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Degradation kinetics and mechanisms of hexafluoropropylene oxide dimer acid (GenX) during VUV photolysis and VUV/sulfite processes : VUV 광분해와 VUV/아황산염 공정에서의 hexafluoropropylene oxide dimer acid(GenX) 제거 동역학 및 메커니즘

DC Field Value Language
dc.contributor.advisor조경덕-
dc.contributor.author김재희-
dc.date.accessioned2024-05-31T18:01:19Z-
dc.date.available2024-05-31T18:01:19Z-
dc.date.issued2023-
dc.identifier.other000000175011-
dc.identifier.urihttps://hdl.handle.net/10371/204016-
dc.identifier.urihttps://dcollection.snu.ac.kr/common/orgView/000000175011ko_KR
dc.description학위논문(석사) -- 서울대학교대학원 : 보건대학원 환경보건학과, 2023. 2. 조경덕.-
dc.description.abstractGenX라고 불리기도 하는 hexafluoropropylene oxide dimer acid(HFPO-DA)는 최근 다양한 수계에서 검출되고 있으며, 환경 내 잔류성과 독성으로 인해 우려의 대상이 되고 있다. 본 연구에서는 질소 포화 조건에서 진공자외선(VUV) 광분해와 VUV/아황산염(SO32-) 반응 동안 수중 GenX의 분해를 연구하였다. 모든 반응에서 GenX의 분해 반응은 유사 1차 반응을 따랐다. VUV 광분해 반응에서는 pH 6에서 제거율이 가장 높게 나타난 반면, VUV/SO32- 반응에서는 높은 pH 조건에서 제거율이 증가하였다. 수산화 라디칼(•OH)은 GenX의 분해에 기여하지 않았으며, VUV/SO32- 공정에서는 부정적인 효과를 보였다. 두 반응에서의 GenX의 제거 부산물은 LC-MS/MS와 LC-QTOF/MS를 사용해 확인되었다. VUV 광분해 반응에서는 3개의 부산물(TFA, PFPrA, TP120)이 발견된 반면, VUV/SO32- 반응에서는 6개의 부산물(TFA, PFPrA (TP164), TP120, TP182, TP186, TP366)이 발견되었다. 또한 GenX의 탈불소화가 관찰되었으며, VUV 광분해와 VUV/SO32-에서 각각 6시간 동안 17%와 67%의 탈불화율을 달성하였다. 식별된 제거 부산물과 친핵성 공격에 대한 반응성을 확인하는 이론적 계산을 기반으로 GenX의 분해 경로를 제안하였다. 분해 반응의 시작은 C-C 결합 절단, C-O 결합 절단 및 탈카르복실화 후의 설폰화로 확인되었다. 또한, ECOSAR 시뮬레이션을 이용한 생태 독성 예측은 분해 부산물의 독성을 간과해서는 안 된다는 것을 보여준다.-
dc.description.abstractHexafluoropropylene oxide dimer acid (HFPO-DA), referred to as GenX, has been recently detected in various water bodies, and become a subject of concern due to its environmental persistence and toxicity. In this study, we investigated the degradation of GenX in water under N2-saturated conditions during vacuum ultraviolet (VUV) photolysis and VUV/sulfite reactions. The decomposition reaction of GenX in all reactions followed the pseudo-first order kinetics. While the removal rate was highest at pH 6 during the VUV photolysis, the removal efficiency increased at high pH conditions in the VUV/sulfite reaction. The hydroxyl radicals (•OH) did not contribute to the degradation of GenX and showed a negative effect during the VUV/sulfite reaction. The transformation products (TPs) of GenX in both reactions were identified using LC-MS/MS and LC-QTOF/MS. Three TPs (TFA, PFPrA, and TP120) were identified in the VUV photolysis reaction while six TPs (TFA, PFPrA (TP164), TP120, TP182, TP186, and TP366) were identified in the VUV/sulfite reaction. Defluorination of GenX was also observed, achieving 17% and 67% for 6 hr in both reactions, respectively. We proposed the degradation pathways of GenX based on the identified TPs and theoretical calculations confirming the reactivity to nucleophilic attack. The initiation reactions for GenX decomposition were found to be C-C bond cleavage, C-O bond cleavage, and sulfonation after decarboxylation. In addition, ecotoxicity prediction using ECOSAR simulation showed that the toxicity of TPs should not be overlooked.-
dc.description.tableofcontents1. Introduction 1
1.1. Background 1
1.2. Previous studies on the degradation of GenX 4
1.3. Vacuum ultraviolet (VUV) studies on the degradation of micropollutants 7
1.4. Objectives 8
2. Materials and Methods 9
2.1. Chemicals 9
2.2. Experimental methods 10
2.3. Analytical methods 12
2.4. Computational methods 13
2.5. In silico toxicity assessment 14
3. Results and Discussion 15
3.1. Degradation kinetics of GenX 15
3.2. Effect of pH 19
3.3. Roles of reactive species 23
3.4. Identified TPs and defluorination 27
3.5. Theoretical calculation and degradation mechanisms 32
3.6. In silico toxicity assessment 40
4. Conclusions 44
5. References 46
6. Supporting Information 54
국문초록 66
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dc.format.extentⅵ, 67-
dc.language.isoeng-
dc.publisher서울대학교 대학원-
dc.subjectGenX-
dc.subjectvacuum ultraviolet-
dc.subjecthydrated electron-
dc.subjecthydrogen atom-
dc.subjecttransformation products-
dc.subjectdefluorination-
dc.subject.ddc363.7-
dc.titleDegradation kinetics and mechanisms of hexafluoropropylene oxide dimer acid (GenX) during VUV photolysis and VUV/sulfite processes-
dc.title.alternativeVUV 광분해와 VUV/아황산염 공정에서의 hexafluoropropylene oxide dimer acid(GenX) 제거 동역학 및 메커니즘-
dc.typeThesis-
dc.typeDissertation-
dc.contributor.AlternativeAuthorJaehee Kim-
dc.contributor.department보건대학원 환경보건학과-
dc.description.degree석사-
dc.date.awarded2023-02-
dc.identifier.uciI804:11032-000000175011-
dc.identifier.holdings000000000049▲000000000056▲000000175011▲-
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