Suspended solids

Suspended solids or suspended solids in water, air (or other surrounding medium ) contained mineral or organic solids that do not go into solution and because of their small size and thus low weight (especially at a similar density as the surrounding medium ) held in suspension or already. distributed again by slight movements of the medium. In contrast, speaks at the bottom or at the surface of materials transported by sediment and floating debris.

Basic Properties

Typical groups of particulate matter are:

• Aerosol particles in the air, dusts of various classes ( sizing possibly influenced the retention ), partly fog
• Fine Sedimentbildner, leading to deposits such as mud or silt
• Suspended solids usually consist of sediment constituents and small flocs in wastewater or rivers. The Reinungung occurs in sewage treatment plants ( sewage treatment ).

Distance

The removal of suspended solids is accomplished by sedimentation basin ( sedimentation), chemical precipitation, flotation, filtration. At a higher removal rate, for example, HEPA filters may be used for liquids.

Measurement

The content of suspended solids can be carried out directly by sampling, separation (for example, electrostatically, or by filtration) and residue measurement. Also possible are indirect method by measuring the turbidity of the ambient medium (optical scattered light or transmitted light measurement). Indirect acoustic measurement methods are under development.

Suspended in hydrology

An impressive example for large amounts of suspended solids are streams such as Amazon, Nile and Mekong or the former tributaries of the Jezero crater lake on Mars. The suspended solids arise depending on the composition of a typical flow for the color. From the alluvial and deposited - often very fertile - suspended solids ( sedimentation) can develop a delta in the millennia since abgelagern suspended solids as a function of flow rate, their particle size and density. At high flow rates, however, can also be an erosion of sediments and thus a redistribution of the suspended solids. Importantly, the terms of the concentration of suspended solids or Schwebstoffbelastung (dry weight per volume ), suspended sediment ( mass per unit time ) and suspended load (mass per fixed unit of time). In general, suspended solids are in aquatic ecosystems together with the water and the sediment is an important part of the ecosystem. Suspended solids in rivers caused mainly by erosion, weathering and decomposition of rock. In general, the limit particle diameter of suspended solids is a function of the conditions of 0.2 to 0.7 mm.