A common approach is to use different VLANs for Student/Employees, and you can use Roles that only permit their specific WLAN access, which can be sent back as a VSA from AD/802.1x.
KBA-2109, NPS Radius with AD:
https://support.ruckuswireless.com/answers/000002109
KBA-2946, User Roles on ZoneDirector:
https://support.ruckuswireless.com/answers/000002946