First of all effluent is ...

First of all effluent is from what type of Industry.

If O G is not much, you can use DAF after MBBR, so-that, you can get enough BOD in MBBR Tank.

Secondly, if COD is Refractory, then, you can either try Anaerobic Treatment or use Bioculture to crack Refractory COD, followed by MBBR followed by DAF / Sec. clarifier.

Thanks,

Sanjay Sheth