You can exclude/block your mentions to be collected from your domain or your social channels.
If you want to exclude your own mentions from your domain, go to Project Settings > Sites add your domain names and select the box for Exclude mentions from specific domains.
If you want to exclude your own mentions from your social channels go to Project Settings > Social Accounts and select Exclude mentions from my brand's social profiles.
This way your project will exclude all the mentions from your social profiles. Make sure to add your Facebook pages and Twitter profiles you want to exclude mentions from.