2019

Global Opportunities To Increase Agricultural Independence Through Phosphorus Recycling, Stephen M. Powers, R. B. Chowdhury, G. K. Macdonald, A, H.W. Beusen, A. F. Bouwman, S. E. Hampton, Brooke Mayer, M. L. Mccracklin, D. A. Vaccari

Civil and Environmental Engineering Faculty Research and Publications

Food production hinges largely upon access to phosphorus (P) fertilizer. Most fertilizer P used in the global agricultural system comes from mining of nonrenewable phosphate rock deposits located within few countries. However, P contained in livestock manure or urban wastes represents a recyclable source of P. To inform development of P recycling technologies and policies, we examined subnational, national, and global spatial patterns for two intersections of land use affording high P recycling potential: (a) manure‐rich cultivated areas and (b) populous cultivated areas. In turn, we examined overlap between P recycling potential and nation‐level P fertilizer import dependency. Populous cultivated …


Adsorption Of Organic Micropollutants Onto Biochar: A Review Of Relevant Kinetics, Mechanisms And Equilibrium, Yiran Tong, Patrick J. Mcnamara, Brooke K. Mayer Mar 2019

Adsorption Of Organic Micropollutants Onto Biochar: A Review Of Relevant Kinetics, Mechanisms And Equilibrium, Yiran Tong, Patrick J. Mcnamara, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

As an alternative to activated carbon, biochar has been considered for removal of organic micropollutants from water and wastewater via adsorption. This review elaborates on the fundamental basis of adsorption kinetics, mechanisms, and equilibrium with respect to biochar-based adsorption of micropollutants. The objectives include: 1) linking biochar surface properties with adsorption abilities, 2) categorizing the kinetics of adsorption of aqueous-phase organic compounds onto biochar, 3) categorizing the molecular-scale interactions between organic micropollutants and biochar, and 4) reviewing existing quantitative methods for characterizing adsorption equilibrium of organic micropollutants from water onto an adsorbent surface. To fulfill these goals, the relationships among …


Inactivation Of The Bacterial Pathogens Staphylococcus Pseudintermedius And Acinetobacter Baumannii By Butanoic Acid, G. M. Kennedy, M. Y. Min, J. F. Fitzgerald, M. T. Nguyen, S. L. Schultz, M. T. Crum, Jeffrey A. Starke, M. A. Butkus, D. D. Bowman, M. P. Labare Mar 2019

Inactivation Of The Bacterial Pathogens Staphylococcus Pseudintermedius And Acinetobacter Baumannii By Butanoic Acid, G. M. Kennedy, M. Y. Min, J. F. Fitzgerald, M. T. Nguyen, S. L. Schultz, M. T. Crum, Jeffrey A. Starke, M. A. Butkus, D. D. Bowman, M. P. Labare

Civil and Environmental Engineering Faculty Research and Publications

Aims

This study was performed to evaluate the efficacy of butanoic acid against bacterial pathogens including Acinetobacter baumannii and Staphylococcus pseudintermedius.

Methods and Results

Vegetative bacteria were exposed to butanoic acid in vitro and log reduction was quantified using viable count assays. The maximum (8 and 9) log inactivation was determined by qualitatively assaying for growth/no-growth after a 48-h incubation (37°C). Membrane integrity after exposure to butanoic acid was determined by propidium iodide staining, scanning electron microscopy, membrane depolarization and inductively coupled plasma analysis. Cytosolic pH was measured by 5-(6-)carboxyfluorescein succinimidyl ester.

Conclusions

Inhibitory concentrations of butanoic acid ranged …


Toxicity Of Various Pyrolysis Liquids From Biosolids On Methane Production Yield, Seyedfatemeh Seyedi, Kaushik Venkiteshwaran, Daniel Zitomer Feb 2019

Toxicity Of Various Pyrolysis Liquids From Biosolids On Methane Production Yield, Seyedfatemeh Seyedi, Kaushik Venkiteshwaran, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

Aqueous pyrolysis liquid (APL) is a high-COD byproduct of wastewater biosolids pyrolysis that is comprised of numerous complex organic compounds and ammonia nitrogen (NH3-N). One potential beneficial use of APL is as a co-digestate to produce more biogas in anaerobic digesters. However, some APL organics and NH3-N are known to inhibit methane-producing microbes. Autocatalytic pyrolysis which uses previously-produced biochar as a catalyst during biosolids pyrolysis, increases energy-rich py-gas while eliminating bio-oil production and reducing COD concentration in the APL (catalyzed APL). However, the catalyzed APL still has a high organic strength and no suitable treatment strategies …


From Micro To Macro-Contaminants: The Impact Of Low-Energy Titanium Dioxide Photocatalysis Followed By Filtration On The Mitigation Of Drinking Water Organics, Brooke K. Mayer, Carlan Johnson, Yu Yang, Nicole Wellenstein, Emily K. Maher, Patrick J. Mcnamara Feb 2019

From Micro To Macro-Contaminants: The Impact Of Low-Energy Titanium Dioxide Photocatalysis Followed By Filtration On The Mitigation Of Drinking Water Organics, Brooke K. Mayer, Carlan Johnson, Yu Yang, Nicole Wellenstein, Emily K. Maher, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

This study evaluated strategies targeting macro- and micro-organic contaminant mitigation using low-energy titanium dioxide photocatalysis. Energy inputs of 1, 2, and 5 kWh m−3 resulted in incomplete oxidation of macro-organic natural organic matter, signified by greater reductions of UV254 and specific ultraviolet UV absorbance (SUVA) in comparison to dissolved organic carbon (DOC). The rate of UV254 removal was 3 orders of magnitude greater than the rate of DOC degradation. Incomplete oxidation improved operation of downstream filtration processes. Photocatalysis at 2 kWh m−3 increased the bed life of downstream granular activated carbon (GAC) filtration by 340% relative …


Closed-Form Solution For Curling Responses In Rigid Pavements, Jaime Hernandez, Imad L. Al-Qadi Feb 2019

Closed-Form Solution For Curling Responses In Rigid Pavements, Jaime Hernandez, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

Closed-form expressions for calculating stresses and displacements of partially restrained concrete pavement caused by a linear temperature gradient are presented. Translational and rotational linear elastic springs along the slab edges defined the partial restraint. In addition to plate theory behavior, the model assumes linear elastic concrete and an infinitely long slab resting on a Winkler foundation. The solutions of curling stresses and displacements were validated using the finite-element (FE) method and quantified the effect of semirigid connections, slab and foundation material properties, and slab thickness and width on them. Rotational and translational restraints, which can be related to joint condition …


Using Online Discussions To Develop The Entrepreneurial Mindset In Environmental Engineering Undergraduates: A Case Study, Lisa B. Bosman, Nathalie Duval-Couetil, Brooke K. Mayer, Patrick J. Mcnamara Jan 2019

Using Online Discussions To Develop The Entrepreneurial Mindset In Environmental Engineering Undergraduates: A Case Study, Lisa B. Bosman, Nathalie Duval-Couetil, Brooke K. Mayer, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Entrepreneurship is an important aspect of the U.S. and global economy. As such, developing an entrepreneurial mindset is crucial for both engineering students and practicing engineers. The purpose of this paper is investigate the role of online discussions, as a pedagogical approach, in the development of the entrepreneurial mindset, and explore a variety of approaches to assess student learning outcomes. Online discussions prompts were created for environmental engineering courses using the Kern Engineering Entrepreneurial Network (KEEN) framework. The framework proposes that an entrepreneurial mindset can be fostered in students by promoting curiosity, encouraging connections, and creating value. This paper describes …


Long-Term Impact On Environmental Attitudes And Knowledge Assessed Over Three Semesters Of An Environmental Engineering Sequence, Benjamin Michael Wallen, Nathaniel Sheehan, Luke Plante, Erick Martinez, Jeffrey A. Starke Jan 2019

Long-Term Impact On Environmental Attitudes And Knowledge Assessed Over Three Semesters Of An Environmental Engineering Sequence, Benjamin Michael Wallen, Nathaniel Sheehan, Luke Plante, Erick Martinez, Jeffrey A. Starke

Civil and Environmental Engineering Faculty Research and Publications

The pedagogy employed in a three-course environmental engineering sequence is investigated to determine the efficacy of enabling long-term improvement of knowledge and attitudes toward the environment. These three courses incorporate concepts of the five grand challenges released by the National Academy of Engineering and National Academy of Sciences and increase the breadth of knowledge for T-professionals. Previous studies of lengths from a few weeks to semester long courses evaluated the potential causality among various demographics and environmental knowledge and attitudes. The research presented herein contrasts and compares changes in environmental knowledge based upon a 12-question survey and changes in environmental …