The present invention provides a process for treating a stream, say, an olefins stream, e.g., propylene, containing at least one ether, e.g., dimethyl ether, and/or at least one of an alkyne and an alkadiene, e.g., methyl acetylene and propadiene, typically present as impurities. The process comprises: contacting the stream with a metal-containing catalyst, e.g., palladium supported on alumina, under conditions sufficient to convert the ether and the at least one of an alkyne and an alkadiene to provide a product stream having a reduced impurities content.