How can I lock down wifi settings on ipad ios 7.1 from pupils

I don't know of a profile that will restrict the ability to configure or connect to wi-fi networks. You can push a specific network. If you are in a relatively controlled environment you could impose some type of controls on your internal wi-fi networks, or you could setup internet proxy.

That would be a desirable feature for iOS devices. There just isn't a configuration profile that will do it right now.

You can't lock settings iOS is still designed as user owned

You'll have to push the users wifi to the device using a MDM solution

I use a configuration SSID on a device level

And assign whatever wifi the users need to be on at the user level

If users delete their profile they are disconnected from the wifi

The device profile will connect to the configuration SSID which is locked down so users can't do anything

And you'd have to push the profiles out again to connect the user to the correct wireless

Basically you have to put some thought into profiles and the what if scenario

Then test. iOS 7 adds more enterprise friendly control you can stop users deleting profiles as well but you'd need to test how this effects what you need to do

If the user deletes all profiles I use apple Configurator to quickly add a basic device profile to get the device back on the MDM and on the configuration wifi. Then push the user profile out with the users wifi VPN Mail etc