Get rid of unwanted edges

[saaswad]

I searched a lot for 2 days and couldn't find a practical and fast solution to get rid of unwanted edges from a specific mesh, all solutions I found are considered manual and time-consuming, is there any easy way to do it without wasting time.

ps: unwanted means edges that will not affect the mesh when removed

[damaggio]

Mesh>Quadrangulate and then some manual clean up.