Roet

Roet is the Dutch term for soot, a black or brownish powder produced by the incomplete combustion of carbon-containing materials such as coal, oil, wood, or biomass. In composition, roet consists mainly of elemental carbon with adsorbed organic compounds, including polycyclic aromatic hydrocarbons, and trace minerals. In air, roet exists as fine particles that can form aggregates and contribute to particulate matter (PM) in the atmosphere.

Formation and occurrence: Roet forms when combustion is incomplete due to limited oxygen, low temperatures, or rapid cooling. Major sources include vehicle exhaust, residential heating with coal or wood, industrial processes, and wildfires. It can accumulate as chimney soot on indoor surfaces and is a significant component of atmospheric aerosols when released into the air.

Environmental and health effects: As a constituent of PM, roet is linked to respiratory and cardiovascular health problems and can carry toxic compounds. Black carbon in roet absorbs sunlight, contributing to atmospheric warming and climate change; deposition on snow and ice can accelerate melt and albedo changes.

Uses and mitigation: Historically roet has been used as a pigment and in lamp-black inks, but modern emissions controls reduce its production. Mitigation measures include cleaner fuels, catalytic converters, diesel particulate filters, and regulations aimed at reducing particulate matter. Improving combustion efficiency and implementing filtration also help lower roet formation and emissions.