Sedimentation Method in Hygiene

Sedimentation methods have been used for a long time in various branches of science and technology to separate particles from a stream of air or gas. However, only now has this method begun to be used in hygiene for the analysis of dust pollution.

Sedimentation as a method of separating particles by size is widely used to analyze air pollutants that can be dangerous to the health of people and animals.

The principle of operation is based on the ability of dust and other particles suspended in the air flow to settle under the influence of gravity. The duration of the dust deposition process depends on the particle size and flow speed. The term “sedimentation methods” refers to all methods based on this principle.

When analyzing dust pollution, there is often a need to quantify the particle content. To do this, it is necessary to separate the resulting aerated flotation concentrate. Sediment is formed by successively settling aqueous suspensions from insoluble impurities in tubular chambers of various shapes and sizes. The separation process is carried out at ambient temperature. At the end of the process, the upper and lower phases are separated from the separator, combining them under the name sedim (lower phase) and gel (upper phase). After appropriate processing and centrifugation of the aqueous suspension, the gels are separated into mineral impurities and liquid, and sediments are separated into the organic part (gel) and mineralized products. Gels are subjected to neutralization and further processing in order to extract minerals and impurities from them. Mineral residues are used in the production of building materials, as fertilizers and feed additives. To prepare liquid fuels and chemical products, decomposition residues are burned or reduced to gaseous fuels. Acids and alkaline solutions after neutralization are used for washing equipment and regenerating adsorbents. The aqueous phase and part of the coal residues are discharged into a reservoir or swamp. After purification, the aqueous suspension in the form of sludge is processed to obtain fatty clay or pitch, or raw materials for the production of carbon black, cement, building materials, etc. Sedimentation processes can only allow a certain ratio of suspension to air. When the particles have time to settle at the speed of the gas flow, but at the same time the rate of suspension

In hygiene, the sedimentation method (leveling method, encopresis) is a method of separating suspended dust from the air through its natural precipitation. This method is used to conduct research and determine the content of harmful substances in the atmospheric air.

The use of this method was first proposed by the German scientist Hempel in