You can select ASP or MBBR. ...

You can select ASP or MBBR. The later is a modern treatment and requires lesser hydraulic retention time. As a rule of thumb, if you provide hydraulic retention time of aeration tank more (say by one third), it will take care of nitrification-denitrification. But the effluent should be biodegradable i.e. BOD to COD ratio should be more than 0.5. Regarding air requirement, it depends on BOD/COD loading. I suggest you can go for software like ETPSOFT03 or ADTREATSOFT02 which will help you in designing.