Mud

Sludge is a mixture of finely divided, mostly very fine-grained solids and a relatively small amount of liquid, usually, but not necessarily caused by sedimentation.

Etymology and colloquial use

The word mud is attributed to the late Middle High German slam (soft, wet sediment ), or to the Middle Low German slam (dirt, mud ). This corresponds to the colloquial meaning today. Mud is here almost synonymous with mud, wet earth, dirt.

More specific use of the term

Technical definition

Generally produces a sludge from a suspension that is predominantly microscopic particles of a solid substance dispersed in a liquid are in limbo. If such a mixture stand for some time quiet, so the suspended solids settle to the bottom, if they have a higher density than the surrounding liquid. The resulting very fine-grained sediment (sediment ) is called the mud. The solid particles are separated here no longer in suspense, but densely packed and only by a thin liquid film. An example of this is the sludge that settles in the clarifier of a wastewater treatment plant.

Geoscience definitions

Sedimentology

In the Sedimentology the definition is narrower. There is known as a very fine-grained sediment sludge, which is formed from natural mineral and organic matter by natural sedimentation in standing, but not necessarily permanent waters. The inorganic sludge particles are composed of different minerals and have different origins. Among the terrigenous muds include the clay slip, since they have their origin in the weathering and erosion of rocks on dry land and through streams and rivers into lakes and flushed into the sea or be mediated by high water, accumulate in lowlands. The particles consist of a Tonschlammes significantly from clay minerals. This contrasts with sludges whose particles directly to the water, on the ground they settle originate. These often consist of the mineral skeletons of micro-organisms living in the water. Depending on the material from which these skeletons, a distinction is made in lime mud ( calcium carbonate, CaCO3) or Kieselschlämme ( silicon dioxide, SiO2). Often the slurry is also directly designated by the microorganisms of the skeletons it consists mainly, on the case of a gravel slurry, for example, as Radiolarienschlamm or in the case of a lime slurry for example, as globigerina mud.

Camps over the course of time, many layers of mud on each other from, the lowest layers come under ever-increasing pressure. Thus they are dehydrated and solidify, partly with the involvement of chemical processes. The result of a soft mud a fine-grained, brittle sedimentary rocks. The geological process of solidification of sludge to a rock falls under the heading of diagenesis. Depending on the starting material is produced mudstone, fine-grained limestone ( micrite ) or chert.

Others

Silt is a clay slurry with a high proportion of organic admixtures, resulting among other things in Watten. If a organikreicher mud deposited in oxygen-deficient or oxygen-free water, it forms hydrogen sulfide among others. One then speaks of a digested sludge ( sapropel ). In a mud pot " bubbling " a mixture of superheated steam and fine-grained volcanic material. Deposited on hillsides volcanic ash, which is softened by heavy rain, can go in the form of a mudslide to the valley.