| dc.identifier.uri | http://hdl.handle.net/11401/77821 | |
| 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 | Mineral-induced Reactive Oxygen Species (ROS) are both harmful to human health as well as useful in degrading persistent organic pollutants. Metal sulfide minerals, particularly pyrite, have been studied for ROS generation and their role in lung diseases. Pyrite has also been known to degrade organic pollutants such as Trichloroethylene (TCE) in aqueous solutions. In hydrometallurgical studies, pyrite is often used along with chalcopyrite for efficient leaching of copper from chalcopyrite. The possible reason for this is the galvanic interaction between two minerals, which causes preferential oxidation of chalcopyrite. Recent studies on bioleaching of copper from chalcopyrite have shown that addition of pyrite leads to lower leaching rates. Therefore, the lack of understanding how pyrite and chalcopyrite interact when both present in minerals slurries, leading to enhanced oxidation of chalcopyrite in abiotic systems while limiting bioleaching through the production of ROS has motivated the study of mixed mineral mechanism in this dissertation. Besides metal sulfide-generated ROS, there is limited data on how other materials, such as simulants relevant to human space exploration or metal ions leached from simulants may produce ROS in water or more realistically, in biofluids. Therefore, ROS production by dissolved metal ions and simulants in simulated biofluids has also been evaluated in this dissertation. In this work, the kinetics and mechanism of production of •OH systematically in abiotic experiments with variable pyrite/chalcopyrite content was studied using adenine probe. This fundamental study was complemented with a study of the effect of pyrite-chalcopyrite composition on the degradation of TCE, a persistent organic molecule, extending earlier work on pyrite-mediated TCE degradation. In addition, the dynamics of H2O2 formation in pyrite-chalcopyrite slurries was evaluated to provide insight on the mechanism involved in ROS formation in these complex slurries along with the dissolved Fe(II) and Cu(II) and their mixtures. In the final component of the applied work, the formation of ROS by a suite of common lunar simulants was evaluated. The studies presented in this work made use of well-established techniques to study the formation of ROS, complemented by a new in situ electrochemical method to determine H2O2 concentration at a sub-second sampling rate, capable of capturing the rapid rise and fall of this •OH precursor in chalcopyrite-pyrite slurries. The results with adenine in this study show non-linear •OH production in the mixed slurries of pyrite-chalcopyrite as compared to pure minerals. The non-linear effect of mixed slurries was also observed with TCE results. Further, the results with electrochemical probe for H2O2 formation show non-linear H2O2 formation in the mixed slurries of pyrite-chalcopyrite. The results for H2O2 formation with dissolved metal ions in simulated biofluids show H2O2 formation in both lung and cerebrospinal fluid. The H2O2 degradation results in biofluids show that mixture of Fe(II) and Cu(II) promote degradation at a higher rate as compared to Fe(II) and Cu(II) alone. The results of H2O2 formation with lunar simulants in simulated lung fluid show continuous generation of H2O2 in lung fluid in contrast to aqueous solution where H2O2 after reaching a peak value starts to decrease. The non-linear behavior of pyrite-chalcopyrite in this study suggests synergy between these two minerals which can be exploited for the development of advanced remediation techniques as demonstrated by the TCE work. The underlying mechanism is likely a combination of the galvanic effect and an effect here referred to as the cofactor model which suggests that H2O2 produced by chalcopyrite is converted to •OH with the help of pyrite. The role of metals dissolved by pyrite and chalcopyrite add an additional level of complexity particularly in biofluids where metal-ligand driven reactions can lead to additional formation of H2O2. These results indicate that co-exposures of pyrite-chalcopyrite may lead to sustained production of ROS. | |
| dcterms.available | 2017-09-26T16:57:25Z | |
| dcterms.contributor | Schoonen, Martin A. | en_US |
| dcterms.contributor | Rasbury, Troy | en_US |
| dcterms.contributor | Reeder, Richard | en_US |
| dcterms.contributor | Hurowitz, Joel | en_US |
| dcterms.contributor | Strongin, Daniel. | en_US |
| dcterms.creator | Kaur, Jasmeet | |
| dcterms.dateAccepted | 2017-09-26T16:57:25Z | |
| dcterms.dateSubmitted | 2017-09-26T16:57:25Z | |
| dcterms.description | Department of Geosciences. | en_US |
| dcterms.extent | 153 pg. | en_US |
| dcterms.format | Monograph | |
| dcterms.format | Application/PDF | en_US |
| dcterms.identifier | http://hdl.handle.net/11401/77821 | |
| dcterms.identifier | Kaur_grad.sunysb_0771E_12598.pdf | en_US |
| dcterms.issued | 2015-05-01 | |
| dcterms.language | en_US | |
| dcterms.provenance | Submitted by Jason Torre (fjason.torre@stonybrook.edu) on 2017-09-26T16:57:25Z
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| dcterms.provenance | Made available in DSpace on 2017-09-26T16:57:25Z (GMT). No. of bitstreams: 1
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Previous issue date: 2015-05-01 | en |
| dcterms.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dcterms.subject | Geochemistry | |
| dcterms.subject | Electrochemical probe, Lunar simulants, Mineral mixtures, Reactive Oxygen Species(ROS), Simulated Biological Fluids, Trichloroethylene (TCE) | |
| dcterms.title | Mineral-Induced Reactive Oxygen Species(ROS) formation and its effect on Organic Pollutants and Human Health | |
| dcterms.type | Dissertation | |
