The correct spelling of the word "de sedimentations" is "desedimentations." The IPA phonetic transcription for this word is /diːsɛdɪmɛnˈteɪʃənz/. The prefix "de-" in English typically means "reverse" or "undo." In this case, it means to undo the process of sedimentation, which is the accumulation of solid material in a liquid or gas. "Desedimentations" refers to the removal of sediment from a solution, making it clear or pure once again.
The word "de sedimentations" does not have a specific etymology because it is not a commonly used word. It appears to be a combination of two elements: "de-" which is a prefix indicating the reverse or removal of something, and "sedimentations" which is the plural form of the noun "sedimentation". "Sedimentation" itself is derived from the Latin word "sedimentum", meaning "settling" or "substance that settles". In general, the word "de sedimentations" could be understood as referring to the removal or reversal of sedimentation processes.