ABSTRACT
Human civilisation increasingly relies on the usage of various metal resources, including heavy metals. Heavy metals were originally sequestered inside the Earth as ore deposits. With industrialisation, great amounts of metals have been excavated and released on the Earth’s surface and dissipated into the environment. The biosphere, atmosphere, hydrosphere, and
CONTENTS
10.1 Life Cycle of Heavy Metals and Trace Elements ...................................264 10.2 Major Biogeochemical Processes Governing Recycling of
Trace Elements ............................................................................................ 266 10.2.1 Oxidation-Reduction Processes .................................................. 266 10.2.2 Adsorption and Desorption Reactions ....................................... 267 10.2.3 Volatilisation Reactions ................................................................. 267 10.2.4 Dissolution and Precipitation ....................................................... 268
10.3 Biogeochemical Cycling of Trace Elements in Mine Tailing ............... 268 10.4 Biogeochemical Cycling of Trace Elements in Sewage/Sludge
Applied Soils .............................................................................................. 270 10.4.1 Distribution of Trace Elements in Sewage Sludge .................... 271 10.4.2 Distribution and Redistribution of Trace Elements
in Sludge-Amended Soils ............................................................. 271 10.4.3Transport and Bioavailability of Trace Elements in Sludge-Amended Soils ............................................................. 272
10.5 Biogeochemical Cycling of Trace Elements in Animal Waste-Applied Soils ................................................................................... 273
10.5.1 Accumulation of Heavy Metals in Animal Waste-Amended Soils ................................................................... 273 10.5.2 Fractionation Distribution of Heavy metals in Animal
Waste-Amended Soils ................................................................... 274 10.5.3Mobility in the Soil Proles .......................................................... 275
10.6 Conclusion .................................................................................................. 275 Acknowledgement .............................................................................................. 276 References ............................................................................................................. 276
pedosphere have been polluted by heavy metals or ngerprinted by human civilisation (Han et al. 2002, 2003). Heavy metals enter the pedosphere in various forms during metal mining, smelting, processing, recycling and the disposals of wastes (Han et al. 2000, 2001a,b,c). Heavy metals are emitted into the atmosphere through human activities, such as combustion of coal, mining and processing, and are transported globally and nally deposited by wet and dry processes into the pedosphere (Nriagu 1979; Nriagu and Pacyna 1988).
