This diploma thesis deals with the mechanism of chromate sorption by variable soils. Therefore first of all a detailed literature research about the different ways of sorption, the behaviour of heavy metals in environment and the composition and properties of soils take place. The practical part of this thesis describes sorption experiments, which should be the base for evidence concerning the sorption behaviour of chromate by different soils and at different pH-values. The experiments are realized in batch-reactors, while measuring the change of chromate concentration in a dilution which is in contact with definite soils. These values are needed to make the calculations for defining the sorption isotherms.