This is the 13609th most frequent Spanish word.
residuales
Residuals; relating to residue or waste.
The word 'residuales' here is used as an adjective to describe chemicals, indicating that these are leftover or remaining substances that have not been removed or used up.
Los productos químicos residuales contaminan los ríos.
Residual chemicals pollute the rivers.
In this sentence, 'residuales' describes water, specifically referring to wastewater or sewage, indicating it is water impacted by human activity and requiring treatment.
Las aguas residuales deben ser tratadas antes de ser liberadas al medio ambiente.
Wastewater must be treated before being released into the environment.
Here, 'residuales' is used to describe effects, indicating leftover or persisting effects that continue to exist even after the primary action has ended.