Natasha, I'm so sorry you are going through this, though I'm not surprised that he is drinking. You had your suspicions, which he has more than confirmed. It sounds like he is also having some HE. Whatever symptoms he had, previous to his short sobriety, will come back in full force.
When you throw the beer away, make sure you empty the cans first. It's good that you told the local merchants not to sell him alcohol again.
While court-ordered admission to a treatment center would be good, it will also take awhile. You have 6 more days of dealing with him. Are there any other family members he could stay with until your sister returns? I hope you can find a solution that will protect you and the children.
Hugs,
Connie