Delayed geochemical hazard: Concept, digital model and case study

Delayed Geochemical Hazard (DGH briefly) presents the whole process of a kind of serious ecological and environmental hazard caused by sudden reactivation and sharp release of long-term accumulated pollutant from stable species to active ones in soil or sediment system due to the change of physical-chemical conditions (such as temperature, pH, Eh, moisture, the concentrations of organic matters, etc.) or the decrease of environment capacity. The characteristics of DGH are discussed. The process of a typical DGH can be expressed as a nonlinear polynomial. The points where the derivative functions of the first and second orders of the polynomial reach zero, minimum and maximum are keys for risk assessment and harzard pridication.The process and mechanism of the hazard is due to the transform of pollutant among different species principally. The concepts of "total releasable content of pollutant", TRCP, and "total concentration of active specie", TCAS, are necessarily defined to describe the mechanism of DGH. The possibility of the temporal and spatial propagation is discussed. Case study shows that there exists a transform mechanism of "gradual release" and "chain reaction" among the species of the exchangeable and the bounds to carbonate, iron and manganese oxides and organic matter, thus causing the delayed geochemical hazard.

作 者： CHEN Ming FENG Liu Jacques Yvon   作者單位： CHEN Ming(National Research Center of Geoanalysis, Beijing 100037, China;College of Chemical Engineer, Beijing University of Chemical Technology, Beijing 100029, China;Laboratoire Environnement et Mineralurgie, BP 50. F-54501, Vandoeuvre les Nancy Cedex, France)

FENG Liu(College of Chemical Engineer, Beijing University of Chemical Technology, Beijing 100029, China)

Jacques Yvon(Laboratoire Environnement et Mineralurgie, BP 50. F-54501, Vandoeuvre les Nancy Cedex, France) 

刊 名： 中國科學D輯（英文版）  SCI 英文刊名： SCIENCE IN CHINA SERIES D(EARTH SCIENCES)  年，卷(期)： 2005 48(z2)  分類號： P59  關鍵詞： environmental geochemistry   delayed geochemical hazard   environmental capacity   geochemistry   hazard   prediction  

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