2007 Volume 116 Issue 6 Pages 906-914
Humic substances (HSs), which are ubiquitous in soil environments, are directly and/or indirectly related to the detoxification of organic pollutants. To enhance the catalytic activity of iron (III) -porphyrins (Fe (III) -Por) and phthalocyanines (Fe (III) -Pc), which mimick the active centers of oxidative enzymes from soil microorganisms, the effects of adding of HSs were examined. In this paper, the author reviews a series of works on the effects of humic substances on the oxidative degradation of organic pollutants by biomimetic catalytic systems. The degradation of pentachlorophenol by both Fe (III) -Por and Fe (III) -Pc was dramatically enhanced in the presence of some HSs with lower polarity. It was found that self-degradation of catalysts resulted in a reduction of catalytic activity. In addition, Fe (III) -Por was incorporated into HS via hydrophobic interactions, and kinetic constants for self-degradation decreased with an increase in the binding constant. Therefore, the formation of a supramolecular complex between Fe (III) -Por and HS can stabilize the catalyst, and this leads to enhanced catalytic activity.