Lajittelu

Lajittelu is a Finnish noun meaning the act of sorting or classifying things into categories. In common usage it most often refers to waste sorting (jätteiden lajittelu), the process of separating waste into streams suitable for recycling or proper disposal. The term can also describe the classification of organisms or data into groups in scientific disciplines.

In waste management, lajittelu typically occurs at household, workplace, and community levels. Households are guided to separate waste into distinct fractions such as paper and cardboard, glass, metal and plastic packaging, bio-waste, and mixed or energy waste. The exact fractions and color codes vary by municipality, but the goal is to reduce contamination and maximize recycling. Hazardous waste (batteries, electrical waste, chemicals) requires special handling. Waste that cannot be recycled is directed to energy recovery or disposal according to local rules.

In recycling facilities, lajittelu continues with automated and manual processes. Conveyors, magnets separate ferrous metals; eddy-current separators and optical sensors distinguish plastics and other polymers; manual pickers remove non-recyclables and contaminants. Efficient lajittelu improves material quality, lowers processing costs, and supports circular economy goals.

Beyond waste, lajittelu is used in biology to describe organizing organisms into taxonomic groups, or in information science for classifying data. In policy terms, increased lajittelu is a common objective of municipal waste plans and national environmental strategies, often tied to producer responsibility and targets for recycled content and landfill reduction.