Sync Photo Albums can not be deleted from my Iphone

You can delete them from the phone by syncing again using the following instructions from Sync your photos manually using the Finder - Apple Support

Stop syncing some albums

1. Open a Finder window and connect your device to your computer using a USB cable. 
2. Your device appears in the sidebar of the Finder window. Click the device to select it.
3. If prompted, trust your device.
4. Click the Photos tab below your device's information.
5. Choose "Selected albums" and deselect the albums or collections that you want to stop syncing.
6. Click Apply.

Stop syncing all photos

1. Open a Finder window and connect your device to your computer using a USB cable. 
2. Your device appears in the sidebar of the Finder window. Click the device to select it.
3. If prompted, trust your device.
4. Click the Photos tab below your device's information.
5. Deselect "Sync Photos" then click "Remove photos."
6. Click Apply.