A mathematical model to predict nickel concentration in karaj river sediments
The contamination of surface waters through human activities has been increased over the past years as population density has increased. To fully understand the anthropogenic impact on an ecosystem, long-term data from chemical, physical and biological indicators are needed. To many people, heavy metal pollution is a problem associated with areas of intensive industry. Metals, such as nickel and cadmium, are also found in road runoff and exhaust. Metals strongly associated with the surface of particles, their transport and deposition in estuarine and coastal systems are often closely related to the transport and deposition of fine-grained sediments (Olsen et al., 1982; Dzombak and Morel, 1987; Davis and Hem, 1989; Scheidigger et al., 1997; Bertsch and Seaman, 1999).
In the absence of significant changes in sediment texture, trace metal accumulation rates in sediment cores can reflect variations in metal inputs in a given system over long periods of time. A large amount of the total elemental constitution of most sediments is in a residual fraction as part of the natural minerals that make up the sediment particles. These residual elements are not bioaccessible; the remaining elements in sediments are adsorbed to or complexed with various sediment components and may be bioaccessible.