list ppa and uninstall with ppa-purge

Remove installed ppa from ubuntu system.

• Install  ppa-purge 

sudo apt-get install ppa-purge

• Run command in terminal to list all configured repositories and ppa in readable format

apt-cache policy | grep http | awk '{print $2 $3}' | sort -u

• Uninstall the ppa with syntax : sudo ppa-purge ppa:<repository-name>/<subdirectory> example in my case

sudo ppa-purge ppa:ubuntu-audio-dev/alsa-daily

• Delete the unwanted source list from the location /etc/apt/sources.list.d. example in my case

sudo rm /etc/apt/sources.list.d/ubuntu-audio-dev-ppa-trusty.list ubuntu-audio-dev-ppa-trusty.list.save