The Collaborative International Dictionary of English v.0.48:
desalinisation \desalinisation\ n. same as desalinization. Syn: desalination, desalinization. [WordNet 1.5]WordNet (r) 3.0 (2006):
desalinisation n 1: the removal of salt (especially from sea water) [syn: desalination, desalinization, desalinisation]