The electron- and γ-irradiation of humic substances

✍ Scribed by Nicola Seriesi; Yona Chen; Morris Schnitzer

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 777 KB
• Volume: 56
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(77)90139-9

✦ Synopsis

Humic substances are often considered as precursors of coal and kerogen, so that the chemistry of humic materials should be of interest to fuel scientists. This paper describes the behaviour of soil humic and fulvic acid toward high-energy irradiation. A humic and a fulvic acid were irradiated as solids with electrons and y-rays, employing dosages ranging from 0.8 to 93.0 Mrads . In addition, the humic materials were also y-irradiated in aqueous solutions at different pH levels. Effects of irradiation were assessed by chemical, spectrophotometric, spectrometric and thermal analyses. Irradiation caused only minute changes, which were limited in the main to decreases in particle size with increasing irradiation when humic and fulvic acid were exposed as solids. When exposed in solution, irradiation at neutral and acid pH tended to bring about aggregation (formation of larger particles), whereas irradiation at high pH favoured dispersion (formation of smaller particles). Aside from causing changes in particle size, irradiation at the levels employed did not appear to cause major changes in the chemical structures of the humic materials. Thus, high-energy irradiation is not a useful method for degrading complex humic substances into simpler molecules.