Glossary

Process whereby the salt load of a water body is increased, e.g. by salts not removable during wastewater purification or through the introduction or recirculation of salts from a seawater desalination system into a body of water.

Entry of salt or brackish water into the groundwater through the movement of fresh/salt water boundaries.

Deposits in water bodies created through settling (sedimentation) of mineral and/or organic solids. We distinguish between clastic (suspended matter, sand, rock), chemical (substances separated from aqeuous solutions, e.g. carbonate) and biogenic sediments (deposited organisms or their remains, e.g. coquina).

Study of the earth’s crust through the use of artificially generated seismic waves.

Test or pilot systems are usually assessed on a smaller semi-industrial scale – i.e. with practical relevance – before a full-size system is built.

Small ponds in which wastewater is cleaned biologically by means of plants.

In sewage plants, water flows into the primary sedimentation tank via the sand and grease trap. In this first treatment chamber, undissolved substances are deposited in the form of sewage sludge (mechanic purification).

Regulates the application of sewage sludge from wastewater treatment plants to agricultural, forested or horticultural land.

Slow filters are based on the principles of natural soil filtration and are characterised by their low flow velocity. The high surface area requirements are a disadvantage of this method. However, slow filters are beneficial wherever surface water is to be used.

Process whereby a solid or liquid substance takes up or holds another gaseous or dissolved substance. The term sorption refers to processes resulting in the enrichment of a substance within a phase (absorption) or on an interfacial surface between two phases (adsorption). The term is used when absorption and adsorption cannot be clearly distinguished. The sorbing substance is also referred to as the sorbent (or sorbent material).

The measurement of a spectrum from a radiation source.

When part of a company or institution is set up as a separate business, this is described as a spinoff.

Geoscience discipline involving the study and dating of rock strata.

Removal of water-based substances through the injection of air/gas. The dissolved substances are transferred to the gaseous phase and consequently removed from the water.

A sparingly soluble compound of ammonium and magnesium named after the scientist Heinrich Christoph Gottfried von Struve (1772–1851).

In fixed bed reactors, which are frequently used in biotechnology, the elements responsible for the substance conversion (microorganisms, enzymes) are bound to fixed carrier materials (fixed bed). A liquid stream directs the other components involved in the process (e.g. substrates, gases) past the fixed bed, which can be made of ceramic, glass, plastic or natural material. In the case of a submerged fixed bed, the carrier material of the fixed bed is fully immersed in the untreated wastewater. Oxygen is supplied by means of pressure aeration (which is also used for flushing purposes).

An interfacial surface is the contact zone between two phases, e.g. between water and air or between oil and water. Surface tension causes the surface of a liquid to behave like an elastic film.

The term suspension is used to describe a liquid containing finely distributed solid particles which are held in a suspended state – e.g. through agitation or stirring.