PCBs의 광화학적 연구: NaOH 및 휴믹산(Humic acid, HA)에 의한 분해특성

• 영문명: Effects of NaOH and Humic Acid on the UV Photolysis of PCBs
• 발행기관: 한국환경보건학회
• 저자명: 신혜승(Hae Seung Shin) 김재현(Jae Hyoun Kim)
• 간행물 정보: 『1. 한국환경보건학회지』제40권 제2호, 147~156쪽, 전체 10쪽
• 주제분류: 공학 > 환경공학
• 파일형태: PDF
• 발행일자: 2014.04.30

영문 초록

Objectives: This study was carried out to examine whether the apparent photolysis with or without sensitizers [NaOH and humic acid(HA)] was prompted photodegradation of polychlorinated biphenyl(PCB) in aqueous solution. Methods: PCBs photodegradation occurred using fluorescence black lamps at λ max = 300 nm. PCB congeners were exposed in 10 ppm HA or 0.05N NaOH solutions, to investigate the decreasing profile of PCB concentration with time. The PCBs were then analyzed by gas chromatography/mass spectrometry(GC-MS). Reductive degradation profile of PCB congeners in the presence of both sensitizers under oxygen-saturated protic conditions was described using the wind-rose diagrams. Results: Use of HA or NaOH decreased PCB concentration with time in the dark and on irradiation, indicating that photolysis underwent through reductive dechlorination through energy transfer and possibly with reactive oxygens. The dechlorination was marked by a chromatographic shift, observed in the GC-MS plots. Therefore it is logical to assume that increasing the dose of sensitizers would increase the photodegradation rates of PCBs. The half-lives of pentachloro-PCB(penta-3) in 0.05N NaOH and 10 ppm HA were estimated at about 47 hours and 39 hours, respectively, under the same experimental conditions of photolysis. It was found that the rate of photolysis of pentachloro-PCB in aqueous solution followed apparent first-order kinetics compared to other congeners. Conclusion: Photochemical degradation(using 328 nm UV light) of penta- and hexa-PCBs in HA or alkaline solution is a viable method for pretreatment method. The results are helpful for the further comprehension of the reaction mechanism for photolytic dechlorination of PCBs in aquatic system.

목차

I. 서 론

II. 재료 및 방법

III. 결 과

IV. 고 찰

V. 결 론

키워드

Humic acid NaOH Photosensitizer Polychlorinated biphenyl UV photodegradation