Settling

Settling is a term used across disciplines to describe the act of becoming settled as well as the physical process by which particles or materials come to rest. In everyday language, to settle means to establish a residence or routine; in scientific and technical contexts, it refers to separation and deposition.

In fluid science, settling, or sedimentation, occurs when particles suspended in a liquid move downward under gravity until they form a sediment at the bottom. The rate depends on particle size, density difference, fluid viscosity, and turbulence. Small, dense particles settle slowly; larger particles settle faster. In engineering, clarifiers and settling tanks are designed to remove solids from water or wastewater, often aided by flocculation or gravitational settling.

In geology and sedimentology, sedimentation is the accumulation of mineral and organic particles over time, forming sedimentary rocks and soils. Settling processes influence layer formation, grain size distribution, and soil horizons, and they record environmental conditions at the time of deposition.

In human geography and sociology, settlement refers to the establishment of a community in a place, including towns, villages, or colonies. Settlement patterns reflect access to resources, land, climate, and infrastructure, and may change with economic and political forces.

In law and finance, a settlement is an agreement to resolve a dispute or claim, often by payment or the fulfillment of conditions, avoiding further litigation. In securities and banking, settlement denotes the completion of a trade, when counterparties exchange securities and funds on a specified settlement date.