Disable private browsing IOS7 iPad

I am an educator who has spent the last two years trying to get iPads into our school so the students can use them at school and this without home computers can use them at home for video and research projects etc.

One of our biggest problems was students accessing appropriate content online. Under the old operating system we were able to circumnavigate the private browsing controls by obviously having the school's filter/router log access but also by tracking the history with various search engines which would store data even if private browsing was turned on. I am concerned about IOS7 which prompts users to turn on private browsing. Am I as to hide this tango make it less obvious? Additionally, on the new system it logs the school out of the accounts with google, so we are not able to track what has been searched.

This is really unacceptable on Apple's part - I have friends with children who are concerned about this as well.

There needs to be a way of disabling private browsing (or tracking somehow) on the iPad because otherwise our school cannot use these devices and 30 sets of iPads are a huge investment only to be rendered useless due to ease of accessing inappropriate content.

Can someone please assist with this?