Matching Items (78)
Description
Consumers purchase point-of-use (POU) devices to further improve the quality of water provided by the tap. As awareness increases of harmful contaminants, an emerging market of advanced POU with claims of removing beyond what a typical activated carbon filter is capable of, such as heavy metals. This research compares four commercially available pitcher filters; two that claim to remove arsenic and hexavalent chromium and two without such claims. Arsenate (As (V)) and hexavalent chromium (Cr (VI)) co-occur in natural geologic formations and are known to have harmful effects on humans when ingested. Pitcher filters Epic Water Filter and Aquagear had claims of removing both As (V) and Cr (VI) up to 99% with a capacity of nearly 200 gallons. In contrast, pitcher filters Brita and Pur had no claims for removal of As(V) and Cr(VI) with a 40-gallon lifespan. A series of experiments were conducted to first determine the efficiency of each filter, then to add the ability or improve removal of As(V) and Cr(VI) in one filter for future design implementations. Experiment 1 was conducted by treating 100 gallons of spiked tap water (50 ppb for As (V) and 100 ppb for Cr (VI)) with each filter. All four pitcher filters showed low performance, resulting in Pur with the lowest removal percentage of 2% and Aquagear with the highest percentage 16% for As (V). For Cr (VI) Pur performed the worst with a removal of 5% and Brita had the best performance of 15%. The functionality of Brita was improved by embedding a selective ion exchange media, which when nanotized successfully removed Cr (VI) in previous studies. The optimal mass of resin to add to the pitcher was experimentally determined as 18.9 grams through Experiment 2. Finally, Experiment 3 compared an alternative placement of the resin material using the same 18.9 grams. The performance in Experiment 3 was significantly worse than Experiment 2. The final recommendation for future design implementation was to add 18.9 grams of SIR-700 resin below the filter media for optimum performance. Overall, the results demonstrate the limited removal of As(V) and Cr(VI) by the four commercial pitcher filters and show that by adding selective ion exchange media, the POUs can be nano-enabled to effectively remove As(V) and Cr(VI) from water.
ContributorsDietrich, Lisa Keri (Author) / Westerhoff, Paul (Thesis director) / Perreault, Francois (Committee member) / Civil, Environmental and Sustainable Engineering Program (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Asphalt pavements deteriorate over time and are subjected to various distresses like rutting, fatigue cracking, stripping, raveling, etc. In this study, an experiment to indirectly assess aggregate stripping was completed in order to evaluate the effect of type of binder, and aging on the binder-aggregate bond under dry conditioning. The asphalts used in the study are commonly used in the state of Arizona, which included both non-polymer modified and polymer modified asphalts. The phenomenon of stripping was simulated using the Bitumen Bond Strength Test (BBS) and evaluated for Arizona binders. The BBS test is a simple test that measures the "pull-off" tensile strength of the bond between asphalt and the aggregate. Polymer modified binders were found to have lower pull-off strength in comparison to the non-modified or neat binder which were found to possess greater pull-off strength, but lower elasticity, causing the failure to become brittle and spontaneous. However, when aged binder was used, the bond strength expectedly reduced for non-polymer modified asphalts but surprisingly increased for polymer modified asphalts. Both un-aged neat and polymer modified binders were observed to have a cohesive failure whereas only the aged polymer modified binders failed in cohesion. The aged non-polymer modified binders were seen to have an adhesive failure.
ContributorsPonce, Esai Jonathon (Author) / Kaloush, Kamil (Thesis director) / Gundla, Akshay (Committee member) / Civil, Environmental and Sustainable Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This dissertation investigates the potential for enzyme induced carbonate cementation as an alternative to Portland cement for creating building material from sand aggregate. We create a solution of urease enzyme, calcium chloride (CaCl2), and urea in water and added sand. The urease catalyzes the synthesis of carbonate from urea, and the carbonate then bonds with a dissociated calcium ion and precipitates from the solution as calcium carbonate (CaCO3). This precipitate can form small crystal bridges at contacts between sand grains that lock the sand grains in place. Using enzyme induced carbonate precipitation we created a cemented sand sample with a maximum compressive strength of 319 kPa and an elastic modulus of approximately 10 MPa. Images from the SEM showed that a major failure mechanism in the cemented samples was the delamination of the CaCO3 from the sand grains. We observed that CaCO3 cementation did not when solutions with high concentrations of CaCl2 and urea were used.
ContributorsBull, Michael Ryan (Author) / Kavazanjian, Edward (Thesis director) / Chawla, Nikhilesh (Committee member) / Barrett, The Honors College (Contributor) / Materials Science and Engineering Program (Contributor)
Created2014-05
Description
Using the Arizona State University chapter of American Concrete Institute (ACI) as my platform, I recently teamed up with several generous companies to donate a new picnic slab and sidewalks to St. Vincent de Paul Elementary School's playground. Material/labor donations from Suntec Concrete, Arizona Materials, Salt River Materials Group, and Dickens Quality Demolition made it possible to complete this project over the course of two Saturdays and at no cost for the school. In addition to the children of St. Vincent de Paul's benefit, this project also gave ASU and MCC students the opportunity to work in the field with industry professionals and gain hands-on experience. Over 20 students were able to witness and participate in demolition, formwork, concrete placement (including a laser screed appearance provided by Suntec), finishing, sawcutting, and more. As for specifics, the project featured a 19' x 40' picnic slab, as well as two 6' wide sidewalks connecting the slab to the playground and the playground to the adjacent access road. Once the second sidewalk reached the access road, it continued to the classrooms with 6' wide ramps on each side for truck accessibility. My role in this project was essentially a superintendent. I served as the primary point of contact for all parties involved, organized the material and labor donations, coordinated the project schedule, and kept all companies informed of the schedule to ensure proper execution and avoid delays. Due to various unavoidable conditions (cold weather, shade on the slab, etc.), I was also forced to make a few critical decisions as the project progressed.
ContributorsTwichell, Bennett (Author) / Ernzen, James (Thesis director) / Standage, Richard (Committee member) / Civil, Environmental and Sustainable Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Current practice and a new technology for mitigating fugitive dust on construction sites are compared on the basis of economic, environmental and social impacts for this assessment. Fugitive dust can have serious health impacts, such as repertory illnesses and valley fever, on affected persons and is regulated by the Environmental Protection Agency and enforced by state and local agencies. Current practice consists of either relatively continuous application of potable water, a valuable resource, or application of expensive polymers, however, water application is considered the best available technology (BAT). The new technology, developed by the Center of Bio-medicated and Bio-inspired Geotechnics at Arizona State University, consists of application of Enzyme-Induced Carbonate Precipitate (EICP) to create an erosion-resistant crust. This crust is considered a "one and done" solution, until it is disturbed, however will last longer and stay more effective than quickly evaporating water. Future work will need to include how much disturbance is required to disturb the crust until ineffective towards mitigating fugitive dust. Results of the comparison show that a single EICP treatment produces 37 times less pollutants, uses 41 times less water and is 1.14 times cheaper than using water treatment to mitigate fugitive dust on a 7 acre site for 2 weeks (14 days). 14 days is the threshold at where EICP treatment becomes less expensive than water application for the purpose of mitigating fugitive dust. The EICP treatment benefits include lowering global warming inducing emissions, providing better air quality, becoming more cost effective, staying constantly effective to mitigate fugitive dust, and saving potable water.
ContributorsFabian, Aaron Jacob (Author) / Fox, Peter (Thesis director) / Kavazanjian, Edward (Thesis director) / Woolley, Miriam (Committee member) / Civil, Environmental and Sustainable Eng Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
Expansive soils in the United States cause extensive damage to roadways, buildings, and various structures. There are several treatment or methods of mitigation for these expansive soils. These treatments can be physical or chemical treatments that serve to provide more suitable building qualities for foundations and roadways alike. The main issue with expansive soils, is the volumetric variations, which are known as swelling and consolidation. These behaviors of the soil are usually stabilized through the use of lime solution, Portland Cement Concrete, and a newer technology in chemical treatments, sodium silicate solutions. Although the various chemical treatments show benefits in certain areas, the most beneficial method for stabilization comes from the combination of the chemical treatments. Lime and Portland cement concrete are the most effective in terms of increasing compressive strength and reduction of swell potential. However, with the introduction of silicate into either treatment, the efficacy of the treatments increases by a large amount lending itself more as an additive for the former processes. Sodium silicate solution does not lend itself to effectively increase the compressive strength of expansive soils. The sodium silicate solution treatment needs extensive research and development to further improve the process. A proposed experiment plan has been recommended to develop trends of pH and temperature and its influence on the effectiveness of the treatment. Nonetheless, due to the high energy consumption of the other processes, sodium silicate solution may be a proper step in decreases the carbon footprint, that is currently being created by the synthesis of Portland Cement Concrete and lime.
ContributorsMeza, Magdaleno (Author) / Zapata, Claudia (Thesis director) / Kavazanjian, Edward (Committee member) / Civil, Environmental and Sustainable Eng Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
This project is focused on local scale sustainability. The goal is to understand the impact of small unsustainable actions of people, and hopefully create a change in their habits. The focus was plastic usage, such as the use of water bottles, grocery bags, or even the packaging that our food and other products typically come in. Plastic has become an integral part of lives, where we do not even think of our actions as we stuff our leftover grocery bags in its designated drawer. My goal throughout this project was to guide people to an environmentally conscious lifestyle by increasing the likelihood of recycling on the ASU campus. I created an interactive informative presentation that focused on recycling and preventing plastic and unwanted trash from ending up in landfills and oceans. The presentation was given to a small group of participants along with two surveys. There was a survey provided before the presentation to gauge a participant's present recycling habits then there was a survey that was given some time after the presentation to track if certain recycling habits had changed due to the presentation. The post presentation survey did report that there were changes to some of the participants' recycling habits. The research provides suggestions to help increase recycling and waste prevention based off surveys that were widely distributed on campus. The top three suggestions that would help make recycling more prevalent on campus are: education on the subject, more accessibility to recycling bins, and creating an incentive program.
ContributorsVazquez, Juliana Evone (Author) / Parrish, Kristen (Thesis director) / Burke, Rebekah (Committee member) / Civil, Environmental and Sustainable Engineering Program (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
This thesis was prepared by Tyler Maynard and Hayley Monroe, who are students at Arizona State University studying to complete their B.S.E.s in Civil Engineering and Construction Engineering, respectively. Both students are members of Barrett, the Honors College, at Arizona State University, and have prepared the following document for the purpose of completing their undergraduate honors thesis. The early sections of this document comprise a general, introductory overview of earthquakes and liquefaction as a phenomenon resulting from earthquakes. In the latter sections, this document analyzes the relationship between the furthest hypocentral distance to observed liquefaction and the earthquake magnitude published in 2006 by Wang, Wong, Dreger, and Manga. This research was conducted to gain a greater understanding of the factors influencing liquefaction and to compare the existing relationship between the maximum distance for liquefaction and earthquake magnitude to updated earthquake data compiled for the purpose of this report. As part of this research, 38 different earthquake events from the Geotechnical Extreme Events Reconnaissance (GEER) Association with liquefaction data were examined. Information regarding earthquake depth, distance to the furthest liquefaction event (epicentral and hypocentral), and earthquake magnitude (Mw) from recent earthquake events (1989 to 2016) was compared to the previously established relationship of liquefaction occurrence distance to moment magnitude. The purpose of this comparison was to determine if recent events still comply with the established relationship. From this comparison, it was determined that the established relationship still generally holds true for the large magnitude earthquakes (magnitude 7.5 or above) that were considered herein (with only 2.6% falling above the furthest expected liquefaction distance). However, this relationship may be too conservative for recent, low magnitude earthquake events; those events examined below magnitude 6.3 did not approach established range of furthest expected liquefaction distance. The overestimation of furthest hypocentral distance to liquefaction at low magnitudes suggest the empirical relationship may need to be adjusted to more accurately capture recent events, as reported by GEER.
ContributorsMonroe, Hayley (Co-author) / Maynard, Tyler (Co-author) / Kavazanjian, Edward (Thesis director) / Houston, Sandra (Committee member) / Civil, Environmental and Sustainable Engineering Program (Contributor) / Construction Engineering (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Midwestern cities are in decline, with shrinking populations and corresponding disinvestment. Many organizations and city governments are working on addressing the problem of vacancy while bringing these urban areas into the global economy. The EcoBlock Organization (EBO), a St. Louis-based non-profit, proposes block-level redevelopment as a method of fostering community and economic development while minimizing the impact on the environment. The EcoCode is a block-level form-based code describing the vision of the EBO and its implementation. This vision is centered around eight key design principles: energy, public health, social, urban design, water, transportation, resilience, and landscape. It manifests as an EcoBlock: a block of buildings surrounding a shared green space, connected by an energy grid and a shared geothermal loop with the goal of net-zero energy. The residences are a mix of building types for a variety of incomes and some building space will be designated for shared use, all physically reflecting the historic design of houses in the city in which the EcoBlock is implemented. Specifications like design, building placement, and mechanisms by which to strive towards net-zero energy and water will be determined in each location in which the EcoBlock is developed. The EcoCode describes the process and the desired outcome, providing a framework for this implementation.
The EcoCode resembles a typical form-based code in structure, but at a smaller geographic scale. General Provisions describes the context of the surrounding area that must be assessed before choosing to create an EcoBlock. Development and Adoption strategy explains the evolving role of the EBO and how the realization of this design is currently envisioned. Regulating Block, Block Development Standards, Building Envelope Standards, and Building Development Standards describe the detail that will need to be developed for the physical aspects of each block. Streetscape Standards describe the vision of the EBO as applicable to the streets surrounding an EcoBlock. Finally, the Sustainability Standards contain the contribution of each board member of the EBO with their unique expertise on implementing the design principles.
As a supplement to The EcoCode itself, this document contains three topics for case studies looking into the feasibility of the EcoBlock as a whole: shared space, net-zero energy, and mixed-income housing. Shared space development and management uses Montgomery Park in Boston to show the potential of community-based organization while warning against gentrification. The West Village campus of the University of California in Davis shows the technical possibility and the financial challenges of a net-zero community. Brogården, an affordable housing community in Sweden, demonstrates the possibility for decreasing energy consumption in public housing. Finally, Via Verde in New York City is an example of combining health, green space, and affordability in a mixed-income housing development. Though there is not yet an example of a fully implemented EcoBlock, these case studies speak to the challenges and the facilitators that the EBO will likely face.
The EcoCode resembles a typical form-based code in structure, but at a smaller geographic scale. General Provisions describes the context of the surrounding area that must be assessed before choosing to create an EcoBlock. Development and Adoption strategy explains the evolving role of the EBO and how the realization of this design is currently envisioned. Regulating Block, Block Development Standards, Building Envelope Standards, and Building Development Standards describe the detail that will need to be developed for the physical aspects of each block. Streetscape Standards describe the vision of the EBO as applicable to the streets surrounding an EcoBlock. Finally, the Sustainability Standards contain the contribution of each board member of the EBO with their unique expertise on implementing the design principles.
As a supplement to The EcoCode itself, this document contains three topics for case studies looking into the feasibility of the EcoBlock as a whole: shared space, net-zero energy, and mixed-income housing. Shared space development and management uses Montgomery Park in Boston to show the potential of community-based organization while warning against gentrification. The West Village campus of the University of California in Davis shows the technical possibility and the financial challenges of a net-zero community. Brogården, an affordable housing community in Sweden, demonstrates the possibility for decreasing energy consumption in public housing. Finally, Via Verde in New York City is an example of combining health, green space, and affordability in a mixed-income housing development. Though there is not yet an example of a fully implemented EcoBlock, these case studies speak to the challenges and the facilitators that the EBO will likely face.
ContributorsJohn, Raveena Susan (Author) / Allenby, Braden (Thesis director) / Redman, Charles (Committee member) / Garcia, Margaret (Committee member) / Civil, Environmental and Sustainable Engineering Program (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The purpose of this research was to produce reduced graphene oxides for the fabrication of desalination membranes. Graphene has typically been considered a way to create more energy efficient desalination membranes. However, graphene is expensive and unstable, while graphene oxide has similar properties, but is less expensive and more stable. Graphene oxide membranes have the potential to perform above the permeability-selectivity tradeoff that is typical in membranes through size-based exclusion. Reduction through heat or Vitamin C reduces the size of graphene oxide nanochannels so salt and organic materials can be rejected in higher numbers. Both reduced and unreduced graphene oxide membranes were created and evaluated by their ability to filter dye and salt in a pressurized membrane cell. The permeability and rejection of the graphene oxide membrane is found to be dependent on the oxidation level of the graphene oxide material and the concentration on the graphene oxide on the membrane. Unreduced graphene oxide membranes were created in three concentrations: 7.37, 14.74, and 29.47 μg/cm2. As graphene oxide concentration increased, dye rejection and salt rejection increased, while water flux decreased. Graphene oxide was reduced in solution using Vitamin C and was used to create a 14.74 μg/cm2 membrane. The reduction resulted in an increase in salt rejection from 12.59% to 100%, an increase in dye rejection from 30.44% to 100%, and a decrease in water flux from 9.502 to 0.198 L/(hr*m2*bar). Future research should focus on creating membranes using different methods of synthesizing graphene oxide from graphene and creating a reduced graphene oxide membrane with a higher water flux.
ContributorsAlbrecht, Alissa Marie (Author) / Perreault, Francois (Thesis director) / Laurin, Eric (Committee member) / Civil, Environmental and Sustainable Engineering Program (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12