asforme,
There's no way to add effects *inside* the mixer, if that's what you mean. All you can do from an outside-the-computer standpoint would be to get some stand-alone units and add them to your signal path. Your mixer does have an FX send bus and a stereo FX return bus, allowng you to patch in comprssors, EQs, reverbs, whatever you want between those buss jacks. For example, say you wanted to add a reverb, you'd run a patch cable from your FX out jack to the reverb, and then run the stereo reverb return outs via another set of patch cables to the FX return jacks on your mixer.
G.