Design of Oil and Grease Trap and MBBR Tank

I have to install 500 KLD of STP plant for one of our clients in India. The inlet parameters of this plant are. BOD=350 mg/l COD=700 mg/l TSS= 850 mg/l Rest of the parameters can be assumed. The question is - what capacity of oil and grease trap and MBBR (aeration) tank we would have to construct for this plant? Best regards MOHD ARSHAD