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Full-Text Articles in Civil Engineering

Pretreatment And Anaerobic Co-Digestion Of Selected Phb And Pla Bioplastics, Nicholas John Norio Benn, Daniel Zitomer Jan 2018

Pretreatment And Anaerobic Co-Digestion Of Selected Phb And Pla Bioplastics, Nicholas John Norio Benn, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

Conventional petroleum-derived plastics are recalcitrant to biodegradation and can be problematic as they accumulate in the environment. In contrast, it may be possible to add novel, biodegradable bioplastics to anaerobic digesters at municipal water resource recovery facilities along with primary sludge to produce more biomethane. In this study, thermal and chemical bioplastic pretreatments were first investigated to increase the rate and extent of anaerobic digestion. Subsequently, replicate, bench-scale anaerobic co-digesters fed synthetic primary sludge with and without PHB bioplastic were maintained for over 170 days. Two polyhydroxybutyrate (PHB), one poly(3-hydroxybutyrate-co-4-hydroxybutyrate) and one polylactic acid (PLA) bioplastic were investigated. Biochemical methane …


Enhancing Frp-To-Concrete Bond Behavior By Epoxy Ribs, Cheng Jiang, Baolin Wan, John Omboko Jan 2018

Enhancing Frp-To-Concrete Bond Behavior By Epoxy Ribs, Cheng Jiang, Baolin Wan, John Omboko

Civil and Environmental Engineering Faculty Research and Publications

The bond between external bonding (EB) of fiber reinforced polymer (FRP) composite materials to concrete is the weakest link in the strengthened concrete flexural members. There are three mechanisms to transfer the interfacial shear between FRP and the concrete substrate, i.e., adhesion, interlocking and friction. This paper proposes a new approach by grooving on the concrete surface before applying epoxy to make epoxy ribs to increase interlocking. An experimental program was conducted to verify the effectiveness of the proposed epoxy ribs. Six grooves perpendicular to the fiber direction were cut on the bonding surface of the concrete blocks. The grooves …


Effect Of Pyrolysis On The Removal Of Antibiotic Resistance Genes And Class I Integrons From Municipal Wastewater Biosolids, Lee Kimbell, Anthony D. Kappell, Patrick J. Mcnamara Jan 2018

Effect Of Pyrolysis On The Removal Of Antibiotic Resistance Genes And Class I Integrons From Municipal Wastewater Biosolids, Lee Kimbell, Anthony D. Kappell, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Wastewater biosolids represent a significant reservoir of antibiotic resistance genes (ARGs). While current biosolids treatment technologies can reduce ARG levels in residual wastewater biosolids, observed removal rates vary substantially. Pyrolysis is an anoxic thermal degradation process that can be used to convert biosolids into energy rich products including py-gas and py-oil, and a beneficial soil amendment, biochar. Batch pyrolysis experiments conducted on municipal biosolids revealed that the 16S rRNA gene, the ARGs erm(B), sul1, tet(L), tet(O), and the integrase gene of class 1 integrons (intI1) were significantly reduced at pyrolysis temperatures ranging from 300–700 …


Construction Engineering Education Committee: Past, Present, And Future, Yong Bai Jan 2018

Construction Engineering Education Committee: Past, Present, And Future, Yong Bai

Civil and Environmental Engineering Faculty Research and Publications

No abstract provided.


Higher Education On Buildings: Case Study In The North Dakota Region, Houjun Yang, Malini Srivastava, Yanmei Xie, Yong Bai Dec 2017

Higher Education On Buildings: Case Study In The North Dakota Region, Houjun Yang, Malini Srivastava, Yanmei Xie, Yong Bai

Civil and Environmental Engineering Faculty Research and Publications

Because of the growing demand for local skilled professionals to improve the health, energy efficiency, and sustainability of residential and commercial buildings in North Dakota, this case study reports the current situation of higher education relating to buildings in the state’s vicinity, including Minnesota, Montana, North Dakota, and South Dakota. In this region, 116 programs relating to buildings were found in 41 postsecondary institutions, and both their majors and courses were then studied with frequency lists. The frequency information was analyzed over nine sets of curriculum areas at both graduate and undergraduate levels for the four states. After the current …


Climate, Not Conflict, Explains Extreme Middle East Dust Storm, Anthony J. Parolari, Dan Li, Elie Bou-Zeid, Gabriel Katul, Shmuel Assouline Oct 2017

Climate, Not Conflict, Explains Extreme Middle East Dust Storm, Anthony J. Parolari, Dan Li, Elie Bou-Zeid, Gabriel Katul, Shmuel Assouline

Civil and Environmental Engineering Faculty Research and Publications

The recent dust storm in the Middle East (September 2015) was publicized in the media as a sign of an impending ‘Dust Bowl.’ Its severity, demonstrated by extreme aerosol optical depth in the atmosphere in the 99th percentile compared to historical data, was attributed to the ongoing regional conflict. However, surface meteorological and remote sensing data, as well as regional climate model simulations, support an alternative hypothesis: the historically unprecedented aridity played a more prominent role, as evidenced by unusual climatic and meteorological conditions prior to and during the storm. Remotely sensed normalized difference vegetation index demonstrates that vegetation cover …


Hydrologic Transport Of Dissolved Inorganic Carbon And Its Control On Chemical Weathering, Salvatore Calabrese, Anthony J. Parolari, Amilcare Porporato Oct 2017

Hydrologic Transport Of Dissolved Inorganic Carbon And Its Control On Chemical Weathering, Salvatore Calabrese, Anthony J. Parolari, Amilcare Porporato

Civil and Environmental Engineering Faculty Research and Publications

Chemical weathering is one of the major processes interacting with climate and tectonics to form clays, supply nutrients to soil microorganisms and plants, and sequester atmospheric CO2. Hydrology and dissolution kinetics have been emphasized as factors controlling chemical weathering rates. However, the interaction between hydrology and transport of dissolved inorganic carbon (DIC) in controlling weathering has received less attention. In this paper, we present an analytical model that couples subsurface water and chemical molar balance equations to analyze the roles of hydrology and DIC transport on chemical weathering. The balance equations form a dynamical system that fully determines …


A Comparative Life Cycle Assessment Between A Metered Dose Inhaler And Electric Nebulizer, Brandon Goulet, Lars E. Olson, Brooke K. Mayer Sep 2017

A Comparative Life Cycle Assessment Between A Metered Dose Inhaler And Electric Nebulizer, Brandon Goulet, Lars E. Olson, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Life cycle assessment (LCA) evaluates the environmental impact of a product based on the materials and processes used to manufacture the item as well as the item’s use and disposal. The objective of this LCA was to evaluate and compare the environmental impact of a metered dose inhaler, specifically the Proventil® HFA inhaler (Merk & Co., Inc., Kenilworth, NJ, USA), and an electric nebulizer, specifically the DeVilbiss Pulmo-Aide® nebulizer (DeVilbiss, Port Washington, NY, USA). GaBi LCA software was used to model the global warming potential (GWP) of each product by using substantiated data and well-justified assumptions for the components, manufacturing, …


Boom And Bust Carbon-Nitrogen Dynamics During Reforestation, Anthony J. Parolari, Megan L. Mobley, Allan R. Bacon, Gabriel Katul, Daniel Deb. Richter, Amilcare Porporato Sep 2017

Boom And Bust Carbon-Nitrogen Dynamics During Reforestation, Anthony J. Parolari, Megan L. Mobley, Allan R. Bacon, Gabriel Katul, Daniel Deb. Richter, Amilcare Porporato

Civil and Environmental Engineering Faculty Research and Publications

Legacies of historical land use strongly shape contemporary ecosystem dynamics. In old-field secondary forests, tree growth embodies a legacy of soil changes affected by previous cultivation. Three patterns of biomass accumulation during reforestation have been hypothesized previously, including monotonic to steady state, non-monotonic with a single peak then decay to steady state, and multiple oscillations around the steady state. In this paper, the conditions leading to the emergence of these patterns is analyzed. Using observations and models, we demonstrate that divergent reforestation patterns can be explained by contrasting time-scales in ecosystem carbon-nitrogen cycles that are influenced by land use legacies. …


Increasing Atmospheric Humidity And Co2 Concentration Alleviate Forest Mortality Risk, Yanlan Liu, Anthony J. Parolari, Mukesh Kumar, Chang-Wei Huang, Gabriel Katul, Amilcare Porporato Sep 2017

Increasing Atmospheric Humidity And Co2 Concentration Alleviate Forest Mortality Risk, Yanlan Liu, Anthony J. Parolari, Mukesh Kumar, Chang-Wei Huang, Gabriel Katul, Amilcare Porporato

Civil and Environmental Engineering Faculty Research and Publications

Climate-induced forest mortality is being increasingly observed throughout the globe. Alarmingly, it is expected to exacerbate under climate change due to shifting precipitation patterns and rising air temperature. However, the impact of concomitant changes in atmospheric humidity and CO2 concentration through their influence on stomatal kinetics remains a subject of debate and inquiry. By using a dynamic soil–plant–atmosphere model, mortality risks associated with hydraulic failure and stomatal closure for 13 temperate and tropical forest biomes across the globe are analyzed. The mortality risk is evaluated in response to both individual and combined changes in precipitation amounts and their seasonal …


A Shared Ontology Approach To Semantic Representation Of Bim Data, Mehrdad Niknam, Saeed Karshenas Aug 2017

A Shared Ontology Approach To Semantic Representation Of Bim Data, Mehrdad Niknam, Saeed Karshenas

Civil and Environmental Engineering Faculty Research and Publications

Architecture, engineering, construction and facility management (AEC-FM) projects involve a large number of participants that must exchange information and combine their knowledge for successful completion of a project. Currently, most of the AEC-FM domains store their information about a project in text documents or use XML, relational, or object-oriented formats that make information integration difficult. The AEC-FM industry is not taking advantage of the full potential of the Semantic Web for streamlining sharing, connecting, and combining information from different domains. The Semantic Web is designed to solve the information integration problem by creating a web of structured and connected data …


Reply To Comment By Fred L. Ogden Et Al. On "Beyond The Scs-Cn Method: A Theoretical Framework For Spatially Lumped Rainfall-Runoff Response", Mark Bartlett, Anthony J. Parolari, Jeffrey Mcdonnell, Amilcare Porporato Jul 2017

Reply To Comment By Fred L. Ogden Et Al. On "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

Though Ogden et al. list several shortcomings of the original SCS-CN method, fit for purpose is a key consideration in hydrological modelling, as shown by the adoption of SCS-CN method in many design standards. The theoretical framework of Bartlett et al. [2016a] reveals a family of semidistributed models, of which the SCS-CN method is just one member. Other members include event-based versions of the Variable Infiltration Capacity (VIC) model and TOPMODEL. This general model allows us to move beyond the limitations of the original SCS-CN method under different rainfall-runoff mechanisms and distributions for soil and rainfall variability. Future research should …


Development Of Adjustment Factors For Mepdg Pavement Responses Utilizing Finite-Element Analysis, Osman Erman Gungor, Imad L. Al-Qadi, Angeli Gamez, Jaime Hernandez Jul 2017

Development Of Adjustment Factors For Mepdg Pavement Responses Utilizing Finite-Element Analysis, Osman Erman Gungor, Imad L. Al-Qadi, Angeli Gamez, Jaime Hernandez

Civil and Environmental Engineering Faculty Research and Publications

The Mechanistic-empirical pavement design guide (MEPDG) provides theoretically superior methodology, as compared with its predecessor, for the design and analysis of pavement structures. The mechanistic part refers to simulating pavement–tire interaction to calculate critical responses within pavement. The empirical part means prediction of pavement distress propagation over time using transfer functions that link a critical pavement response to a particular pavement distress. The mechanistic part of MEPDG simulates tire–pavement interaction in three steps: subdivision of pavement layers; complex modulus calculation at the middepth of each sublayer, considering velocity and temperature; and running the multilayered elastic theory (MLET) software, …


Inclusion Of An Introduction To Infrastructure Course In A Civil And Environmental Engineering Curriculum, Esmaeili Behzad, Philip J. Parker, Steven D. Hart, Brooke K. Mayer, Led Klosky, Michael R. Penn Apr 2017

Inclusion Of An Introduction To Infrastructure Course In A Civil And Environmental Engineering Curriculum, Esmaeili Behzad, Philip J. Parker, Steven D. Hart, Brooke K. Mayer, Led Klosky, Michael R. Penn

Civil and Environmental Engineering Faculty Research and Publications

Civil infrastructure refers to the built environment (sometimes referred to as public works) and consists of roads, bridges, buildings, dams, levees, drinking water treatment facilities, wastewater treatment facilities, power generation and transmission facilities, communications, solid waste facilities, hazardous waste facilities, and other sectors. Although there is a need to train engineers who have a holistic view of infrastructure, there is evidence that civil and environmental engineering (CEE) programs have not fully addressed this increasingly recognized need. One effective approach to address this educational gap is to incorporate a course related to infrastructure into the curriculum for first-year or second-year …


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 …


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 …


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.


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 …


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 …


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) …


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.


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 …


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 …


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 …


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.


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 …


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 …


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, …


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 …


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 …