Yes, it's possible now. You can operate two WhatsApp account on a single handset. First check settings of your mobile, whether your handset manufacturer provided this facility already. For example, my Mi Redmi 3S handset allows me to do so without rooting or installing any third party app. Otherwise, you need to install third party app like Parallel Space, 2Accounts: Multi User Switch, etc.
Multi-account is useful for multi need, like the professional account with the family account or two family user on a single handset. Sametime very helpful when you have two continue both mobile numbers due to any reason like roaming or business need.
In case you are using Mi product, then follow the below guide,
- Go to Setting > App Settings > Dual Apps
- Now enable the switch button in front of WhatsApp
- Done..! Now you can see two WhatsApp accounts on a home screen.
In case you have other than Xiaomi / Mi handset, then you can install following apps from Google Play store.
If you have another solution, please share it.. Enjoy Dual life.. 
