If I get a duel citizenship with lebanon, can I ever remove it later on?

Although I am not familiar with Lebanese law and immigration processes, from what I do know in regard to general multiple citizenship and the citizenship operations in Canada, I believe that you would be able to do so. I think you are best to contact the respective immigration departments in Lebanon, and possibly Canada as well. Sorry I cannot give a detailed help, but honestly this is a very specific case and can really only be given an accurate answer by the respective nations involved.