DEGRADATION OF HUMIC SUBSTANCES BY UV IRRADIATION

被引：116

作者：

ALLARD, B ^{[1
]}

BOREN, H ^{[1
]}

PETTERSSON, C ^{[1
]}

ZHANG, G ^{[1
]}

机构：

[1] LINKOPING UNIV,DEPT WATER & ENVIRONM STUDIES,S-58183 LINKOPING,SWEDEN

来源：

ENVIRONMENT INTERNATIONAL | 1994年 / 20卷 / 01期

关键词：

D O I：

10.1016/0160-4120(94)90072-8

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Aqueous solutions of humic substances (humic and fulvic acids) were irradiated with light at lambda = 254 nm followed by analyses of total organic carbon (TOC), ultraviolet (UV) absorbance and molecular weight distribution. A degradation of the dissolved humic compounds by up to 50% after 6 h was observed. The average molecular weight decreased (from 1800 to approx. 300) as well as the UV absorbance of the remaining organic fraction. Low molecular weight organic acids were formed during the irradiation and tentatively identified by capillary electrophoresis (formic, acetic, succinic, and oxalic acids). The low molecular organic acids continued to degrade by further irradiation; the loss of TOC is assumed to be due to CO2 formation. Indications of a large-scale photo degradation process in nature was observed as a seasonal variation of the ratio humic substances/TOC related to the length of the day. Weekly sampling and analysis of UV absorbance and TOC in the Kalix River in northern Sweden indicate a higher humic fraction of the TOC during winter (dark period) than during summer.

引用

页码：97 / 101

页数：5

共 8 条

[1]

de Haan, de Boer, UV-degradation of aquatic humic substances, Finn. Humus News, 3, pp. 177-182, (1991)

[2]

Frimmel, Huber, Liquid chromatography with three dimensional detection of humic substances and oxidation products, Finn. Humus News, 3, pp. 127-132, (1991)

[3]

Gilbert, Einwirkung von Ozon auf Huminsäuren in wässrigen Lösungen, Vom Wasser, 55, pp. 1-13, (1980)

[4]

Gjessing, Gjerdahl, Influence of ultraviolet radiation on aquatic humus, Vatten, 26, pp. 144-145, (1970)

[5]

Kieber, McDaniel, Mopper, Photochemical source of biological substrates in seawater: implications of carbon cycling, Nature, 341, pp. 637-639, (1989)

[6]

Nowell, Hoigne, Photolysis of aqueous chlorine at sunlight and ultraviolet wavelengths. I. Degradation rates, Water Res., 26, pp. 593-598, (1992)

[7]

Pettersson, Ephraim, Allard, On the composition and properties of humic substances isolated from deep groundwater and surface waters, Org. Geochem., (1994)

[8]

Strome, Miller, Photolytic changes in dissolved humic substances, Verh. Int. Verein. Limnol., 20, pp. 1248-1254, (1978)

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