| dc.identifier.uri | http://hdl.handle.net/11401/76341 | |
| dc.description.sponsorship | This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree. | en_US |
| dc.format | Monograph | |
| dc.format.medium | Electronic Resource | en_US |
| dc.language.iso | en_US | |
| dc.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dc.type | Dissertation | |
| dcterms.abstract | This dissertation focuses on the use of composite materials for environmental applications. For the first time, applications of both fresh and aged concrete as inexpensive adsorbents for nitrogen dioxide (NO2) removal is demonstrated. Concrete is the most widely used composite material of the modern era. Cement manufacturing (a major component of concrete) is considered to be one of the leading contributors to air pollution, resulting in 7% of the global carbon dioxide emissions along with a number of other harmful pollutants such as oxides, mercury and particulates. These emissions aide in the formation of acid rain, smog, and toxic ground level ozone, causing detrimental effects such as respiratory illnesses, visibility reduction, eutrification and global warming. This thesis offers a novel and sustainable solution in mitigating NOX emissions, by introducing the significant adsorption potential of recycled concrete. The work is based on both commercially available cement paste and already aged concrete samples, providing truly scalable solutions. The concrete samples aged for different periods of time were exposed to NO2 to measure their adsorption capacity. The results show that all of the concrete samples (fresh and aged) exhibited excellent NO2 adsorption capacity, with the fresh concrete samples removing almost 100% of the NO2. Furthermore, to compare the effects of long term aging, 12 year-old recently demolished concrete samples were obtained and its NOX removal was shown to be almost 60%. The experimental results provide evidence of nitrate and nitrite species formation from chemical reactions occurring between NO2 and surface alkaline species. This important discovery can be utilized for NO2 removal and subsequent NOX sequestered demolished concrete (NSDC) recycling in new concrete, either as a set accelerating admixture or as a corrosion inhibitor, a big leap towards better sustainability and longevity of the new reinforced concrete structures. The rest of this thesis focuses on development of a new generation of ceramic membranes utilizing thermal spray techniques to produce highly scalable and extremely cost effective filtration membranes. Thermal spray method of membrane manufacturing has the advantage of economic scalability (up to tens of square meters) along with performance enhancement as compared to conventional wet casting process. In addition to developing a proof of concept for this approach, several strategies on how to improve ceramic membranes’ performance via spraying process optimization are also described. Specifically, several thermal sprayed Alumina membrane samples were prepared by varying different process parameters. These samples were characterized using known techniques and subjected to permeability and size exclusion tests to correlate spraying parameters with membranes’ performance. The membrane samples showed excellent clean water flux comparable to commercially available membranes and had rejection rates up to 96%. These results show that the membranes produced in this research achieve outstanding performance at a fraction of the cost of commercially produced membrane, enabling the use of membrane filtrations units in developing countries. | |
| dcterms.abstract | This dissertation focuses on the use of composite materials for environmental applications. For the first time, applications of both fresh and aged concrete as inexpensive adsorbents for nitrogen dioxide (NO2) removal is demonstrated. Concrete is the most widely used composite material of the modern era. Cement manufacturing (a major component of concrete) is considered to be one of the leading contributors to air pollution, resulting in 7% of the global carbon dioxide emissions along with a number of other harmful pollutants such as oxides, mercury and particulates. These emissions aide in the formation of acid rain, smog, and toxic ground level ozone, causing detrimental effects such as respiratory illnesses, visibility reduction, eutrification and global warming. This thesis offers a novel and sustainable solution in mitigating NOX emissions, by introducing the significant adsorption potential of recycled concrete. The work is based on both commercially available cement paste and already aged concrete samples, providing truly scalable solutions. The concrete samples aged for different periods of time were exposed to NO2 to measure their adsorption capacity. The results show that all of the concrete samples (fresh and aged) exhibited excellent NO2 adsorption capacity, with the fresh concrete samples removing almost 100% of the NO2. Furthermore, to compare the effects of long term aging, 12 year-old recently demolished concrete samples were obtained and its NOX removal was shown to be almost 60%. The experimental results provide evidence of nitrate and nitrite species formation from chemical reactions occurring between NO2 and surface alkaline species. This important discovery can be utilized for NO2 removal and subsequent NOX sequestered demolished concrete (NSDC) recycling in new concrete, either as a set accelerating admixture or as a corrosion inhibitor, a big leap towards better sustainability and longevity of the new reinforced concrete structures. The rest of this thesis focuses on development of a new generation of ceramic membranes utilizing thermal spray techniques to produce highly scalable and extremely cost effective filtration membranes. Thermal spray method of membrane manufacturing has the advantage of economic scalability (up to tens of square meters) along with performance enhancement as compared to conventional wet casting process. In addition to developing a proof of concept for this approach, several strategies on how to improve ceramic membranes’ performance via spraying process optimization are also described. Specifically, several thermal sprayed Alumina membrane samples were prepared by varying different process parameters. These samples were characterized using known techniques and subjected to permeability and size exclusion tests to correlate spraying parameters with membranes’ performance. The membrane samples showed excellent clean water flux comparable to commercially available membranes and had rejection rates up to 96%. These results show that the membranes produced in this research achieve outstanding performance at a fraction of the cost of commercially produced membrane, enabling the use of membrane filtrations units in developing countries. | |
| dcterms.available | 2017-09-20T16:50:03Z | |
| dcterms.contributor | Orlov, Alexander | en_US |
| dcterms.contributor | Kim, Tae Jin | en_US |
| dcterms.contributor | Halada, Gary | en_US |
| dcterms.contributor | Walker, Harold. | en_US |
| dcterms.creator | Ramakrishnan, Girish | |
| dcterms.dateAccepted | 2017-09-20T16:50:03Z | |
| dcterms.dateSubmitted | 2017-09-20T16:50:03Z | |
| dcterms.description | Department of Materials Science and Engineering. | en_US |
| dcterms.extent | 187 pg. | en_US |
| dcterms.format | Monograph | |
| dcterms.format | Application/PDF | en_US |
| dcterms.identifier | http://hdl.handle.net/11401/76341 | |
| dcterms.issued | 2015-12-01 | |
| dcterms.language | en_US | |
| dcterms.provenance | Made available in DSpace on 2017-09-20T16:50:03Z (GMT). No. of bitstreams: 1
Ramakrishnan_grad.sunysb_0771E_12486.pdf: 5518859 bytes, checksum: d347b16ee670ddfc89c37e3497a18dbf (MD5)
Previous issue date: 1 | en |
| dcterms.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dcterms.subject | Materials Science | |
| dcterms.subject | Adsorbents, Alumina, Concrete, Filtration, Membranes, Sequestration | |
| dcterms.title | Development of New Generation of Ceramics for Environmentally Focused Chemical Separations | |
| dcterms.type | Dissertation | |
