Rapid sand filtration is a purely physical drinking water purification method. Rapid sand filters (RSF) provide rapid and efficient removal of relatively large suspended particles. Two types of RSF are typically used: rapid gravity and rapid pressure sand filters. For the provision of safe drinking water, RSFs require adequate pre-treatment (usually coagulation-flocculation) and post-treatment (usually disinfection with chlorine).
with great suddenness the car in front stopped abruptly, and we almost hit it Synonyms short, suddenlyRelated Words surprisingly, unexpectedly; directly, immediately, incontinently, instantaneously, instantly, promptly, pronto, right, right away, right off, straightaway; fast, full-tilt, posthaste, quick, quickly, rapidly, readily, snappily, ...
very suddenly and to a great degree; - Example: conditions that precipitously increase the birthrate - Example: prices rose sharply [syn: precipitously, sharply] 2. abruptly; in a precipitous manner; - Example: the mountains rose precipitously from the shore The Collaborative International Dictionary of English v.0.48: Precipitous \Pre*cipi*tous\, a. [L. praeceps, -cipitis: cf. OF. precipiteux. See Precipice.] 1. Steep, like a precipice; as, a precipitous cliff or mountain. [1913 Webster] 2. Headlong; as, precipitous fall. [1913 Webster] 3. Hasty; rash; quick; sudden; precipitate; as, precipitous attempts.