Samenvatting

The goal of this thesis has been to test Phoslock® as an artificial tracer that can be used as a time marker in the sediment. The application of Phoslock® is a method to restore a lake by removing phosphate from water. Phoslock® consists of bentonite and lanthanum. It was decided to test Phoslock® because a prior internship showed that lanthanum is easily retraceable in lake sediment by elemental analysis. The bachelor thesis was closely connected to the internship results but investigates the mobility of lanthanum in sediment under laboratory conditions and the possible application in the field.