An evaporation apparatus 10 is shown in the form of an inflatable elongate plastic tube 12 that is fitted with fluid control means in the form of an inlet gas fan 14 and a gas outlet hole 16. The capacity of the inlet gas fan 14 and the size of the outlet hole 16 are matched so that the degree of inflation of the tube 12 can be maintained. In use the inflated tube 12 is partially filled with a volume of liquid 18 in a pool at a base thereof to be heated and evaporated by solar radiation and carried out of the tube 12 by a flow of gas therethrough. The pool of liquid 18 may include solid matter 19, or even contain substances such as dissolved solids or salts. Over time a significant quantity of this material can become deposited in the tube 12, and can be reclaimed.