Edit /etc/fstab:
device mountpoint mounttype option ....
modify the option:
user: If you set option to user, then you can use non-root account to mount the device. To set to users means you can umount the device by other account
group: every account which have a group matching the group of the device can mount the device. So you need to use root account to change the group ownership of the device.
chown -R :group mountpoint