You can moderate the comments made on your blog posts if you have been made a moderator. If you haven't, follow the steps in the support article Changing Your Blog Commenting Settings and Moderators. 

To moderate your blog comments:

1. Login to your Facebook account. If you have multiple Facebook accounts, ensure you are logging in using the one that has been used to create your moderator account
2. In a new window or tab, open your Blog
3. Click on Comments down the bottom of the Blog post with the comment you wish to moderate
4. Click on Moderator View
5. In this view, you'll see a list of all the comments made on this post. To moderate them, click on Moderate and select an option from the drop down menu
   • Hide Comment: The comment will be hidden from everyone except the user's Facebook friends
   • Ban User: The user's comments, both current and future, will only be visible by the user's Facebook friends
   • Boost Comment: The comment will be moved to the top of the comments list
6. Click on Public Comments to see how your Blog comments will appear to anyone who is not a moderator