Yes. Owners and Admins can remove other members from a Pool.
Removing the Owner: The current Owner must first transfer ownership to another member. The new Owner can then remove the former Owner.
Removing a member has the same effect as the member leaving the Pool, they immediately lose access, their card and account/routing numbers for that Pool stop working, and any recurring deposits into the Pool are canceled.
For the full list of what changes when a member is removed, and what happens if they rejoin later, see How do I remove someone from a Pool?.