When playing as the alchemist and you kill an enemy on a trap they die leaving an ingredient as normal and destroying the trap. So far this is the only way to disarm the pitfall traps that I know of. It works for getting rid of corruption traps.
I can't push my enemy onto corruption traps. Not sure if that was intended or if the herb was supposed to have moved near by. Have not killed anyone on a pitfall trap so I don't know how that is working. I had a hard time with the 'trap master' achievement.