Planet Minecraft

So I have a Tekkit server that offers a creative world and survival world openly, but the problem is, people can go into the creative world, take items out and use it in the survival world. So I was wondering if there was a plugin or some kind of configuration I could do to give each world its respective inventory?

I know some servers with both worlds where one world is a completely different world. Not sure what plugin that is though sorry.

There are a few plugins that can do that. Multiverse is probably one of the best multiple-world plugins out there. There are multiple plugins that rely on Multiverse-Core, one of them is Multiverse-Inventories, which essentially means players can have separate inventories and a whole host of other features per world. It's a little advanced for a plugin, but I'm sure you can figure it out.
http://dev.bukkit.org/server-mods/multiverse-core/